Avaliação da adição de pequenas frutas (Berries) na produção de cerveja artesanal: análise físico-química, sensorial, compostos fenólicos e atividade antioxidante

Abstract

The objective of this study was to evaluate the addition of small berries such as strawberries and blueberries in the development of a craft beer in order to obtain a product with higher concentration of phenolic compounds and antioxidant activity. Preliminary tests were carried out to standardize the beer formulation, with a standard beer style Witbier (CW) and another Fruit Beer style beer (CF). Microbiological analysis of the CW beer was performed at the beginning of the fermentation and every 12 hours, by counting the cells in the Neubauer chamber, in order to determine the fermentation time. Alcohol analysis was performed during the same sampling period. Experimentally developed beers (CW and CF) and commercially purchased Pilsen (CC) and Witbier (CA) beers were compared by physical-chemical analysis, such as pH, total soluble solids, alcohol content, density, color and phenolic compounds. CC, CW and CF samples were compared by sensory analysis means using acceptance test for appearance, color, aroma, taste, overall impression and purchase intention attributes. It was used the central composite rotational design (CCRD) for the evaluation of the variables pH, density, color, reducing sugar, real extract, apparent extract, primitive extract, alcohol content, polyphenols and antioxidant activity, at 10% significance level, varying blueberry and strawberry concentration. The fermentation time of the wort was 216 hours and in this period the alcohol content was 4.8%. For all sensory analysis attributes, the minimum average of the scores attributed by the tasters was higher than 6.0 (I liked it slightly). For the purchase intention, the highest preference was commercial beer followed by Witbier style beer and Fruit Beer. The physical-chemical analyzes between CC, CA, CW and CF samples, resulted in parameters within those established by the legislation and the guidelines of each beers style. However, the phenolic compounds concentration in CF sample was higher than in the other samples. In relation to experimental planning, the increase of blueberry and strawberry concentrations resulted in increased concentration of phenolic compounds, a behavior not observed for antioxidant activity.