发酵乳杆菌RC4对咸肉亚硝酸盐含量及挥发性风味物质的影响

为降低咸肉中亚硝酸盐含量, 将具有高效降解亚硝酸盐的发酵乳杆菌RC4应用于咸肉制作中, 研究其对咸肉亚硝酸盐含量、品质和风味的影响. 通过单因素实验及正交实验, 对添加发酵乳杆菌RC4的实验组咸肉制作工艺进行优化, 比较接菌组和未接菌发酵对照组在感官评分、亚硝酸盐含量、pH、色差、水分、硫代巴比妥值及挥发性风味成分的差异. 结果表明: 实验组咸肉亚硝酸盐含量降解显著, 降解率为78.60%; 实验组咸肉的最佳发酵条件为接种2.0%(μL·mL^-1)的发酵乳杆菌RC4菌液, 18℃发酵10d. 与对照组相比, 实验组咸肉pH降低; 色差及水分含量与对照组差异不显著(P＞0.05); TBA值的变化量明显小于对照组(P＜0.05). 在鉴定出的87种挥发性物质中, 庚醛为RC4发酵产生, 苯甲醛等的含量显著高于对照组, 而这几种醛均为特征风味化合物. 由此可知, 在咸肉制备工艺中, 添加发酵乳杆菌RC4能显著降低咸肉的亚硝酸盐含量, 提高咸肉保质期, 增加其特征风味化合物含量.

Application of Lactobacillus fermentum RC4 on salted meat for nitrite degradation and quality improvement

Lactobacillus fermentum (L. fermentum) RC4 with efficient nitrite degradation ability were applied to prepare salted meat and decrease its nitrite content. The effects of L. fermentum RC4 on the nitrite content, quality and flavor of salted meat were examined. Single-factor experiments and orthogonal experiments were used to optimize the processing technology of experimental group salted meat by including L. fermentum. The sensory score, nitrite content, pH, color difference, moisture, thiobarbital (TBA) value and volatile flavor components were detected to compare the experimental and control group. The results showed that the optimal fermentation conditions for the experimental group salted meat were as follows: inoculating 2.0% (μL·mL^-1) L. fermentum on salted meat and fermenting for 10d at 18℃. The nitrite content of the experimental group and that of the control group was 3.22 and 15.28 mg·kg^-1 respectively. The nitrite content of the experimental group was 21.07% of the control group, 78.60% lower than prior to fermentation. During fermentation of the experimental group, the pH decreased from 6.9 to 6.45. The color and the water content were not significantly different from the control group (P>0.05). The TBA value increment was significantly lower than the control group (P<0.05), which indicated that lipid oxidation was significantly inhibited by adding L. fermentum. A total of 87 kinds of volatile substances were identified. Aldehydes, alcohols, acids and ketones significantly affected the flavor of salted meat. Heptaldehyde produced by L. fermentum fermentation was not detected in the control group. Heptaldehyde, benzaldehyde, octanal and furfural obviously increased in the experimental group and these compounds are characteristic flavor compounds in the experimental group. Conclusion: By including L. fermentum RC4 with nitrite degradation characters in processing salted meat can significantly reduce the nitrite content of salted meat and increase its quality and flavor.