苹果果胶对不同来源油体乳液稳定性和脂肪酸利用率的影响

Effect of Apple Pectin on the Storage Stability and Fatty Acid Accessibility from Various Oil Bodies Emulsion

为探究果胶(0~5 g/L)对大豆或花生油体复合乳液稳定性和脂肪酸利用率的影响,借助动态光散射、凝胶电泳、激光共聚焦显微镜和气相色谱等评价复合乳液储存稳定性,并在此基础上,研究体外模拟消化对复合乳液界面蛋白结构、乳液结构和脂肪酸利用率的影响。得出结果:当果胶含量<3 g/L时,乳液的储存稳定性高度依赖于果胶含量;当果胶含量>1.5 g/L时,果胶通过降低乳液聚集程度和增加液滴间静电排斥的方式,显著改善乳液稳定性;当果胶含量介于3~5 g/L时,果胶对乳液的稳定作用达到平衡。在体外模拟消化试验中,胃蛋白酶水解界面蛋白形成低于15 ku的小肽,而果胶可抑制胃蛋白酶水解界面蛋白。负电肽的形成和胆盐的添加以及游离脂肪酸的释放使得乳液ζ-电位显著降低。与大豆油体相比,果胶通过延缓界面蛋白水解和控制大豆复合乳液粒度大小,使得大豆复合乳液脂肪酸利用率降低3.3%。相反,与花生油体相比,因花生复合乳液具有更大的胰蛋白酶水解面积,故花生复合乳液脂肪酸利用率增加33.8%。

In order to investigate the influence of concentration of AP to the storage stability and fatty acid accessibility,different concentration of AP(0-5 g/L)was applied as the stabilizer.The storage stability was determined by dynamic light scattering and visual stability.Meanwhile,the influence of in vitro simulated digestion on the protein structure,emulsion structure and fatty acid accessibility was also investigated using the sodium dodecyl sulfate-polyacrylamide gel electrophoresis,dynamic light scatting technologies,confocal laser scanning microscopy,the release of fatty acid and gas chromatography.The results show that the storage stability of SOB and POB is highly dependent on the AP concentration when the AP concentration is less than 3 g/L.The storage stability of emulsions is significantly improved when the AP concentration is higher than 1.5 g/L,this is due to the decreasing of aggregation and increasing of surface charge values.When the AP concentration is between 3-5 g/L,the influence of pectin to the stability of emulsion reaches a balance statue.During in vitro simulated digestion,the activity of pepsin can be inhibited by adding AP,peptides below 15 ku is formed during the testing.Theζ-potentials of emulsion significantly reduces due to the formation of negatively charged peptides,increasing of bile salts,and releasing of free fatty acids.In the testing,the free fatty acid accessibility decreases by 3.3%with 1.5 g/L of AP compared with OBs without AP,this is due the inhibits of pepsin during the hydrolysis of OBs proteins and the controlling of SOB-AP size.However,the free fatty acid accessibility increases by 33.8%with POB.This is due to the bigger hydrolyzed area of trypsin in POB-AP.