School of Biological Sciences
The University of Hong Kong
Professor C.Y. Ma
To study the protein quality in soybeans related to the processing characteristics in oriental soyfoods such as soymilk, tofu, miso and other fermented products. Critical examination of the physicochemical characteristics of soy proteins (e.g., flow characteristics, thermal properties, gelation rheologiy and kinetics, etc.) will provide a better understanding of the mechanisms involved in the making of high quality soyfood products. Development of simple screening tests (e.g., apparent viscosity of soymilk) will assist plant breeders to select for specific traits for end users.
In the manufacture of soymilk and tofu, spent residue (okara) is produced as a by-product with little market value. Okara contains about 27% (dry basis) protein which can be extracted at alkaline pH, and possesses functional properties comparable to commercial soy protein products. To enhance the utilization of okara protein as a food ingredient, further processing including chemical modifications and thermoplastic extrusion will be attempted. A collaboration with Hong Kong Polytechnic University has been initiated to look at the cholesterol lowering effect of soy protein from okara and soymilk.
The relationship between structure (physicochemical characteristics) and function (functional properties) of proteins from selected cereal and legume crops are being studied. These include cereal crops such as oats and rice, pseudo-cereals such as buckwheat and amaranth, and some under-utilized Chinese legumes. Apart from enhanced utilization of these plant proteins as food ingredients, the study can lead to better control of product quality in protein foods.