Changes in the Profile of Volatiles of Canned Coconut Milk during Storage

Abstract

The alteration of the profile of volatiles of canned coconut milk was monitored during storage at ambient temperature. Canned coconut milk was thermally processed (121 °C for 5 min), and then stored at ambient temperature (32 to 35 °C) for 6 mo. Volatile compounds were assessed monthly using direct solvent extraction (diethyl ether), followed by high-vacuum distillation and gas chromatography-mass spectrometry analysis. Six groups of compounds consisting of alcohols, aldehydes, ketones, acids, esters, lactones, and others were identified. Two stages of major changes in profile of volatiles were observed. The 1st occurred after 2 mo as indicated by a high abundance of alcohols, acids, and lactones. The 2nd was observed after 5 mo and corresponded to a large increase in lactones, short-chain free fatty acids, 3-methyl-2(5H)-furanone, and phenol. Acetic and butyric acids observed after 5 mo could contribute to the potential of off-odor development in the product as indicated by their high odor activity values. Lactones increased approximately 10-fold. Identification of 3-methyl-2(5H)-furanone indicated that Maillard reaction had occurred in conjunction with the development of a coconut, toffee-like, and caramel odor.