Optimization of nutritional profile and quality attributes in maple syrup-enriched yogurts via Chlorella vulgaris supplementation

This study aimed to investigate the microbiological, physicochemical, and sensory properties of four different yogurt types produced using varying concentrations of 0.50%, 0.75%, and 1% Chlorella vulgaris, along with 1% maple syrup, to develop a functional yogurt enriched with nutritional content. The viable counts of Lactobacillus and Streptococcus in the yogurts during storage ranged from 6.97 to 8.51 log₁₀ cfu/g and 7.23 to 8.22 log₁₀ cfu/g, respectively. Yeast and mold counts in all samples were found to be below the detectable level (< 2 log₁₀ cfu/g) throughout the storage period. The viscosity of the yogurts ranged from 1063 to 2405 cP, with significant variation observed based on the concentration of Chlorella vulgaris (p < 0.05). The control yogurt had the lowest total phenolic content (47.62 mg GAE/g), while the highest value was found in the yogurt variety produced with 1% Chlorella vulgaris (47.62 mg GAE/g). Additionally, the lowest total antioxidant value (15.49%) was observed in the control sample and the highest (58.90%) in the yogurt with 1% Chlorella vulgaris. The lowest total sugar content (7.37%) was determined in the control sample on the 21st day of storage, while the highest value (16.58%) was found in the yogurt with 1% Chlorella vulgaris. Sensory evaluation revealed that panelists preferred the sample containing 0.50% Chlorella vulgaris and 1% maple syrup.