Analysis of Browning and Reactive Oxygen Species and Membrane Lipid Metabolism in Husk of Three Pomegranate Cultivars
Pomegranate(Punica granatum L.)husk is prone to browning which would decrease the storage quality during cold storage.Different pomegranate cultivars have different storability.In the present study,three pomegranate cultivars('Tunisia soft seed','Jingpitian'and'Lishanhong)were used as raw material to explore the relation between husk browning and active oxygen species and membrane lipid metabolism,and further to compare the differences among three cultivars.The results showed that the browning index increased during storage time.The browning index of'Tunisia soft seed'husk was relatively lower,reaching 1.25 on the 90th day of storage,while the browning index of'Jingpitian'husk was as high as 3.85.The scavenging rates of O2·-and·OH radicals of three pomegranate husks decreased.The scavenging rates of OH radicals of'Jingpitian'and'Lishan red'husk s were 0.97％and 4.12％on the 90th day of storage.The O2·-generation rate of'Tunisia soft seed'pomegranate husk was 25.31 μmol/min·g at the end of storage.The activity of superoxide dismutase(SOD)decreased,and the activity of peroxidase(CAT)did not change significantly.The contents of endogenous antioxidant substances such as glutathione(GSH),carotenoids and chlorophyll were signifi-cantly reduced.After 60 days of storage,the GSH content of'Tunisia soft seed'pomegranate was maintained at 252.9-273.7 μmol/g,which was higher than that of the other two cultivars.The content of ASA in'Lishanhong'pomegranate husk was between 108.0-121.8 μg/g,which was at the highest level.Cell membrane permeability of three pomegranate husks increased,malondialdehyde(MDA)accumulated,and soluble protein content did not change significantly.The re-sults of correlation analysis showed that the browning of pomegranate husk was negatively correlated with O2-and OH free radical scavenging rate,hydrogen peroxide content,SOD activity,glutathione content and chlorophyll content of ac-tive oxygen metabolism and positively correlated with the O2-production rate;positively correlated with tissue electrolyte leakage and malondialdehyde content of membrane lipid metabolism.Additionally,the results of principal component analysis further confirmed that the browning of pomegranate husk was closely related to the metabolism of reactive oxygen species and membrane lipid,and the storage quality of'Tunisia soft seed'pomegranate was obviously different from those of'Jingpitian'and'Lishanhong'.
pomegranatehusk browningreactive oxygen species and membrane lipid metabolismcorrelation analysisprincipal component analysis
万方数据
维普
