APPLICATION OF MACRO AND MICROALGAE COMBINED IN YOGURT

The macroalga Gracilaria gracilis is a valuable resource mainly due to its content of agar and the phycoerythrin (PE) protein, characterized by its pink color. Chlorella vulgaris is one of the most best-known microalgae, composed of at least 50% of protein. The objective of this study is to develop a nutrient enriched yogurt with an appellative natural color through the incorporation of micro and macroalgae. Three yogurts were produced: a control yogurt (CY), one yogurt supplemented with 5%(v/v) of G. gracilis extract (GY) and one yogurt supplemented with both 5%(v/v) of G. gracilis and 2% (w/v) of white Chlorella (GCY). Physicochemical analyses were performed after fermentation and during the 21 days of storage, namely in terms of carbohydrates, proteins, moisture, color and texture. Total phenolic compounds (TPC) content was measured using the Folin-Ciocalteu method, expressed as mg gallic acid equivalent per 100 g of sample, and antioxidant activity using ABTS methodology. The results showed no significant differences in carbohydrate, moisture, ash content, or antioxidant activity. There was also no significant difference in protein levels and TPC between the CY and GY, 24.7±0.1% and 24.1±1.1% for proteins, respectively, and for TPC 13.18±0.01 and 12.41±0.01mg_GAE per 100g. However, there was a difference with the GCY sample, 28.4±0.3% of protein and 14.88±0.01 mg_GAE per 100g for TPC. The pink color of GY and GCY remained stable throughout the 21-day storage period, but for the sample with white Chlorella, the yogurt's pink coloration was affected due to the slight green coloration of the algae. The addition of G. gracilis extract led to a decrease in firmness, whereas the inclusion of white Chlorella increased firmness, but in all samples the texture remained consistent during storage. This study concludes that it is possible to develop a nutrient enriched yogurt with natural color.