Effect of storage time on the microbial,physicochemical and sensory characteristics of ovine whey-based fruit beverages

The aim of this study was to establish the physicochemical, sensory and microbiological quality of ovine whey-based fruit beverages produced from pasteurised ovine whey (mango flavoured–sugar sweetened M-Su], pineapple flavoured–extra sugar sweetened P-ESu], and tropical fruit flavoured–stevia sweetened T-St]), and the changes in quality of these beverage types during the 15-day storage. The beverages were evaluated for their pH, colour, sediment and particle size distribution, microbiological count and sensory quality. No significant differences in the pH and the microbial counts among the beverages were noted during the storage period; however, the particle size distribution reflected the sediment formation that significantly decreased during the same period in all beverage types. The beverages were getting lighter during storage, which was evident by increasing L* and decreasing a* values for colour. All three beverage types had very high scores for taste and odour after 9 days, and colour and sediment after 5 days of storage. Beverage-type T-St was most preferred by consumers, with the highest scores for taste, odour and sensory appearance. These results can assist in the better determination of the deteriorative changes in a variety of ovine whey-based beverages, necessary changes in product composition that might result in improved product quality, and yet reducing losses incurred during ovine milk processing. In this sense, this research's findings contribute to the utilisation of whey beverages by the dairy industry to the development of functional products.