Based On The Delivery Of Whey Protein To Produce The ?-carotene Nanoemulsion And Improve The Bioavailability Of ?-carotene

This research was powered by the national science and technology pillar program during the 12^th five-year plan period–Research and development on application technology of whey protein?2013BAD18B07?.?-carotene,the main dietary source of provitamin A,is required for maintaining optimum human health.The bioaccessibility of?-carotene can be greatly improved when ingested with fat.Using an oil-in-water nanoemulsion to carry?-carotene could significant protect the stable of?-carotene and improve the bioaccessibility.The aim of this study were to select different proper oil?palm oil,coconut oil,fish oil or corn oil?and emulgator?hydration whey protein,thermal modification whey protein or enzyme crosslinking whey protein?as a carrier to form stable nanoemulsion that can effectively enhance the stability and bioaccessibility of?-carotene.In the emulgator screening experiment,we found that the particle size of the nanoemulsion which made by thermal modification whey protein or enzyme crosslinking whey protein were high,but the zeta potential values were low.The embedding rate of?-carotene in all samples were up to 90%.The stability and?-carotene retention rate of all sample were good during 4 week storage.In the carrier oil screening experiment,the particle size of the nanoemulsion?initial particle size=168¹85 nm?was below 200nm during 7 week storage at 25 ^oC.The retention rates of beta-carotene in nanoemulsion were 69.36%,63.81%,49.58%and 54.91%with palm oil,coconut oil,fish oil and corn oil,respectively.However,the particle size of the nanoemulsion increased significantly in the 55^oC accelerated experiment?p<0.05?,in which the retention rates of beta-carotene were 48.56%,43.41%,29.35%and 33.60%with palm oil,coconut oil,fish oil and corn oil,respectively.The bioaccessibility of ?-carotene nanoemulsions which made by different emulgator or carrier oil were investigated through a in vitro digestion experiment.All samples have been hydrolyzed by pepsin and pancreatin.The system of nanoemulsion has been destroyed and the negative charge was increased significant?p<0.05?.We found a negative correlation between the particle size and bioaccessibility in the nanoemulsions made by 2⁵%hydration whey protein,thermal modification whey protein or enzyme crosslinking whey protein.After in vitro digestion,the?-carotene retention rate of emulsion made by enzyme crosslinking whey protein?⁹0%?was higher than hydration whey protein?p<0.05?.However,the?-carotene bioaccessibility of the former?⁵0%?was significant lower than the latter?p<0.05?.The?-carotene retention rate of the sample made by palm oil,coconut oil,fish oil or corn oil were maintained at 90%.In vitro digestion of beta-carotene nanoemulsion showed that the bioaccessibility of beta-carotene were as followed in order:Palm oil=Corn oil>Fish oil>Coconut oil?p<0.05?.From above we conclude that WPI stabilized beta-carotene nanoemulsion with palm oil as the carrier is the most suitable nanoemulsion to increase bioaccessibility and stability of lipid soluble bioactive compounds such as beta-carotene.