韩国泡菜制作过程中理化特性及微生物的变化

Changes in the Physico-chemical and Microbiological Characteristics of Kimchi during Manufacture

为研究韩国泡菜制作过程中品质的变化,测定其在腌制、发酵过程中一系列理化指标及微生物指标。结果表明:腌制过程中,水分含量由96.23%降低为91.34%;pH值略微下降至6.46,而总酸含量上升至2.91 g/kg;硬度降低了19.26%,降低至188 6 N;菌落总数、乳酸菌总数、酵母菌数量及大肠菌群略微上升。在发酵期间,水分含量持续降低,降至82.54%;pH值下降至3.87,而总酸含量上升至7.02 g/kg;硬度降低了68.08%至565 N;L*(亮度)值与a*(红度)值显著增加,而b*(黄度)值显著降低;菌落总数下降至3.3×102 CFU/g;乳酸菌总数达到1.3×107 CFU/g;酵母菌数量先上升后下降,最终降低为9.1×102 CFU/g;大肠菌群在第4天达到最大值93 MPN/g,随后迅速下降,低于3 MPN/g。

This study was performed to investigate quality changes of kimchi during production by measuring its physico-chemical and microbiological indexes at the stages of salting and fermentation. The results showed that during salting, the moisture content of kimchi was decreased from 96.23% to 91.34%. The pH value was decreased slightly to 6.46, while the total acid amount was increased to 2.91 g/kg. The hardness was decreased by 19.26% to 1 886 N. The numbers of aerobic bacteria, lactic acid bacteria, yeast and coliforms of kimchi were increased gently during this period. The moisture content of kimchi was sharply decreased to 82.54% during fermentation. The pH value was decreased to 3.87, while the total acid amount was increased to 7.02 g/kg. Hardness was decreased by 68.08% to 565 N. L* value(brightness) and a* value(redness) were increased significantly, while b* value(yellowness) was decreased. The number of aerobic bacteria fell to the minimum value of 3.3 × 102 CFU/g, while the lactic acid bacteria reached 1.3 × 107 CFU/g. The number of yeast was decreased remarkably to 9.1 × 102 CFU/g after a slight increase. The number of coliforms was increased to 93 MPN/g on the 4th day of fermentation, followed by a decrease to lower than 3 MPN/g.