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.

摘要：提取与凝固工艺是豆腐生产的关键工序。本研究探讨了提取与凝固工艺对大豆提取液、豆渣及豆腐理化特性的影响。本研究采用三种提取工艺，分别为手工热提、手工冷提以及机械辅助冷提，以盐卤（nigari）作为凝固剂；对照组则遵循小型豆腐作坊采用乳清凝固剂的标准生产工艺。研究在各工艺环节开展物料衡算，并对产物进行含水率、灰分、蛋白质、脂肪、镁含量及质构特性的测定。实验结果表明：提高料水比与提取温度均可提升提取所得的蛋白质含量。采用盐卤凝固的实验组中，热提工艺的豆腐得率为22.18 kg，冷提工艺为19.61 kg，机械辅助冷提工艺为17.60 kg；对照组的豆腐得率为36.8 kg。对照组的豆腐含水率高于其余三个实验组。采用盐卤凝固的实验组，其蛋白质含量、镁含量、硬度及咀嚼性均显著高于乳清凝固剂对照组。