Microwave heating and conventional roasting of cumin seeds (Cuminum cyminum L.) and effect on chemical composition of volatiles

Microwave processing and cooking of foods is a recent development, which is gaining momentum in household as well as large-scale food applications. Processing of spices using microwaves is a newer dimension. This alternative methodology is preferred, due to the convenience and ease of handling. In Indian tradition, most of the spices are subjected to roasting before addition to food preparations. In the present study, cumin seeds are subjected to heating by microwaves, using various power levels, and conventional roasting at different temperatures. The conditions were standardized in both methods. The volatile oils distilled from these samples were analysed by GC and GC–MS. The results indicated that the microwave-heated samples showed better retention of characteristic flavour compounds, such as aldehydes, than did the conventionally roasted samples. Comparative data on yield, chemical composition, flavour quality and physicochemical parameters of the volatile oils are presented.