不同产地特级初榨橄榄油品质对比及抗氧化活性分析OA北大核心

The acid value,peroxide value,UV absorbance at 232 and 270 nm(A232和A270)and main chemical components of 40 commercial extra-virgin olive oil(EVOO)samples from China,Spain,Italy and Greece were studied.The antioxidant activities of polyphenol extracts from different countries were determined,and the correlation between total polyphenol content and half inhibitory mass concentration(IC50)value was analyzed.The results showed that the qualification rates for acid value(＜1.60 mg/g)and peroxide value(＜10 mmol/kg)of these 40 samples were 97.5％,while whose for A232(1.02-1.80)and A270(0.05-0.13)indexes reached 100％.The total polyphenol contents in EVOO samples from four countries differed significantly,with the concentrations of hydroxyltyrosol,tyrosol,oleocantthal and oleacein in Chinese EVOO samples being(11.66±2.50),(9.61±2.65),(273.63±43.09),and(332.04±49.08)mg/kg,respectively,significantly higher than those in EVOO samples from the other three countries(p＜0.05).No significant differences were observed in the contents of major fatty acids,sterols,and tocopherols.In addition,three antioxidant assays(DPPH·、·ABTS+,and β-carotene bleaching)consistently demonstrated strong antioxidant activity in EVOO.The ranges of IC50 were(74.1±3.0)to(560.0±15.0),(71.9±3.0)to(701.7±12.0),and(68.0±2.3)to(617.0±17.0)g/L.Correlation analysis showed a negative relationship between total polyphenol content and IC50 values(an indicator of antioxidant capacity)(p＜0.05),with the slopes of the correlation equation were-1.665,-1.931 and-1.792.