46E-13 Tofu made from soybean and apricot kernel. I. With GDL or cucumber juice as coagulant

H. ZHANG, Cereal and Food Sciences, North Dakota State University, 113 Harris Hall, Fargo, ND 58105 and X. Wei, Department of Food Science, Beijing Agricultural College, Beijing, 102206, China.

Conventional Tofu is promoted as a component of healthy diet. However, bland flavor affects its palatability. Besides having physiological benefits, apricot kernel and cucumber juice possess a distinct “nutty” and a “coolish” flavor, respectively. Moreover, with Ca ²⁺and Mn²⁺contents, cucumber juice becomes a potential coagulant.

Our objective was to investigate the variables influencing the quality of Tofu samples.

A common method to make GDL Tofu and 100% cucumber juice was adopted. Tofu quality was measured by water holding capacity (WHC,%), sensory evaluation (total score 30) and firmness of Tofu (g/cm²). Orthogonal main effect plan for four factors using eight treatment combinations was employed.

Levels	A Apricot kernel: soybean	B Raw material: water	C GDL added to syrup (%, w/v)	D Coagulative temperature (°C)
1	1:1	1:2	0.24	92
2	1:3	1:2.5	0.27	82
3	1:5	1:3	0.30	87

It was found that Tofu made from A2B2C3D1 and A1B2C1D3 had highest firmness; range analysis showed that factor A played a dominating role in Tofu firmness; decreasing apricot kernel fraction, increasing firmness. The optimum conditions for WHC were A2B3C1D2 and A3B2C1D3, and Factor D dominated the difference in WHC (i.e., the higher the temperature, the lower the WHC). The highest sensory score was achieved at A2B3C1D2 and A3B2C1D3, and A was still the dominating factor.

Regarding the overall quality of Tofu, A3B2C1D3 was the optimum combination. Cucumber juice added at ratio of 1:4 with syrup can coagulate very well to form a Tofu product with greenish color and “coolish” flavor. Lastly, Tofu made at A3B2C1D3 was compared with commercial GDL Tofu. Firmness, WHC and sensory score of the former and latter were 39.8, 40.1; 74.0, 67.7; 27, 26, respectively. .

This experiment implies that novel Tofu product with comparable quality to commercial GDL Tofu can be made.