Effectiveness of Yogurt and Kefir in Reducing Salmonella spp. Numbers on Chicken Skins

Introduction: Yogurt and kefir are the most known and consumed fermented milk products. These products contain many beneficial microorganisms, such as lactic acid bacteria. These good microorganisms have been used to fight against common foodborne pathogens including Salmonella spp.

Purpose: This study was carried out to determine the effect of yogurt and kefir on the fate of Salmonella on raw chicken skins.

Methods: Raw chicken skin pieces (20 cm²) were artificially contaminated with Salmonella and divided into four groups. The groups included a control group (C): non treated with yogurt or kefir; Group I: treated with yogurt; Group II: treated with kefir; and Group III: treated with yogurt plus kefir. All the groups were stored at 4±1 °C in a cooled incubator for 6 days. Analyses for the numbers of Salmonella in the samples were performed at 0, 3, and 6 days of storage. The Salmonella spp. were enumerated on XLT4 agar and the colonies were counted after 18-24 h of incubation at 37°C.

Results: No significant differences were found between groups during the storage period (P >0.05). At the end of the storage (6^th day), Group I and Group II showed reduced Salmonella populations by 0.56 and 0.53 log cfu/cm², respectively, while the reduction for Group III was 1.08 log cfu/cm².

Significance: The results of this study indicate that the combined use of yogurt plus kefir is more effective than yogurt or kefir alone in reducing Salmonella numbers on chicken skins.