温水脱涩温度对柿果实营养成分和抗氧化活性的影响

Changes of nutrients and antioxidant activities of persimmon fruits during astringency removal in warm water

为了解不同脱涩温度对柿果实中营养成分和抗氧化活性的影响。采用35、45和55℃温水对‘磨盘柿’和‘次郎，进行脱涩，测定果实中的单宁含量、类黄酮、VC、总酚以及ABTS自由基清除能力的变化。结果表明：不同温度处理，‘磨盘柿’果实中的总单宁含量变化介于20．11～25．36mg／g，而可溶性单宁、缩合单宁、类黄酮、VC、总酚以及ABTS自由基清除能力都呈下降趋势。其中35℃处理的磨盘柿果实可溶性单宁、缩合单宁、类黄酮和ABTS在16h明显下降，比45和55℃处理的滞后8h。而次郎果实中单宁含量、类黄酮、VC、总酚以及ABTS自由基清除能力变化不大并维持较低水平。本试验中发现‘磨盘柿’具有较强的抗氧化活性，但经过不同温度处理后，其营养成分和抗氧化活性会有极大程度地降低。

This paper is concerned on the changes in nutrients and antioxidant activities of Mopanshi persimmon and Jiro persimmon fruits during astringency removal in warm water. The measured parameters included fruit tannin content, fiavonoids, Vitamin C, total polyphenols and ABTS radical scavenging activities of the persimmon fruits. During astringency removal in warm water with 35,45 and 55℃ ,total tannin content of Mopanshi persimmon varied between 20. 11 and 25.36 mg/g. Soluble tannin,flavonoids,Vitamin C,total polyphenols and ABTS radical scavenging activities decreased gradually. The contents of soluble tannin, condensed tannin, fiavonoids, ABTS radical scavenging activities of Mopanshi fruits reduced quickly at 16 h when treated at 35℃,8 h later than that at 45 ℃ and 55 ℃. But the tannin content,flavonoids, Vitamin C, total polyphenots and ABTS radical scavenging activities of the Jiro persimmon fruit remained lower levels. It is evident that persimmon has strong antioxidant activity. However, the nutritional composition and antioxidant activity may greatly decrease following treatment under different temperatures. Further work is required to look for suitable method and conditions to remove astringency.