Effects On Quality And Storage Properties Of Table Grapes By Application Of Ethanol, Gibberellic Acid And6-benzyladenine

Using grape （Vitis vinifera L. cv.‘Redglobe’ and ‘Crimson Seedless’） fruits asmaterial, this study evaluated the effect on ripening and storage physiology of preharvestapplications of ethanol and calcium chloride. Ethanol and hot water treatment were applied tothe grape as alternative methods, and their effects and resistance mechanism to postharvestdiseas were investigated in detail. Meanwhile, the quality at harvest, and physiologicalchanges during0℃storage of the fruits that received preharvest applications of GibberellicAcid (GA3) and6-benzyladenine (6-BA) were studied. The main results were exhibited asfollows:1.‘Redglobe’ grapevines that were sprayed with15%ethanol and1%calcium chlorideat veraison were evaluated.The accumulation of total soluble solids, total anthocyanin contentand process of coloring was significantly delayed in EtOH-treated and CaCl2-treated fruit,resulting in a7-day and15-day delay in harvest. The process of coloring, accumulation ofTSS and anthocyanin was delayed by ethanol treatment. Calcium chloride showed strongeffect on increased berry weight and TSS, but anthocyanin content with a slight decrease wasobserved. An ultra sensitive method based on online solid phase extraction coupled withhigh performance liquid chromatography tandem mass spectrometry was proposed for thedetermining of various endogenous plant hormones. Engogenous abscisic acid level wasdecreased during maturation period for ethanol and calcium chloride treated berries, whichcorrelated to the delay of coloring and ripening. Grapes received preharvest calcium chlorideand ethanol treatment showed similar ABA change profiles during the ripening process, andthe ABA peak value was decreased by calcium chloride treatment. During the whole ripeningprocess, calcium treated grapes had lower ABA concentration and thus delayed the coloringand ripening process.2. The physiological, microbiological control and quality changes were studied inseedless (‘Crimson Seedless’) and seeded (‘Redglobe’) table grape cultivars that receivedpreharvest applications of10%,15%and20%ethanol (EtOH) solution, containing1%CaCl2,at harvest and during cold (0℃) storage. Fruits were harvested at commercial maturity stageand stored for75d (‘Redglobe’) and70d (‘Crimson Seedless’) at0℃, respectively. Withpreharvest spray with ethanol and calcium chloride, respiration rate was significantly suppressed and decrease of fruit firmness was delayed after75days of cold storage.Preharvest applications of ethanol and CaCl2treatments reduced yeast and mold developmentin table grapes. The losses due to rotten clusters dropped from12.4%and8.2%in controls to4.3%and3.7%in grapes treated with EtOH combination CaCl2of ’Redglobe’ and ‘CrimsonSeedless’, respectively. The activities of phenylalanine ammonialyase (PAL) and polyphenoloxidase (PPO) were both significantly increased after EtOH and CaCl2treatment.3. The effect of preharvest applications of10,30mg·L-1and50mg·L-1Gibberellic Acid(GA3) on quality and storage physiology on ‘Redglobe’ and ‘Crimson Seedless’ grapes (Vitisvinifera) were evaluated. The results showed that30mg·L-1GA3treatment increased the mainfruit quality parameters, including berry weight and cluster weight. Compared with untreatedgrape, berry weight of treated grape increased29.33%and32.30%, cluster weight of grapetreated increased49.71%and33.36%, on ‘Redglobe’ and Crimson Seedless, respectively.During the cold storage, the losses due to fruit decay and cluster shatter were reducedcompared with control group, and the respiration intensity of treated grapes was inhibited.Meanwhile, higher firmness remained in grapes of treated group than the control group at theend of storage. The decrease of titritable acids was also reduced in treated grapes. We foundthat GA3treatment evidently delayed the increase of MDA content，and kept integrity of cellmembrane.4. The effects of preharvest application of10,20mg·L-1and30mg·L-16-benzyladenine(6-BA) on fruit quality and storage physiology were investigated on ‘Redglobe’ and ‘CrimsonSeedless’grapes (Vitis vinifera). The results demonstrated that20mg·L-16-BA treatmentincreased the main fruit quality parameters, including berry weight and cluster weight of twogrape cultivars at harvest. During the cold storage, the losses due to fruit decay and clustershatter were reduced compared with control, and the respiration rate of treated grapes wasinhibited significantly. Meanwhile,6-BA treatment retarded the decrease in titratable acids,maintained the firmness and soluble solids content of grape fruits. The deterioration ofmembrane permeability was also improved in treated samples. Appropriate6-BA treatmentled to improved table grape quality during the cold storage period.5. The ‘Munage’ table grape were treated with30%,40%and50%ethanol and stored inlow temperature of0℃. The results demonstrated that better decay control was obtained with40%ethanol dips and had no significance effect to soluble solids content at the same time.Furthermore,40%ethanol can control descending of fruit firmness and titratable acid content,suppressed the increasing of relative electric conductivity and improved quality during coldstorage. The ‘Munage’ grape were also used to study the effects of hot water treatment onstorage effectiveness. Fresh-cut grape fruits were treated at45℃hot water for6min,8min, and10min before storage. The results indicated that the optimum results was obtained with45℃8min hot water treated and there were no significance effect to soluble solids contentand titratable acid content at the same time. Further more,45℃hot water for8minsuppressed the increasing of relative electric conductivity, retarded the descending of fruitfirmness and CAT activities, and increased POD activities of fruit. Therefore,45℃hot waterfor8min improved quality during cold storage.