In this study, the effects of different microwave treatment times (10, 20, 30, 40, 50, and 60 s) on fat loss, fatty acid profile, lipid transfers, and microstructure of pork subcutaneous back fat (PSBF) were investigated. Results showed that the fat loss of PSBF after microwave treatment for 60 s was significantly increased (53.31%). Microwave treatment increased the proportion of saturated fatty acids but reduced the relative content of monounsaturated and polyunsaturated fatty acids. Cryo-scanning electron microscopy, ordinary optical microscope and confocal laser scanning microscope analysis demonstrated that microwave treatment facilitated a large outflow of fat from the adipocytes, and the increasing and then decreasing changes in the size of individual adipocytes. Magnetic resonance imaging enabled the visualization of fat migration of PSBF. Overall, PSBF can be used as a biological model to evaluate the effect of microwave treatment on the change and migration mechanism of fat.
Dengmei Liu,Yao Xu,Xianming Zeng,Bowen Lv,Miao Zhang,Di Zhao,Chunbao Li
Replacing animal fat with vegetable oil occurred extensively in the meat products, but whether these replacements will affect the nutrition of meat protein was seldom revealed. Effect of substitution of back fat (BF) by vegetable oils or their oleogels in emulsion-type sausage on the digestion process of meat protein was investigated. Replacement of BF with vegetable oils and their oleogels decreased the G'/G" values of meat paste, and oleogels largely weakened the structure of sausages. The substitution significantly reduced the liberation of -NH 2 during the initial gastric and intestinal digestion, and resulted in bigger digests in CLSM images. The reduced gastric digestibility induced by substitution was shown to be related to the reduced stability of gastric digests, which can be attributed to the larger particle size and reduced viscosity of digests. These results highlighted stability of digests as a key point changing the digestion process of meat protein.