A High-Efficiency Radio-Frequency-Assisted Hot-Air Drying Method for the Production of Restructured Bitter Melon and Apple Chips
Nowadays, consumers are increasingly demanding processed food products with high levels of beneficial components. Bitter melon and apple are both nutritious foods rich in bioactive compounds. In this study, restructured bitter melon and apple chips were processed using four drying techniques: hot-ai...
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MDPI AG
2024-01-01
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| Series: | Foods |
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| Online Access: | https://www.mdpi.com/2304-8158/13/2/197 |
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| author | Wei Jin Min Zhang Arun S. Mujumdar |
| author_facet | Wei Jin Min Zhang Arun S. Mujumdar |
| author_sort | Wei Jin |
| collection | DOAJ |
| description | Nowadays, consumers are increasingly demanding processed food products with high levels of beneficial components. Bitter melon and apple are both nutritious foods rich in bioactive compounds. In this study, restructured bitter melon and apple chips were processed using four drying techniques: hot-air drying with/without exhaust air recirculation (EAR), and radio-frequency-assisted hot-air drying (RFHAD) with/without EAR. The drying characteristics, effective moisture diffusivity (D<sub>eff</sub>), specific energy consumption (SEC), total energy consumption (TEC), and some selected quality characteristics of the dehydrated chips were evaluated. The experimental results show that the application of radio frequency (RF) energy significantly facilitates water evaporation in the drying material, resulting in a significant (<i>p</i> < 0.05) reduction of drying duration by 31~39% over the experimental test parameters. The higher D<sub>eff</sub> values obtained from RFHAD and RFHAD + EAR were 6.062 × 10<sup>−9</sup> to 6.889 × 10<sup>−9</sup> m<sup>2</sup>/s, while lower SEC values ranged from 301.57 to 328.79 kW·h/kg. Furthermore, the dried products possessed better or fairly good quality (such as a lower color difference of 5.41~6.52, a lower shrinkage ratio of 18.24~19.13%, better antioxidant capacity, higher chlorophyll, total flavonoid, and total phenolic content, a lower polyphenol oxidase activity of 49.82~52.04 U·min<sup>−1</sup>g<sup>−1</sup>, smaller diameter and thickness changes, and a lower hardness of 27.75~30.48 N) compared to those of hot-air-dried chips. The combination of RF-assisted air drying and partial recirculating of dryer exhaust air achieved the highest saving in TEC of about 12.4%, along with a lower moisture absorption capacity and no deterioration of product quality attributes. This drying concept is therefore recommended for the industrial drying of several food materials. |
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| series | Foods |
| spelling | doaj.art-f6d24fbdc1e14795ad438d4c70f3966f2024-01-29T13:51:47ZengMDPI AGFoods2304-81582024-01-0113219710.3390/foods13020197A High-Efficiency Radio-Frequency-Assisted Hot-Air Drying Method for the Production of Restructured Bitter Melon and Apple ChipsWei Jin0Min Zhang1Arun S. Mujumdar2State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi 214122, ChinaState Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi 214122, ChinaDepartment of Bioresource Engineering, Macdonald Campus, McGill University, Sainte-Anne-de-Bellevue, QC H9X 3V9, CanadaNowadays, consumers are increasingly demanding processed food products with high levels of beneficial components. Bitter melon and apple are both nutritious foods rich in bioactive compounds. In this study, restructured bitter melon and apple chips were processed using four drying techniques: hot-air drying with/without exhaust air recirculation (EAR), and radio-frequency-assisted hot-air drying (RFHAD) with/without EAR. The drying characteristics, effective moisture diffusivity (D<sub>eff</sub>), specific energy consumption (SEC), total energy consumption (TEC), and some selected quality characteristics of the dehydrated chips were evaluated. The experimental results show that the application of radio frequency (RF) energy significantly facilitates water evaporation in the drying material, resulting in a significant (<i>p</i> < 0.05) reduction of drying duration by 31~39% over the experimental test parameters. The higher D<sub>eff</sub> values obtained from RFHAD and RFHAD + EAR were 6.062 × 10<sup>−9</sup> to 6.889 × 10<sup>−9</sup> m<sup>2</sup>/s, while lower SEC values ranged from 301.57 to 328.79 kW·h/kg. Furthermore, the dried products possessed better or fairly good quality (such as a lower color difference of 5.41~6.52, a lower shrinkage ratio of 18.24~19.13%, better antioxidant capacity, higher chlorophyll, total flavonoid, and total phenolic content, a lower polyphenol oxidase activity of 49.82~52.04 U·min<sup>−1</sup>g<sup>−1</sup>, smaller diameter and thickness changes, and a lower hardness of 27.75~30.48 N) compared to those of hot-air-dried chips. The combination of RF-assisted air drying and partial recirculating of dryer exhaust air achieved the highest saving in TEC of about 12.4%, along with a lower moisture absorption capacity and no deterioration of product quality attributes. This drying concept is therefore recommended for the industrial drying of several food materials.https://www.mdpi.com/2304-8158/13/2/197restructured bitter melon and apple chipsradio-frequency-assisted hot-air drying (RFHAD)exhaust air recirculation (EAR)drying characteristicsquality attributes |
| spellingShingle | Wei Jin Min Zhang Arun S. Mujumdar A High-Efficiency Radio-Frequency-Assisted Hot-Air Drying Method for the Production of Restructured Bitter Melon and Apple Chips Foods restructured bitter melon and apple chips radio-frequency-assisted hot-air drying (RFHAD) exhaust air recirculation (EAR) drying characteristics quality attributes |
| title | A High-Efficiency Radio-Frequency-Assisted Hot-Air Drying Method for the Production of Restructured Bitter Melon and Apple Chips |
| title_full | A High-Efficiency Radio-Frequency-Assisted Hot-Air Drying Method for the Production of Restructured Bitter Melon and Apple Chips |
| title_fullStr | A High-Efficiency Radio-Frequency-Assisted Hot-Air Drying Method for the Production of Restructured Bitter Melon and Apple Chips |
| title_full_unstemmed | A High-Efficiency Radio-Frequency-Assisted Hot-Air Drying Method for the Production of Restructured Bitter Melon and Apple Chips |
| title_short | A High-Efficiency Radio-Frequency-Assisted Hot-Air Drying Method for the Production of Restructured Bitter Melon and Apple Chips |
| title_sort | high efficiency radio frequency assisted hot air drying method for the production of restructured bitter melon and apple chips |
| topic | restructured bitter melon and apple chips radio-frequency-assisted hot-air drying (RFHAD) exhaust air recirculation (EAR) drying characteristics quality attributes |
| url | https://www.mdpi.com/2304-8158/13/2/197 |
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