soy.net

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All of the effects of trypsin inhibitors, lectins, goitrogens, phytates--are not generally ever seen in western diets where soy is consumed, because of the way soy is processed and because soy is only part of the varied western diet. The issues of antinutrients become potentially problematical and require circumvention where soy comprises all or most of a nutritional resources for a population group. Soy processing affects its final chemical components. Fermentation reduces trypsin inhibitors (TI), phytates, soyasaponins, and oligosaccharides, while increasing aglycone isoflavone content. The production of soy milk starts with soaking beans in a highly alkaline solution, the puree is heated to about 115 degrees in a pressure cooker, which destroys most of the trypsin inhibitors, lectin phytohemagluttinin, but not all of the phytates. Very high heat processing reduces the antihypercholesterolemic effects of soyasaponins by about 17%. Any water processing removes some oxalate. Ethanol processing removes extra isoflavones. Cross-linked amino acids are not unique to soy as they are formed in soy and cow's milk casein products via processing.  LAL and HAL are cross-linkers which naturally accumulate in corneal, kidney tissues, bone, aorta, collagen as part of the aging process, LAL is reported as a nephrotoxin. Soaking soybeans in a very basic solution can produce lysinoalanine by reacting base with serine and cysteine and alanine. Lysinoalanine or LAL is sometimes mistakenly called lysinaline. LAL is a cross-linked amino acid formed by base reaction with serine or cysteine and then an intermediate reacts with alanine. LAL is also found in heat-treated cow's milk protein (casein) and wheat protein products as well as alkali-treated soy products. HAL or histadinoalanine is a cross-linked protein found only in heated cow's milk products at the same levels as LAL in alkali-treated soybean products, in addition to milk LAL; dairy yogurt was found to contain these (HAL + LAL) and other unknown crosslinked amino acids. Alkali-treated lactalbumin accumulates more than double the LAL as would alkali-treated isolated soy protein. Casein HAL was found over a thousand times higher in corneal concentrations as LAL in cataractous lenses. LAL is not significantly produced during the production of edible soy protein produced under milder alkaline conditions, and its production may be reduced in the presence of SH-amino acids such as cysteine, N-acetyl cysteine, or glutathione. Mild or no alkaline processing and SH amino acid supplementation would both drastically reduce LAL and improve SH amino acid profiles. LAL effects may be more pronounced in sole-source foods such as formulated liquid diets. LAL levels in milk caseinate enteral nutrition formulas are notoriously high, up to 8 times higher than drinkable cow's milk, and should be minimized for persons restricted to single food forms such as bedridden patients dependent upon enteral nutrition or infants on formula.