| ’Ruiyang’（Malus domestica Borkh.cv）and ’Ruixue’（M.domestica Borkh.cv）are two new late-ripening apple varieties bred by Northwest A＆F University.It has excellent quality,strong adaptability,high yield rate and good comprehensive character performance.However,there are few studies on the harvest period and storability of apples,which seriously affects the large-scale storage and large-scale promotion of ’Ruiyang’ and ’Ruixue’ apples.In this study,the starch staining pattern and related quality of apples of ’Ruiyang’ and ’Ruixue’ during the ripening process were studied,and the appropriate harvesting period was determined.Ruixue’apple scientific harvesting and refrigeration provides theoretical basis.The main findings are as follows:（1）The starch content of ’Ruiyang’ decreased significantly,the soluble solid content increased significantly,and the fruit began to mature at about 160 d after the flowering period.With the delay of harvesting,about 180 days after the full flowering period of ’Ruiyang’,the fruit firmness decreased significantly,climacteric change began,and the endogenous ethylene content increased significantly,and the fruit reached the fully mature stage at this time.The content of starch and titratable acid decreased significantly,the content of soluble solids increased significantly,and the fruit began to ripen about 170 days after the flowering period of ’Ruixue’.At 195 d after the full bloom period,the climacteric change began,the hardness decreased significantly,and the endogenous ethylene content increased significantly,reaching the mature stage.（2）The starch staining maps of ’Ruiyang’ and ’Ruixue’ apples were prepared respectively,which were divided into 8 grades according to the degree of staining.Combined with the analysis of other fruit maturity indicators,’Ruiyang’ reached the harvestable maturity at about 160 days after the full bloom period.The specific physiological indicators are as follows:starch dyeing grade 3,fruit firmness 7.270 kg·cm-2,soluble solid content 12.80%,titratable acid content 0.39,starch index 3,respiration intensity 2.26 ml·kg-1·h-1 and endogenous ethylene concentration 4.62μL·kg-1·h-1.The fruit of ’Ruixue’ reached harvestable maturity about 170 days after the full bloom period.The specific physiological indicators are as follows:starch dyeing grade 3,hardness 7.800 kg·cm-2,soluble solid content 13.70%,titratable acid content 0.33,starch index 3.The respiratory intensity is 2.60 ml·kg-1·h-1 and the endogenous ethylene concentration is 6.72 μL·kg-1·h-1.（3）For ’Ruiyang’ apples,during harvest stage Ⅰ（160 d after full-blooming stage）,the fruit had the earliest respiration peak and the earliest ethylene release peak time.The hardness,starch and titratable acid content were high at harvest,but at the end of storage.The largest drop after that.During the harvest period of ’Ruiyang’（170d after full bloom）,the fruit firmness,soluble solids,and titratable acid starch content changed little during storage,the fruit color was brighter,and the fruit quality was high.The peak ethylene release peak and the soluble solid content were the highest during the fruit storage period of ’Ruiyang’ harvest period Ⅲ（180 d after the full bloom period）,but the time when the soluble solid content began to decrease was also the earliest.In addition,the weight loss rate of Ruiyang’ harvest period Ⅰwas significantly higher than that of harvest period Ⅱ（p<0.05）,and extremely significantly higher than that of harvest period Ⅲ（p<0.01）.The diseased fruit appeared earlier in harvesting stage Ⅰ than in harvesting stage Ⅱ and Ⅲ,and the diseased fruit rate in harvesting stage Ⅲ was significantly higher than that in harvesting stage Ⅱ（p<0.05）.But ’Ruiyang’ harvest stage Ⅱfruit peroxidase（POD）,catalase（CAT）,superoxide dismutase（SOD）and polyphenol oxidase（PPO）;resistant substances such as ascorbic acid（ASA）),glutathione（GSH）,total phenolics and flavonoids during storage were significantly higher than those in harvesting periods Ⅰ andⅢ,and the content of malondialdehyde（MDA）was also significantly lower than those in harvesting periods Ⅰ and Ⅲ.Therefore,fruits in harvest stage Ⅱ are suitable for long-term storage.Harvest stage Ⅱ is about 170d after full bloom,soluble solids are 13.5%,titratable acid is 0.41%,hardness is about 7.180 kg·cm-2,respiration intensity is 2.77ml·kg-1·h-1,ethylene The release rate was 6.18 μL·kg-1·h-1,and the starch staining pattern was grade 4.（4）For ’Ruixue’ apples,the peak of fruit respiration and ethylene release appeared at 90 days of storage during harvest period I（170 days after full bloom）,and the hardness,starch and titratable acid contents were the highest,but the peaks of fruit respiration and titratable acid were the highest at 135 days of storage.After that,the decline was the largest.The respiration intensity and ethylene release peak appeared later in the harvest period Ⅱ（180 days after the full bloom period）and were lower than those in the harvest period Ⅲ.In harvest stageⅢ（190 d after full bloom）,the fruit soluble solid content was the highest,the titratable acid content decreased the lowest,but the respiration intensity and ethylene release peak were higher.Judging from the weight loss rate and diseased fruit rate,the weight loss rate of ’Ruixue’apple harvesting period Ⅱ was extremely significantly lower than that of harvesting period I（p<0.01）,and significantly higher than that of harvesting period Ⅱ（p<0.05）.The earlier the harvest time,the higher the probability of fruit disease and browning.From the perspective of disease-resistant enzyme activities and resistant substances,the enzyme activities such as POD,CAT,SOD,PPO and the contents of ASA,GSH,total phenols and flavonoids in fruits of’Ruixue’ harvest stage Ⅲ were significantly increased.Therefore,the fruit of harvest stage Ⅲis suitable for long-term storage in cold storage.About 190 days after the full bloom period,the soluble solid content is 14.5%,the titratable acid is 0.28%,the hardness is about 6.943 kg·cm-2,and the respiration intensity is about 2.15ml·kg-1·h-1,the release rate of ethylene was 8.84 μL·kg-1·h-1,and the grade of starch staining pattern was about grade 4.（2）The starch staining maps of ’Ruiyang’ and ’Ruixue’ apples were prepared respectively,which were divided into 8 grades according to the degree of staining.Through comprehensive analysis of single fruit weight,firmness,soluble solid content,titratable acid content,starch index,respiration intensity and endogenous ethylene content at different harvesting periods,the fruit weight of’Ruiyang’ is 273 g and the hardness is 7.270 kg·cm-2.The soluble solid content is 12.80%,the titratable acid content is 0.39,the starch index is 3,the respiration intensity is 2.26 ml·kg-1·h1,and the endogenous ethylene concentration is 4.62 μL·kg-1·h-1.maturity.The fruit weight of’Ruixue’ is 277.09g,the hardness is 7.800 N·cm-2,the soluble solid content is 13.70%,the titratable acid content is 0.33,the starch index is 3,the respiration intensity is 2.60 ml·kg-1·h1,and the endogenous The harvestable maturity was reached when the ethylene concentration was 6.72μL·kg-1·h-1. |
PDF Full Text Request