Physicochemical and microbiological stability of fermented dairy beverages added with red rice extract

Abstract Fermented dairy beverages added with red rice extract and whey were the developed, physicochemical and microbiological properties were evaluated. A central composite rotatable design was applied, using nine treatments with three replicates. The pH indicated that the beverages could be consumed without the addition of preservative for up to 28 days of storage. The beverages are characterized as partially skimmed, with high protein content, zinc, manganese and copper levels, similar potassium and iron levels and low sodium, magnesium and calcium levels, if compared to the recommended daily index. The absence of pathogens and numbers of viable lactic acid bacteria above the established minimum level were observed. The physicochemical parameters were evaluated by ANOVA and PCA, grouping the beverages into four groups according to their physicochemical properties and three groups according to mineral levels. It is suggested that the most adequate treatments contain between 20 and 34% of red rice extract and from 26 to 54% of whey because of their lower copper contents.