Several volatile sulphur compounds have been detected in raw and processed milk. These are hydrogen sulphide, methanethiol, carbonyl sulphide, dimethyl sulphide, carbon disulphide, dimethyl disulphide, dimethyl trisulphide, dimethyl sulphoxide, and dimethyl sulphone. Many of these increase in milk during heat processing and are associated with the cooked flavor of heat-treated milks, particularly UHT and sterilized milk. Several researchers have attempted to explain the origin of these volatiles in both raw and processed milk, and how to reduce the associated cooked flavor that has a negative impact on consumer acceptability of processed milk. These compounds are difficult to detect and analyze due to their high volatility, sensitivity to oxidation and heat, and in some cases, their very low concentrations. However, methods of detection and quantification have improved in recent years. Pre-concentration methods such as solid phase microextraction (SPME) together with gas chromatography equipped with sulphur-selective detectors now enable low concentrations of these compounds to be analyzed. In this review, methods of extraction and analyzes of these volatile sulphur compounds are compared, and their occurrence in milk is reviewed.

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Camembert cheese was manufactured from pasteurized cow's milk by the traditional method in order to determine changes in the microflora, physicochemical, and biochemical characteristics over a 30-day ripening period. The total bacteria counts were high in cheese throughout ripening, with lactic acid bacteria being the main microbial group both on the surface and the center of the curd. However, the microbial activity was more important on the surface than in the center. Each group of microorganisms showed a typical variation during ripening on the surface and in the center. External heterogeneous microflora containing yeasts, molds and halophilic bacteria induced a higher rate of proteolysis and lipolysis on the surface than in the curd of the cheese at the end of ripening (30 days). Migration of salt from the curd reached equilibration after 23 days of ripening. A fast increase in the pH of the surface was observed and the pH differential was maintained between the surface and the center during the ripening period. Rheological analysis demonstrated the softening of Camembert cheese during ripening due to extensive proteolysis. *Corresponding

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