Drying of Tarhana dough by Refractance Window™ technology under vacuum/atmospheric conditions: Characterization of physical and quality parameters

Abstract

This study aimed to produce dried tarhana using a refractance window drying (RWD) system. The drying process was also carried out under vacuum; the current study is the first in the literature. Using different heating mediums, the maximum temperature can be adjusted to a level above that used in RWD studies. Considering results, process time savings in RWD were over 85% and 75% compared to control groups (oven and hot air dryer), respectively. Tarhana samples dried in RWD were also faster (50%) under vacuum conditions than atmospheric ones. The highest preservation of total phenolic content (TPC) and total antioxidant activity (TAA) was for samples dried by RWD at 110°C under atmospheric conditions. Techno‐physical properties were better than the control group. The rheological behavior of tarhana soups was similar to pseudoplastic flow behavior and well defined by the Power law and Herschel–Bulkey models. In conclusion, RWD can be a promising technique for tarhana production.