Study On The Changes Of Phenolic Compounds On Okra Fruits Varieties, Harvested Stages And Preservation Process

The Okra fruit had abundant biological activities.In this paper,the changes of corresponding quality and phenolic compounds were studied in variety okra fruits,different maturation stages and different preservation methods.The main results were as follows:1.Comparison of phenolic compounds of different varieties okra fruitsThe changes of phenolic compounds and related activities were studied by using five variety okra fruits(Alonuschus esculentus L),the name of five variety okra fruits were as follows: Kalong 3 Alonuschus esculentus L,Kalong 8 Alonuschus esculentus L,Shuiguo Alonuschus esculentus L,Taiwan Wufu Alonuschus esculentus L,and Royal Red Alonuschus esculentus L.The content of phenolic compounds,antioxidant activity and inhibition of digestive enzymes in five varieties okra fruits were from high to low: Shuiguo Alonuschus esculentus L,Kalong 3 Alonuschus esculentus L,Kalong 8 Alonuschus esculentus L,Taiwan Wufu Alonuschus esculentus L,and Royal Red Alonuschus esculentus L.The HPLC-DAD analysis revealed that protocatechuic acid,catechin derivatives,quercetin-3-O-gentiobiose,quercetin derivative a,quercetin derivative b,rutin and isoquercitrin were the main phenolic compounds in okra fruits.2.The changes of physical properties and phenolic compounds at different harvesting stages okra fruitsThe okra fruits harvested at seven different period : 4 days post-anthesis(4 DPA),5 days post-anthesis(5 DPA),6 days post-anthesis(6 DPA),7 days post-anthesis(7 DPA),8 days post-anthesis(8 DPA)and 9 days post-anthesis(9 DPA).These okra fruits were used as experimental material to investigate the changes of physical properties,phenolic compounds and relevant activities in different harvesting stages okra fruits.The fruit weight,length,diameter,and firmness were rapidly growed at the stage from 5 DPA to 8 DPA.The content of phenolic compound,antioxidant ability,hypolipidemic,and hypoglycemic activity were increased at the stage from 4 DPA to 6 DPA,and slightly decreased at the stage from 7 DPA to9 DPA.It is determined that the best harvest time of the okra fruit was 5 DPA to 8 DPA.3.The changes of quality and phenolic compounds on different preservation methods okra fruitsThe preservation methods of okra fruits were incoulded 0.5% calcium chloride combined with 1.34 ?L/L 1-methylcyclopropene(1-MCP),0.5% citric acid combined with 1.34 ?L/L1-MCP,and 1.0% chitosan.The changes of quality indexes and phenolic compounds on different preservation methods okra fruits were studied.During the storage,the quality index of okra fruits was decreased,and the three treatment groups showed a slower decline from the6 th to the 8th day of storage compared with the control check,but the phenolic compounds were increased at first and then decreased.Principal component analysis showed little difference in the content of phenolic compounds treated with 1.0% chitosan.