RECENT PROGRESS ON BIOTECHNOLOGY OF SOYBEAN PROTEINS AND SOYBEAN PROTEIN FOOD-PRODUCTS

Recently it has been recognized that the action of the enzymes contain ed in soybeans has negative effects on the qualities of soybean protei n foods. Based upon these findings, new manufacturing techniques for h igh quality soybean protein foods have been developed through the cont rol of such enzyme action. For instance, new soybean seeds lacking lip oxygenases have been developed which reduce the production of grassy-b eany flavors. The gel hardness of tofu can also be controlled through the action of the lipoxygenases contained in soybeans. In addition obj ectionable after-tastes develop through the hydrolysis of soybean isof lavones by the beta-glucosidases which are found in soybeans. Genetic engineering of soybean proteins made a great progress in improving the ir functional and nutritional qualities through the modifications of g enes encoding for soybean storage proteins. The application of a biore actor for soy sauce is also described as an example of the progress on the biotechnology.