Impact of microencapsulation and milk matrix on Lactobacillus acidophilus survivalin yoghurt-based icecreams

This study examined the effects of milk origin (cow versus buffalo), probiotic delivery form (free cells versus alginate-encapsulated Lactobacillus acidophilus ATCC 4356), and inulin supplementation on microbial viability, physicochemical properties, and melting behaviour of yoghurt ice cream over a 60 day storage period. Ten formulations were evaluated on days 1, 15, 30, and 60 for total and probiotic counts, yeast and mould levels, pH, titratable acidity, drip time, viscosity (measured at 30 and 50 rpm), and overrun. Buffalo milk samples containing encapsulated probiotics and inulin showed the highest Lactobacillus acidophilus counts (reaching 5.97 log CFU·g–¹), the greatest resistance to melting (first drip: 97.14 min), the highest viscosity (20.166 Pa.s at 30 rpm), and the highest overrun (34.77%), whereas cow milk controls exhibited the lowest microbial survival and melting performance. Encapsulation markedly improved probiotic stability; in most encapsulated samples, yeast and mould counts remained below 2.00 log CFU·g–¹ after 30 days, and this was accompanied by higher pH values (maximum 4.99 ± 0.04) and more controlled titratable acidity levels (0.57–0.87%). These findings indicate that alginate microencapsulation, particularly within buffalo milk matrices, effectively enhances probiotic viability and the functional quality of frozen dairy products.