Survival of probiotic bifidobacteria in buffalo curd and their effect on sensory properties

The feasibility of incorporating Bifidobacterium longum NCTC11818 in buffalo curd to produce a probiotic product was investigated. Fermentation at tropical ambient temperature (29 (plus_minus) 2 °C), two storage temperatures (29 (plus_minus) 2 °C and 4 (plus_minus) 2 °C), and in three packaging materials (clay pots, plastic cups, and glass bottles) was investigated. Bifidobacteria survived for 3 days above the required population level of 10^6 CFU g^-1 in buffalo curd packed in clay pots at 29 (plus_minus) 2 °C. They did not persist at acceptable levels over the 4-day shelf life because of the combined effects of temperature, acidity, and redox potential. Chill storage slows post-fermentation acidification and prolongs bifidobacterial viability while packaging materials, which present a greater barrier to oxygen, had a similar effect. The results indicated that bifidobacteria could be successfully incorporated into buffalo curd to give a product which has improved acceptability. Probiotic buffalo curd, when compared to uninoculated curd, had significantly higher (P (less than) 0.05) sensory scores for properties such as taste and mouth-feel resulting in a significantly higher (P (less than) 0.001) overall acceptability.