Influence of pH on the physicochemical and sensorial characteristics of strawberry frozen yogurt

Abstract

Frozen yogurt is a frozen fermented dessert which presents structural characteristics similar to ice cream and nutritional and sensorial properties which resemble to yogurt. The acidification of ice cream mix by means of lactic bacteria can influence the properties of frozen yogurt. For that reason, the present work aimed to evaluate the influence of pH on the physicochemical and sensorial characteristics of strawberry frozen yogurt. The formulation consisted of 6 % of milk fat, 10 % of milk solids-not-fat, 11 % of sucrose, 3 % of corn syrup, 0.3 % of emulsifiers and 0.5 % of stabilizers. The frozen yogurt mixes were made with different fermentation endpoints, pH values of 4.5, 5.0 and 5.5. The strawberry fruit mixture was added to the fermented frozen yogurt mix at a level of 4 % (w/w). According to the results, the pH of the frozen yogurt mix did not influence the concentrations of protein, fat and ash whereas the contents of acidity, reducing, non-reducing and total sugars underwent influence of pH due to fermentation. The acceptability of frozen yogurt in relation to the attributes flavor, texture, overall acceptance and ideal acidity was evaluated. It was found that pH influenced the acceptance of frozen yogurt; the treatments with final pH of 5.0 and 5.5 presented higher acceptability for all the treatments evaluated and acidity close to the ideal. By means of the principal component analysis, it was found that the physicochemical characteristics acidity content and sugar concentration (reducing, non-reducing and total) had effect on the acceptance of the product. In conclusion, the strawberry frozen yogurts with pH 5.0 and 5.5 demonstrated good sensorial acceptance and thus, presented potential of being better explored by the ice cream industries.