Ripening temperatures influence biosynthesis of aroma volatile compounds in 'Kensington Pride' mango fruit

Uniformly green mature 'Kensington Pride' mangoes (Mangifera indica L.) were ripened at five temperatures (15degreesC, 20degreesC, 25, 30 or 35degreesC) with 60% r.h. to investigate the effects of ripening temperature on the ripening process and biosynthesis of aroma volatile compounds. The aroma volatile compounds were extracted by headspace solid phase micro-extraction and analysed using a gas chromatograph (GC) fitted with a flame ionization detector (FID) and reconfirmed by GC-MS (mass spectrometry). An increase in the temperature significantly increased the rate of respiration and total carotenoids in pulp. Increased ripening temperature up to 30degreesC also increased ethylene production in fruit and total fatty acids in pulp. All the fatty acids in pulp increased as the ripening temperature increased during ripening except palmitic, palmitoleic and linolenic acids. However, pulp of the fruit ripened at 25degreesC exhibited significantly higher concentrations of individual fatty acids, except stearic and linoleic acids. Fruit ripened at 20degreesC exhibited significantly higher total monoterpenes, sesquiterpenes as well as most of their individual compounds as compared with all other ripening temperatures. Increased ripening temperature resulted in significantly higher concentrations of tetradecane, P-ionone, esters and alcohols. On the other hand increased ripening temperature tended to decrease aromatics and aldehydes except carvacrol, p-cymen-8-ol and hexanal. There were significant positive correlations between fatty acids and sesquiterpenes, alcohols and esters especially on day seven of ripening. A significant positive correlation between carotenoids and norisoprenoids was also recorded. A ripening temperature of 20degreesC seems to be the best for ripening and biosynthesis of aroma volatile compounds in the 'Kensington Pride' mango.