Effect of two fresh-keeping methods on flavor and color quality in Navel orange fruit

This study was carried out with the cold storage fruits and fruits staying on tree of Newhall Navel orange produced in Gannan district of Jiangxi province. The aim was to study the effect of fruits storage method on thequality. High performance liquid chromatography (HPLC) technology was used to investigate the changes in color and carotenoid contents in fruit peel (rind) and pulp. The results showed the ratio of total soluble solids and total titratable acids of cold storage fruit(17.08) were 4.28 less than control (21.36),whereas the ratio of the fruits staying on tree increased to 33.33 which were twice as that of cold storage fruits. Post-harvest pigment synthesis was found in cold storage navel,especially β-cryptoxanthin and zeaxanthin,indicating that light was not the necessary condition in carotenoid synthesis. Furthermore,the color of the peel on cold storage fruits turned to yellow,and it was possibly due to the proportion of different carotenoid components and their spatial distribution in peel tissues. The total carotenoids level of the fruits staying on tree was 1.5 times as that of the cold storage fruits,and the peel color was smart orange,on account of obvious accumulation of violaxanthin and (9Z)-violaxanthin.