Safety and Quality Evaluation of Spirulina-Fortified Milk During Refrigerated Storage

The microalga Spirulina (Arthrospira platensis) is a rich source of protein in dairy products and has high antioxidant properties as a functional food ingredient.The cow milk samples were fortified with 0.25%, 0.50% and 1.00% Spirulina and the unfortified milk was taken as control.Milk samples fortified with Spirulina were subjected to physicochemical, phytochemical, antioxidant, microbiological, and sensory quality assessment during the 15 days of refrigeration at 4 ± 1 °C.The amount of protein, total soluble solid, total phenolic content, total flavonoid content and DPPH radical scavenging activity increased significantly (p < 0.05) after fortification of spirulina in milk, which increased the nutritional and functional properties of milk.Additionally, fortified samples showed improved physicochemical stability and microbiological quality throughout storage, as seen by increased pH stability, decreased titratable acidity, and decreased coliform, yeast, and mold counts.Due to its unique green color and the algal taste, increasing the concentration of spirulina adversely affected the sensory attributes, such as sensory color, sensory flavor and overall acceptability.Among the treatments, 0.25% spirulina gave the best results in terms of improved microbial, antioxidant and nutritional parameters with an acceptable sensory parameter.The findings revealed that spirulina is a promising natural fortifying ingredient of functional milk with added value, which enhanced its nutritional composition, storage stability, and antioxidant properties.