Application of β-d-glucans isolated from mushrooms Pleurotus ostreatus (pleuran) and Lentinus edodes (lentinan) for increasing the bioactivity of yoghurts

The objective of the model experiment was to examine the microbiological (yeasts, moulds, coliform bacteria) and sensory (appearance, colour, consistency, taste) qualities as well as the lifetime of white and fruit yoghurts enriched with different additions of two types of hydrogels of beta-d-glucan, namely pleuran (from Pleurotus ostreatus) and lentinan (from Lentinus edodes). The yoghurts were stored for 30 days under the refrigerator conditions (5°C ± 2°C), the sampling being done on the 1st, 15th and 30th day of the storage. The results obtained by the analyses of yoghurts with the addition of pleuran and lentinan showed that the fermentation ability of white and fruit yoghurts was not inhibited by the addition of hydrogels before this process; the acid equivalent (°SH) and pH of samples showed values typical for this kind of product during a month-lasting storage; the groups of microorganisms followed (coliform bacteria, yeasts and moulds) did not appear during the whole storage period (< 1 CFU/g); the application of both hydrogels added to yoghurts had no negative influence on the sensory acceptability of the products; all samples maintained a very good quality during the whole storage period and did not differ significantly from one another in the individual parameters evaluated.