Page 34 - Spring2010

It is not phytase, soaking does not usually sufficiently to urge caution in including grains, nuts and

necessary to eliminate phytic acid. Soaking of millet, soya legumes into your diet. It is not necessary to
bean, maize, sorghum, and mung bean at 92 completely eliminate phytic acid from the diet,
completely degrees F for 24 hours decreased the contents of only to keep it to acceptable levels.
eliminate phytic acid by 4–51 percent. With these same An excess of 800 mg phytic acid per day is
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phytic acid grains and beans, soaking at room temperature probably not a good idea. The average phytate
for 24 hours reduced phytic acid levels by 16–21 intake in the U.S. and the U.K. ranges between
from the diet, percent. However, soaking of pounded maize 631 and 746 mg per day; the average in Finland
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only to keep for one hour at room temperature already led to is 370 mg; in Italy it is 219 mg; and in Sweden a
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it to a reduction of phytic acid by 51 percent. mere 180 mg per day.
Sourdough fermentation of grains contain-
In the context of a diet rich in calcium,

acceptable ing high levels of phytase—such as wheat and vitamin D, vitamin A, vitamin C, good fats and
levels. rye—is the process that works best for phytate lacto-fermented foods, most people will do fine
reduction. Sourdough fermentation of whole on an estimated 400-800 mg per day. For those
wheat flour for just four hours at 92 degrees F led suffering from tooth decay, bone loss or mineral
to a 60 percent reduction in phytic acid. Phytic deficiencies, total estimated phytate content of
acid content of the bran samples was reduced to 150-400 mg would be advised. For children
44.9 percent after eight hours at 92 degrees F. 46 under age six, pregnant women or those with
The addition of malted grains and bakers yeast serious illnesses, it is best to consume a diet as
increased this reduction to 92-98 percent. An- low in phytic acid as possible.
other study showed almost complete elimination In practical terms, this means properly
of phytic acid in whole wheat bread after eight preparing phytate-rich foods to reduce at least
hours of sourdough fermentation (See Figure 6). 47 a portion of the phytate content, and restricting
A study of phytates in recipes used typically their consumption to two or three servings per
by home bread bakers found that leavening with day. Daily consumption of one or two slices of
commercial yeast was much less effective at genuine sourdough bread, a handful of nuts,
removing phytates. Yeasted whole wheat breads and one serving of properly prepared oatmeal,
lost only 22-58 percent of their phytic acid con- pancakes, brown rice or beans should not pose
tent from the start of the bread making process any problems in the context of a nutrient-dense
to the complete loaf. diet. Problems arise when whole grains and beans
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become the major dietary sources of calories—
PHYTIC ACID AND YOU when every meal contains more than one whole
The purpose of this article is not to make grain product or when over-reliance is placed
you afraid of foods containing phytic acid, only on nuts or legumes. Unfermented soy products,

FIGURE 6: REDUCTION OF PHYTIC ACID IN WHOLE WHEAT SOURDOUGH BREAD 47

Percentage of
Phytic Acid

Yeast Fermentation

Sourdough Fermentation

Time
34 Wise Traditions SPRING 2010