影响乳清分离蛋白-羧甲基纤维素钠油乳液体外消化因素探究

Exploration of factors affecting the in vitro digestion of WPI-CMC oil emulsion

该文分别以椰子油、紫苏籽油、橄榄油、棕榈油和稻米油为芯材,乳清分离蛋白(whey protein isolate,WPI)和羧甲基纤维素钠(carboxmethylcellulo sesodium,CMC)为壁材制备5种不同类型的油乳液,并模拟体外消化实验,探究不同酶浓度、加样量、含油量对椰油乳液脂肪酸释放率的影响以及不同油类型对乳液脂肪酸释放率及脂肪酸组成的影响。结果显示,在口腔和胃阶段,WPI-CMC稳定的椰油乳液的脂肪酸释放率整体偏低,不随酶浓度(0. 15~1. 5 mg/mL)、加样量和含油量的增加而变化;在小肠阶段,胰酶的浓度越高,乳液脂肪酸释放越快,而最终脂肪酸的释放率也越高;随加样量的增加乳液的脂肪酸释放率反而减小,随油含量的增加乳液的黏弹性变好,流动性变差,脂肪酸释放率减小。乳液脂肪酸的最大释放水平依次为椰油>橄榄油>棕榈油=稻米油>紫苏籽油(P<0. 05);长链甘油三酸酯的速率速率低于中链甘油三酸酯,长链多不饱和脂肪酸的释放速率低于长链单不饱和脂肪酸;包埋对椰油、紫苏籽油和橄榄油主要脂肪酸组成无影响,但使棕榈油的主要脂肪酸组成比例下降,对稻米油主要脂肪酸组成比例构成一定的破坏;椰油、紫苏籽油和橄榄油中其他脂肪酸的释放速率要高于多不饱和脂肪酸。可见,不同酶浓度、加样量、含油量和油类型对脂肪的体外释放均有影响。

In this paper,oil emulsion was prepared using coconut oil,perilla seed oil,olive oil,palm oil,and rice oil as the core material and whey protein isolate(WPI),carboxmethylcellulose sodium(CMC)as the wall material,respectively.An in vitro simulated gastrointestinal tract was used to investigate the effects of different enzyme concentrations,sample loadings,and oil contents on the fatty acid release rate of coconut oil emulsions,and the effects of different lipid types on the release rate and fatty acid composition of emulsion.Results showed that following passage through the simulated mouth and stomach phase,the fatty acid release rate of WPI-CMC stabilized coconut oil emulsion was generally low and stable with the increase in enzyme concentration(0.15-1.5 mg/mL),sample loading and oil content;Following exposure to the simulated small intestinal stage,with higher trypsin concentration came faster fatty acid release and higher release rate of the emulsion;There was a sharp decline in the fatty acid release rate with the increase of sample or oil content;With the increase in oil content,the viscoelasticity of emulsions increased and the fluidity became worse.The emulsions with coconut oil had the highest release level of fatty acid,followed by those with olive oil,palm oil,rice oil and perilla seed oil;The release rate of long-chain triglycerides were slower than medium-chain triglycerides,and long-chain polyunsaturated fatty acids were slower than long-chain monounsaturated fatty acid;Embedding hardly affected the fatty acids composition of the main components in coconut oil,perilla seed oil and olive oil,but it made the proportion of main fatty acids composition of palm oil decrease,and caused certain damage to the main fatty acids composition ratio of rice oil;Release rate of other fatty acids in coconut oil,perilla seed oil and olive oil were higher than polyunsaturated fatty acids.It demonstrated that the enzyme concentrations,sample loadings,oil contents and lipid types significantly affect the digestibility of fat.