Quality Variety of Traditional Soybean Paste and Antibacterial Effect of Its Antiseptic System during Storage

This paper used constant temperature acceleration method to investigate the changes of color, total acid, amino acid nitrogen, reducing sugar and sensory in traditional soybean paste storage at 25, 38, 50℃ for 28 days. Inhibitory effect of its antiseptic system on different microorganisms was investigated by microbial challenge test. With the prolonging of storage time, the browning degree, total acid, reducing sugar increased, amino acid nitrogen and sensory characteristic score decreased. Meanwhile, this change was aggravated by raise the storage temperature. After storage 28 days at 25, 38 and 50℃, browning index increased by 2.1%, 12.2% and 23.5%, total acid content increased by 0.03, 0.06 and 0.18 g/100 g, color ratios increased by 1.14, 1.36 and 1.76 times. Under the condition of 38 and 50℃ storage after 28 d, the reducing sugar were increased by 0.3 and 0.9 g/100 g. The concentration of membrane producing yeast, Aspergillus oryzae and salt-tolerant lactic acid bacteria could be reduced from 10⁴ CFU/g to less than 10 CFU/g within 28 days under the traditional soybean paste sealing condition. The anti-corrosion system under the open condition had the same bactericidal ability to the film-producing yeast and salt-tolerant lactic acid bacteria, while Aspergillus oryzae still had 7.9×10² CFU/g after 28 days.Mould, yeast and lactobacillus could be inhibited in traditional soybean paste by itself antiseptic system during storage at sealing condition.