Incorporation of Agglomerated <i>Spirulina platensis</i> Powder in Yogurt: A Strategy for Enhancing Nutritional Quality and Bioactive Compounds

The incorporation of <i>Spirulina platensis</i> has been studied as a strategy to enrich food with bioactive compounds. Recent studies have expanded the use of <i>Spirulina</i> in yogurts, seeking to combine its nutritional value with the practicality of functional foods. This study evaluated the physicochemical and bioactive compounds characteristics of yogurt incorporating commercial and agglomerated (with 30% maltodextrin, efficient carrier agent, in a fluidized bed) <i>Spirulina platensis</i> powder, at concentrations of 0.5–2.0% (<i>w</i>/<i>v</i>) prior to fermentation. This study is novel as it is the first to report the incorporation of <i>S. platensis</i> agglomerated in a fluidized bed into yogurt. Fermentations were carried out at 42 °C for 5 h and then the stirred yogurts were stored at 4 °C for 28 days for stabilization. All yogurts obtained achieved characteristic values according to the Brazilian Normative Instruction 46/2007 with total acidity (0.6–1.5%), pH (3.5–4.6), and viable lactic bacteria of at least 10⁷ CFU.g⁻¹, without significantly affecting the quality of the final product or the activity of lactic acid bacteria. For the nutritional composition, it was observed that the greater the amount of cyanobacteria incorporated, the higher the concentrations of proteins (4.2–5.6%) and ashes (1.3–1.8%) in the product, and for the bioactive compounds, the phenolic compounds ranged between 2.98 and 14.96 mg.100 g⁻¹ and significantly enriched the yogurt with phycocyanin (2.19–3.65 mg.100 g⁻¹), β-carotene (4.73–6.37 mg.100 g⁻¹), and chlorophyll <i>a</i> (12.39–13.77 mg.100 g⁻¹), for the formulations using commercial and agglomerated <i>S. platensis</i> powder. Agglomeration improved the stability of bioactive compounds after fermentation and stabilization processes of the yogurts. Also, it was found that the agglomerated <i>S. platensis</i> powder preserved a higher amount of bioactive compounds in the yogurt, which fulfills one of the main objectives of incorporating this cyanobacterium.