Production of Soy Cheese for ISS and Planetary Outpost 2004-01-2563
We have developed two methods of making cheese-flavored products from soy protein. In the dough method soy protein (white flakes or soy protein isolate), oil, cheese culture (Streptococcus salivarius spp. thermophilus and Lactobacillus delbrueckii spp. Bulgaricus), cheese whey, protease, lactose, water and sodium nitrite are mixed and fermented. After the pH reaches a minimum, the pH is adjusted to 5.2 with sodium carbonate solution and the cheese is stored anaerobically at 4°C. In the wet method, soymilk (9% solids) is prepared from white flakes, pasteurized, mixed with fat and homogenized. Next, whey, culture and sodium nitrite are added and the mixture is fermented at 40°C. to pH 4.6. The curd is cut and cooked to 50°C, whey is removed and the curd is pressed, adjusted to pH 5.2 with sodium carbonate, protease is added and the product is stored anaerobically at 4°C. The wet method product is a smooth paste. The dough method gave a dryer paste but had a much more granular texture. Products made with high-oleic vegetable oils had a bland flavor with little typical soy protein flavor. Products made with milk fat had a pleasant cream cheese-like flavor. The flavor of product made with milk fat could be reproduced in product made with vegetable oils by the addition of a mixture of lactones, ketones, and short-chain fatty acids typical of milk fat. The flavor was well developed after one month at 4°C and did not change noticeably with additional storage. The addition of amino acids derived from casein to the products a few days before consumption only marginally improved their cheese-like flavors.