Comparison of Yields and Physicochemical Properties of Lime Juice with Acetic Acid and Calcium Chloride Coagulated Soybean Curds

Abstract

The yield, proximate composition and functional properties of soybean curd produced using lime juice as coagulant was compared with those produced using acetic acid and CaCl2. Curd was produced from soymilk using 0.5% of lime juice (6.32% citric acid). Guided by the titratable acidity of lime juice, curds were also produced using 0.5% of 6.32% solutions of acetic acid and CaCl2 in water, respectively. The lime juice produced significantly (p < 0.05) lesser curd than acetic acid. The proximate analysis revealed that only the protein and carbohydrate contents of curds differed significantly (p < 0.05). The lime juice-coagulated curd had the highest protein but lowest carbohydrate contents. Functionally, only protein solubility, emulsion activity and foaming capacity of the curds differed significantly (p<0.05) with the lime juice coagulated curds having the highest values. Judging by the amount of protein precipitated and the functional properties, lime juice may have produced better curd than acetic acid and CaCl2. However, curds with higher protein content and better functional properties may be expected should acetic acid and CaCl2 be applied as pure liquid or solid as reported in the literatures; and local processors in Nigeria that use lime juice as coagulant must use higher volume of the juice to optimize the yield and quality of curd.