The effect of extraction method and types of coagulants on the results and physicochemical properties of tofu

Abstract Extraction and coagulation techniques are essential stages in tofu production. This research studies the effect of extraction and coagulation techniques on physicochemical properties of soybean extract, soy pulp, and tofu. This study applies three extraction techniques, namely manual heat extraction, manual cold extraction, and cold extraction using mechanical devices. They used nigari coagulant. As a control, the process of making tofu follows the procedure process as in the small industry of tofu with whey coagulant. The measurement of material mass balance is done at each stage of the process, while the evaluation of the product includes water content, ash, protein, fat, magnesium, and texture. The experimental results show that an increase in the ratio of water to soybeans and the increase of extraction temperature can increase the amount of extracted protein. The coagulation using nigari produced 22.18 kg tofu in hot extraction treatment, 19.61 kg in cold extraction and 17.60 kg in machine extraction. The control treatment produced 36.8 kg of tofu. The water content in the control treatment was higher than the other three treatments. Protein levels, magnesium levels, hardness and chewing power for treatment with nigari coagulant were significantly higher than those with whey.