Influence of fortification with inulin and Hi-maize on textural and sensory properties of set-type probiotic yoghurt

The aim of this research was to investigate the effect of fortification with inulin and resistant starch (Hi-maize) on textural and sensory properties of set-type probiotic yoghurt containing Lactobacillus acidophilus during 21 days of storage. Textural characteristics were evaluated by determining firmness, adhesiveness and apparent viscosity parameters. Milk was fortified with inulin or Hi-maize at 2 % or 4 % ratios, whereas the control group had no supplement. Probiotic yoghurt supplemented with 2 % Hi-maize was firmer than that supplemented with 2 % inulin, except at the beginning of storage. There were no significant differences among the firmness values of yoghurt samples fortified by inulin and Hi-maize when the ratio increased to 4 %. The addition ratio of inulin or Hi-maize did not significantly affect adhesiveness. Supplementation with 2 % inulin or Hi-maize did not alter viscosity of yoghurts at most of the storage days. Sensory attributes were evaluated as taste, appearance, aroma, texture and overall acceptability. In general, there were no significant differences in sensorial parameters between yoghurts added with inulin or Hi-maize. Neither the addition rate nor the storage period affected the sensory scores of the samples. Significant reductions (P<0.05) of taste, appearance, aroma and overall acceptability scores of the control probiotic yoghurt were determined at the end of storage when compared to the 1st day.