Atividade antimicrobiana de suco misto de cranberry e uva

Abstract

The addition of natural antimicrobials can be a good alternative to increase the shelf life of processed foods, thus reducing health risks and economic loss due to microbiological contamination. Studies of the cranberry, a red fruit, bitter and astringent taste, showed that the same has antioxidant properties and inhibiting the growth of microorganisms. Thus, the present work had as objective to evaluate the antimicrobial activity of cranberry and grape mixed juice, cranberry extract and grape extract against Escherichia coli, Penicillium expansum and Botrytis sp. First analyzed the microbiological quality of juices, after made the antifungal and antimicrobial test. Also examined the sensitivity of Escherichia coli to mixed juice by disk-diffusion method. The microbiological analysis showed that the juice is within the limits established by the law, because there was only the growth <104 UFC.mL-1 for yeasts and molds, not showing bacterial growth. Analyzing the antifungal activity of cranberry can be observed that it has effect on the growth of spoilage moulds as Botrytis sp., where he had to complete inhibition at a concentration of UFC 1x103 UFC.mL-1 in 1.5% concentration of cranberry and complete inhibition at concentrations of 1x104 and 1x103 UFC.mL-1 in 2% concentration of cranberry extract. Evaluating the antibacterial activity of cranberry extract, one can observe that the cranberry 48 proved to be more efficient than the 0 and 24 am only the growth of 8x106±0 UFC.mL-1 in the after the procedure, concentration of E. coli at a concentration of 1% of cranberry, with complete inhibition in the other concentrations. The mixed juice cranberry and grape proved to be more efficient than when analyzed separately, where 0 am observed that growth ranged between formulations, not observing the growth in all concentrations of the microorganism and juice 24 and 48 h. From the analysis it can be seen that cranberry has effect when E. coli cells are exposed to the juice, so the compounds with the aid of low pH act in the cell wall. Also noted that the mixed juice cranberry and uva is more efficient than when analyzed separately, the fact can be associated with large amount of phenolic compounds that the grape also features, as well as to the anthocyanin dye added in its formulation. So the juice mixture of cranberry and grape presents itself as a good antimicrobial, as well as a good conservation agent in mixed juice cranberry and grape, and can increase the shelf life, reduce economic losses and still provide health benefits to their consumers.