Alteration of Basic Quality Attributes of Set Yogurts as Added Sugar and Milk Fat Reduction

Fat and sugar-free is a popular health claim for yogurts. However, eliminating these two components may alter the inherent quality attributes of the product. Knowledge of these alteration patterns is vital in the product development process. Present study was designed using general full factorial design, with two factors (and levels) as milk fat (0%, 1.5%, and 3.3%) and added sugar (0%, 3.5%, and 7%) to investigate individual and combined effects of fat and sugar levels on fermentation kinetics, total solid content, instrumental color values, lactic acid bacterial viability, texture profile, and rheology of set yogurt. Milk fat 3.3% and added sugar 7% yogurt was considered as the control. Results showed that fermentation kinetics not largely influenced by fat levels. Fermentation time not significantly differ with the fat/sugar alteration. Total solid content increase with milk fat and added sugar levels. Whiteness (L*) of the yogurt reduces with milk fat content but not significantly affected by added sugar levels. Yogurt bacteria counts were reduced with added sugar and milk fat levels. Full cream low sugar (3.3%, 3.5%) better texture profile over full cream high sugar (3.3%,7%) yogurts. Texture integrity reduces with the reduction of fat content. The consistency index also increased with fat levels. Both milk fat and added sugar have interaction effects on tested quality parameters. Accordingly, the reduction of added sugar and milk fat is favorably influenced some quality attributes of yogurt.