Development of Guava probiotic dairy beverages: application of mathematical modelling between consumer acceptance degree and whey ratio

摘要

Twenty One probiotic dairy guava beverages were processed from admixture of cow milk and unsalted Ras cheese whey. 100% cow milk were partly replaced by 20, 35, 50, 65, 80 and 100% vol/vol unsalted Ras cheese whey. Three types of probiotics culture inoculated to the different combinations of milk + whey, namely (2% Lactobacillus acidophilus LA-5 "vol/ vol" "T_1"), (2% Bifidobacterium bavidium vol/vol "T_2") and (1% of both bacteria Lactobacillus acidophilus LA-5 vol/vol" and Bifidobacterium bavidium"T_3 "). Results showed that replacing cow milk by whey had highly significant (p<0.001) effect on pH values of T, treatments. The highest pH values (5.039 to 5.173) were for T_2 treatments, while the lowest values (4.083 to 4.246) were for T treatments.Replacing whey with cow milk had highly significant (p<0.001) effect on pH and counts of both L. aciophilus and B. bavidium. In contrast admixing both bacteria (T3) showed non-significant effect (p=0.609) on B. bavidium as a result of replacing whey bycow milk. Organoleptic evaluation showed higher consumer acceptance degrees, 7.267, 7.567 and 7.767 out of total scoring point degrees (9), for T_1, T_2 and T_3 treatments, respectively at 35% whey replacement beverages. Lower values (5 degrees) was scored for 0% and 80% whey replacement in T treatments, and 3.233 and 3.867 degrees at 100% whey beverage of T_2 and T_3 treatments. Mathematical Modelling was established to explain the relationship between consumer acceptance evaluation degrees (C) and whey ratio replacement (W) at each type of the three starters group. Sinusoidal modelling was resulted with a standard error ranging between (0.3 8 or 0.40).