Chemical Composition and Sensory Properties of Tofu Coagulated with Grape Juice and exposed to different Heat Treatments

Abstract

Background: Tofu is a gelatinous food made from soybean with the potentials to offer high protein and micronutrients content  depending on the coagulants used in the production. 

Objective: This study aimed to evaluate the chemical composition and sensory  properties of tofu coagulated with grape juice and exposed to various heat treatment. 

Methods: In order to obtain the milk, soybean was  sorted, winnowed, soaked in clean water overnight. It was thereafter rinsed, dehulled, milled and filtered. The milk was boiled,  coagulated with grape juice, and then subjected to several heat treatments. Nutrient and anti-nutrient properties were analysed using  standard methods. Sensory evaluation was also done and the result obtained compared with the control (deep-fried chicken). 

Result:  Processing reduced moisture content from 64.84% in fresh Tofu (FRT) to 21.79% in baked Tofu (BDT). Protein, fiber, ash and carbohydrate  increased from 16.46%, 0.32%, 1.17% and 14.45% in fresh tofu to 18.65%, 1.20%, 2.29% and 52.68% in baked tofu respectively. Steamed  tofu had the highest mineral composition which ranged from 4.06mg/100g in sodium to 121.85mg/100g in magnesium as well as the highest anti-nutrient levels (0.28-1.33mg/100g). Fried tofu was the most preferred of all the tofu samples. 

Conclusion: Processing  reduced the moisture, mineral and the anti-nutrient properties of tofu but increased the other nutrients including protein which makes it  a healthier alternative to combat protein energy malnutrition and curb non-communicable disease risk due to its low sodium content.