Monday, April 6, 2009

Bugging Me

I am currently reading Thrive: The Vegan Nutrition Guide to Optimal Performance in Sports and Life by Brendan Brazier. So far so good, no truly outrageous claims, what he is saying is largely making sense. If you are interested in sports nutrition or a whole foods diet that excludes major food allergens (corn, wheat/gluten, dairy, soy, active yeast, and peanuts) or just want information on getting more whole and raw foods into your diet you should check this book out.

However, I am reading the section on food sensitivities and he discusses 'active yeast', as in the stuff you use to make bread rise (as distinguished from nutritional yeast, which is inactive). He says that "it is not destroyed by the heat of baking; it enters our body when we eat the bread and survives by feeding on our body's sugars" (Brazier, 69). My problem with is claim is this: when you proof yeast for baking (not necessary if you are using instant yeast, but that is a different blog topic) you must use water or liquid under 120*F, preferably more in the 100 - 110* range, or the yeast will die and proofing will not happen. We can then infer that active yeast has a difficult time surviving temperatures in excess of 120*F. As a point of comparison, the USDA's minimum safe temperature guidelines for cooking meat (a perhaps more risky food to eat for a variety of reasons) tops out at 165*, a temperature at which the USDA considers potential food borne pathogens to be neutralized. Now, when I bake yeast bread I generally cook it to an internal temperature of 185 - 190*F as measured on an instant read thermometer, well above all previously discussed temperatures at which things die. Consequently, I am hard pressed to understand how he arrived at the conclusion that yeast survive the bread making process. In fact bread making is all about controlling the life-cycle of yeast, allowing it to live and multiple (rise the dough) until it reaches whatever stage we desire, at which point we kill it (by baking or otherwise cooking). Therefore, while I can buy that some people may be sensitive to yeast or yeast byproducts or whatever medium in which the yeast has been used, I find the claim that people are sensitive to yeast because it has survived cooking to continue living on in our digestive tract highly implausible.

That's all for now. I'll have the weekly menu and and an informational post on bolting plants for you tonight.

Have a happy Monday!

1 comment:

Anonymous said...

who are you and what have you done with my daughter?