The milk composition of free-ranging indigenous African cattle breeds was analysed. These breeds were chosen because they have not been bred specifically for milk production and might be considered the closest to a "natural" or "wild type" of the Bos species. It was found that the nutrient composition of the milk of these cattle, in particular the dry matter, is as low as that of European beef breeds. The content of whey proteins and NPN is also lower than that of dairy breeds. Statistically significant differences in milk fatty acid composition between the Sanga-type cattle and the Afrikaner and its derivatives were observed for the content of lactose, whey protein and non-protein nitrogen, as well as fatty acid composition regarding medium long chain and long chain fatty acids. A genetic relationship is evident and suggests the preference of certain fatty acid synthesis pathways. ________________________________________________________________________________

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Water soluble autolysate of yeast, usually utilised for microbial growth support, was used as additive in yoghurt fermentation. The yeast extract (YE) resulted in a decrease of fermentation time by 21% to reach a pH of 4·6. However, the YE resulted in unacceptable flavour and taste. By size exclusion chromatography, a fraction of the YE was obtained that could account for the observed 21% decrease in fermentation time. The fraction contained molecules of low molecular weight, consisting of minerals, free amino acids and peptides. The acceleration of the yoghurt fermentation was ascribed to the short peptides in the fraction. It is proposed that the application of this extract in industrial yoghurt manufacture would result in savings for both the industry and the consumer.

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