HTST Pre-Drying Influence on Vacuum Drying Kinetics and Carrot Slices Quality Parameters Evaluation

Abstract

Jokić S., Velić D., Bilić M., Lukinac J., Planinić M., Bucić-Kojić A. (2009): Influence of process parameters and pre-treatments on quality and drying kinetics of apple samples. Czech J. Food Sci., 27: 88-94. The aim of this research was to determine the influence of the process parameters and pre-treatment methods on the quality and drying kinetics of apple samples of the Florina variety using standard analytical methods: thermo-gravimetry, rehydration, colorimetry. The Apple samples were dried in a laboratory tray drier at different temperatures (50, 60, and 70°C), airflow velocities (1.5 m/s and 2.75 m/s), and pre-treatment methods (dipping in 0.5% ascorbic acid solution; 0.3% l-cysteine solution; 0.1% 4-hexyl resorcinol solution; 0.5% sodium metabisulfite solution; mixed solution of 0.05% 4-hexyl resorcinol and 0.5% sodium metabisulfite; blanching in hot water at 85°C). According to the drying time, rehydration and colour characteristics, the optimal drying parameters found were: temperature of 60°C and airflow velocity of 2.75 m/s. The drying kinetic equations were estimated using Page's mathematical model. The results of the estimation showed a good agreement with the experimental data. The best results were achieved when the samples were pre-treated with 4-hexyl resorcinol. Blanching in hot water resulted in a higher drying rate and higher rehydration ratio, but also in unacceptable changes in the colour appearance of the apple samples.

Probabilistic Model of Drying Process of Leek

“…Food drying is one of the oldest and most effective ways of processing agricultural products (vegetables, fruits). It can be carried out using various methods, such as: drying in the sun [1], convective drying [2] (which is the most common), microwave drying [3], vacuum drying [4] or infrared drying [5] and also combinations of these methods. Drying is a process of the simultaneous diffusion of water from the material and the transfer of heat into the material in order to reduce the moisture content, as well as the water and microbiological activity in the material.…”

Suitable model for thin-layer drying of root vegetables and onion

“…However, the models discussed are time consuming because the diffusion equations governing the process are complicated (Kaleta and Górnicki, 2010b). Theoretical models have been applied to describe the drying kinetics of such biological materials as apples (Kowalski and Rybicki, 2017), carrots (Mahapatra and Tripathy, 2018;Sánchez-Sáenz et al, 2015), cherry tomato (Bennamoun et al, 2015), green bean (Doymaz et al, 2015;Tekin et al, 2017), hazelnut (Giraudo et al, 2018), peach (Doymaz, 2014), pumpkin (Agrawal and Methekar, 2017;Junqueira et al, 2017), peppermint leaves (Ashtiani et al, 2017), poppy seeds (Stakić and Urošević, 2011), pre-gelatinized potato starch (Jiang et al, 2017), red beets (Kaleta and Górnicki, 2010b), spinach leaves (Doymaz, 2009), and sunflower seeds (Darvishi et al, 2013).…”