BACKGROUND: Tofu from aged soybeans is of poor quality, mainly with respect to texture. Texture defects described in the literature are contradictory. No study has investigated all sensory properties simultaneously. The objective of the present study was to evaluate the effect of soybean aging conditions [natural: ambient temperature and RH, 18 months, and accelerated: 30 °C, 84% relative humidity (RH), 6 months] on all of the sensory characteristics and the acceptance of tofu. Texture and color were also evaluated via an instrumental method. The control condition was -20 °C and 47% RH. Coodetec 214 and BRS 267 cultivars were studied. RESULTS: The effect of soybean accelerated aging on tofu sensory characteristics and acceptance was more pronounced compared to the natural condition. The two cultivars had a similar behavior. Tofu control exhibited a light, uniform and bright color, cohesive appearance, sweet aroma and flavor, as well as a firm and elastic texture. Tofu made from both aged cultivars showed a gray color with dark spots, a rough appearance, fermented aroma, rancid flavor, an astringent and bitter taste, a fracturable texture and adherence to the oral cavity after chewing. These characteristics of tofu from aged soybeans implied a low acceptance by consumers. CONCLUSION: Tofu from natural and accelerated aged soybeans has sensory attributes of appearance, as well as aroma, flavor and damaged texture, that are unacceptable by consumers.
BACKGROUND: Tofu from aged soybeans is of poor quality, mainly with respect to texture. Texture defects described in the literature are contradictory. No study has investigated all sensory properties simultaneously. The objective of the present study was to evaluate the effect of soybean aging conditions [natural: ambient temperature and RH, 18 months, and accelerated: 30 °C, 84% relative humidity (RH), 6 months] on all of the sensory characteristics and the acceptance of tofu. Texture and color were also evaluated via an instrumental method. The control condition was -20 °C and 47% RH. Coodetec 214 and BRS 267 cultivars were studied. RESULTS: The effect of soybean accelerated aging on tofu sensory characteristics and acceptance was more pronounced compared to the natural condition. The two cultivars had a similar behavior. Tofu control exhibited a light, uniform and bright color, cohesive appearance, sweet aroma and flavor, as well as a firm and elastic texture. Tofu made from both aged cultivars showed a gray color with dark spots, a rough appearance, fermented aroma, rancid flavor, an astringent and bitter taste, a fracturable texture and adherence to the oral cavity after chewing. These characteristics of tofu from aged soybeans implied a low acceptance by consumers. CONCLUSION: Tofu from natural and accelerated aged soybeans has sensory attributes of appearance, as well as aroma, flavor and damaged texture, that are unacceptable by consumers.