Spray Drying of Yogurt: Optimization of Process Conditions for Improving Viability and Other Quality Attributes
Makaleler > Tam Makale · 2010
Yazarlar: Banu KOC, Melike Sakin YILMAZER, Pınar BALKIR, Figen ERTEKİN
DRYING TECHNOLOGY, SCI Expanded İndekslerine Giren Dergi, Uluslararası, 2010, cilt 28, ss 495-507
DOI: 10.1080/07373931003613809
Özet
Plain yogurt was subjected to spray drying to determine the optimum processing conditions that yield maximum survival ratio of lactic acid bacteria, maximum overall sensory attributes, minimum color change, and acceptable moisture content. The inlet (150-180 degrees C) and outlet air temperatures (60-90 degrees C) and the feed temperature (4-30 degrees C) were the independent factors. A pilot-scale spray dryer was used to conduct a set of drying experiments where the process conditions were selected according to central composite rotatable design (CCRD). The resulting yogurt powder at each condition was also subjected to the measurement of some physical properties (water activity, titratable acidity [lactic acid, %] and pH) to determine the effects of spray-drying conditions. The morphological structure of the powder was inspected by scanning electron microscopy (SEM) analysis. Optimization by the application of the desirability function method resulted in air inlet temperature of 171 degrees C, air outlet temperature of 60.5 degrees C, and feed temperature of 15 degrees C as the optimum processing condition. The mathematical optimum condition was experimentally verified.