郫县豆瓣后发酵过程中脂肪和脂肪酸代谢变化

本研究以8个不同后发酵时间郫县豆瓣为研究对象,通过石油醚提取、硫酸-甲醇甲酯化,气相色谱内标法定性定量分析了其脂肪及脂肪酸变化过程。结果表明:粗脂肪含量为3.46%~4.29%,总脂肪酸含量为8.258~18.484 mg/g;不同后发酵期均检测出9种脂肪酸,分别为:亚油酸(4.963~11.668 mg/g)、油酸(1.186~2.706 mg/g)、棕榈酸(0.751~1.649 mg/g)、亚麻酸(0.405~0.886 mg/g)、硬脂酸(0.296~0.856 mg/g)、肉豆蔻酸(0.131~0.305 mg/g)、反式油酸(0.126~0.230 mg/g)、棕榈油酸(0.056~0.142 mg/g)、月桂酸(0.030~0.113 mg/g)。主成分分析结果表明,提取到前两主成分的贡献率分别为75.09%、15.21%,累积贡献率达90.30%,可较好反映所有脂肪酸组成的基本信息,同时可将后发酵期脂肪酸变化大致分为三个阶段,分别为后发酵前期(1~3 M)、发酵中期(6~9 M)和发酵后期(12~36 M),且脂肪酸在后发酵前期的变化程度远远大于发酵中后期。该研究结果可为郫县豆瓣工业化生产控制产品品质与建立生产质量控制体系提供科学依据。

Changes of Fat and Fatty Acid Metabolism in Post-fermentation Process of Pixian Soybean Paste

Gas chromatography(GC)internal standard method was used to qualitatively and quantitatively analyze the fatty acids of Pixian soybean paste with eight different post-fermentation stages,which was extracted with petroleum ether and methylated with sulfuric acid-methanol.The results showed that the crude fat contents was 3.46%~4.29%,and the total fatty acid contents was 8.258~18.484 mg/g.There were nine fatty acids detected at different post-fermentation stages,which were linoleic acid(4.963~11.668 mg/g),oleic acid(1.186~2.706 mg/g),palmitic acid(0.751~1.649 mg/g),linoleic acid(0.405~0.886 mg/g),stearic acid(0.296~0.856 mg/g),myristic acid(0.131~0.305 mg/g),transoleic acid(0.126~0.230 mg/g),palmitoleic acid(0.056~0.142 mg/g)and lauric acid(0.030~0.113 mg/g).The results of principal component analysis showed that the contribution rates of the first and second principal components were 75.09%and 15.21%respectively,and the cumulative contribution rate was 90.30%,which could be better reflect the basic information of all fatty acid compositions.Moreover,the fatty acid changes in the post-fermentation period could be roughly divided into three stages(post-fermentation early stage,post-fermentation middle stage and post-fermentation late stage),and the changes of fatty acids in the early stage were far greater than those in the middle and late fermentation stage.The results of the study could provide a scientific basis for Pixian soybean paste industrialized production control product quality and establishment of production quality control system.