| Pitaya, also known dragon fruit, native to Brazil, Mexico and so on zone from centralAmerica to South America. In China’s Hainan, Fujian, Guangdong, Guangxi and otherplaces have grown. According to pulp and peel color, pitaya varieties divided into red,white, yellow three kinds. Pitaya appearance is unique, delicious taste, rich nutrition andit contains one kind of plant albumin that is seldom in general fruits. In addition, fruitscontain betacyanin pigment and water soluble dietary fiber and all kinds of enzymes, richin unsaturated fatty acids and antioxidant substances, and rich vitamin A, B1, B2, B3, B12,C, E and calcium, phosphorus, iron and other minerals. However, because pitaya isperishable during storage and its supply period is very short. Scales of postharvest pitayaappear yellow and wilting at the room temperature for3days of storage; On7d ofstorage, pitaya fruits appeared obvious shrinkage phenomenon and wilting of pitayasscales became very serious; On12d of storage, scale base and areola of pitaya fruitsbegan to rot and decay was more serious. So the paper used pitayas as experimentalmaterial, researched double film wrapping, high atmospheric O2packaging and heattreatment and ClO2sterilization synergy for high O2atmospheric packaging on thecharge of physiology and quality in pitaya or fresh-cut pitaya, in order to providetheoretical basis for industrialization in pitaya.The main research contents and results asfollows:(1) The experiment studies a series of changes of physiologic properties and qualityin double PO film wrapped pitaya at8℃and25℃of storage process. The result showedduring storage of8℃, respiration rate, total soluble sugar, pH, soluble protein content inpitayas and PPO activities in peel had a increased trend, and the SSC, Vc content andfirmness of pulp and peel had been decreased, the change of color in pitaya fruits chargedvery little; For8days storage of25℃, respiration rate, total soluble sugar, pH, solubleprotein content and SSC had a increased trend, and total Vc content, PPO activities inpeel and firmness of pulp and peel had been decreased, the change of color in pitayafruits was not obvious.(2)This experiment studied the effects of heat treatment and ClO2sterilizationsynergy for high O2combined with PO film packaging on quality and physiologicalchanges of pitaya during storage at shelf temperature (4℃), don’t make any deal withpitaya as control group. The results showed that heat treatment and ClO2sterilizationsynergy for high O2packaging could avoid anaerobic glycolysis and promote therespiration rate of pitaya during0-21days of storage. The sensory quality (firmness) andnutritional quality (total vitamin C, soluble sugar total phenolic and betacyanin) ofpitayas by heat treatment and ClO2sterilization synergy for high O2packaging werebetter than the control for the first7days of storage. In addition, heat treatment and ClO2 sterilization synergy for high O2packaging could obvious maintain firmness in pulp andSSC content in juice during storage, but had no influence soluble protein in pulp. In aword, heat treatment and ClO2sterilization synergy for high O2packaging couldeffectively maintained the quality and extend storage period in pitaya.(3) High O2atmospheric modified packa of ging is efficient, safe and convenient thepreservative technology for commercial application. The aim of this study was toinvestigate the effects of super-atmospheric oxygen modified atmosphere combined withcast polypropylene film packaging on the sensory and nutritional quality of fresh-cutpitayas during storage at shelf temperature (5℃). Packaging box filled with air as control.The results showed that the sensory quality (firmness) and nutritional quality (totalvitamin C, soluble sugar and protein) of fresh-cut pitayas packaged by high-atmosphericoxygen were better than the control．But high O2atmospheric packaging had nosignificant influence on color of pulp and accelerated total vitamin C degradation inpitaya. In general, the quality of fresh-cut pitayas was effectively maintained by high O2modified atmosphere combined with cast polypropylene film packaging. The results canprovide a reference for commercial production of fresh pitayas.(4) Postharvest treatment technology was very important impact on the quality andphysiology of pitayas. Hence, pitayas postharvest handing processing: harvestingâ†'hierarchicalâ†'sortingâ†'preservative treatmentâ†'dryingâ†'packagingâ†'pre-coolingcryogenic storageâ†'sales. And the establishment of export fresh pitayas production ofGMP (Good Manufacturing Process Specification) and HACCP (Hazard Critical ControlPoint) quality management system, and in the production and application, reducing theamount of pesticide residues Pitaya. |
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