Study of phycocyanin powder on probiotic bacteriologically and antioxidant properties of yogurt at 4 °C

The nutritional richness of pigments derived from microalgae makes them a popular choice for food and food additives, serving as colorants in various food products. This study presents a new food prototype that combines phycocyanin-fortified yogurt and its derivative.

We conducted a comprehensive analysis of its physicochemical composition, colorimetric properties, antimicrobial and antioxidant capabilities, and sensory evaluation over a period of 28 days. A total of 12 different yogurt variations were produced, each containing either 1% or 2% phycocyanin or a starter culture consisting of Bifidobacterium animalis subsp. lactis (BB-12), Lactobacillus acidophilus (La-5), Streptococcus thermophilus, and L. bulgaricus.

The pH and syneresis results showed that codes 1 (yogurt + milk powder) and 12 (yogurt + milk powder + Bifidobacterium animalis subsp. Lactis (BB12) + Lactobacillus acidophilus (La-5) + 2% phycocyanin) had the highest and lowest values, respectively. In contrast, code 1 showed the least, while the code 12 had the highest measurement results for acidity and viscosity. The results of dry matter, ash, fat, sugar, and salt, as well as antioxidant activity, indicated that the highest and lowest results belonged to codes 12 and 1, respectively. Based on the results of probiotic starter bacteria, the highest value was observed in codes 9 (yogurt + milk powder + Bifidobacterium animalis subsp. Lactis (BB12) + 2% phycocyanin) and 12. In other words, the passage of time, and phycocyanin concentration had a direct link to the number of probiotic starter bacteria. In addition, the highest sensory score of odor, flavor, color, and texture and overall acceptability was obtained by code 11 (yogurt + milk powder + Bifidobacterium animalis subsp. Lactis (BB12) + Lactobacillus acidophilus (La-5) + 1% phycocyanin). It can be interpreted that an increase in phycocyanin concentration and passing time caused a decrease in the sensory evaluation score.

In summary, pigments derived from Spirulina spp. have the potential to enhance the nutritional value and color of yogurt, making it a valuable organic effective component.