Production of yogurt from milk fortified with dried soapwort extract

The purpose of this study was to examine some features of set type yoghurt manufactured from reconstituted milk supplemented with dried soapwort extract. For this purpose, 4types of yoghurt samples were produced from reconstituted milk supplemented with lyophilized soapwort extract at the concentrations of 0.000% (control), 0.025%, 0.050% and 0.100% before heat application. Titratable acidity (as lactic acid), pH, dry matter, protein, fat, gel firmness, syneresis,viscosity, colour (ΔE*, L*, a*, and b*), scanning electron microscopy and sensory evaluation analyses of the yoghurt samples were performed. Yoghurts had 14.38-14.86% dry matter, 4.94-5.54% protein, 1.33-1.39% titratable acidity, 4.20-4.30 pH, 1959-2801 mPa·s viscosity, 244.1-375.8 g gel firmness, %5.42-31.49 syneresis, 85.97-87.78 L*, (-)3.67-(-)2.14 a*, 7.32-9.52 b* and 0.56-1.84 ΔE* values. The gel structure was irregular in the samples with soapwort extract powder. Although a denser structure was observed in some areas, the variability in pore sizes was much higher than in the control yogurt. The control yoghurt sample received the highest overall acceptance score (5.4) from the sensory evaluation.