Anais do Congresso Brasileiro de Ciência e Tecnologia de Alimentos

Introduction: Food borne pathogens are extremely important to be avoid as contaminant in food products. Kefir is viscous fermented milk, with slightly foamy body, acid taste, and characteristic flavor due to the presence of yeasts (Bengoa et al., 2019). In particular, sheep milk has higher concentrations of proteins, fats, minerals, and vitamins when compared to milk from other domestic species, thus being an interesting raw material for the production of Kefir (Balthazar et al., 2017). No study has evaluated the impact of substituting sucrose for different types of sugar are available for kefir.
Objective: Thus, this study aimed to evaluate the antagonistic activity against four foodborne pathogens of sheep milk Kefir added with different types of sugar (sucrose, demerara, brown, fructose, coconut sugar and honey).
Methodology: Sheep milk kefir was elaborated; and microbiological and technological-functional analyzes performed according Larosa et al. (2020).
Results: All the formulations showed microbial viability according and acceptable by law for kefir microorganisms. The use of most non-conventional sugars increased the viability of Lactobacillus (p <0.05), Lactococcus (KIII), Leuconostoc (KII and KVI), and yeasts (KIII) (p <0.05). In contrast, the demerara sugar (KII) led to a decrease in the viability of Lactococcus (KII, p <0.05), while honey led to a decrease in Lactobacillus, Lactococcus, and yeast viability (p <0.05). Kefir showed antagonistic activity ranges as (mm): 3-4.33 (Listeria), 0-3.33 (Salmonella), 2.33-3 (E. coli), and 2.33-2.67 (Staphylococcus). No antagonistic activity was observed for B. cereus. The type of sugar had no significant effect on the inhibition of Listeria, E. coli, and Staphylococcus (p > 0.05). demerara sugar (KII), coconut sugar (KV) and honey (KVI) showed greater antagonistic activity against Salmonella (p < 0.05).
Conclusions: The use of unconventional sugars improved the antagonistic activity against pathogens. These results are important for the dairy industry since the replacement of refined sugar by components with health benefits is of great interest for consumers.