| Pomelo fruitlets is produced from physiological fruit and artificial thinning,the annual output is large but the utilization rate is low,the pomelo fruitlets contains a variety of active substances including flavonoids,its content is much higher than the mature fruit,and the young fruit collection and processing is relatively easy,is the best choice for the deep processing of pomelo raw materials.Therefore,this research USES the ultrasonic-microwave technology to optimize the assembling together young fruit extraction technology of flavonoids from nine methods,such as microwave,ultrasonic was studied in yield,total flavonoids flavonoids ingredients,cell surface structure,antioxidant capacity were analyzed,and at the same time,using the AB 8 macroporous resin method for the optimal conditions of flavonoid constituents LCMS analysis,adopt AAPH erythrocyte hemolysis induced model to explore its oxidation resistance and its mechanism.The results show that:(1)the optimal conditions of ultrasonic-microwave synergistic extraction of flavonoids from pomelo fruitlets were as follows: microwave power was 410 W,ultrasonic power was 420 W,liquid-material ratio was 11:1,and extraction time was42 min.Through verification,the yield of total flavonoids under this condition was up to 68.57%,which was close to the predicted value of 70.03%.(2)ultrasonic-microwave synergistic technology can effectively improve the yield of total flavonoids.And this is directly related to the formation of cell spatial structure by the extraction system.The experiment found that different extraction methods can make the pomelo fruitlets powder with planar structure change in different degrees,among which temperature,time,power and treatment method are important factors affecting the formation of spatial structure.In addition,the flavonoid components were different in different extraction methods,and the total flavonoid yield was not directly related to the number of flavonoid species.Naringin and 2'-o-acetyl-3 '-o-methylrutin were present in all treatment groups.According to the clustering analysis of flavonoid compounds in different treatment groups,it was found that the extraction of flavonoids by ultrasonic-microwave synergistic technology was significantly different from that by ultrasonic or microwave treatment alone,and the difference in M400+ u400-40 treatment group was more significant.(3)the antioxidant activity of the extracts was investigated by using chemical antioxidant method and AAPH-induced hemolysis model,and it was confirmed that all treatment groups showed excellent ABTS,DPPH free radical scavenging ability,and a certain degree of Fe ion reducing ability.The extracts of each treatment group could inhibit the erythrocyte hemolysis induced by AAPH,and the chemical antioxidant capacity of the same treatment group was positively correlated with the antioxidant capacity of cells.(4)after purification of AB-8 macroporous resin,CF flavonoids were obtained,which were analyzed by LCMS to be composed of Narirutin,2'-o-acetyl-3'-o-methylrutin and 5,7,8,3'-tetrahydroxy-3,4'-dimethoxy flavone.After CF pretreatment,AAPH-induced erythrocyte hemolysis was inhibited in a dose-dependent manner.Specifically,the production of MDA and the overflow of LDH decreased,indicating that the integrity of cell membrane was protected.The contents of GSH,GSSG and H2O2 were not significantly different from the normal group,and the activity of SOD and GSH-px was significantly decreased,indicating that the red blood cells were not under oxidative stress.Therefore,it can be inferred that CF inhibits red blood cell hemolysis caused by AAPH by directly scavenging free radicals to protect cells from free radical attack. |
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