Abstract: The physical properties of yuba were determined with a texture analyzer, a chromometer and a scanning electron microscope. We studied the correlation between the raw material components and the yield and eating quality of yuba, and we optimized the processing conditions. The results showed that when the soybean milk concentration was 6%, pH 8.0, temperature 90 ℃, the ratio of protein to fat 3:1, and the ratio of protein to carbohydrate 4:1, the highest yield of yuba of 43.13% was obtained with a tensile strength of 12.46 g/mm2 and an elongation at break of 9.85%. The eating quality of yuba prepared from soybean milk with a ratio of 11S to 7S protein of 4:1 was the best. Compared with the traditional production process, the yield and tensile strength at break of yuba produced using the optimized process were increased by 10.11% and 74.02%, respectively. In comprehensive evaluation of yield, mechanical properties and color, the optimized yuba scored 17.7% higher than that produced using the traditional process.

Key words: yuba; process optimization; soybean protein; tensile strength; eating quality