Effect of natural antimicrobials on in vitro Escherichia Coli in Minas Frescal cheese

Abstract

Purpose The growing consumer demand for microbiologically safe and quality products with sensory properties similar to those of natural products has spurred the search for natural flavourings with an antimicrobial effect on foods. The purpose of the present study is to evaluate the in vitro antimicrobial activity of “malagueta” chili pepper and “dedo de moça” hot pepper on Minas Frescal cheese supplemented with Escherichia coli strains. Design/methodology/approach Each cheese contained 0, 10, 15 and 20 per cent concentrations of “malagueta” chilli pepper and “dedo de moça” hot pepper supplemented with 200 µL of E. coli/kg cheese. The cheeses were stored under refrigeration at 7 °C for 28 days. The E. coli, pH and titratable acidity were analysed for this cheese. Findings “Dedo de moça” hot pepper showed a bacteriostatic effect on E. coli strains being more efficient on day 1. However, the “malagueta” hot pepper showed bactericidal effect and was efficient during the 28 days of storage. The pH showed a gradual decrease (p = 0.000) throughout the storage period; therefore, the acidity was increased even when the CFU/g count remained constant. The peppers had an antimicrobial effect on E. coli strains, and thus might be an alternative to extend the shelf life of Minas frescal cheese. Originality/value The study of natural condiments as an antimicrobial alternative is important because they prevent infections and food infections, increase shelf life and make it possible to offer differentiated products in the market.