A trail of research revisted.

The author describes how his interest in the nutritional value of soybeans led to a trail of research that had many ramifications. In an attempt to account for the poor nutritional value of raw soybeans and the beneficial effect of heat treatment, a protein displaying hemagglutinating activity and capable of inhibiting the growth of rats was isolated and characterized. This protein subsequently proved to be an example of a class of proteins that were later referred to as "lectins".

Effects of processing on antinutritional factors in legumes: the soybean case.

The author recounts his personal trail of research which has ultimately led to better understanding of the factors which contribute to the poor nutritive value of unheated soybeans. Among the techniques that were employed were the isolation of a lectin from raw soybeans, the use of affinity chromatography to remove the trypsin inhibitors, and the nutritional evaluation of soybean varieties which lacked the lectin or the Kunitz trypsin inhibitor. Based on a consideration of the results obtained by these experiments, it was estimated that the trypsin inhibitors accounted for approximately 40% of the growth inhibition on raw soy, of which two-thirds could be attributed to the Kunitz inhibitor and one-third to the Bowman-Birk inhibitor.

Possible adverse effects of soybean anticarcinogens.

For soybeans to serve as a good source of protein for feeding animals as well as humans, a certain amount of heat treatment or some other form of processing must be applied. This is because there are present in soybeans certain heat-labile factors that exert an adverse effect on the nutritional value of the protein. The so-called protease inhibitors have received the most attention in this regard and have been shown to exert their antinutritional effect in the short term by causing pancreatic hypertrophy and hyperplasia in the rat, the underlying cause for an inhibition of growth in these animals.