Heat treatment temporarily inhibits aroma volatile compound emission from Golden Delicious apples.

摘要

Volatile compounds were collected by porous polymer trapping from Golden Delicious apples (Malus domestica [M. pumila]) that had been heat-treated for 4 days at 38deg C, a treatment developed to alleviate physiological and pathological disorders duringstorage, and then stored at 1degree C. Heat treatment of apple fruits markedly inhibited emission of total volatile esters (compounds commonly associated with apple aroma) and total volatiles (comprised principally of the volatile esters and alpha-farnesene) from apples within 1 day of treatment. However, after extended refrigerated storage at 1degree C, the heat-treated fruit recovered and produced more total volatiles; expressed in terms of the amount of volatiles released from non-heat-treated fruit, the amount increased from 4% immediately after heat treatment to 145% after 6 weeks of storage. Total volatile production of non-heat-treated fruit declined more than 5-fold during the 6 weeks of cold storage, while that of heat-treated fruit increased more than 6-fold. The release rate of total volatile esters from heat-treated fruit declined in the 1st week of storage but had increased 4-fold from the initial value after 6 weeks of storage. The effect of heat treatment on emission of volatile compounds was observed immediately after heat treatment. The fruit cuticle and epidermis were not barriers to volatile emission by heat-treated fruit since slicing both heat-treated and non-heat-treated fruit after treatment resulted in total volatile yields similar to thatfrom intact fruit. The increasing emission over time by heat-treated apples suggests that heat treatment either (1) temporarily inhibited but did not destroy the enzyme systems catalysing volatile compound synthesis, or (2) destroyed them but allowed their resynthesis.