Study on Effects of Freezing Treatment on Aroma Components in Litchi Fruit

The aroma components in fresh litchi fruit and litchi fruit after frozen for 60 days were extracted by head space solidphase microextraction. The aroma compounds were analyzed and identified by GC-MS. The results indicated that the differences of aroma compound conpositions and relative contents in fresh litchi and frozen litchi are significant. The aroma compounds varieties identified in fresh litchi fruit and frozen litchi fruit are 36 and 29,respectively,including 8 mutual components,with the relative percents of the total peak area 96.97% and 99.98%,respectively. The main aroma components of litchi fruit are alkenes. After freezing treatment,the relative contents of alcohols and alkanes are increase distinctly,but the relative content of esters decreases. Besides,one kind of aether,aldehyde or carboxylic acid is determined in frozen litchi fruit respectively.