The aim of this researchwas to develop an optimum fermentation and composition model for a newfermented pumpkin-based beverage with high probiotic survival and -glucosidase inhibitory activity. Relationship between fermentation temperature, inoculum and ingredient concentration with response variables (fermentation time at the fermentation endpoint pH 4.5, survival rate of Lactobacillus mali K8 in pumpkin-based beverage treated with simulated gastrointestinal tract enzyme fluids, -glucosidase inhibitory activity and sensory overall acceptability after 4 weeks of refrigerated storage) was investigated using response surface methodology. Optimal formulation was obtained at an approximation of 40% pumpkin puree concentration, 8 Log CFU/mL inoculum and at 35 C. The product derived from this optimum formula reached the fermentation endpoint after 28.34±0.10 h and the quality change during 4 weeks storage was studied. The product achieved 88.56±0.67% of L. mali survival after treatment with simulated gastric and intestinal juices; demonstrated 95.89±0.30% -glucosidase inhibitory activity, as well as scored 6.99±0.40 on sensory overall acceptability after 4 weeks of storage. These findings illustrated that the model is effective in improving probiotic survival and -glucosidase inhibitory activity with excellent sensory acceptability, thus may offer a dietary means for the management of hyperglycaemia.
Keywords:Probiotics; Response surface methodology; Box-Behnken; Hyperglycaemia; Functional food