Sweet whey, a by-product at cheese production, is a source of whey proteins with remarkable high biological value and of the highest quality. At the same time, due to the large quantities produced daily, whey is a great ecological and economic problem in terms of its exploitation and disposal. Therefore, whey is still an important topic of the researches to find novel approaches of its exploitation. The aim of our study was optimization of sweet whey fermentation with lactic acid bacteria solely and with lactic acid bacteria combined with yeasts to obtain stable and sensory acceptable product. We used fifteen different commercially available starter cultures which were inoculated to the samples of pasteurized whey. The course of fermentation was monitored by microbiological analysis and pH measurement at certain time intervals. Whey fermentation was repeated by using same starter cultures, when concomitantly with starter cultures inoculation, the lactase enzyme was added to hydrolyze lactose. After both fermentations were acomplished, a panel of 6 sensory evaluators analyzed the samples. From the results of sensory analysis, we selected 3 best-rated samples from each group and repeated the fermentation and hydrolysis. After, the products were properly stored for 24 days and their quality throughout storage period was monitored by microbiological and sensory analysis. Results enable to set the optimum shelf life. Further, fruit preparations made of plums, pears, and apples were added to the selected 6 samples. At the end, we were able to select the product which has shown the best stability and sensory quality. This was a sample of whey, which we have fermented with starter culture ABY-3 and hydrolyzed by enzyme lactase. Due to the results of sensory analysis of the samples with different fruit preparations we would enrich it with a fruit preparation of raw apples.
|
