Colour, Texture, Microstructure and Nutrient Retention of Kiwifruit Slices Subjected to Combined Air-Impingement Jet Drying and Freeze Drying

Abstract

The aim of this study was to select an appropriate drying technique from air-impingement jet drying (AIJD), hot air drying (HAD) and microwave drying (MWD) which can be combined with freeze drying (FD). Results showed that AIJD with relatively high efficiency, low energy consumption and good drying quality was suitable to be combined with FD. To further improve the drying technology of kiwifruits, the energy consumption and quality of dried kiwifruit with different conversion point during combined FD and AIJD were also tested. The energy consumption obtained for AIJD+FD and FD+AIJD was lower than that obtained for FD alone. Among the products, the kiwifruit processed by AIJD+FD not only showed better attractive green colour and higher sweetness perception, but also revealed higher rehydration ratio than FD and FD+AIJD kiwifruits, which was positively related to microstructure changes. The best AIJD+FD process, from nutrient retention and antioxidant activity considerations, was the combination of 65 min AIJD pre-drying and FD finish drying. Therefore, AIJD pre-drying and FD finish drying as a promising way with short drying time and strong nutrient retention capacity may be applied to the drying processing of agricultural products.

Effects of air‐impingement jet drying on drying kinetics, color, polyphenol compounds, and antioxidant activities of Boletus aereus slices

“…(2014) also found a similar result in American ginseng during AIJD processing. In this study, the drying dynamics of B. aereus slices were affected by drying temperature, which is similar to the results of AIJD in kiwifruit slices (Huang et al., 2017) and onion (Li et al., 2015). Figures 1(a) and 1(c) showed that the water diffusion rate of B. aereus slices accelerated with the increasing of drying temperature, which resulted in a shorter time spent in drying.…”

“…Xiao et al (2014) also found a similar result in American ginseng during AIJD processing. In this study, the drying dynamics of B. aereus slices were affected by drying temperature, which is similar to the results of AIJD in kiwifruit slices (Huang et al, 2017) and onion (Li et al, 2015). Figures 1(a (Li et al, 2013).…”

“…In addition, at the same drying temperature (60 • C), AIJD method could accelerate DR and cut the drying time by 52% when compared to HAD, the results also indicated that the DR of AIJD was higher than that of HAD. Similarly, compared with HAD and microwave drying, higher DR and less drying time were found in AIJD dried kiwifruit (Huang et al, 2017) and Allium cepa (Li et al, 2015). Luo et al (2021) also showed that AIJD was more suitable to produce distinguished sensory quality of shiitake mushroom than HAD and vacuum freeze drying (VFD).…”

Nutritional quality of heat-sensitive food materials in intermittent microwave convective drying

“…Kiwifruit has been investigated for convective drying by several researchers ( 21 , 27 – 30 ). Similarly, changes in colour ( 25 , 31 , 32 ) and physical properties ( 33 , 34 ) of hot air convective dried kiwifruit have been published. The influence of conventional drying conditions on bioactive compounds in fresh and dried kiwifruit has also been examined by Tian et al ( 22 ), Orikasa et al ( 23 ) and Kaya et al ( 24 ).…”

Hava Jeti̇ Çarpmali Kurutma İçi̇n Farkli Dai̇resel Nemli̇ Nesne Geometri̇leri̇ni̇n Isi Ve Kütle Transferi̇ Üzeri̇ndeki̇ Etki̇si̇ni̇n Araştirilmasi

“…(2016) sıcak haddelemede en önemli işlemlerden biri olan ve herhangi bir sanayi sürecinde en fazla su tüketimlerinden birine sahip olan soğutma sürecinin taşınım ısı transferi olgusunu anlamak için kaynama noktasının altındaki sıcaklıklarda sıcak bir düz çelik plaka üzerine türbülanslı su jeti çarpmasıyla ısı transferinin sayısal araştırmasını yapmışlardır. (11) Yukarıdaki denklemler aşağıdaki giriş ve sınır şartlarının kullanılmasıyla FLUENT programında kullanıcı tanımlı bir fonksiyon kodu (UDF) yazılarak çözülmüştür.…”