Physico-chemical characterization of yogurt added with lyophilized liposome coencapsulating vitamin D3 and B12

The objective of coencapsulation in liposomes can be the development of formulations rich in different bioactives. Due to the known instability of liposome dispersions, lyophilization becomes interesting to ensure long-term stability, prolonging the integrity and stability of the encapsulated bioactive and reducing the risk of microbiological contamination In this work, the objective was to produce liposomes coencapsulating vitamins D3 and B12 with unsaturated/non-hydrogenated phospholipids (Lipoid S45) for incorporation into yogurts. Three yogurt formulations were evaluated: B0 (control, only yogurt), B1 (yogurt incorporated with 1% (m/m) of lyophilized liposome) and B2 (yogurt incorporated with 1% (m/m) of lyophilized liposome and 3% (m/m) of lyophilized strawberry). Yoghurts were submitted to analysis of color, pH and total titratable acidity (g lactic acid/100 g). The pH of the yogurts was 4.0±0.0 for B0 and B1, and 3.7±0.1 for B2. The titratable acidity values were 1.10±0.01 for yogurt B0, 1.05±0.01 (B1) and 1.49±0.02 (B2). It was found that the addition of strawberry lowered the pH of the yogurt samples and increased the titratable acidity. In the colorimetric analysis, the parameter L* (luminosity) was 96.5±0.2 for the control, 92.3±0.2 and 78.0±1.0 for samples B1 and B2 respectively, it is observed that the addition of strawberry reduced the luminosity. The colorimetric parameter a* was -1.6±0.1 (control), 4.7±0.1 (B1) and 12.3±0.5 (B2). The positive values of a* indicate a color trend towards red, which makes the results consistent with the color obtained from the B1 yogurts by the addition of the lyophilized liposome, which has a pink color given by the encapsulation of vitamin B12, and from the B2 yogurts, the color is given by the incorporation of the liposome and strawberry.