The nutritional and food hygienic character of the new developed soy protein concentrate and soy protein isolate in Heilongjiang province were studied by chemical analysis and rat experiment. These products have not yet been reported in China. The results indicated that the content of protein of soy protein concentrate and isolate was 69.76 and 83.11%(as anhydr-ate basic), the PER 2.00 and 1.34, the apparent digestibility 77.54 and 85.72%, the true digestibility 84.33 and 93.19%, the biological value 79.80 and 62.54%, the NPU 67.39 and 58.28% respectively.The essential amino acid composition of the two samples was the same as the products prepared in the other countries. By the hematological and pathological examination in rats, the contents of serveral harmful substan- ces were allowable or not detected. The authors belived that the nutritional quality of the two soy protein products was nearly the same as those in other countries, and its food safety was satisfactory.

The sunflower protein concentrate studied in this paper is a new developed food protein resource in Heilongjiang Province. Up to now the studied report on this product has not been seen in China. Using casein as reference protein and soy protein isolate and gluten from wheat flour as comparable substances we studied the content of major nutrients and the composition of essential amino acid in the sunflower protein concentrate by chemical analysis method, and also studied protein efficiency ratio (PER) and other indicators related to nitrogen metabolism in the animal experiment by the recommended method of AOAC. Some common harmful substances in the samples were examined quantitatively. The results showed that the protein content (as anhydrate basic), the PER, apparent digestibility, the true digestibility, the biological value, and NPU of the sunflower protein concentrate were 62.43%, 1.96, 96.83%, 98.51%, 96.81% and 95.35% respectively. The essential amino acid composition was the same as analogous products prepared in other countries. The blood indicators and pathological observation of tested rats were normal. The content of several harmful substances in the product was allowable.All of these results indicated that the nutritional quality of the sunflower protein concentrate is about the same with some similar porducts prepared in other countries. We believe that these products are safe to consumers in the aspect of food hygiene.