Evaluation of the quality of retail Labneh produced using different processing techniques in Lebanon

Abstract

The aim of this study was to assess the quality of different types of retail Labneh products, in Lebanon, during their market shelf-life. The samples were produced using the traditional and modern automated processing techniques, with and without prebiotic addition. Microbiological, physiochemical and sensory parameters were examined during storage at 4 ºC. Lactic acid bacteria were tested for Lactobacillus bulgaricus and Streptococcus thermophilus, also yeasts and molds were examined. Physicochemical analysis of moisture, acidity and pH were conducted and exopolysaccharides were isolated and quantified. Quantitative descriptive analysis was evaluated for five different sensory attributes by ten trained panelists and the acceptability of Labneh samples was valued by another ten panelists. Lactic acid bacteria count decreased during Labneh storage in all samples, whereas yeast and mold count increased with higher values for traditional Labneh samples at the end of shelflife. Acidity increased and pH decreased during the storage period. EPS count decreased in all samples, with the highest values recorded in the automated samples enriched with prebiotics and were correlated with serum separation and mouthfeel thickness. Panelists were able to differentiate between the sensory attributes, especially at the end of shelf-life. Acidity and bitterness increased with time and negatively affected the acceptability of Labneh samples.