| Actinidia eriantha Benth,which rich in antioxidants,ascorbic acid and other nutrients,is a unique germplasm resource in China,and it has the qualities of strong disease resistance,high heat resistance,easy peeling and high AsA content.It is a kind of wild berry resources with great development potential Plant polyphenols,with antioxidant,anti free radicals and other functional properties,are a class of secondary metabolites in plants,and aslo have a direct impact on the color,taste,firmness,flavor and storage characteristics of fruits.Because of the rich content of phenolic substances,the taste of fresh fruit is acerb,which is the main bottleneck restricting the commercial cultivation.In order to reveal the accumulation rule of phenolic compounds in the fruits of A.eriantha.,the varity of A.eriantha named 'Ganmi-6' was used as experimental material,and 'Jinkui' of A.deliciosa.and 'Hongyang' of A.chinensis were used as controlsto optimize the extraction process of phenolic compounds and determine and analyze the dynamic changes of total phenolics,flavonoids,related components and antioxidant activities.The results of this study will lay a good foundation for understand the accumulation regularity and the molecular mechanism of the formation of astrictivein A.eriantha in further studies,and it also provides new ideas and theoretical basis for germplasm innovation and breeding.The main results are as follows:Firstly,the optimum extraction solvent was determined as acetone using the single factor experiment,and it was found that the concentration,time,temperature of extraction and the ratio of liquid to material had a great influence on the total phenol extraction rate.Response surface methodology was used to optimize the main factors to determine the optimum extraction conditions:the concentration of acetone was 51%,the extractiontemperature was 47? the extraction time was 43 minutes,the ratio of liquid to material was 7:1.Using this optimized condition,the extraction rate of total phenols of A.eriantha reached 519.235 mg/100 g.Secondly,the total phenolics,flavonoid content and antioxidant activity in the three cultivars were determined.During the whole development period,the total phenolic content of 'Ganmi-6' was significantly higher than the control cultivar 'Hongyang' and'Jinkui',and the highest content was as high as 1112.26 mg/100 g,and the lowest was 466.06 mg/100 g,and the mature period was 568.20 mg/100 g.The highest content of the control varieties 'Hongyang' and 'Jinkui' was 214.33 mg/100 g and 245.76 mg/100 g,respectively.There were significant correlation between total phenolics,flavonoids and antioxidant activity,indicating that total phenolics and flavonoid compounds play important roles in the antioxidant activity.The total phenol of 'Ganmi-6' and ·O2-removal capacity has significantly correlated(p<0.01)withcorrelation coefficient reached 0.882,and flavonoids was also significantly correlated with the ability to clear ·O2-and · OH-(p<0.01)and the correlation coefficients were 0.796 and 0.823,respectively.Thirdly,the content of phenolic constituents in the development of kiwifruit(gallic acid,catechin,hydroxy benzoic acid,epicatechin,caffeic acid,vanillic acid,rutin,ferulic acid,quercetin)were determined,and the results showed that there were some differences in the contents of different components in different development periods.The ealated components of phenolic compounds in the fruit development of 'Ganmi-6'were significantly(p<0.01)higher than that of 'Jinkui' and 'Hongyang'.Gallic acid,the main form of phenolic substances in 'Ganmi-6',can reach to the highest content of 620.55 mg/100 g during fruit dvelopmen,while the lowest content was 109.13 mg/100 g.The contents of gallic acid,rutin,epicatechin,caffeic acid and quercetin were all higher during various development period in the three cultivars of kiwifruit,and thus we can concluded that they are the main part of kiwifruit phenolics,and they may affect the taste of kiwifruit. |
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