油茶籽美拉德反应产物及其抗氧化能力

采用不同加热时间与温度处理的油茶籽油,测定加热前后油茶籽油的氧化稳定时间、水分、褐变程度、色值以及美拉德反应产物含量及其抗氧化性等指标。结果表明:压榨油茶籽油的氧化稳定时间随加热时间延长呈先增大后趋于平稳的变化规律,在加热前期(20min),氧化稳定时间上升最显著,在加热20 min时30,60,90,120,150℃下的氧化稳定时间分别比加热前增加2.10,4.46,4.93,5.20,6.17倍。随着加热时间的延长油茶籽油中水分呈下降趋势,褐变程度加剧,颜色加深。采用高效液相色谱测定油茶籽油中的美拉德产物,发现加热前后油茶籽油中未检测到羟甲基糠醛;随着加热时间的延长,丙酮醛的含量呈先增加后趋于降低,150℃加热20min时含量最多达到0.76μg/g,是加热前的3.35倍。在150℃加热60min时油茶籽油中开始检测出3-脱氧奥苏糖和乙二醛,含量分别为1.114,7.030μg/g。油茶籽油在150℃加热60min时产生美拉德产物最多且具有明显抗氧化能力,DPPH自由基清除率为95.27%;抗氧化活性系数为64.17%。说明美拉德反应后其产物的抗氧化能力增强,推测发生美拉德反应的油茶籽油中起到抗氧化作用的产物可能是乙二醛、3-脱氧奥苏糖和丙酮醛等。

Effect of maillard reaction on antioxidation of Camellia oleifera seed oil

In order to study the relationship between Maillard reaction products and antioxidant activity of Camellia oleifera seed oil,determined the Camellia seed oil treated with different heating time and temperature before and after heating was used to determine its oxidation stability time,moisture,browning degree and color value,and the content and oxidation resistance of Maillard reaction products.The results showed that the oxidation stability time of pressed Camellia seed oil after heating first increased and then stabilized.In the early stage of heating(20 min), the oxidation stability time increased most significantly.It increased by 2.10,4.46,4.93,5.20 and 6.17 times,respectively,when heating at 20 min,the oxidation stability time at 30,60,90,120 and 150 degrees.As the heating time was extended,the moisture in the Camellia oleiferaseed oil tended to decrease.The Maillard reaction product in Camellia oleifera L.was determined by high performance liquid chromatography.It was found that no hydroxymethylfurfural was detected in the Camellia oleifera seed oil before and after heating.With the prolongation of heating time,the content of pyruvic aldehyde increased first and then decreased.The content at 150 ℃is up to 0.76μg/g when heated to 20 min,which is 3.35 times before heating.3-Deoxyosesuose and glyoxal were detected in Camellia oleifera seed oil at 150 ℃ for 60 min,and the contents were 1.114 and 7.030 μg/g,respectively.Camellia seed oil heated at 150℃for 60 min produced the most Maillard reaction products and has significant antioxidant capacity,DPPH.Free radical scavenging rate was 95.27%;antioxidant activity coefficient was 64.17%.It is preliminarily understood that the antioxidant capacity of Camellia seed oil increases after Maillard reaction.It is concluded that the anti-oxidation product of Camellia seed oil in Maillard reaction may be glyoxal,3-deoxy sucrose and acetone aldehyde.