| Popis: |
In the present study, beers with an original extract 12°P, 14°P and 16°P were obtained. During the maturation process, on different stages, bilberries (Vaccinium myrtillus L.) from Bulgaria were added. Changes in the protein profile of the beers were investigated, as well as the influence of these changes on the body in the mouthfeel and the head retention of the resulting beers. The electrophoretic analysis of the proteins was performed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The protein concentration was determined by the Bradford method. The sensory evaluation of the beer’s body and head retention was conducted by a trained five-membered testing panel. It was found that independently of the original extract, the bilberry addition led to a significant reduction of the protein concentration and the number of protein fractions. Beers with bilberry addition contained between 74% and 94% less protein, than control beers. The number of protein fractions decreased from 10 in the control beers to 4–6 in the beers with bilberry. The fractions with molecular weight 31 kDa and below 14 kDa were the most stable to the bilberry addition. Their part in the beers with bilberry remained the highest. Despite of the significant changes in the protein profiles, the beers with bilberry had very good mouthfeel body and head retention. |
