COMPARISON OF VOLATILE COMPOUNDS IN TWO SEASONS IN APPLES: GOLDEN DELICIOUS AND GRANNY SMITH

Abstract

Fruit of varieties Golden Delicious and Granny Smith, were harvested at commercial maturity in two comecutive years (1993 and 1994). The aroma components obtained were analyzed by the dynamic headspace method and quantified by gas chromatograph-mass spectrometry. In Golden Delicious the total esters represented more than 80% of the total volatile components in both years, consistent with Drawen's classification (1975). However, Granny Smith did not, since the esters made up 72 and 88% of total volatiles in the years 1993 and 1994, respectively. The aroma components are different in class and quuntity and give a characteristic sensorial perception for each type offruit and variety. In Golden Delicious, ethyl propionate and butyl acetate gave a fnrity aroma in 1993 and ethyl acetate, ethyl propionate and propyl acetate were the predominant compounds in 1994. In Granny Smith the aroma composition was slighfly different in the two years. In 1993 the aromatic profile did not show the predominance of any compound, while in 1994 it was more fruity due to the higher content of ethyl propionare and propyl acetate.

Biochemistry of apple aroma: A review

“…This occurs in both fatt y acid and amino acid catabolism (15,43,44). In ripe apples, alcohols constitute 6 to 16 % of the total volatiles (8), whereas esters represent, depending on the apple variety, from 80 % in Golden Delicious and Golden Reinders (14,45) to 98 % in Starking Delicious (36). Esters can have linear or branched chains, and their concentration depends on the availability of precursors (37,46,47) and on the selectivity and activity of the enzymes involved (48)(49)(50)(51).…”

“…Linear alcohols are derived from the fatt y acid catabolism, whereas branched-chain alcohols are produced by the metabolism of branched amino acids (31,32). Alcohols are the second most important compounds that contribute to the aroma of ripe apples aft er esters (33), the most abundant being 2-methyl-1--butanol, 1-butanol, 1-hexanol, 1-propanol and 2-methyl--1-propanol (14,(34)(35)(36). They are direct precursors of esters (6), which may occasionally be fragmented to their corresponding alcohols and fatt y acids by the action of esterases (37)(38)(39)(40)(41).…”

“…Butyl acetate, hexyl acetate, 2-methylbutyl acetate and ethyl 2-methyl--butanoate are the most important esters due to their high content and impact on apple aroma of several varieties (6,52). Table 2 (6,12,14,(25)(26)(27)45,48,(53)(54)(55)(56)(57)(58)(59)(60)(61)(62) shows the main alcohols and esters in apples found in diff erent apple varieties at the moment of harvest.…”

“…All the volatile compounds are of great importance for the complete characteristic aroma profi le of apples (8). Their composition and concentration diff er among varieties (4,13,14), and their production can also be aff ected by several factors before, during and aft er the harvest.…”

A history of mass spectrometry in Australia

“…21 These findings were later confirmed in separate GC-MS studies. 23 Impressed by the many capabilities of mass spectrometers, Morrison contributed an article to the Royal Australian Chemical Institute (RACI) journal in the same year explaining the virtues of mass spectrometer for chemical applications including the determination of bond energies. 24 …”