Blog Directory - Blogged foodliterate: 2009

Friday, November 13, 2009

The Roots of Fall

I know I’ve been MIA and that I missed Halloween, (in fact it’s getting pretty darn close to Thanksgiving!) and for this I apologize. So I’ve had plenty of time to think about what my next topic should be & was inspired by the cooler temperatures and my favorite holiday All Hallows Eve. Its origins lie in the Celtic holiday: the feast of Samhain. Back then lanterns were made of carved turnips (hey – I guess you use what you have!) to ward off evil spirits. Later when Celtic immigrants came to the Americas, they didn’t find turnips – they found pumpkins and thus the tradition began.

Nice story – huh? But you want to know what this has to do with food, right? Well pumpkins, beets, turnips – they are all winter vegetables and we don’t cook or eat as much of them in the US as they do elsewhere. Maybe it’s just because we don’t know enough about them to try.

Turnips are part of the Cruciferae family along with cabbages, radishes, mustard, horseradish, broccoli, cauliflower and many others. Specifically they are Brassica rapa, part of the Brassica genus (cabbage). Both the roots and leaves are edible; in fact Bok Choy (aka Chinese cabbage) is a variety of Brassica rapa that is just grown for its leaves. The turnip root has a flavor similar to radishes and cabbage (not too surprising), while the leaves taste like mustard greens. Turnip roots are high in vitamin C, vitamin A, vitamin K, folate, calcium and lutein. They can be boiled, roasted, or braised, while the leaves are best steamed or braised.

Rutabagas (Brassica napobrassica) are a cross between a cabbage and a turnip; and like the turnip, both the leaves and root are edible. Both turnips and rutabagas have anti-cancer properties (a trait shared by the Cruciferae family) by acting as an androgen receptor antagonist. The roots are high in vitamin C, folate, vitamin B6, potassium and manganese. The cooking for rutabagas is the same as for their cousins the turnips.

Parsnips (Pastinaca sativa) are related to the carrot, as can easily be discerned by their appearance. Parsnips are known for their sweetness, but their flavor doesn’t develop until they’ve been exposed to near-freezing temperatures for 2 – 4 weeks. In fact, if you want really sweet parsnips, leave the roots in the ground to overwinter & pick them in the spring; the starches will have converted to sugar. Parsnips can be used as a replacement for potatoes in recipes and can be roasted, boiled, braised, fried, sautéed, or steamed. They are higher in potassium and fiber than carrots, high in folic acid, calcium & zinc. When choosing parsnips, look for ones that are 8” or smaller, so they won’t be woody, and that are crisp & firm. Their flavor is sweet & nutty, while their aroma is similar to celery.

Beets (Beta vulgaris) are part of the amaranth family, along with chard and sugar beets. The most familiar color of beet is red, but there are golden beets (my personal favorite) and candy-striped beets called Chioggia (think peppermints). The color of beets is due to betalain pigments; the betacyanins are red to purple, while the betaxanathins are yellow to orange. The earthy aroma and flavor of beets comes from Geosmin, an organic compound that humans can detect a levels of 5ppm of lower. Beet roots are high in folic acid, potassium, vitamin C, calcium and antioxidants (betacyanin). The leaves, also edible, are high in vitamin A, potassium, calcium and iron. Beet roots can be pickled, steamed, baked or roasted, while the leaves are best braised or steamed.

I hope that these underused vegetables have become a little less scary and a little more interesting to those of you who may never had tried them. Now is the perfect time to grab some at your grocery store or farmer’s market and enjoy some of the fall harvest on your dinner plates!

Friday, October 9, 2009

MSG - Good or Bad?

MSG – monosodium L-glutamate. One of the most commonly despised ingredients in the US. What is so horrible about this ingredient that hundreds of pages of the Internet are spent on its bashing? I’m not sure why it is so vilified, but I do know quite a bit about the ingredient.

MSG is the sodium salt of the amino acid glutamic acid. It is produced by fermentation of glucose (usually from molasses) to glutamic acid which is then neutralized with sodium hydroxide to produce sodium L-glutamate. In 1908 a Japanese scientist was researching the flavor enhancing properties of a seaweed used in cooking (Laminaria japonica). But MSG does more than “enhance” flavor; in fact, I don’t like that particular description. MSG is more of a potentiator than an enhancer. It attaches to receptors on your taste buds so that you taste things more intensely. It also affects your perception of mouthfeel, complexity and roundness/harmony of flavors. We call this sensation Umami – the fifth flavor (the other four are: sour, sweet, bitter, salty).

Glutamates (there are other salt versions besides sodium) occur naturally in vegetables, meats (beef, poultry, pork, fish), and milk (including human breast milk). Some foods with the highest levels of glutamates include mushrooms, tomatoes, cheese, chicken, soy sauce, and Worcestershire sauce.

Glutamates are often misrepresented as MSG. Many of the websites demonizing this material infer that those of us in the food industry are purposely misleading consumers by hiding MSG in other ingredients such as caseinate, whey protein, yeast extract, gelatin, etc. when in reality these are naturally occurring sources of gluamates and not “hidden” MSG. That is not to say we don’t add MSG to foods, we do, but it is labeled.

If you firmly believe that you react to MSG, then nothing I’m saying is going to change your opinion, and that is fine. (Personally, I have a jar of MSG in my spice rack; I love adding it to soups and gravies.) Avoiding MSG should prove rather easy, glutamates less so, and glutamic acid nearly impossible. (I just have to say, I’ve never heard someone who just ate a big piece of chicken cooked with mushrooms and tomatoes ever complain about symptoms).

There has been and continues to be ongoing research into the effects of MSG consumption. Although to date, nothing conclusive has been produced (and reproduced) to show any negative effect of consumption, if you are at all concerned, make sure you eat other foods along with your MSG. The dilution effect should be enough to ward off any potential side effects. And of course if you are watching your sodium intake, you should be aware of the high sodium content of MSG containing foods.

I hope that this was informative (and no, I do not work for or with any MSG companies – I’m not working any angles here). Please let me know what other questions you have about the foods you eat - I'm here to help!

Wednesday, September 30, 2009

Defining Natural - Part II

Last week, I told you about the FDA definition of "natural", their lack of one, and told you that they may start by looking at the USDA's. The branch of the USDA that is involved in allowing a natural claim is the FSIS - Food Safety and Inspection Service.

The FSIS first issued its guidance on November 22, 1982 in a Standards and Labeling Policy Memo (#055) stating that the term "natural" could be used in the labeling of meat & poultry when:
  • The product does not contain any artificial flavor or flavoring, coloring, ingredient, or chemical preservative (as defined in 21 CFR 101.22), or any other artificial or synthetic ingredient; and
  • The product and its ingredients are not more than minimally processed, which may include (a) those traditional processes used to make food edible, to preserve it, or to make it safe for human consumption, e.g. smoking, roasting, freezing, drying, and fermenting, or (b) those physical processes that do not fundamentally alter the raw product or that only separate a whole, intact food into component parts, e.g. grinding meat, separating eggs, pressing fruit.
  • Relatively severe processes, e.g. solvent extraction, acid hydrolysis and chemical bleaching would clearly constitute more than minimal processing.

This sounds good - right? It is much more precise than the FDA definition, and the FSIS, like the FDA, reviews label submissions on a case-by-case basis for clarification. So why is it that even this definition is under review?

While I can't speak for the USDS/FSIS, it is probably because this still has a lot of grey areas. For instance, sodium, calcium, and potassium lactate (from corn sources) were allowed at levels up to 2% as flavoring. That is until the FSIS discovered that at that level, those products had an antimicrobial effect and they decided to re-evaluate those labeling claims individually for technical function and intended use. There are other ingredients that have similar stories. So in 2006 the FSIS took comments from the public and industry to try to clarify the term "natural" - they received over 12,000 comments that contained wildly divergent views on the topic.

So this year they decided to try again; they are soliciting comments until November 13, 2009 (if anyone wants to know how to submit their own comments send me an email & I'll send you the information). Some people want a very rigid definition, but that is difficult because it means the FSIS must think of almost every circumstance to close any potential loopholes; while others want flexibility so that the context can be considered (whether an ingredient is used as an antioxidant or as a flavor - like rosemary extract). And this is a complex issue; for instance, vinegar is a natural product, as is sea salt, but depending on their usage, it could mean a product cannot be legally labeled as natural.

So, what is the likely outcome for both the USDA/FSIS and the FDA? Well, with lawsuits and public comments pending, some changes will likely be forthcoming. We may very well end up with a system similar to that for organic products - kind of a tiered labeling system: 100% Natural, Natural, Made with all Natural Ingredients, Naturally Raised, etc.

I for one, am interested both as a consumer and as a food technologist, to see how these governmental agencies resolve this issue. And I hope you have gained a better understanding of the issues that impact the foods you consume and the regulations that govern their manufacture.

Monday, September 21, 2009

Defining Natural

I originally started this conversation on my post dated 11-20-08, but this topic just keeps reappearing, so I'm going to delve a bit deeper today.

Natural. Everyone can define this word - right? Per Webster, natural means: "existing in or produced by nature". Pretty simple & straightforward. So why is it that the FDA and USDA are having such trouble creating a working definition for this term? Perhaps it is because natural, when pertaining to foods, is not so easily defined. You see, there is a lot of grey area; there are many natural things, including chemicals, out there that you wouldn't want to be eating, so the dictionary definition simply won't work.

Let's start with the FDA. Way back in the early 1990's, they were petitioned to create a definition of "natural" for the industry to use. But in January of 1993, the FDA declined to establish a formal definition of natural and instead gave us this informal definition we've been using ever since. Natural means "nothing artificial or synthetic has been included in, or has been added to, a food that would not normally be expected to be in the food." [58 Fed. Reg. 2302, 2407 (January 6, 1993)]. Hence, the FDA decided not to attempt to restrict the use of the term natural except for added color, synthetic substances, and flavors.

Here's why this gets interesting. The FDA's Food Labelling and Standards department reviews the use of the term "natural" on a case-by-case basis since this statement of policy is just an advisory opinion and not a regulation. Or in plainer English, while companies and courts follow the FDA's opinion, it does not constitute federal law. One case currently being fought in the US courts is the against Snapple Beverage Corp. for their use of "All Natural" on their beverages containing high fructose corn syrup (HFCS).

In April 2008, the FDA's office of Nutrition, Labeling and Dietary Supplementation, stated that HFCS, due to the manufacturing process, would not qualify for a "natural" labeling term. But in July 2008, after clarification from one of the manufacturers about the process used to create HFCS, the FDA reversed its decision and declared that HFCS (when produced by the process submitted) can be considered "natural". (If anyone wants details on the processes involved, send me an email & I'll explain) Snapple argued that the FDA has authority regarding the naming & labeling of its drinks and the original court (New Jersey US District Court) found in favor of Snapple. Unfortunately, the US Court of Appeals for the Third Circuit last month reversed this decision and sent it back down for further review; their opinion is that the FDA's opinion has no force of law.

Unfortunately, there have been a number of other lawsuits (Ben & Jerry's, Cadbury Schweppes, Kraft, Arizona Beverage Co., etc.) also surrounding the use of the term "natural" (although not all concerning the use of HFCS). So what does this mean to consumers? Well, the industry is hoping it may force the FDA to adopt a formal policy regarding the definition of the term "natural". And the place they may start is with the USDA definition; but that will be my next post - so be sure to check back soon!

Thursday, September 3, 2009

Good Gluten-free Alternatives - Part 3

I've saved the least well known options for this post, and the first one is seldom considered as human food in the US. This pretty looking picture on the left is millet (Panicum miliaceum). Yep, I said millet - but that's bird feed!

Why yes it is, but it is also people food (the pearle millet is anyway). In fact it is a staple in India, Africa, and China. It has been cultivated since prehistoric times. Its amino acid profile is better than wheat or corn and it can be used to make soups, stews, cooked cereal, and can be popped, roasted or sprouted.

To cook, roast 1 cup of millet in a saute pan in 1 tablespoon oil over moderately high heat and cook (stirring frequently) until it makes popping sounds and begins to turn golden. Remove the pan from heat. Then in a small saucepan bring 2 cups water to a boil and stir in the roasted millet. Cook covered, over low heat 20 minutes, or until water is absorbed. One cup of cooked millet has 207 calories, 6 grams of protein, 1.75 grams of fat, and 41 grams of carbohydrates, 2 grams of which are fiber. Millet has a good quantity of niacin (2.3 mg per cup of cooked) and zinc (1.58 mg per cup of cooked).

Sorghum (Sorghum spp.) is a cereal grain that is common to Africa and Asia. In fact it is one of the top five cereal grains in the world. It has been around since about 8000 BC and is related to millet. It is good nutritionally, but does lack the amino acid lysine.

You will most commonly find sorghum as either the flour or as a sweetener (like molasses). I've not seen the grain available whole in the stores in my area. However, if you could find it, 100 grams would contain 339 calories, 11 grams of protein, 3 grams of fat and 75 grams of carbohydrate, 6 grams of which are fiber. It is a good source of iron as well, containing 4.4 mg per 100g.

The last gluten-free alternative on my list is teff. Teff (Eragrostis tef) is a tiny grain, primarily found in Ethiopia where it is ground into a flour or consumed as a porridge. Teff has been domesticated since around 4000 BC.

You can find teff as whole seeds in some health food stores, but will probably find the flour is more common. When teff is cooked, it becomes gelatinous which allows it to be used to thicken soups, stews, gravies and even puddings. Of course the flour can be used to make gluten-free baked goods as well.

One cup of cooked teff contains 255 calories, 9.75 grams of protein, 1.5 g fat, and 50 grams of carbohydrate, 3 grams of which is fiber. It is considered a complete protein (all essential amino acids present), but is a bit low on the lysine. And teff has a good amount of calcium (387 mg per cup of cooked) and iron (15 mg per cup of cooked).

I hope you found this series on gluten-free alternatives interesting and that it peaked your interest in learning more about grain alternatives. The internet is a wonderful source of recipes using these lesser known ingredients, especially as the gluten-free market expands. As I've said many times before, please drop me a note with future topics you'd like me to cover - I'm always here to help you become more foodliterate!

Wednesday, August 26, 2009

Good Gluten-free Alternatives - Part 2

Keeping my word about other alternatives for those trying to live a gluten-free lifestyle, this week's post is on some of the other seeds and grains available. Now, most if not all of these, are going to be more difficult to obtain outside of a health-food/specialty store, but that doesn't mean you shouldn't try them if you do stumble upon them!

Amaranth (Amaranthus cruentus - pictured left) is a plant that many of you have seen growing in gardens, perhaps even your own, and never had an inkling that there was something edible lurking there.

This beautiful plant has tiny seeds, about the size of poppy seeds, that are quite edible. They were a staple of the Aztec people and are still consumed in that part of the world. Amaranth is technically an herb, not a grain and it is related to cockscomb. It is high in tocotrienols (vitamin E), has a nutty flavor, and approaches the nutritional value of milk.

One cup of cooked amaranth has 251 calories, 9.5 grams of protein, 4 grams of fat, and 46 grams of carbohydrate, of which 5 g is fiber. You can find amaranth flour, noodles, and baked products like cookies in health food stores. To cook the seeds, boil one cup of amaranth in 2.5 cups of water for 18-20 minutes, drain off any excess water and use as you would other grains.

Next up is buckwheat (Fagopyrum sagittatum). It is a seed, not a true grain, and despite its name, not related to wheat. Buckwheat hails from Asia and has been cultivated since about 6000 BC. It is very popular in China, Japan and Russia and has been grown in the US since the colonial days, but most Americans only consume it in pancakes or as soba noodles.

Buckwheat can also be found as groats, known as kasha, that are very tasty and can be eaten as a cereal or in soups and stews. One cup of cooked buckwheat groats has 155 calories, 5.7 grams of protein, 1 gram of fat, and 33.5 grams of carbohydrate, of which 4.5 grams is fiber. It is a good source of niacin (1.6 mg per cup of cooked) and lutein (1.1 micrograms per cup of cooked).

Kasha/buckwheat can be used to make veggie burgers, or a side salad as well as a hot breakfast cereal option. The cooking is usually to boil 1 cup of kasha in 2 cups of water for around 12 minutes or until tender.

I still have 3 other alternatives which I will save for my next post. I hope you are inspired to find some recipes on the internet or in cookbooks for these two gluten-free alternatives. You never know what new and exciting creations are just waiting to be served!

Thursday, August 20, 2009

Good Gluten-free Alternatives - Part 1

As I stated in my last post, those who are gluten intolerant do have some options and you don’t have to have an issue with gluten to enjoy these! Perhaps the most common option these days (outside of corn) is quinoa. Let me tell you a bit more about it.

Quinoa (Chenopodium quinoa) is often considered a grain, but it in fact a seed which comes from the same botanical family as spinach and beets. (Although the leaves of the quinoa plant are also edible, I've not seen them available anywhere for purchase.) Quinoa has been cultivated and consumed for more than 5000 years originating with the Incas. It is native to the Andes mountains and the name quinoa means “mother grain” in Inca.

The seeds of the quinoa have a protective pericarp layer of saponin (a really bitter substance) which must be removed by alkali before the quinoa is edible. This is most commonly performed before you buy the quinoa, but I recommend rinsing the quinoa in 3 changes of water before cooking, just in case there is residual saponin still present.

What is really interesting about quinoa though is its nutritional profile. It is considered a complete protein (has all of the essential amino acids present) and the FAO have deemed it comparable to dried whole milk. One cup of cooked quinoa contains 222 calories, 8 grams of protein, 3.5 grams of fat, 39 grams of carbohydrates, 5 grams of which are fiber (64% insoluble, 36% soluble). It also is a good source of iron (2.8 mg per cooked cup).

This is all great right? But you really want to know what does it taste like and what do I do with it. It has a slightly nutty flavor and can be consumed for every meal of the day. You can cook it and add milk, cinnamon & some fruit for breakfast, or make a cold salad with it for dinner. I’m going to share my favorite recipe for this fascinating little seed with you to get you started.

1) Cook 1 cup of quinoa in 2 cups of water (salted) for 10-15 minutes (until tender). If there is water still remaining, drain in a sieve, and then add to a bowl big enough to do some mixing.
2) Drain & rinse 1 can (15 oz) of cooked black beans and place in the bowl.
3) Defrost 12 oz of frozen corn and place in the bowl.
4) Finely chop 1 small (or medium) red onion and add to bowl.
5) Add your favorite salsa – I prefer to use Fronterra Double Roasted Tomato Salsa for this recipe, it has a great smoky flavor - no quantity here, just to the flavor and consistency you desire.
6) If desired, add chopped fresh cilantro to taste, salt & pepper.
7) Mix all ingredients together.
8) This dish can be served warm or cold as a side dish or main dish.

I hope this has inspired you to give the little quinoa seed a try, after all variety is the spice of life! I'll be back with some other gluten-free alternatives next time.

Tuesday, August 11, 2009

When Good Protein Goes Bad - Gluten

Ahhh summer - so beautiful, so busy! Seems like I always fall off the blog wagon this time of year (conferences, vacations, etc.), I hope you all understand. Today's topic is gluten -a protein found in some grains.

First, what is gluten & where does it come from? When water is added to the endosperm of: wheat, (including spelt, durum & semolina), rye, oats, barley, triticale or kamut, the proteins gliadin (a monomeric protein "single chain") and glutenin (a polymeric protein - "many chain") combine to form a colloid complex called gluten. It is the intermolecular interaction of these two proteins which produce the viscoelastic properties of gluten (i.e. elasticity of dough). Gluten is also known as the water-insoluble protein which remains behind when the starch of the grain is washed away.

Gluten is responsible for trapping air bubbles in baked goods providing the lightness in yeast or leavened baked goods. Because of this, it is difficult to replace; you have to find something, or a combination of things, that work structurally similar to gluten. Anyone who has read a "gluten-free" label has probably seen many of these items: rice flour, sorghum, tapioca starch, xanthan gum, soy flour, potato starch, corn starch, guar gum, buckwheat (which isn't a wheat) or chickpea flour. Most of these plant proteins will do part of the job of the gluten, but are usually needed in combination to the job of both providing elasticity and water binding.

Ok, so you know what gluten is, but why all the fuss about it? Are there really that many people out there with celiac disease? Probably not, but there is another fraction of the population that is regarded as gluten-intolerant and limiting their intake of gluten makes them feel better. To that end, in 2008 gluten-free sales were almost $1.6 billion (retail) and is expected to almost double by 2012 (from Packaged Foods 2009 report).

Now those who choose, or must, remove gluten from their diets still need fiber and B-vitamins, both of which are found in these grains. So what choices exist? Don't worry, there is quinoa, amaranth, millet, corn and teff. Which, other than corn, are lesser known in the US but are widely consumed grains in other parts of the world and aren't that hard to find here.

I'll be talking about these grains in my next post -because the scariest items are the ones we know the least about and I don't want these grains to be scary! Until then - be well!

Tuesday, July 14, 2009

Random Thoughts: Fats & Weight Loss

Because our society loves fat, and lets face it - that is where all the flavor, satiety, and mouthfeel come from, a lot of research is being conducted on the effects of dietary fat on our body fat. Scientists are trying to find out what fats are better (or worse) for us and the answer doesn't seem to be an easy one.

These researchers were trying to determine how where you store your fat (apple vs pear shapes) influence your body's response to dietary fats - and apparently it does!

Obesity related disorder treatments have been utilizing the conversion of patients from PUFAs (polyunsaturated fatty acids) to MCTs (medium chain triglycerides). This is because they metabolize differently, MCT breaks down quickly and goes to your liver rather that going to fat storage. However, their research suggests that this conversion is only really good for pear shaped people. Apple shaped patients fed MCT rich diets had inflammation of their fatty tissues, not the result they were going for!

So, research will continue, and those of us who carry more weight around their middle (like me) will just have to wait to see what works best for us!

Wednesday, July 8, 2009

Random Thoughts: Nitrates

Nitrates take such a beating in the press and on documentaries, that I thought it was time for some additional information about this compound to come out. Listening to the anti-additive crowd, you would have thought it was created in a laboratory some where with lots of little white rats, but in reality nitrate is a naturally occurring part of the nitrogen cycle.

Many people know that nitrate is an approved food additive used in cured meats (like hot dogs, lunch meats, and sausages), but few know that it is also a component of plants - especially their leaves. Nitrate breaks down into nitrites, which possess antimicrobial activity, N-nitroso compounds, and nitric oxide, which plays a role in the plant's vasoregulation.

Any guess as to the typical amount of nitrate found in cured meats? 156 mg/kg. Want to guess the typical amount of nitrate found in arugula? 4667 mg/kg! Ok, you say, but you don't eat arugula. How about mixed lettuce (like the blends you buy at the grocery store)? 2000 mg/kg. Celery? 1100 mg/kg. Spinach? 1000 mg/kg. Reality is you consume far more nitrate than you think. The FAO/WHO (JECFA) set the acceptable daily intake at 3.7 mg/kg per kg of weight per day (for a 190# person that would work out to 318 mg/kg per day). That number certainly seems low given the results of the new research on the nitrate levels in plants (can be found here.)

So the next time your health-conscious friend belittles you for chomping on that hot dog, lamenting all of those nasty nitrates you are consuming, you can just turn and smile knowing the amount of nitrates found in their salad!

Wednesday, June 24, 2009

The ABC's of Vitamins - Vitamin K

Well, it has been a while since my last post and for that I do apologize. As the weather warms up, my work load seems to increase (and not in that fun vacation sort of way, at least not yet!). But nonetheless, today marks the last of the vitamin series - vitamin K. Vitamin K was discovered back in 1929 and was first synthesized in a lab in 1939, so why is it that in 2009 so few people know anything about it?

Without sounding too much like a broken record, vitamin K is also the generic term for a group of compounds; the two natural forms being K1 and K2. (There are 3 more synthetic forms) K1 is also known as phylloquinone and comes from plants and is very biologically available. K2 is a family of menaquinones and are produced by bacteria, including those that live in your gut.

So, what's the big deal about vitamin K? The biggest, perhaps most important job is its role in blood coagulation. (It works with prothrombin and other proteins to cause coagulation) It also plays a role in bone metabolism which may help to prevent osteoporosis. SCIENCE ALERT: Both of these functions have to do with vitamin K's role as a co-factor for gamma-glutamyl carboxylase (the enzyme that catalyzes the conversion of bound glutamate (Glu) to gamma-carboxyglutamate (Gla) and the binding of calcium ions to the Gla giving it bioactivity - also known as the "vitamin K dependent glutamate gamma-carboxylation reaction").

The lack of vitamin K seems to lead to a higher incidence of calcified atherosclerotic plaques - not good. And newer research is looking into vitamin K's role in neuronal survival and its potential in the treatment or prevention of Alzheimer's.
Are you wondering "where can I get this wonderful vitamin"? Good, the best sources are green leafy vegetables like broccoli, kale, spinach, turnip greens, asparagus, and cabbage. Vitamin K, as an oil soluble vitamin, is also found in canola, soybean and olive oil. The recommended daily intake varies depending on age and gender, but is generally between 65 -120 micrograms per day. Most of us have no problem getting this amount from our diet, but those who are on a highly restricted diet, or are on sulfa drugs may need to supplement. Those who are on anticoagulant drugs should watch their intake of vitamin K containing foods, as vitamin K can interfere with their medication (make sure to talk to your doctor!).

So, we've covered the world of vitamins (sort of in the "Reader's Digest" kind of way) and I hope it makes you feel more comfortable about what you need, in what quantities, and why you need them. July is another crazy month for me at my job (and my committee work, and vacation, etc.) but I will try to get at least of couple of posts in. Please let me know what you want to learn about next - I'm open to ALL suggestions, so don't be afraid to ask!

Friday, June 5, 2009

The ABC's of Vitamins - Vitamin E

Vitamin E – this is another one of those vitamins that we all assume we know quite a bit about, so let’s see what you really do know about our next to last vitamin.

Vitamin E is not a single chemical, but rather two groups of compounds: tocopherols and tocotrienols; and within each of these there are 4 compounds (alpha, beta, delta, gamma) and their mirror images (known as isomers) – very confusing! The best bioactive form is alpha-tocopherol and that is what all of the various compounds are measured against. The natural form is d-alpha-tocopherol and the synthetic version is dl-alpha-tocopherol. It is one of the few vitamins that your body can distinguish between the natural and synthetic versions, but both are very bioactive and therefore effective.

The name “tocopherol” means “to bring forth in childbirth” in Greek and it is because the vitamin was discovered by feeding pregnant rats a specialized diet and finding that a previously unknown compound was needed for them to carry their fetuses to term. And although Vitamin E was once referred to as an “anti-sterility vitamin” it does not appear to help with that problem.

Vitamin E is stored in your adipose tissues because of its high lipid solubility. It is best known perhaps for its antioxidant properties; it is the major antioxidant found in the lipid portion of the cellular membranes in your body protecting them from peroxidation.

Vitamin E counteracts the artherogenic effects of the breakdown of good cholesterol (LDL) which involves too many processes too complicated to go into here (like nitric-oxide mediated arterial relaxation and inhibition of platelet aggregation), so let’s just suffice to say that Vitamin E is good for your heart and circulatory system.

It also helps with your immune system, especially when phagocytosis is involved, but you need to ingest levels 4-6 times higher that what normal diets contain. So in essence: the older you are – the more depressed your immune system gets – and the more vitamin E you should be consuming.

Good sources of vitamin E are grains, nuts, beans, seeds and their oils, eggs, and butter. This is unfortunate, because these are “fatty foods” that many people are cutting out of their diet, or at least cutting back on, and that means we are getting less vitamin E. The good news is that vitamin E from food sources is not toxic, so you can’t get too much of a good thing that way!

Well, how well did you do; did you know vitamin E as well as you thought? Good, next will be the last vitamin, vitamin K, one of the least well known of its brethren. However, it will be a couple of weeks between posts as I'm off to attend the Institute of Food Technologists conference tomorrow. And as always, let me know what you want to know about - we are about to move onto a new chapter and I want to make sure it is a chapter you want to read!

Monday, May 18, 2009

The ABC's of Vitamins - Vitamin D

And so we come to Vitamin D, which had been the object of some squabbling over whether it should even be called a vitamin (the other camp voted for it to be a hormone), but alas, a vitamin it became. Vitamin D is a fat soluble vitamin like vitamin A, and it has two primary forms: ergocalciferol (D2) and cholecalciferol (D3) both of which are secosteroids.

D2 is the form found in plants and is created by the irradiation (from the sun, not a lab) of ergosterol in the plant. D3 is the form people produce through photosynthesis in the skin by activation of the sunlight on 7-dehydrocholesterol. (And you thought only plants performed photosynthesis!) Both D2 and D3 are biologically inactive and have to be converted to their hormonal (thereby active) forms through two hydroxylations to create dihydroxylated vitamin D.

Not all solar rays have the required energy to penetrate the epidermis and create vitamin D3, so there are a number of factors that affect the production. First, we need UVB rays, which we also know are related to skin cancer, so sunscreen (with a SPF as low as 8) does reduce the amount of vitamin D produced. Also, skin pigmentation plays a role; while pale ol’ me needs only about 15-30 minutes of exposure, someone who has very dark skin may need 3 hours to produce an equivalent amount of vitamin D.

Age also plays a role in the production of vitamin D, the younger you are, the more vitamin D is produced in the skin. As we age, our epidermis thins out and negatively affects our ability to photosynthesize. Luckily we can get our vitamin D from supplementation (recommended: 200 IU/day if you are under 50, 400 IU/day if you are over 50, and 600 IU/day if you are over 70). Just be aware, there is no toxicity from naturally produced vitamin D, but there is the chance of toxicity from supplements – at high levels it can cause hypercalcaemia and ultimately kidney failure. We can also get vitamin D from fortified milk, fatty fish, egg yolks and butter.

What does vitamin D do for us? It is required for the homeostasis of calcium and phosphorus, bone remodeling (takes minerals away and puts them back to create new bone), and the modulation of cell proliferation (increase in number) and differentiation (different kinds of cells). Vitamin D also plays a role in our immune system like macrophage activation (those cells that gobble up pathogens) and as an immunoregulator (your T-cell response). Perhaps best known is its relationship with calcium; they are inextricably connected, calcium absorption depends on vitamin D.

Well, we have covered all of the water soluble and half the fat soluble vitamins. Only vitamins E & K are left to tackle. I'm going to be taking a quick vacation for the Memorial weekend so look for my next post around the end of May or beginning of June. Until then, eat well & be well!

Monday, May 11, 2009

The ABC's of Vitamins - Vitamin C

Vitamin C. This is one where you are probably thinking, “Please, I know all about Vitamin C why even bother…”. And you might be correct, but I’m guessing there are some things about Vitamin C of which you may not be aware or that you may at least find interesting. Let’s see if I’m correct.

Vitamin C is the generic term for ascorbic acid and dehydroascorbic acid. It is a water soluble vitamin like the B vitamins we’ve been discussing. Ascorbic acid is found freely in your plasma and is distributed to all the cells of the body, especially the adrenal and pituitary glands. It is also stored in the brain where it functions as a neuromodulator, is involved in myelination and in the biosynthesis of noradrenaline (a neurotransmitter).

Ascorbic acid aids in inorganic iron absorption by acting as a chelator and reducing agent (this converts the iron to its ferrous state which is more soluble). In fact, taking vitamin C with a meal can increase your iron intake by around 6 fold. Ascorbic acid is required for the biosynthesis of carnitine (needed for the production of energy in your mitochondria) and enhancement of prostaglandin synthesis (modulates cardiovascular, pulmonary, immune and reproductive functions). Ascorbic acid also prevents the formation of N-nitroso compounds (aka nitrosamines, found in cured meats) which have been implicated in gastric cancer. Ascorbic acid stimulates collagen production as a co-factor in the polypeptide chain which aids in wound healing.

Perhaps one of ascorbic acid’s best known roles is that of antioxidant; it is an aggressive scavenger of free radicals. Lesser known, but of great interest to those of us who are allergy sufferers, is its role in the degradation of histamine. It decreases blood histamine levels thereby acting as an antihistamine.

Deficiencies are rare, but mild scurvy is seen in alcoholics & drug addicts, where it is manifested as weakness, lethargy, shortness of breath, and aching joints and muscles. Hopefully you are all getting the recommended daily intake of 90mg from citrus fruits, strawberries, papayas, dark green leafy vegetables and broccoli. If not, there are a world of supplements out there from both natural and synthetic sources (both have good bioavailability). If you are getting your vitamin C from supplements, it is better to take many small doses throughout the day rather than one large dose. You can also increase your absorption of supplemental vitamin C by taking it with a meal.

So, do you feel like you know this vitamin a little better than you did before? Good, now we will move on to Vitamin D it should be D-lightful!

Tuesday, April 28, 2009

The ABC's of Vitamins - Vitamin B12

Alas, B12 is the last of the B vitamin family; that is not to say that it is not as interesting as its kin. Vitamin B12 has the most complex chemical structure of all the vitamins and contains a molecule of cobalt. And has been the case with a number of its cousins, B12 is just an inclusive name for all cobalamins that have anti-pernicious anemic activity [say that three times fast :)]. You see, this vitamin was discovered by research into pernicious anemia and was finally isolated in 1948.

The most stable, and most commonly seen, form of B12 is cyanocobalamin. And the two forms that act as co-enzymes in the body are methylcobalamin and adenosylcobalamin. These co-enzymes work with the inactive form of folate to convert homocysteine into methionine. In the process, the inactive folate is activated and goes to work in DNA synthesis, thus making B9 & B12 very symbiotic.

Vitamin B12 can only be found in animals and microorganisms; no plants can make this vitamin. The best sources are organ meats like liver, heart and kidney, but other muscle tissues, milk, cheese, eggs and shellfish are good sources. Because this vitamin is not found in plants, vegans and very strict vegetarians must pay attention to their intake of B12.

We only need about 1 microgram per day, although the USDRI is set at 2.4 micrograms. This seems such a small amount, that you are probably wondering how big of a deal is it? It is really big! While it is rare to be deficient, it is not unheard of and those who suffer from Crohn’s/celiac disease are at a greater risk (along with those vegans/vegetarians). Some of the manifestations of a deficiency are megablastic anemia (aka pernicious anemia), demyelinization of nerve tissues (which is irreversible) and death.

So, we have finally reached the end of the B vitamins, but that doesn't mean that we have finished our conversation on vitamins just yet. The next post will be on our friend Vitamin C, probably the best known and perhaps most talked about vitamin out there. Hope to "C" you back!

Monday, April 13, 2009

The ABC's of Vitamins - Vitamin B9

Vitamin B9 is the next vitamin in the series, which may lead some to ask, what happened to B8? B8 was used for adenylic acid (a DNA metabolite) until it was discovered that is synthesized by the human body & wasn’t a vitamin. Vitamin B9, like a lot of its B-vitamin brethren, is a generic term for all forms of pteroic acid with vitamin activity. The other common generic name in use is folate; but folic acid is how you are most likely to see this vitamin designated even though it is not the form found commonly in nature.

The folate found in food is bound and must be digested by enzymes in the small intestine before we can utilize it; the same is not true for the form typically found in supplements and fortifications. Luckily, folate is an essential biochemical constituent of living cells, making it pretty easy to find in foods. Orange juice, eggs (cooked), beans, spinach, whole grains, asparagus, and peanuts are all good sources of B9. In addition, folate is added as a fortification to cereals and grain products (required in all commercial grain products per the FDA).

Folate is required for DNA and RNA synthesis, metabolism of some amino acids (proteins), cognitive function, metabolism of fat and reducing homocysteine levels which reduces the risk of cardiovascular disease. The recommended daily intake is 400 micrograms per day, and because we don’t absorb it well (that whole breaking it down problem) and because so many of us don’t eat very well, many people are deficient.

Deficiencies, especially long-term ones, can lead to elevated plasma homocysteine levels which are an early indicator of atherosclerosis and the potential for DNA breaks which may lead to an increased cancer risk. Deficiency during pregnancy is related to the elevated occurrence of neural tube defects (probably the effect with which most people are familiar).

Vitamin B9 works closely with vitamin B12 and that’s great, because that is our next vitamin and the last of the B vitamins to be covered. “B” there for the next post!

Tuesday, April 7, 2009

The ABC's of Vitamins - Vitamin B7

Boy am I behind on my posts - sorry! But I'm back and the next B vitamin on our list is B7, more commonly known as Biotin. Unlike so many of the other B vitamins we've been discussing, vitamin B7 is just biotin, not a generic term for a group of compounds. And the only active form, which coincidentally is the one that occurs in nature, is d-Biotin.

While biotin is present in both animal and plant tissues, even the very best sources are still pretty low in biotin compared to the other B vitamins. Whole eggs, soybeans and peanuts are good sources, as are wheat bran, oatmeal, muscle meats, fish and dairy products. The biotin found in animals, nuts & cereals is usually protein bound, while the biotin found in veggies, fruits and dairy products is "free" biotin. Biotin can also be made by the bacteria in your large intestine, some of which can be absorbed by the body, but it isn't a major contributor.

Biotin acts as a coenzyme for carboylases which is part of the acetyl-CoA formation process; it helps you derive energy from carbohydrates. Biotin also appears to play a role in the removal of glucose in the bloodstream and its storage as glycogen. And it aids in the breakdown of amino acids so they can be used by the body to build necessary proteins.

Because biotin is so widely available, deficiencies are pretty rare, although there are two genetic conditions that exist where biotin cannot be metabolized (known collectively as multiple carboxylase deficiency or MCD). A deficiency manifests itself as anorexia, weakened immune system and skin rashes. The recommended daily requirement for biotin is only 30 micrograms per day.

Wow, we are in the closing stretch of the B vitamins - six down and only two are left. I promise not to wait another two weeks before discussing vitamin B9, so please come back!

Tuesday, March 24, 2009

The ABC's of Vitamins - Vitamin B6

Ahhh, another day, another B vitamin! Today’s vitamin is vitamin B6, and you may have guessed from the other B vitamins, it too is not a single chemical. Vitamin B6 is the generic term for a group of derivatives which include pyridoxine (PN), pyridoxal (PL) and pyridoxamine (PM). Vitamin B6 was discovered in 1934 and was named “the rat dermatitis factor” due to the finding that a lack of this compound led to dermatitis in rats – how pleasant! (It didn’t take to long for them to figure out there were other B vitamins involved).

Pyridoxine is found primarily in plant tissues, while pyridoxal and pyridoxamine are found primarily in animal tissues. All of these derivatives convert to the main active form pyridoxal 5-phosphate (PLP) in the body. Vitamin B6 is also a coenzyme for over 100 enzymes involved in amino acid metabolism (protein). It is involved in the manufacture of serotonin, melatonin, dopamine and norepinephrine, and is integral to the functioning of our central and peripheral nervous systems. Vitamin B6 also has a role in modulating steroid homone activity in the body and it promotes red blood cell production. Wow! Good thing it is pretty widely available!

Our bodies can’t manufacture this vitamin, so we get it from our diet. Vitamin B6 can be found in potato skins, salmon & trout, bananas, avocados, yeast, whole grains, nuts, pulses, lean meats and liver. Like other water soluble vitamins, it can be lost in processing due to heat or removal of the germ & bran from grains. Because B6 is vital to protein metabolism, as your protein intake increases, so should your B6 intake. The USRDA is 1.3mg per day, or 16 mcg per gram of protein consumed. While this vitamin is not stored in the body, it can become toxic at levels above 50 mg/day causing neurological toxicity. Please come back to learn about vitamin B7 - Biotin.

Sunday, March 15, 2009

The ABC's of Vitamins - Vitamin B5

Vitamin B4 isn’t a vitamin at all (it is actually adenine a DNA metabolite synthesized by the body), and as such has been removed from the list. So that means the next vitamin is vitamin B5. And like so many of its other B-complex cousins, it too has multiple forms: pantethiene, phosphopantethiene, and phosphopantothenic acid. You will find it most commonly referred to as pantothenic acid.

Panto is greek for everywhere, and that pretty well describes this vitamin. It is so pervasive because it is part of coenzyme-A (Co-A) which is found in plants and animals. We cannot manufacture vitamin B5 and must get it from our diet so Co-A is our dietary form of pantothenic acid.

Coenzyme-A (and thus Vitamin B5) is active in many biochemical reactions in the body. It is part of the citric acid cycle (which involves the release of energy from carbohydrates, fats, and protein), necessary for synthesis of red blood cells, synthesis of essential fatty acids, cholesterol and steroid hormones. Milk has the highest amount of unbound vitamin B5 (~90%), but other good dietary sources include mushrooms, avocados, salmon, lobster, soybeans, and yeast. Deficiency is practically unheard of, except in cases of drug-interaction, so there is no recommended daily intake set, although 5mg per day is recommended. There is also been very little toxicity information available, as excess vitamin B5 is water soluble and thus excreted.

Well, we are half way through the B vitamins. I do hope you’re interested in the rest of the family, as B6 is on the sidelines waiting impatiently to be called up. Until next week, eat well & be well.

Tuesday, March 10, 2009

The ABC's of Vitamins - Vitamin B3

Much like vitamin B2, vitamin B3 is not a single substance; the nomenclature covers both niacin and niacinamide. Niacin is the generic name used for nicotinic acid, whereas niacinamide is used for the amide structure (-NH2) nicotinamide.

Nicotinamide is the reactive part of the co-enzymes NAD & NADP. NAD & NADP and their associated co-enzymes are involved in many of the body’s oxidative & reductive reactions (example: lactate to pyruvate to Acetyl-CoA). NAD also plays a role in DNA repair.Vitamin B3 can be made by our bodies from the amino acid tryptophan, but we also get it from chicken, tuna, liver, lean red meats, legumes and peanuts. Like so many of the B vitamins, vitamin B3 is also readily found in many cereal grains. Unfortunately much of it (80-90%) is as bound nicotinic acid, which is not very bioavailable, although treatment with acid or alkali can unbind it and make it more available. And vitamin B3 is completely lost in the milling process, which is why cereal & grain products in the US are fortified; all those wonderful vitamins are stripped away in the processing from whole grain to refined grain.

Normal protein intakes, without any other sources will meet our body’s requirement for this vitamin which means deficiency of vitamin B3 is rare, but among those who are extremely malnourished it can still happen. The symptoms associated with deficiency include dementia, diarrhea, dermatitis and eventually death. Interestingly, pregnancy makes the conversion of tryptophan to niacin twice as efficient and contraceptive pills also increase efficiency too (although not quite as much). Toxicity is rare, but at levels greater than 100mg per day, skin flushing occurs and in even higher doses it can cause gouty arthritis and liver damage.

I’ll be moving on down (or is it up?) the list of the B vitamins, so please come back!

Saturday, February 28, 2009

The ABC's of Vitamins - Vitamin B2

I'd like to introduce you to vitamin B2; it is actually a group of compounds called flavins which contains riboflavin, riboflavin-5'-phosphate (FMN) and riboflavin-5'-adenosyldiphosphate (FAD). Riboflavin's name comes from what it looks like, both physically and chemically. It is a florescent yellow-orange color and flavin comes from flavus meaning yellow in latin the ribo comes from ribitol which is the sugar part of the molecule.

FMN and FAD exist primarily as part of flavoproteins (flavin enzymes) and living cells require them. They work in the oxidoreductive processes - that is they can accept hydrogen atoms - and are used in biological processes like the conversion of pyruvate to acetyl-CoA (for fatty acid metabolism).

This is also one of the vitamins we need to get from our food. Milk, cheese, meat, yeasts, eggs, wheat bran, liver and kidney are all good sources of this vitamin. Riboflavin is absorbed in the intestine; FAD & FMN are converted to riboflavin before they are absorbed. Some of the absorbed riboflavin is converted by the body to FMN and most of that FMN is then converted to FAD in the cells. Vitamin B2 is used in energy production and the conversion of tryptophan to niacin.

Again, this is not a vitamin that is commonly deficient, both due to supplementation and its availability in commonly consumed foods. It doesn't even have any really fun symptoms, you'd most likely experience cracked lips and inflammation of the tongue. Riboflavin is currently being evaluated as a treatment in the prevention of migraines.

So, you've met two of the B vitamins, more to come in the weeks ahead. In the meantime, eat well and be well!

Saturday, February 21, 2009

The ABC's of Vitamins - Vitamin B1

The vitamin du jour is Thiamin (or Thiamine depending on where you are from) which is also known as vitamin B1; it was discovered and named by Robert R. Williams in the early 1930's. Thiamin is found in all plants and animals, but pulses, nuts, cereals/grains, yeasts and pork contain larger quantities than beef, chicken, eggs, veggies and fruits.

Thiamin is not one of the vitamins we can produce so it has to come from our diet. Thiamin is usually found in one of three phosphorylated forms: monophosphate ester, triphosphate ester, and thiamin pyrophosphate (TPP). The triphos form has a role in nerve transmission but the TPP has a much larger role in the body.

TPP is a co-enzyme for several metabolic pathways. It works in the decarboxylation and transketolation processes involved in turning carbohydrates in to energy (tricarboxylic acid cycle). In the body TPP is hydrolyzed to free thiamin in your intestines where it is converted back to TPP in your cells (seems a little silly - huh?). Our cardiovascular and nervous systems need carbohydrates and carbohydrate metabolism needs thiamin - so the amount you need depends is directly dependent on the amount of carbohydrates you eat.

Thiamin is considered to be one of the vitamins with a high bioavailability, probably due to the fact that is most often found in the form our bodies can use (TPP) and because so many foods are supplemented with it, so deficiencies are pretty uncommon. That doesn't mean it can't happen - alcoholics, persons with intestinal issues (especially diarrhea and vomiting), genetic malabsorption issues or those who only eat junk food can all run into issues with deficiency. Some of the symptoms associated with a lack of vitamin B1 are anorexia, muscle weakness, and cardiovascular irregularities. If you really get deficient, you can look forward to paranoia, manic/depressive episodes, confusion and beriberi. Just so you can avoid these conditions keep these facts in mind: thiamin is sensitive to heat and baking soda can inactivate it; while tea and coffee can interfere with its absorption.

So, now you know about the first of the B vitamins - quite a large family as you will see, so come back to meet its cousins!

Sunday, February 15, 2009

The ABC's of Vitamins

I received some ribbing about jumping right in to the vitamins without starting from the basics. Since I am guilty as charged, and in an effort to make amends, I am going to take a step backward before I continue to move forward with the B-vitamins. The word vitamin comes from the Polish scientist Casimir Funk who thought they were “vital amines” (meaning nitrogen containing) and called them vitamines. When it was later determined that not all of them had nitrogen, they simply dropped the ‘e’ from the end giving us “vitamin”.

Vitamins are organic compounds that are essential to us, in order to maintain bodily functions, in very small amounts. There are about 13 vitamins that we need to maintain our health, one of which we can make (D) and another the bacteria in our gut can make for us (K) and the rest of which we need to obtain from our diets. While not used for energy, some vitamins are required for energy production. Other vitamins are used much like hormones (D especially) and others as co-enzymes (B group).

The vitamins were named alphabetically, so why does it go A, B, C, D, E, K? Well, originally lots of things were thought to be vitamins that turned out not to be. What was vitamin F is really essential fatty acids, vitamin G was renamed Riboflavin (B2), vitamin H was renamed as Biotin (B7), vitamin J is catechol… you get the point.

Obviously some of the vitamins have subsets – the B vitamins being the most familiar, but there are others; and they are further divided into water soluble and fat soluble. Fat soluble vitamins include: A, D, E, K and the carotenoids. Water soluble vitamins include: the B’s (thiamin, riboflavin, niacin, pyridoxine, pantothenic acid, biotin, folate, cyanocobalamin) and C. ). Excess fat soluble vitamins are stored for future use and most of the excess water soluble vitamins are excreted and so must be ingested daily.

The US government has distributed a Recommended Daily Amount (RDA) for many of the vitamins. (The RDA is calculated as the daily intake that is sufficient for 97-98% of healthy individuals in a particular age/gender group.) You’ll see the effects of this on a nutrition data panel on the foods you purchase as % daily value. Most Americans get all the vitamins they need from the foods they consume; the fact that my industry adds (supplements) many of the foods consumed definitely helps in this regard. But some still choose to take supplements daily. There are some groups for whom supplementation makes good sense: elderly, pregnant, Chron’s disease, low calorie diets, high protein (low veggie) diets, and those with intestinal issues (diarrhea).

So, now that the basics have been covered, I’ll get back on the bus and take us to B-town - the vitamin B group. Hope to see you there!

Saturday, February 7, 2009

The ABC's of Vitamins - Vitamin A Carotenoids

Last week I discussed preformed vitamin A and this week I'll be talking about provitamin A, also known as carotenoids. Carotenoids (beta-carotene, lycopene, xanthophylls) are compounds found in plants and photosynthetic microorganisms that work as light-harvesting pigments with chlorophyll. Animals cannot produce carotenoids and must get them from their diets.

A molecule of retinol must be present in the structure of a carotenoid in order for it to possess provitamin A activity. The most common and well known of the carotenoids is beta-carotene which has 2 retinol molecules and therefore the highest provitamin A activity. Only about 50 of 500 carotenoids are considered provitamin A.

Fruits and vegetables are where we get our carotenoids. Yellow, orange and red are where we expect to find them, but they are also present in dark green leafy vegetables too. As with preformed vitamin A, carotenoids are available as supplements, primarily as beta-carotene. Crystalline beta-carotene supplements are absorbed at about 50% efficiency; while a raw carrot is only absorbed at about 1% efficiency. Luckly, cooking vegetables increases the efficiency of carotenoid absorption (sorry all you raw food fans!).

Carotenoids that are not used immediately by the body are stored in the fatty tissues, liver and organs much like preformed vitamin A. However, since the carotenoids are not yet in the biologically active form, they are perfectly safe and do not induce toxicity. Carotenoids consumed in large quantities can cause hypercarotenosis (a yellowing of the skin) which is reversible and doesn't have any long-term toxic effects. No USRDI has been established for carotenoids, but 10 -30 mg/day seems to be the target.

Much of what you hear about beta-carotene involves its role as an antioxidant. Carotenoids have the ability to trap peroxyl free radicals and to deactivate singlet oxygen molecules. This appears to be due to their extensive conjugated double bond systems and helps us by reducing some of the mechanisms associated with some cancers. In addition to this, carotenoids help enhance our immune system. See, your mom was right all along - you have to eat your fruits & vegetables. They may just help to save your life!

Sunday, February 1, 2009

The ABC's of Vitamins - Vitamin A

I've spent a fair bit of time discussing the macronutrients (protein, fat, carbs), so I thought it was time to start on the micronutrients. Because I am a scientist and like things orderly, I'm going to go alphabetically rather than oil vs. water soluble. That means today's vitamin is A.

Vitamin A isn't a single thing, rather it is a generic term for compounds (other than carotenoids) having the biologic activity of retinol. The retinoids include: retinol, retinaldehyde and retinoic acid. These compounds are referred to as preformed vitamin A because they do not need to undergo metabolic conversion to be biologically active.

Vitamin A is essential to several of our life processes like metabolism, skeletal and soft tissue growth, formation and maintenance of epithelial tissues (skin & mucous membranes), reproduction and vision (although retinoic acid cannot support these last 2 because they need retinol or retinaldehyde).

Dietary sources of preformed vitamin A are animal tissues and milk - the animals convert carotenoids into vitamin A which we then consume as meat, milk, cheese, butter, etc. We can also get our vitamin A from supplements. Vitamin A is measured in IU (international units) and 1 IU is equal to the biologic activity of 0.3 micrograms of retinol. The USRDI for vitamin A is 3000 IU (900 micrograms) with an upper limit (the maximum daily intake that can be safely consumed) of 10000 IU (3000 micrograms). Vitamin A deficiencies are not very common, at least not in developed nations, but if you don't eat dairy, fruits or vegetables you could get into trouble. Early symptoms of deficiency include night blindness, dry skin and susceptibility to infection. If left untreated, it can result in permanent blindness. Vitamin A can become toxic since it is stored in the fatty tissues, liver and organs, but only if you are taking massive amounts of supplements or eating nothing but liver.

Preformed vitamin A absorption occurs in the small intestine and about 5-20% of the vitamin A ingested is not absorbed and is eliminated from the body. Everyone has a different absorption ratio, but typically vitamin A is absorbed at only 20-50% efficiency. In order to use and metabolize vitamin A, it needs some friends. Since vitamin A is an oil soluble vitamin, it stands to reason that it is better absorbed when consumed with fat. But vitamin A also needs protein; the lack of protein will result in a lack of vitamin A metabolism due to a decrease in enzyme levels. Zinc is also needed; a lack of it causes low plasma vitamin A levels even when vitamin A supplementation is given. And vitamin E is necessary; a lack of vitamin E causes a lack of vitamin A to be stored in the liver.

Next time I'll talk about provitamin A, also known as carotenoids, so eat well to be well!

Saturday, January 24, 2009

Fermentable Facts: Saccharomyces

Like last week's fermenting friend Lactobacillus, Saccharomyces is a very helpful little bug. Saccharomyces is a eukarotic, osmophillic yeast. And while there are many species in this genus, the most studied, and most used species is S. cerevisiae.

Fermentation using yeasts has been around for some 4000 years with evidence of breads and beer being found in Egyptian tombs. Yeasts are what turn dough into bread, malt into beer, molasses into rum, grapes into wine and rice into sake.

While the actual definition of fermentation, as I stated previously, is the breakdown of carbohydrates under anaerobic conditions, a common definition is the breakdown of sugars into carbon dioxide and alcohol under aerobic conditions. Saccharomyces species multiply better under aerobic conditions (which was used to great advantage by Charles Fleischmann in 1868 to produce the first commercially available yeast) but ferment better under anaerobic conditions like in a dough.

Obviously alcohol is not the by-product of fermentation we are looking for in bread; its the carbon dioxide that we want for leavening. However, the alcohol produced helps extract flavor compounds that are not water soluble and creates some of the characteristic flavors associated with baked bread. Saccharomyces cerevisiae is also known as baker's yeast and it is what you buy in those little envelopes at the grocery store.

Alcohol is what we want when making wine and beer, with the carbon dioxide adding a nice fizz. Saccaromyces ellipsoideus is used to ferment grape juice into wine. while two different species are used in beer manufacturing depending on what you are brewing. Saccharomyces cerevisiae is a top fermenter (top of the vessel) and produces ales while Saccharomyces pastorianus is a bottom fermenter and produces lagers. Yeasts are also used in the production of industrial ethanol for fuel.

So, what to take away from all of this? Well, how about that microorganisms can be your friend as well as your enemy and that they can make what we eat more fun to eat.

Thursday, January 15, 2009

Fermentable Facts: Lactobacillus

With all the news about bad bacteria (Salmonella, Listeria, E.coli) in the press, I thought it was time to talk about some good bacteria. Today’s helpful bacteria is Lactobacillus. Lactobacillus are, (in microbiology speak), regular, non-spore forming, gram positive rods. They are found naturally on plants, in our bodies (and those of other warm blooded animals), and in foods – fermented foods. As is you may guess by their name, they produce lactic acid as a by-product of fermentation.

Fermentation is not new – it has been around for ages. It happened naturally, unaided but not unnoticed by man, who saw that some foods underwent a transformation which affected both the appearance and flavor. They also noticed that this change kept food safe to eat for longer periods of time as compared to fresh food; thus it became a preservation method. The definition of fermentation is the breakdown of carbohydrates or carbohydrate-like materials, under anaerobic (lack of oxygen) conditions. And Lactobacillus species are among some of the most common fermenters used in foods.

Lactobacillus changes cucumbers into pickles, cabbage into sauerkraut, meat into salami and milk into sour cream, yogurt and cheese. But in addition to making these tasty treats, they have the ability to inhibit the growth of food spoilage and pathogenic bacteria that may also be present in the food (this is called lactic antagonism). While not fully understood, it is likely to be due to a combination of lowered pH, the production of lactase and other inhibitory compounds and by outcompeting pathogens for nutrition.

These bugs and the compounds they produce during fermentation have some other great benefits as well:

1) improved digestive tract health – some species are used as probiotics (like L. casei, L. acidolphilus)
2) synthesize vitamins (Vitamin B12, folic acid)
3) enhanced immune system (link)
4) may help reduce the risk of colon cancer (link)
5) enhance the bioavailability of nutrients by breaking down indigestible plant materials

Too bad the helpful bacteria in our world get so little press. I’ll be discussing some other favorite fermenters in my next post – the kind that make alcohol, so please come back!

Wednesday, January 7, 2009

2008 Recap

Happy New Year! Sorry for the extended absence - the Christmas holiday always is busy for me and I found I had too few hours in my day, so something had to give. I decided that today's post would be on three interesting topics from 2008 headlines.


Wow - was this ever a topic in 2008; the Chinese milk scandal was covered around the world. Melamine, for those still wondering exactly the newscasters were talking about, is a chemical compound used in the making of plastics that contains nitrogen (C3H6N6) and that's important. You see, many high protein foods are priced by the quantity of protein present; the higher the protein levels the higher the price and the way we test for protein content is my measuring nitrogen levels. But the Chinese manufacturers wanted to sell protein they didn't have and bumped up their nitrogen levels with the addition of melamine. Not good - when used as a plasticizer, even for food contact surfaces, melamine is fine (although you should never put melamine in the microwave - it can melt and enter your food). But ingesting melamine is tough on your organs - especially for infants who's systems cannot handle toxins. The Chinese government has now stepped up inspections and testing and our own FDA and FSIS have increased the number of samples pulled and tested as well.


Mandatory Country of Origin Labeling (technically the: Food, Conservation, and Energy Act of 2008 expanded list of commodities). This new USDA/AMS regulation took effect on September 30, 2008. It is intended to provide consumers with information about the source of their: beef, veal, pork, lamb, goat, chicken, fish and shellfish (wild & farmed), perishable (fresh & frozen) fruits and vegetables, peanuts, pecans, macadamia nuts and ginseng. Whew! This information can be placed on a placard, sticker, twist tie, sign, band or pin tag as long as it is legible and conspicously located for the consumer. Of course there are always exceptions. All processed foods are excluded, so any food "that has undergone specific processing resulting in a change of character (e.g. cooking, curing, smoking, restructuring); or that has been combined with another food component" will not be subject to this rule. So roasted peanuts = no COOL, peanuts in shell = COOL; plain pork loin = COOL, teriyaki pork loin = no COOL. So while some are still not happy with the workings of this act, it should provide those concerned with the origins of some of the foods they eat with valuable information about the food source.


I talked a bit about this back on my March 16th post, so for those who want to know more about this sweetener please click on that link. As of December 17, 2008, Rebaudioside A (a highly purified derivative of one of the two primary sweet glycoside compounds contained in the Stevia plant) was granted GRAS approval by the FDA for use in foods and beverages. This is great news for those seeking a natural high-intensity sweetener (200 - 300 times sweeter than sugar) that does not induce a glycemic response (no increased blood sugar levels). Cargill's tradename is Truvia and is working with Coke for the use of its product in Sprite, Odwalla and Glaceau Vitaminwaters. Whole Earth Sweetener's tradename is Purevia and they are working with Pepsi to add the sweetener to SoBe Lifewater, and Trop50. These beverages, and probably many others, should hit the market in the begining of 2009. This won't be an inexpensive sweetener given that Rebaudioside A is only 2-4% of the stevia plant (stevioside - the other sweet glycoside is 5 -10% of the plant), but its low usage rate (due both to its intensity & slight licorice taste) will make it desirable to manufacturers.

So, that is my look back at 2008. This new year looks to be just as interesting as the last and I should have plenty of topics upon which to opine. As always, send me your questions, concerns or just topics you'd like to know more about!