Influence of Different Hot Air Drying Temperatures on Drying Kinetics, Shrinkage, and Colour of Persimmon Slices

Abstract

Drying characteristics of persimmon, cv. “Rojo Brillante”, slabs were experimentally determined in a hot air convective drier at drying temperatures of 45, 50, 55, 60, and 65 °C at a fixed air velocity of 2.3 m/s. It was observed that the drying temperature affected the drying time, shrinkage, and colour. Four empirical mathematical models namely, Enderson and Pabis, Page, Logarithmic, and Two term, were evaluated in order to deeply understand the drying process (moisture ratio). The Page model described the best representation of the experimental drying data at all investigated temperatures (45, 50, 55, 60, 65 °C). According to the evaluation of the shrinkage models, the Quadratic model provided the best representation of the volumetric shrinkage of persimmons as a function of moisture content. Overall, higher drying temperature (65 °C) improved the colour retention of dried persimmon slabs.

Convective Hot Air Drying of Chilli Pepper: Process Optimization and Modelling the Drying Kinetics and Quality Attributes of Dried Product

“…lower PMC) with reduced or lower TPC. This observed reduction in PMC in relation to increase in drying time is in accord with other workers observation for the drying of fruits and vegetables (Idah et al, 2010;Zhao et al, 2017;Senadeera et al, 2020).…”

“…Thus, the Page model may be proposed to be the best model to describe the drying kinetics or behavior of chilli pepper. Similar observation has been reported for the HAD of red pepper (Agarry, 2017), tomato (Doymaz, 2007), red chillies (Tunde-Akintunde and Ajala, 2010), quinces (Tzempelikos et al, 2014), basil leaves (Taheri-Garavandi et al, 2015), bitter leaf (Agarry, 2017), thyme leaves (Turan and Fıratlıgil, 2019), and persimmon slices (Senadeera et al, 2020), respectively. The result revealed that under cabinet hot air drying of chilli pepper best described by Page model, the drying constant ' k '…”

“…The parameters of the different model equations were determined with the use of the nonlinear regression (NLR) tool of MATLAB 6.5 version computer software. The model that had the highest coefficient of determination ( ) and the lowest root mean square error (RMSE) was selected (Senadeera et al, 2020). The values of and RMSE obtained by the NLR analysis are presented in Table 5.…”

“…Thus, mathematical and empirical models are commonly utilized for the prediction of material drying kinetics and for optimizing the operating parameters and conditions (Salehi and Kashaninejad, 2018). Drying time and moisture (mass) transfer during drying have been predicted using several proposed mathematical and empirical drying models (Agarry, 2017;Salehi and Kashaninejad, 2018;Turan and Firatligil, 2019;Senadeera et al, 2020). The drying model is very essential for process optimization, improvement of product quality and equipment design.…”

Physico-Chemical and Microstructural Changes during the Drying of Persimmon Fruit cv. Rojo Brillante Harvested in Two Maturity Stages

“…Color is one of the most important sensory resources for determining consumer acceptability and product quality of dried food [ 28 ]. During persimmon drying, browning occurs which leads to evident fruit color changes [ 24 , 29 ].…”