The Effect Of Storage Conditions On The Citrus Fruit Quality

In present study, effects of storage temperature (20°C and4°C) on the carotenoid,sugar, acid contents and essiential oil in the fruit of ‘Cara Cara’ navel orange (C.sinensis Osbeck) was investigated. The aim of present study was to reveal the rule ofthe main intrinsic factors affecting quality of ‘Cara Cara’, and therefore to providetheoretical basis for the preservation of postharvest citrus fruit. The effects of differentconcentrations of1-MCP on Ponkan (Citrus reticulata Blanco) postharvest qualitywere also investigated. The main results were as follows:1. Storage temperatures could affect the carotenoids contents in the peel and thepulp of ‘Cara Cara’ in a tissue-specific manner. Storage temperature at20°C showed apositively promotive role in the peel of ‘Cara Cara’ only before6weeks of storage,but the total carotenoids remained a nearly stable level with time progressed. Incontrast, except a slight increase in the contents of β-carotene, lutein, α-cryptoxanthinat10weeks of storage, carotenoids contents in the pulp of ‘Cara Cara’ stored at20°Cwas not influenced. Low temperature (4°C) could maintain the carotenoid contents inthe peel of ‘Cara Cara’, while dramatically induced the massive accumulation of thatin the pulp.2. The contents of sugars were at the steady peak during midterm storage (4-8w)at4°C, suggesting that4°C was benefitial to sugar accumulation. Before4weeks ofstorage, there was a rapid increase in the contents of sugars in the peel after coldstorage, but the sugar content in the pulp declined rapidly. When the storagetemperature was at20°C, the contents of sugar significantly increased in later storageperiod.3. The essential oil of ‘Cara Cara’ was analyzed by gas chromatography andgaschromatography mass spectrometry (GC MS). Results showed that limonene wasthe major component (about50%). The impact of storage temperature on theessential oil components was varibale. Storage temperature did not show any obviouseffect on limonene, β-pinene, β-linalool, α-citral and α-terpineol. The formation ordegradation of α-pinene, β-phellandrene and n-octyl alcohol was greatly affected bystorage temperature, with their contents quite different despite similar changing trend.Formation or degradation pathways of octanal and nerol may be changed by storagetemperature, the changing pattern was obviously opposite under different temperatures.4. The1-MCP (0.05and0.1μL/L) was observed to remarkably delay for thedegradation of chlorophyll in the Ponkan peel, thereby prolonging the shelf life offruits and improving commercial value of Ponkan. In addition, the weight loss、TSSand TA in1-MCP treated fruit was not changed.