The Influence of Protein Content on Beer Quality and Colloidal Stability

Protein content and beer composition depend on the raw materials and enzymatic reactions used in brewery technology. In order to improve the colloidal stability of beer, it is necessary to remove both protein and polyphenolic complexes or prevent their formation. This study aims to determine the protein content in all production stages and to evaluate its influence on beer quality and colloidal stability. Analyzes of total protein content were performed by Kjeldahl and spectrophotometric methods. Statistically significant change was observed in the protein content of the final product, which was less than that in wort (P lt%253B 0.05). Turbididy, colour, extract, alcohol, bitterness, foam and pH were also measured. Haze forcing tests (incubation at 200C, 400C and 600 C) were conducted to evaluate the colloidal stability of the final product. Results of tests showed that the highest level of product stability was ensured after treatment of beer with both silica gel and polyvinylpolypyrrolidone (PVPP)