Yang Xiaoyu, Wang Yan, Hao Ming, Li Liang
College of Food Science, Northeast Agricultural University.
J Oleo Sci. 2020 Nov 1;69(11):1455-1465. doi: 10.5650/jos.ess20102. Epub 2020 Oct 15.
In this study, a new way to produce tofu with lactic acid bacteria (Lactobacillus casei, L. casei) and salt coagulant (magnesium sulfate) has been developed and optimized in order to improve the quality characteristics and the storage stability. Processing parameters (bean-water ratio, inoculation amount, magnesium sulfate concentration and pressing time) of tofu were studied. Yield, water holding capacity (WHC), texture and sensory were measured for evaluating quality characteristics of tofu. Based on the single factor and response surface methodology (RSM), the optimized conditions of tofu were determined as follows: bean-water ratio was 1:4 g/mL, fermentation time was 5 h at 37°C when the inoculation amount was 4.0%, magnesium sulfate concentration was 2.0 mol/L and pressing time was 1 h. Under the optimum conditions, the yield of the tofu was 140.45 g, the WHC was 87.25 %, the hardness was 420.36 g, and the tofu had better sensory characteristics, soft, uniform texture, as well as good flavor. The shelf life and stability of tofu during storage were also evaluated under the optimum conditions. The results showed that fermented tofu had a longer shelf life than unfermented tofu at room temperature. Compared with the "pasteurization + low temperature" group and "low temperature" group, the fermented tofu in the "microwave + low temperature" group had a longer shelf life and better-quality properties during storage. Tofu, prepared by the lactic acid bacteria fermentation and salt coagulant, would be accepted as a new type of tofu according to its quality characteristics and storage stability.
在本研究中，已开发并优化了一种用乳酸菌（干酪乳杆菌）和盐类凝固剂（硫酸镁）生产豆腐的新方法，以改善其品质特性和储存稳定性。研究了豆腐的加工参数（豆水比、接种量、硫酸镁浓度和压制时间）。通过测量产量、持水能力（WHC）、质地和感官指标来评估豆腐的品质特性。基于单因素和响应面法（RSM），确定了豆腐的优化条件如下：豆水比为1:4 g/mL，接种量为4.0%时，在37°C下发酵5小时，硫酸镁浓度为2.0 mol/L，压制时间为1小时。在最佳条件下，豆腐产量为140.45 g，持水能力为87.25%，硬度为420.36 g，且豆腐具有更好的感官特性，质地柔软、均匀，风味良好。还在最佳条件下评估了豆腐在储存期间的保质期和稳定性。结果表明，在室温下，发酵豆腐的保质期比未发酵豆腐更长。与“巴氏杀菌+低温”组和“低温”组相比，“微波+低温”组的发酵豆腐在储存期间保质期更长，品质特性更好。根据其品质特性和储存稳定性，由乳酸菌发酵和盐类凝固剂制备的豆腐将被认可为一种新型豆腐。
