Probiotic dairy dessert supplemented with whey protein concentrate: effect on the viability of Lactobacillus acidophilus, on texture, physicochemical and sensory features

This study aimed at developing a flan-type dairy dessert supplemented with Lactobacillus acidophilus La-5 and whey protein concentrate (WPC). Four flan-type dairy desserts containing L. acidophilus La-5 were produced: F1 (0% WPC), F2 (1.5% WPC), F3 (3% WPC) and F4 (4.5% WPC). Instrumental texture, physicochemical and microbiological analyses were done throughout 28 days of refrigerated storage. Sensory evaluation and purchase intention tests were carried out after 7 and 14 days. Initial counts of probiotic bacteria were 9.30 log CFU•g-1, 9.16 log CFU•g-1, 9.19 log CFU•g-1 and 9.40 log CFU•g-1 (F1, F2, F3 and F4, respectively). During storage, L. acidophilus La-5 counts were above the minimum required for probiotic food (6.00 log CFU•g-1), varying from 9.40 log CFU•g-1 to 8.53 log CFU•g-1 (F4 and F1, respectively). All formulations presented an increase in hardness, adhesiveness, titratable acidity (p < 0.05) and a decrease in pH (p < 0.05). All formulations exhibited excellent sensory acceptance (p > 0.05). The manufacture of a probiotic flan-type dairy dessert enriched with WPC was feasible, with suitable counts of L. acidophilus La-5 for a probiotic food and good acceptance in both sampling periods of sensory evaluation.