Optimized fermentation of goat cheese whey with Lactococcus lactis for production of antilisterial bacteriocin-like substances

- Goat cheese whey is able to support production of antilisterial substances as low cost medium.
- Fermented goat cheese whey may be used as functional food ingredient.
- Synergy 1® prebiotic ingredient had little influence on antimicrobial activity.

The high cost of the culture media for bacteriocin production has encouraged studies that apply industrial by-products, focusing on maximization of production and reduction of expenses. The aim of the present study was to determine the best conditions for production of substances with antilisterial activity by Lactococcus lactis cultured in goat cheese whey by optimizing temperature and prebiotic inulin ingredient. Central Composite Rotatable Design (CCRD) was employed to optimize the independent variables, temperature and quantity of prebiotic ingredient to maximize the antilisterial activity and cell viability. The dependent variables were antimicrobial activity (AA), L. lactis culture viability (CV) and pH. The highest AA values (10- mm inhibition zone) were obtained after 18 h of fermentation in the absence of prebiotic and at the temperature of 31 °C while CV was optimal at 28 °C with the addition of 9 g/100 ml of the prebiotic. This fermented goat cheese whey may be used for the production of substances with bacteriocin-like activity with antilisterial properties and also as a functional ingredient for future application to improve food safety, but studies are required to test the efficacy of this fermented compound as a biopreservative in food models against L. monocytogenes.