Study on the in vitro digestion characteristics of different lipids in starch-based pickering emulsions
[Objective]In this study,the oil in water(O/W)Pickering emulsions were prepared using octenyl succinic anhydride(OSA)modified rice starch as particulate emulsifier and four different oils(coconut,corn,sunflower and olive oils)as oil phases.An oral-stomach-intestine three-stage diges-tion model was established to explore the effects of different lipid types on in vitro digestion characteris-tics of emulsions.[Method]The particle size and microstructure of the emulsions were measured by laser particle size analyzer and confocal laser scanning microscope.At the same time,four kinds of emulsions were prepared,stored at room temperature for 80 days and emulsified index was calculated to determine the stability of emulsions.The automatic potentiometric titrator was used to determine the release rate of free fatty acids in emulsions during digestion.The droplet sizes and microstructure of the emulsion at different digestion stages were determined to characterize the change of emulsion stability.The free fatty acid compositions of the original oil and the digested oils in emulsions were determined by gas chromatograph,and the influence of fatty acids(FFA)on lipid digestion was analyzed.[Result]All four types of lipids could form stable emulsions,among which corn oil emulsion had the highest emul-sion stability with an emulsification index of 91.73%at 80 days,followed by olive oil emulsion(83.53%).There was no significant difference between coconut oil emulsion and sunflower seed oil emulsion.The results of in vitro digestion showed that the emulsion flocculated and aggregated after oral digestion,and the droplet size increased.After stomach digestion,the starch particles wrapped around the droplets decreased,but the structure of emulsion remained.After small intestine diges-tion,the structure of emulsion was completely destroyed,most of the oil was hydrolyzed,and the size of oil droplets decreased obviously.The release rate of free fatty acids in descending order was coconut oil(25.71%)>olive oil(12.64%)>corn oil(11.16%)>sunflower oil(8.99%).Under the same emulsification conditions,the difference in the digestibility of emulsified lipids was mainly due to their different saturation and initial droplet sizes.The saturation was:coconut oil(91.41%)>olive oil(16.58%)>corn oil(14.63%)>sunflower oil(10.85%).[Conclusion]All four types of emulsions had good stability and digestibility,and the fatty acid composition of oils significantly affected the lipid digestibility of emulsions.The lipid digestibility increased with the increase of oil saturation,and it was also related to the initial droplet sizes.
万方数据
维普
