纯种发酵技术对发酵甘蓝中亚硝酸盐含量的影响

以Lactobacillus pentosus和Leuconostoc mesenteroides为发酵剂分别发酵甘蓝,自然发酵甘蓝作为对照,测定甘蓝中亚硝酸盐含量的变化。结果表明:纯种发酵甘蓝中亚硝酸盐含量比自然发酵低2倍多,且未形成“亚硝峰”。纯种发酵甘蓝中导致亚硝酸盐形成的肠杆菌及乳酸菌之外的需氧嗜温菌数量显著低于自然发酵(P<0.05),乳酸含量高于自然发酵,且发酵第2~5天达到差异显著(P<0.05)。从纯种发酵甘蓝卤中分离122株菌株,其中6种乳酸菌占分离菌株总数的90.16%。这6种乳酸菌消耗亚硝酸盐的能力均比对照高2倍多,消耗亚硝酸盐均超过96%,最高达到99.623%,远高于自然发酵(31.580%)。纯种发酵方法能够抑制肠杆菌及乳酸菌之外的需氧嗜温菌生长,抑制“亚硝峰”的形成。

Effect of starter cultures on nitrite concentration of fermenting Chinese cabbage

The nitrite concentrations were measured,during the spontaneous fermentation and pure inoculation fermentation(with Lactobacillus pentosus and Leuconostoc mesenteroides as fermentation agent) of Chinese cabbage.It was found that the maximum nitrite concentration(nitrite peak) in the pure inoculation fermentation cabbage was two times lower than that in the spontaneous fermentation cabbage and the reason could be concluded from a serials of experiments as follows: enumeration of lactic acid bacteria,mesophilic aerobic bacteria and enterobateriaceae,changes of pH value and lactic acid concentration.Numbers of mesophilic aerobic bacteria(enterobateria and lactic acid bacteria not included) that could produce the nitrite peak in the pure inoculation fermentation cabbage was less than these of in the spontaneous fermentation cabbage.And the numbers of lactic acid bacteria and concentrations of lactic acid in the former was more than these in the latter.The decrease velocity of pH value of the former was lower than the latter.Hence,nitrite concentration in the pure inoculation fermentation cabbage was lower than that in the spontaneous fermentation cabbage.