Storage Characteristics And Preservation Methods Of Passion Friut

Passion friut(Passiflora edulis Sim), as a tropical fruitwith rich nutritious and highly medicinal value is more and more popular. But the postharvest qualities of passion fruits are prone to deterioration, such as peel shrinkage quickly, flavor and nutrients lost rapidly,resulting in short shelf-life and decreased value. Therefore, it is necessary to do research on the fresh-keeping method of passion fruit. Therefore, in this paper, the storage characteristics and preservation methods of the passion fruit was studied as follows:1. Study on the storage characteristics of passion fruit. The variation of physiological and nutritional quality was investigated.Thus respiration rate, soluble solids, acidity,vitamin C(Vc), weight loss, the degree of shrinkage, soluble protein and polyphenols were determined in Vietnam passion fruit packaged by polyolefin(PO) bags and stored at temperatures of 8 ℃ and 25 ℃. The results showed that the respiration rate, degree of shrinkage and weight loss of passion fruit stored at 8 ℃ were only 1/10,1/3 and 1/10 of the samples at 25 ℃, respectively, and the value of p H was decreased by 0.2 compared with the samples at 25 ℃. In addition, the contents of soluble solids, Vc and soluble protein were 15.8%, 31% and 80.5% higher than the samples at 25 ℃, while the total phenol content was approximately twice more than that at 25 ℃. Thus, the treatment with the storing temperature of 8 ℃ and PO bags package is a good preservation method to maintain the quality of passion fruit during storage.2. Effects of orange peel extract coating on the storage quality of passion fruit. In the paper, the coating solution was composed of orange peel extract, and monoglycerides(MG)as film-forming additives. The effects of treatments of coating solutions of orange peel extract and MG(0,5.0% + 0.5%, 5.0% + 1.0% and 5.0% + 1.5%), combined with polyolefin film( PO) packaging, on the sensory and nutritional quality of passion fruit were investigated during storage at 25 ℃. The results showed that compared with the control, the treatments significantly delayed the shrinking, maintained the colour, and inhibited the respiration rate of passion fruits. In addition, compared with the control, the contents of Vc, total flavonoids and soluble solids in the treated passion fruit were higher,and p H were lower. However, the coating solutions didn’t benefit the maintenance of total phenolics in passion fruit. In summary, the coating solutionwith 5.0% orange peel extract +1.5% MG was best, the second was 5.0% + 1.0% coating solution.3. Effect of high oxygen atmospheric packaging on the postharvest quality of passionfruit. The changes of appearance characteristics and nutritional quality in the passion fruit under three different levels of high oxygen(50% O2,70% O2,90% O2, balance N2),packaged in PO plastic bags storaged at 15 ℃, were studied. Compared with the control(air packaging), 70% and 90% of high oxygen atmospheric packaging were significantly(P< 0.05) inhibited the respiratory intensity, the degree of shrinkage and the decay of passion fruit. The contents of Vc and soluble solids, packaged with high oxygen, were higher than control at the end of storage. Throughout the storage period, the content of total polyphenol under three different levels were higher than control. In addition, the value of L*(luminance) of decreased significantly under high oxygen packaging. In conclusion, 70%O2 and 90% O2 high oxygen atmospheric packaging effectively inhibited the respiration of passion fruit, maintained the firmness, TSS, Vc contents, total polyphenol and total flavonoids contents. High oxygen atmospheric packaging was beneficiary to maintain the nutritional quality in passion fruit, but not beneficiary of the maintenance of luminance.