Identification and Assessment of the Acidifying Activity of Lactic Acid Bacteria Isolated from Probiotic Products
Session
Agriculture, Food Science and Technology
Description
The aim of this study was to identify and evaluate the acidifying activity of lactic acid bacteria (LAB) present in several probiotic products, including traditional yogurt, commercial yogurt, kefir, “Activia” yogurt, and naturally fermented cabbage juice. The study was conducted over a two-month period, during which samples were cultured on selective media including PCA, OSA, RBA, and Acetobacter agar for the isolation of LAB colonies. After incubation, bacterial colonies (CFU/ml) were counted, and pH values were measured to assess the acidifying activity of lactic acid bacteria. The maximum LAB counts in the tested products were as follows: traditional yogurt - 80 CFU/ml (pH = 5.2), kefir - 74 CFU/ml (pH = 4.35), yogurt - 36 CFU/ml (pH = 4.26), Activia - 9 CFU/ml (pH = 4.45), and fermented cabbage juice - 5 CFU/ml (pH = 3.7). Microscopic analysis of bacterial colonies in the yogurt sample revealed the presence of the genus Leuconostoc. The results indicate that the analyzed dairy products contained higher populations of lactic acid bacteria, whereas naturally fermented products such as fermented cabbage juice exhibited lower bacterial activity but higher acidity. All samples demonstrated a clear acidifying activity, contributing to pH reduction and product stability. This study highlights the importance of probiotic products as sources of active lactic acid bacteria and emphasizes the need for further research on species-level identification and the evaluation of their functional probiotic properties.
Keywords:
LAB, probiotic products, Leuconostoc, pH
Proceedings Editor
Edmond Hajrizi
ISBN
978-9951-982-41-2
Location
UBT Lipjan, Kosovo
Start Date
25-10-2025 9:00 AM
End Date
26-10-2025 6:00 PM
DOI
10.33107/ubt-ic.2025.179
Recommended Citation
Nura, Arianeta; Ajdini, Luljeta; Gashi, Dardan; Ajazi, Flutura C.; Buca, Enis; and Ferati, Albina Mustafa, "Identification and Assessment of the Acidifying Activity of Lactic Acid Bacteria Isolated from Probiotic Products" (2025). UBT International Conference. 24.
https://knowledgecenter.ubt-uni.net/conference/2025UBTIC/AFCT/24
Identification and Assessment of the Acidifying Activity of Lactic Acid Bacteria Isolated from Probiotic Products
UBT Lipjan, Kosovo
The aim of this study was to identify and evaluate the acidifying activity of lactic acid bacteria (LAB) present in several probiotic products, including traditional yogurt, commercial yogurt, kefir, “Activia” yogurt, and naturally fermented cabbage juice. The study was conducted over a two-month period, during which samples were cultured on selective media including PCA, OSA, RBA, and Acetobacter agar for the isolation of LAB colonies. After incubation, bacterial colonies (CFU/ml) were counted, and pH values were measured to assess the acidifying activity of lactic acid bacteria. The maximum LAB counts in the tested products were as follows: traditional yogurt - 80 CFU/ml (pH = 5.2), kefir - 74 CFU/ml (pH = 4.35), yogurt - 36 CFU/ml (pH = 4.26), Activia - 9 CFU/ml (pH = 4.45), and fermented cabbage juice - 5 CFU/ml (pH = 3.7). Microscopic analysis of bacterial colonies in the yogurt sample revealed the presence of the genus Leuconostoc. The results indicate that the analyzed dairy products contained higher populations of lactic acid bacteria, whereas naturally fermented products such as fermented cabbage juice exhibited lower bacterial activity but higher acidity. All samples demonstrated a clear acidifying activity, contributing to pH reduction and product stability. This study highlights the importance of probiotic products as sources of active lactic acid bacteria and emphasizes the need for further research on species-level identification and the evaluation of their functional probiotic properties.