Inhibition Effect Of Rosemary Extract On Lipid Oxidation During Simulated Gastriointestinal Digestion

Lipids can be oxidised during gastrointestinal digestion,and the products of lipid oxidation are lipid peroxidation(LOOH),4-hydroxy-2-trans-hexenal(4-HHE),and ?,?-unsaturated aldehydes,which cause potential risk to human health.So it is necessary to inhibite the lipid oxidation during gastrointestinal digestion.The present studies mainly focuse on lipid oxidation reactions during processing and storage of food,but not enough attention have been given to the formation of lipid oxidation products during simulated gastrointestinal digestion.Rosemary,a spice plant,contains numerous active ingredients,and rosemary extract(RE)was widely used as food additive.However,the effects of RE on lipid oxidation during digestion have not been well investigated at present time.Therefore,the aim of this work was to evaluate the inhibitory effect of RE on lipid oxidation during simulated gastrointestinal digestion.The main research contents and results of this paper were as follows:(1)Inhibition effect of RE on oxidative damages in lipids,proteins,and DNA.The results showed that RE at final concentrations of 10~500 ?g/mL could significantly inhibit the oxidation of cod oil induced by free radicals.RE at concentrations of 2.5 to 50.0 ?g/mL could significantly inhibit oxidation of linoleic acid(LA)and carbonylation of bovine serum albumin(BSA)induced by free radicals(p<0.05).Meanwhile,RE significantly protected herring sperm DNA against AAPH-induced oxidative damage at concentrations of of 2.5~50.0 ?g/mL.In summary,RE can effectively inhibit lipid and DNA oxidative damage,and suppress oxidative damage and carbonylation of proteins.(2)The inhibitory effects of RE on lipid oxidation during simulated gastrointestinal digestion.After simulated gastric and intestinal digestion,the malondialdehyde(MDA)content of RE-treated cod oil digestion samples was decreased by 41.28% and 42.62%,respectively.The addition of RE at 100mg/kg pork decreased the MDA of pork sample by 56.07% after in vitro gastric digestion,as compared with control group.A similar trend was obtained for lipid peroxidation(LPO).In addition,RE dissolved in distilled water or potassium hydrogen phthalate-hydrochloric acid buffer solution(pH 3.0,simulated gastric digestion environment)both exhibited strong scavenging activities against 1,1-diphenyl-2-picrylhydrazyl(DPPH)and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)(ABTS)radicals as well as ferric ion reducing antioxidant power(FRAP).The inhibitory effects of RE on lipid oxidation during simulated gastrointestinal digestion may be attributed to the antioxidant activities of phenolic compounds in RE.(3)Changes of total phenol content and antioxidant activity of RE during simulatedgastrointestinal digestion.The results showed that the content of total phenol in RE digestion products increased by 17.88% after in vitro gastric digestion.After simulated gastric digestion,the scavenging activities of RE digestive products against DPPH· and superoxide radical increased by 20.36% and22.07%,respectively.Moreover,the FRAP of RE digestion products increased by 11.76%(p<0.05).The total phenol content of RE digestion products decreased by 19.64% after simulated intestinal digestion.After simulated intestinal digestion for 120 min,the scavenging activities of RE against DPPH· and superoxide radicals decreased by 74.08% and 50.00%,respectively,and the FRAP of RE decreased by 52.13%.The above results showed that simulated gastrointestinal digestion significantly affected the contents and antioxidant activities of polyphenols in RE.