Drying kinetics and quality properties of Mellaki (Pyrus communisL.) pear slices dried in a novel vacuum‐combined infrared oven

Abstract

Pear (Pyrus spp.) with more than 6000 varieties is one of the most widely consumed fruit in the whole world. The annual production of pear was more than 23.7 million tons in 2018. Pear can be consumed as fresh, dried, juice, canned food, etc. Dried pear can also be used as raw material and additive in the production of various food products such as fruit ice cream, yogurt, cereals, and bakery products (FAOSTAT, 2019;Özaydin & Özçelik, 2016).The high nutritional content of dried products is the main reason for their increasing popularity. Therefore, new techniques such as ultrasound, radio frequency, infrared, etc., are used for the production of nutritious and high-quality dried products (Guo et al., 2020;Zhou et al., 2019). These novel technologies provide high-quality product, short process times, and energy savings compared to traditional drying methods. On the other hand, if the appropriate novel technology and parameters are not selected, burning problem in foods and high HMF formation in sugary products may occur (Türker & İşleroğlu, 2017;Zhou et al., 2019). Infrared is defined as a form of electromagnetic radiation, that travels at the speed of light like all electromagnetic waves such as UV light, radio waves, visible light, X-rays, and gamma rays. Infrared energy is transmitted directly from the heat source to the product surface, so the product is heated more quickly and homogenously without heating the surrounding air (Jafari et al., 2020). Infrared technology has important advantages including high thermal efficiency, fast heating rate, short response time, uniform drying temperature, and easy process control (Doymaz et al., 2016;Liu et al., 2020). However, there is a possibility of partial burning or browning in the product because of the fast-heating rate during infrared drying. Therefore, the infrared power and distance between the product