Modern analyses and binding studies of flavour volatiles with particular reference to dairy protein products

Various techniques are used to separate and isolate mixtures of volatile flavour compounds from sample matrices. These include headspace sampling (static and dynamic), distillation followed by liquid-liquid extraction, simultaneous distillation-extraction, solid-phase extraction and new methods of extraction such as solid-phase microextraction and membrane-based systems. After clean-up and concentration, most mixtures of volatiles are separated and analysed in gas chromatographs using open-tubular columns. Gas chromatographic injection techniques, columns and detectors are discussed. Mass spectrometry coupled with gas chromatography is a major method used to identify volatile flavour compounds. Establishment of the real flavour profiles perceived by humans is discussed with reference to some appropriate experiments. Volatiles can be lost from foodstuffs by oxidation, polymerisation, reactions with other components in the foodstuff and evaporation. Effective binding of flavour constituents is important during storage and transportation of foodstuffs. On the other hand, the release of off-flavours from a foodstuff is desirable before consumption or formulation with other foodstuffs. Binding experiments discussed include those in liquid systems, desiccation experiments with dry foods and microencapsulation. Copyright (C) 1996 Canadian Institute of Food Science and Technology. Published by Elsevier Science Ltd