Effects of types and purple sweet potato ratios on the quality of purple tofu

Abstract

The study was conducted to investigate the possibility of adding purple sweet potato to the manufacturing process of traditional tofu through the alteration of nutrient content (moisture, protein content, lipid content) and physicochemical properties (water holding capacity, elasticity, recovery yield and color) of purple tofu. Accordingly, the impact of purple sweet potato forms (powder, steamed, and slurry), with supplementation ratios (1.6, 2.4, 3.2 and 4.0 g db), was investigated on the tofu production process. It was found that supplementing purple sweet potato in slurry form at a ratio of 3.2 g db resulted in tofu with moisture content (75.88%), protein content (13.02%), total fat content (8.81%), water holding capacity (4.75 g water/g protein), recovery yield (180.49%), elasticity (11.55 N), and color values L* (69.15), a* (10.01) and b* (1.10).