香辛料对涪陵榨菜微生物菌落结构及挥发性风味成分的影响

Effects of Spices on Microbial Community Structure and Volatile Flavor Components of Fuling Pickled Mustard Tuber

摘要:

【目的】研究香辛料对涪陵榨菜微生物菌落结构及挥发性风味物质的影响，并探究主要优势微生物菌属与挥发性风味成分种类间的相关性。【方法】采用高通量测序和顶空固相微萃取-气相色谱质谱联用（HS-SPME-GC-MS）技术研究香辛料对腌制涪陵榨菜微生物菌落结构和挥发性风味成分的影响，基于Pearson相关系数揭示主要优势微生物菌属与挥发性成分种类间的相关性，并检测了榨菜总酸、亚硝酸盐和还原糖等理化特性。【结果】对照组主要优势菌属为乳杆菌属（Lactobacillus，35.61%）、盐单胞菌属（Halomonas，15.13%）、明串珠菌属（Leuconostoc，10.40%）、德巴利氏酵母属（Debaryomyces，77.51%）等；添加香辛料组主要优势菌属为乳杆菌属（Lactobacillus，80.49%）、德巴利氏酵母属（Debaryomyces，43.17%）、未指明酵母菌（unclassified_k_Fungi，28.33%）等。对照组检测出挥发性风味成分60种（总质量分数为1 286.94 μg/kg），主要为酯类、有机硫化物类和酸类；添加香辛料组检测出挥发性风味成分84种（总质量分数为14 304.21 μg/kg），主要为醇类、醚类和酸类。添加香辛料组的总酸质量分数（10.95 g/kg）高于对照组（7.14 g/kg），亚硝酸盐质量分数（5.57 mg/kg）也高于对照组（3.13 mg/kg）。乳杆菌属与醇类、醚类、烯烃类、酸类、酮类和酚类呈高度显著正相关（P<0.001），与有机硫化物呈高度显著负相关（P<0.001）；德巴利氏酵母属、盐单胞菌属、明串珠菌属与大部分挥发性风味成分种类呈显著负相关（P<0.05）。【结论】添加香辛料能增加榨菜酸度，提高乳酸菌属相对丰度以及真菌优势菌群数；调控榨菜发酵过程的乳杆菌属、节担菌属和链格孢属的丰度，有助于改善榨菜的风味。

Abstract:

[Objective]This study aims to investigate the effects of spices on the microbial community structure and volatile flavor compounds of Fuling pickled mustard tuber and explore the correlations between dominant microbial genera and volatile components.[Method]The effects of spices on microbial community structure and volatile flavor components of Fuling pickled mustard tuber were investigated by high-throughput sequencing and headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS). Pearson correlation coefficients were calculated to reveal the correlations between dominant microbial genera and volatile components. The mass fractions of total acids, nitrite, and reducing sugar were determined.[Result]The dominant microbial genera in the pickled mustard tuber without spices addition (control) were Lactobacillus (35.61%), Halomonas (15.13%), Leuconostoc (10.40%), Debaryomyces (77.51%), etc. In the pickled mustard tuber with spices addition, Lactobacillus (80.49%), Debaryomyces (43.17%), and unclassified_k_Fungi (28.33%) were dominant. A total of 60 volatile flavor compounds were detected in the control group, with the total mass fraction of 1 286.94 μg/kg, mainly including esters, organic sulfides, and acids. 84 volatile flavor compounds were detected in the spices addition group, with the total mass fraction of 14 304.21 μg/kg, mainly including alcohols, ethers, and acids. The pickled mustard tuber with spices addition had higher total acid mass fraction (10.95 g/kg vs. 7.14 g/kg) and higher nitrite mass fraction (5.57 mg/kg vs. 3.13 mg/kg) than the control group. Lactobacillus showed positive correlations with alcohols, ethers, alkenes, acids, ketones, and phenols (P<0.001) and negative correlations with organic sulfides (P<0.001). Debaryomyces, Halomonas, and Leuconostoc showed negative correlations with most volatile flavor components (P<0.05).[Conclusion]Spices can increase the acidity of pickled mustard tuber, the relative abundance of Lactobacillus, and the number of dominant fungi. By regulating the abundance of Lactobacillus, Wallemia, and Alternaria during the fermentation process, spices help improve the flavor of pickled mustard tuber.