荔枝皮结构及有机元素在贮藏过程中的变化研究

摘要

以“黑叶”和“中华红”荔枝为材料,分别进行常温和冷藏处理,研究了贮藏期间果实果皮纤维结构及有机元素含量(C、H、O、N、S)的变化.结果表明:两种荔枝在常温下不耐贮藏,果皮在10d后已完全褐变,在冷藏条件下完全褐变时间可延长至约50 d;扫描电镜结果显示在常温贮藏过程中细胞结构较冷藏时明显,表面结构由原来密集饱满的半球状变为明显的蜂窝状结构,断面结构排列零乱;有机元素分析结果显示:黑叶荔枝果皮中C元素含量较中华红高,O含量较中华红低,N、H、S的含量则相差不大;常温贮藏过程中,O、H含量变化不明显,C、S呈轻微下降趋势,N呈轻微上升趋势;与常温下相比较,在冷藏条件下,0元素含量的变化最为明显,呈现明显的上升趋势,其它元素含量变化不大.%"Black leaf" and "China red" litchi were used as materials to study the changes of pericarp structure and organic elements(C,H,O,N,S)during normal temperature and cold storage period.The results showed that the two kinds of Lychee browning completely after 10 days when stored in normal temperature conditions,while under the cold temperature the time can be extended to about 30 d.Scanning electron microscope(SEM) images showed that pericarp structure changed obviously in the process of normal temperature storage,with the surface structure transformed from full and intensive semi-sphericalstructure into honeycomb-like structure and the cross section structure arranged disorderly.The analysis of organic element revealed that the C content was higher in the"Black leaf"litchi pericarp than that in the "China red" litchi pericarp,while that of O was lower and N,H and S had no obvious difference.During normal temperature storage,the O and H content changed a little,C and S content were decreased and N content was increased slightly.Compared withthe storage in normal temperature condition,there was an obvious increasing fr O content and relatively stable content for other four elements under cold storage condition.