猪五花肉红烧过程中脂肪和脂肪酸的变化规律

Changes in Fatty Acid Composition and Fat Content during Processing of Braised Pork Belly in Brown Sauce

目的：探讨以猪五花肉为原料的红烧肉加工过程中脂肪和脂肪酸的变化,以期对红烧肉的风味、营养、质地等研究提供参考。方法：对红烧肉加工过程中原料、油炸、炖煮过程样品（0~2 h,每30 min取样）以及成品的粗脂肪含量、过氧化值（peroxide value,POV）、硫代巴比妥酸（thiobarbituric acid reactive substances,TBARS）值以及脂肪酸含量进行测定。结果：五花肉红烧过程中脂肪含量显著下降（P〈0.05）,成品红烧肉脂肪含量比原料肉下降12.14%;POV先增大后减小,在炖煮30 min达到最大值;TBARS值逐渐增大,在炖煮过程中变化显著（P〈0.05）;油酸、棕榈酸、亚油酸和硬脂酸是五花肉脂肪中的主要脂肪酸,在红烧过程中饱和脂肪酸（saturated fatty acid,SFA）含量变化不大（P〉0.05）,单不饱和脂肪酸（monounsaturated fatty acid,MUFA）含量显著上升（P〈0.05）,多不饱和脂肪酸（polyunsaturated fatty acid,PUFA）含量显著下降。结论：五花肉红烧过程中脂肪含量下降、脂肪发生适度氧化、脂肪酸组分构成发生了改变。

Objective： The changes of fat content, lipid oxidation products and fatty acid composition during the processing of stewed pork belly in brown sauce were analyzed in order to provide a reference for future study on flavor, nutrition and texture of stewed pork in brown sauce. Methods： Crude fat content, peroxide value（POV）, thiobarbituric acid reactive substance（TBARS） value and fatty acid composition were measured during the whole processing procedure（raw material, deep frying, stewing（0, 30, 60, 90 and 120 min） and the final product）. Results： Fat content of pork belly decreased significantly（P〈0.05） during the whole processing procedure, by 12.14% when comparing the final product with the raw meat. POV reached the peak level after stewing for 30 min followed by a decline, while TBARS increased gradually（P〈0.05）. The content of monounsaturated fatty acids（MUFAs） revealed a significant increase（P〈0.05） during the whole process, while the content of polyunsaturated fatty acids（PUFAs） significantly decrease（P〈0.05）, and there was no significant difference（P〉0.05） in the content of saturated fatty acids（SFAs）. Conclusion： A decline in fat content, moderate lipid oxidation and a series of changes in fatty acid composition occur during the processing of stewed pork in brown sauce.