Numerical optimization of probiotic Ayran production based on whey containing transglutaminase and gel.

The purpose of this study was to optimize the functional properties of probiotic Ayran. Two-level fractional factorial design with four center points was used to investigate the effect of five independent variables including, reconstructed whey protein (70-90% of milk), salt (0.5-1 g/100 g), gel (0-30 g/100 g), transglutaminase enzyme (0-14 unit/100 g) and storage time (1-21 days).