Effect of salep powder on the development of some probiotic bacteria

This study was conducted to evaluate the effects of salep powder on probiotic bacteria under in vitro conditions and within a fermented milk model. In the first phase of the study, the growth capacities of Lactobacillus casei and Bifidobacterium bifidum were compared across a control group without any added carbohydrates and experimental groups supplemented with 2% glucose, inulin, or salep powder. Measurements taken at 0, 24, and 48 hours during the fermentation period revealed a significant increase in the populations of L. casei and B. bifidum in the salep-containing groups. The data on optical density (OD650), pH, and probiotic activity score (PAS) indicated that salep may serve as an effective fermentation substrate for probiotic bacteria. In the fermented milk matrix, probiotic yogurt supplemented with salep powder was prepared and stored at 4 ± 1 °C for 28 days. During this storage period, microbiological analyses, pH measurement, color evaluation, textural assessments, total phenolic content, antioxidant capacity (via the DPPH method), and analyses of selected free amino acid profiles were conducted. When compared to the yogurt group without salep, the salep-supplemented yogurt showed better maintenance of probiotic viability, and exhibited positive effects on color and texture, while also increasing the levels of phenolic compounds, antioxidant capacity, and certain free amino acids. In conclusion, this study demonstrates that salep possesses both prebiotic properties and potential applicability in the development of functional dairy products, thereby contributing scientifically to the incorporation of a traditional ingredient into modern food technology.