• Immunoreactivity;
  • milk proteins;
  • sensory quality;
  • transglutaminase;
  • yoghurt


Fermented beverages were produced through the milk fermentation (at 37 °C and 42 °C) by yoghurt bacteria Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus and simultaneous addition of microbial transglutaminase (m-TG). The results proved that the addition of m-TG enzyme and storage at 4 °C for 28 days caused a significant reduction in the immunoreactivity of caseins in yoghurt produced at 37 °C and did not decreased their sensory quality. The reaction between yoghurt proteins and antibodies towards α-lactalbumin (α-la) and β-lactoglobulin (β-lg) was not observed. The results of yoghurt produced at 42 °C were different, and the reduction of κ-casein only and the lack of β-lg immunoreactivity was noticed. Statistically significant attributes, which differentiated the sensory profiles of yoghurts, were descriptors of taste (yoghurty, creamy) and mouth-feel (density, creaminess and smoothness). The quantitative descriptive analysis (QDA) results were confirmed by principal component analysis (PCA). Two components (PC1, PC2) explain 90.68% of the variation of the sensory qualities of the yoghurts.