Association effect of green banana pulp flour and inulin on the multiplication of Streptococcus thermophilus in fermented milk

Fermented milks and prebiotics are considered functional foods and have aroused the interest of the industries. The objective of this study was to evaluate the influence of green banana pulp flour (GBPF) and inulin on the multiplication of Streptococcus thermophilus during the fermentation process and for a period of 28 days of storage of fermented milk. The experiments were performed in three treatments with three replications, in which formulation A consisted of milk without adding of GBPF and inulin, formulation B contained milk, and GBPF and formulation C contained milk, GBPF and inulin. The GBPF had 14.25% moisture, 4.01% ash, 2.28% protein and 1.38% ether extract. The initial pH values of formulations A, B and C were 7.30, 7.14 and, 7.15, respectively, and after 4 hours of fermentation they reached 4.57, 4.73 and 4.66, respectively. The initial titratable acidity values of formulations A, B and C were 0.15%, 0.16% and 0.14%, respectively. At the end of the process, acidity reached the values of 0.93%, 0.98% and, 0.86%, respectively. The S. thermophilus counts of formulations A, B and C did not present significant differences in the periods of 1, 14 and 28 days and the average counts were, respectively, 9.04, 9.20 and 8.77 log CFU/g. Thus, the use of GBPF and inulin did not influence the production process of fermented milk inoculated with S. thermophilus and the multiplication of the microorganism during product storage.