Impact of Vacuum Assisted Oven Drying of Kurut on Product Quality and Drying Characteristics

Abstract

Kurut is an ancient flavor of central Asia, produced by sun-drying of yogurt. Kurut is used in preparation of pasta, soup and also in the form of yogurt by mixing with water. Alternative to sun drying, this study was aimed at conducting Kurut production by use of vacuum-oven drying (VOD) and oven drying (OD) techniques at two different temperatures (35 °C and 45 °C). Samples were coded as KV35, KV45 and K35, K45 for VOD and OD techniques, respectively. All samples were concentrated by drying in proximate composition (p > 0.05). Less progress of acidity, lower solubility ratio (p > 0.05) and lower hydroxymethyl furfural (HMF) values were maintained by VOD than OD (p < 0.05) in the 1st day. All Kurut samples were very distinctly different (ΔE ˃ 3), more yellowish (b*) and less bright (L*) than strained yogurt. Redness (a*) was observed only in OD-applied samples (p < 0.05). Yagcioglu, Wang and Singh, Midilli and two-term models were best fitting models for predicting drying behavior of KV35, KV45, K35 and K45, respectively. Drying time for VOD and OD were determined as 2 days and 8 days, respectively. Difference in means of drying temperature was found statistically significant in terms of HMF, L*, a* and b* in the OD technique (p < 0.05). In the industrial aspect use of VOD, especially with the establishment of continuous systems, Kurut production in a shorter time with better preservation of quality is possible.