Cumulative changes in the content of polyphenols in virgin olive oils with the growth and development of olive fruits
The cumulative changes in the contents of polyphenols(PPs)in virgin olive oils(VOO)with the growth and development of olive fruits were investigated so as to provide the guidance for olive oil quality evaluation and fresh olive fruits harvest.The VOO were extracted by pressing from 8 varieties of fresh olive fruits with different maturity in Longnan,Gansu Province.The contents of 9 kinds of PPs in VOO were simultaneously determined by reversed phase-high performance liquid chromatography(RP-HPLC).The results showed that the content of total polyphenols in VOO was mainly determined by tyrosol and oleuropein.The oleuropein content was the highest,and its content changed most obviously with olive maturity index(MI).Luteolin content in VOO was lower,and ferulic acid and apigenin were detected only in a few varieties,while rutin was not detected in all detected VOO.The evaluation data of PPs in VOO extracted from the fresh olive fruits of Ascolana Tenera,Ezhi-8,Zhongshan-24 and Frantoio were good,with the best performance at MI of 0-1.0,2.0-4.0,0-2.0 and 5.0-7.0,respectively.These four olive fruits varieties were suggested to be harvested in late September,early November,late September to early October and late November respectively.While the comprehensive data of Chemlal performed poorly combined in terms of polyphenols species and total content.In conclusion,the harvest time of fresh olive fruits of different olive varieties can be determined according to the content of olive polyphenols especially tyrosol and oleuropein in different MI,and the quality of olive oil can also be evaluated by the contents of polyphenols.
NETL
NSTL
万方数据
维普
