Optimization of Functional Peach Beverage Formulation and Study of Its Sensorial and Physicochemical Properties

The objective of present study was to develop a functional peach juice beverage. To this end, formulation ingredients of the beverage including whey protein concentrate (WPC) (1-5%), stevia (0.04-0.08%) as sugar replacer and inulin (4-8%) were optimized according to a central composite design (CCD) using response surface method. The results showed that the brix was profoundly promoted as the level of WPC or inulin increased but it was not affected by stevia. It was observed that while beverages with higher whey protein concentration had greater sedimentation tendency, inulin had a noticeably decreasing effect on it. However, they both significantly resulted in higher turbidity for the beverages. Moreover, stevia showed no significant effect on sedimentation degree and turbidity of the samples. Four optimum formulations including the sample with the least sedimentation (code 1), the sample with the least sedimentation and the most stevia (code 2), the sample with the least sedimentation and the most WPC (code 3) and the sample with the least sedimentation and the most stevia and WPC (code 4) were selected using response surface optimization. The results revealed that all the optimized samples had a shear-thickening behavior, albeit negligible differences were observed between their flow behavior indices. Similarly, the optimized samples did not significantly differ in terms of sensory attributes of flavor, odor and mouth feel; the sample code 2, however, received the highest score for total acceptability. In conclusion, the sample code 2 (WPC 1.19, Stevia 0.08 and inulin 7.34 % w/w) as the sample with the lowest sedimentation degree and the highest organoleptic quality could be introduced as the best sample.
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