Mathematical modeling of low temperature high velocity (LTHV) drying in foods

Abstract

The main purpose of this study is the mathematical modeling of low temperature and high velocity (LTHV) drying method with different temperatures and its comprehensive evaluations in fish. For this purpose, 200g of trout (Oncorhynchus mykiss) was dried with a single layer dryer by using 7m/s air velocity and approximate to 40-50% relative humidity at 4, 10, 15 and 20 degrees C. Based on the experiments, weight loss (percentage), final moisture content and drying times were determined. Twenty-three different mathematical models were applied to the observed data to perform a nonlinear regression analysis and the result was comprehensively evaluated by using 14 evaluation criteria. Moreover, the exponential forms of thin-layer drying curves of fish samples were derived. Consequently, the most suitable mathematical models were selected for the LTHV drying conditions considering evaluation criteria. in this regard, the most suitable six models (Logarithmic, Midilli-Kucuk, Demir et al., Hii et al., Balbay-Sahin and Alibas) were selected for the LTHV drying at 4 degrees C that is the most suitable drying temperature for food quality. After comprehensive evaluations, it was understood that some of the evaluation criteria give same results in similar drying conditions as the residual sum of squares (RSS), total sum of squares (SST) and sum of squares (SSE). Practical ApplicationsLTHV drying method is a cold drying process that performed at very low temperatures (20 degrees C) and high velocities (7m/s). LTHV drying refers an indoor thin-layer drying of food products, which is entirely exposed to the cold drying air moving throughout the food product. in the open literature, this new drying method has some preservative effects on food quality especially at 4 degrees C. in addition, it is well known that the drying equations can easily be applied to industrial drying applications. in this regard, thin-layer LTHV drying equations can contribute to the drying characteristics of perishable and semidried food. This study allows researchers to select the suitable drying equations and provide which of them should be preferred. the study also provides a comprehensive evaluation of mathematical models for specific products.(c) 2016 Wiley Periodicals, Inc