Lutein as a functional ingredient in sheep milk yogurt: development, characterization and extraction recovery

Abstract The research aimed to evaluate the behavior of different concentrations of lutein added in sheep milk yogurt. The work verified the effect on acidity, pH, color, lutein degradation, and recovery during storage. Different added lutein concentration into yogurt were compared: 0.00 mg; 3.0 mg; 3.45 mg; and 3.9 mg (·100 mL-1). Analyzes were performed on days 1st, 15th, 30th, and 45th of refrigerated storage (5 °C). Lutein did not influence fermentation patters, but post acidification was observed, mainly in groups with the highest lutein concentrations. The amount of lutein recovered was different between groups (P < 0.05) due to treatment. Some differences (P < 0.05) in the same treatment occurred over time, tending to decrease lutein recovery. For all treatments, up to the end of storage, the final amount of lutein characterized the product as a nutritional source of this element. However, lutein recovery in G4 has reached the minimum daily intake recommended by researchers for health benefits. Recovery ranged from 81.9 ± 0.76·100-1 (w·w-1) to 76.31 ± 1.07·100-1 (w·w-1) on the storage period. L* has no difference (P > 0.05) between groups with different added lutein concentrations. In contrast, a*, b*, c*, and YI (yellowness index) were different (P < 0.05).