| Anthocyanins(ACNs),as a water-soluble natural pigment,has a wide range of physiological activities including antioxidate,anticancer,anti-inflammatory,cardiovascular protective,and improving vision activities.However,ACNs usually show a poor chemical stability and low bioavailability,since they are easy to be degraded due to the influences of p H,light,temperature,oxygen,ascorbic acid and enzymes.Therefore,the applications of ACNs in the food industry are very limited.In this work,we used two different water-soluble Chitosan(CS)derivatives,Chitosan hydrochloride(CHC),Carboxymethyl Chitosan(CMC)and ?-Lactoglobulin(?-Lg)to fabricate the ACNs-loaded CS/?-Lg nanocomplexes,which can effectively improve the stability and the bioavailability of ACNs,and then expand the application of ACNs in the food industry.Using the retention rate of anthocyanins,the particle size,and the encapsulation efficiency as the indices,the preparation of ACNs-loaded CS/?-Lg nanocomplexes was optimized,and its properties were characterized.In addition,the release property,stability,and bioavailability of ACNs-loaded CS/?-Lg nanocomplexes were investigated under in vitro simulated gastrointestinal(GI)conditions.Then,the antioxidant activity in vitro,cytotoxicity,and cellular uptake of ACNs-loaded CS/?-Lg nanocomplexes were studied.This study as follows:1.Preparation and properties measurement of ACNs-loaded CS/?-Lg nanocomplexes.The factors affecting the preparation of nanocomplexes were studied,including ?-Lg concentration,CMC concentration,and p H of CMC solution.Based on single factor experiments,the optimization of nanocomplexes preparation was performed by response surface methodology(RSM)combined with desirability function.The results found that the optimized conditions were 5.16 mg/m L of ?-Lg,1.45 mg/m L of CMC,and p H 6.09 of CMC solution.Based on the optimized conditions,the retention rate of anthocyanins,particle size and encapsulation efficiency of the ACNs-loaded CS/?-Lg nanocomplexes were 68.9%,91.71 nm,and 69.33%,respectively.2.Study on characterization and in vitro releasing of ACNs-loaded CS/?-Lg nanocomplexes.The ACNs-loaded CS/?-Lg nanocomplexes was analyzed by FT-IR spectroscopy,the results indicated that nanocomplexes was formed by electrostatic interactions and hydrogen bonds in intramolecular and intermolecular.Compared with ACNs-loaded CS nanocomplexes,transmission electron microscopy(TEM)showed that ACNs-loaded CS/?-Lg nanocomplexes had small particle size,good dispersibility and smooth surface.Compared with ACNs solution(unencapsulated ACNs)and ACNs-loaded CS nanocomplexes,the in vitro releaseing test showed that ACNs-loaded CS/?-Lg nanocomplexes exhibited a relatively good sustainable release property in different conditions(p H 1.2 and p H 6.8).3.Study on stability of ACNs-loaded CS/?-Lg nanocomplexes in simulated GI conditions.The results showd that ACNs concentration in ACNs solution,ACNs-loaded CS nanocomplexes,and ACNs-loaded CS/?-Lg nanocomplexes did not exhibit a significant change after mouth and gastric in vitro digestion with or without the participation of enzymes.However,compared with ACNs solution(unencapsulated ACNs)and ACNs-loaded CS nanocomplexes,the ACNs-loaded CS/?-Lg nanocomplexes exhibited a favorable stability in different conditions(with and without enzymes participation)after in vitro intestine digestion.4.Study on bioavailability of ACNs-loaded CS/?-Lg nanocomplexes.The results showed that,after 6 h of incubation in GI with enzymes,the ACNs bioavailability was17.2%,26.8% and 40.1% in ACNs solution(unencapsulated ACNs),ACNs-loaded CS nanocomplexes and ACNs-loaded CS/?-Lg nanocomplexes,respectively.However,GI conditions without enzymes resulted in a decrease for the ACNs bioavailability,which were only 0.37%,1.23% and 5.23%,respectively.Compared with ACNs solution and ACNs-loaded CS nanocomplexes,the ACNs-loaded CS/?-Lg nanocomplexes significantly improve the bioavailability of ACNs during GI conditions.5.Studied on the in vitro antioxidant activity,cytotoxicity and cellular uptake of ACNs-loaded CS/?-Lg nanocomplexes.The results showed that both nanocomplexes had a higher in vitro antioxidant activity than unencapsulated ACNs as determined by DPPH·,·OH and O2-·scavenging ability.Further,the results showed that there was no cytotoxicity for nanocomplexes and ACNs solution.The cellular uptake of ACNs was significantly improved through nanocomplexes delivery systems with 1.24 and 1.54 fold of increase for CS and CS/?-Lg,respectively,compared to unencapsulated ACNs. |
PDF Full Text Request