不同成熟度塞外红苹果营养品质及抗氧化活性研究OA

In order to clarify the impact of the harvest period on the storage performance of Saiwaihong apples,and investigated the nutritional quality and antioxidant activity of Saiwaihong apples at different harvest maturities,taking Saiwaihong apples harvested 116(harvest period A),125(harvest period B),and 134 d(harvest period C)after the full-bloom stage as raw materials,the color difference,nutritional quality indicators,sugar components,organic acid and free amino acid content,antioxidant activity were measured.Combined with the principal component analysis(PCA)and mathematical models,a comprehensive evaluation of the storage quality of Saiwaihong apples in the 3 harvest periods was carried out.The results showed that,with the increase in maturity,the lightness value(L*)and blue-yellow value(b*)of Saiwaihong apples gradually decreased,while the red-green value(a*)first increased and then decreased.The hardness,moisture content and titratable acid content decreased significantly(P<0.05),while the contents of soluble solids,soluble protein,vitamin C,total phenol and flavonoid increased significantly during the ripening process(P<0.05).The main soluble sugars in Saiwaihong apples were fructose,sucrose and glucose,showing an upward trend during the harvest period.The main organic acids were malic acid and citric acid,showing a downward trend during the harvest period.The free amino acids mainly included aspartic acid,glutamic acid,serine,leucine,etc..With the ripening of the fruits,the total free amino acids first increased and then decreased,reaching the highest content at harvest period B.The antioxidant activity evaluation showed that the 1,1-diphenyl-2-picrylhydrazyl radical(DPPH)free radical scavenging ability and ferric ion reducing antioxidant power of the apples in harvest period C were higher than those in other harvest periods.PCA analysis indicated that the harvest period had a significant impact on the comprehensive quality of the fruits.The scores of harvest period A and B were similar and lower than the critical value of 0,while the score of harvest period C was much higher than the former two,indicating that the fruit quality had deteriorated at this time.Based on the comprehensive analysis of various indicators,Saiwaihong apples reached good nutritional quality and storage quality at harvest period B.Above results could provide a scientific basis for farmers,consumers,and other entities to choose the harvest period of Saiwaihong apples according to their purposes.