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Qing S, Long Y, Wu Y, Shu S, Zhang F, Zhang Y, Yue J. Hot-air-assisted radio frequency blanching of broccoli: heating uniformity, physicochemical parameters, bioactive compounds, and microstructure. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2023; 103:2664-2674. [PMID: 36647340 DOI: 10.1002/jsfa.12458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 01/12/2023] [Accepted: 01/17/2023] [Indexed: 06/17/2023]
Abstract
BACKGROUND Vegetables are often blanched before drying. The hot-water blanching (HWB) of broccoli reduces quality and is environmentally harmful. In this work, hot-air-assisted radio frequency heating blanching (HA-RFB) of broccoli was developed for use before further drying processes. Blanching sufficiency, heating uniformity, and heating rate during HA-RFB were investigated to improve the product's physicochemical properties and texture. Suitable heating conditions were achieved when HA-RFB was applied with hot air at 70 °C, with an electrode gap of 10.7 cm, using a cylindrical container for the broccoli. RESULTS Under these conditions, the relative peroxidase activity in broccoli decreased to 3.26% within 117 s, with 13.45% of weight loss. In comparison with HWB broccoli, the products blanched by HA-RFB preserved their texture, bioactive compounds, and microstructure better. The ascorbic acid, sulforaphane, and total glucosinolate content in HA-RFB products were 251.1%, 131.9% and 36.7% higher than those in HWB broccoli, and HA-RFB treatment led to a greater weight loss (13.45 ± 0.50%) than HWB (8.70 ± 1.70%), which is very helpful for the subsequent drying process. CONCLUSION This study demonstrated that HA-RFB could be a promising substitute for HWB to blanch broccoli and other flower vegetables, especially as a pretreatment in the drying process. © 2023 Society of Chemical Industry.
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Affiliation(s)
- Shuting Qing
- Bor S. Luh Food Safety Research Center, College of Agriculture and Biology, Key Laboratory of Urban Agriculture, Ministry of Agriculture and Rural Affairs, SJTU-OSU Innovation Center for Food Control and Environmental Sustainability, Shanghai Jiao Tong University, Shanghai, China
| | - Yangyang Long
- Bor S. Luh Food Safety Research Center, College of Agriculture and Biology, Key Laboratory of Urban Agriculture, Ministry of Agriculture and Rural Affairs, SJTU-OSU Innovation Center for Food Control and Environmental Sustainability, Shanghai Jiao Tong University, Shanghai, China
| | - Yiwen Wu
- Bor S. Luh Food Safety Research Center, College of Agriculture and Biology, Key Laboratory of Urban Agriculture, Ministry of Agriculture and Rural Affairs, SJTU-OSU Innovation Center for Food Control and Environmental Sustainability, Shanghai Jiao Tong University, Shanghai, China
| | - Shumin Shu
- Kangshi (Shanghai) Food Science and Technology Co., Ltd, Shanghai, China
| | - Fei Zhang
- Kangshi (Shanghai) Food Science and Technology Co., Ltd, Shanghai, China
| | - Yan Zhang
- Kangshi (Shanghai) Food Science and Technology Co., Ltd, Shanghai, China
| | - Jin Yue
- Bor S. Luh Food Safety Research Center, College of Agriculture and Biology, Key Laboratory of Urban Agriculture, Ministry of Agriculture and Rural Affairs, SJTU-OSU Innovation Center for Food Control and Environmental Sustainability, Shanghai Jiao Tong University, Shanghai, China
- Shanghai Jiao Tong University Sichuan Research Institute, Chengdu, China
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Cui B, Ye P, Wang K, Sun Y, Mao C, Pang H, Fu H, Wang Y, Chen X, Wang Y. Developing radio frequency (RF) heating protocol in packed tofu processing by computer simulation. Curr Res Food Sci 2023; 6:100474. [PMID: 36926418 PMCID: PMC10011744 DOI: 10.1016/j.crfs.2023.100474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 02/15/2023] [Accepted: 02/27/2023] [Indexed: 03/05/2023] Open
Abstract
Packed tofu was produced by reheating the mixture of preheated soymilk and coagulant in a sealed container. This study aimed to replace the conventional heating method with RF heating during the reheating of soymilk for packed tofu production. In this study, dielectric properties (DPs), thermal properties (TPs), and rheological properties of soymilk were determined. A mathematical model was developed to simulate the RF heating process of soymilk to determine the appropriate packaging geometry. Water holding capacity (WHC), texture analysis, color measurement, and microstructure observation were performed to evaluate the quality of RF-heated packed tofu. Results showed that soymilk added with Glucono-Delta-Lactone (GDL) coagulated at the temperature above 60 °C, and the loss factor (ε″) was slightly reduced when soymilk was converted to tofu at coagulation temperature. Based on the simulation results, the cylindrical vessel (φ50 mm × 100 mm) was chosen as the soymilk container for desired heating rate (5.9 °C/min) and uniformity (λ = 0.0065, 0.0069, 0.0016 for top, middle, and bottom layers). The texture analysis revealed that the hardness and chewiness of packed tofu prepared by RF heating were enhanced (maximum 1.36 times and 1.21 times) compared with commercial packed tofu, while the springiness were not significantly changed. Furthermore, the denser network structure was observed inside RF-heated packed tofu by SEM. These results indicated that packed tofu prepared by RF heating was of higher gel strength and sensory quality. RF heating has the potential to be applied in packed tofu production.
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Affiliation(s)
- Baozhong Cui
- Northwest A&F University, College of Food Science and Engineering, Yangling, Shaanxi, 712100, China
| | - Pengfei Ye
- Northwest A&F University, College of Food Science and Engineering, Yangling, Shaanxi, 712100, China
| | - Ke Wang
- Northwest A&F University, College of Food Science and Engineering, Yangling, Shaanxi, 712100, China
| | - Yanan Sun
- Northwest A&F University, College of Food Science and Engineering, Yangling, Shaanxi, 712100, China
| | - Chao Mao
- Northwest A&F University, College of Food Science and Engineering, Yangling, Shaanxi, 712100, China
| | - Huiyun Pang
- Northwest A&F University, College of Food Science and Engineering, Yangling, Shaanxi, 712100, China
| | - Hongfei Fu
- Northwest A&F University, College of Food Science and Engineering, Yangling, Shaanxi, 712100, China
| | - Yequn Wang
- Northwest A&F University, College of Food Science and Engineering, Yangling, Shaanxi, 712100, China
| | - Xiangwei Chen
- Northwest A&F University, College of Food Science and Engineering, Yangling, Shaanxi, 712100, China
| | - Yunyang Wang
- Northwest A&F University, College of Food Science and Engineering, Yangling, Shaanxi, 712100, China
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Zuo Y, Li Q, Zhang Z, Yang H, Wang S, Hou L. Developing a square container with ideal dielectric constant for improving radio frequency heating uniformity in low-moisture agricultural products. J FOOD ENG 2022. [DOI: 10.1016/j.jfoodeng.2022.111386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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Thermal and Dielectric Properties of Wolfberries as Affected by Moisture Content and Temperature Associated with Radio Frequency and Microwave Dehydrations. Foods 2022; 11:foods11233796. [PMID: 36496604 PMCID: PMC9738072 DOI: 10.3390/foods11233796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 11/18/2022] [Accepted: 11/22/2022] [Indexed: 11/26/2022] Open
Abstract
Knowledge of the thermal and dielectric properties of wolfberries is essential for understanding the heat transfer and the interaction between the electromagnetic field (10-3000 MHz) and the sample during radio frequency (RF) and microwave (MW) drying. The thermal and dielectric properties of wolfberries were determined as influenced by moisture content from 15.1% to 75.2%, w.b.) and temperature from 25 to 85 °C. The results showed that as the moisture content increased from 15.1% to 75.2% (w.b.), the true density of wolfberries decreased, but the specific heat capacity and thermal conductivity increased with increasing temperature and moisture content. The dielectric properties (DPs) of wolfberries decreased with increasing frequency from 10 to 3000 MHz. The dielectric constant increased with increasing temperature at lower a moisture content (below 45% w.b.) but decreased with increasing temperature at a high moisture content (above 60% w.b.). The cubic and quadratic polynomial models (R2 = 0.977 - 0.997) were best for fitting the dielectric constant and loss factor at four representative frequencies of 27, 40, 915, and 2450 MHz, respectively. The penetration depth increased with the decreased frequency, temperature, and moisture content, and was greater at RF frequencies than MW range, making the RF heating more effective for drying bulk wolfberries. These findings offered essential data before optimizing RF or MW dehydration protocols for wolfberries via computer simulation.
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Successive Two-Stage Hot Air-Drying with Humidity Control Combined Radio Frequency Drying Improving Drying Efficiency and Nutritional Quality of Amomi fructus. FOOD BIOPROCESS TECH 2022. [DOI: 10.1007/s11947-022-02928-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Microstructure Analysis and Quality Evaluation of Jujube Slices Dried by Hot Air Combined with Radio Frequency Heat Treatment at Different Drying Stages. Foods 2022; 11:foods11193086. [PMID: 36230160 PMCID: PMC9562017 DOI: 10.3390/foods11193086] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 09/19/2022] [Accepted: 10/01/2022] [Indexed: 11/24/2022] Open
Abstract
Jujubes have been favored by consumers because of their rich nutrition and wide use. Hot air drying has been commercially and typically used to prolong shelf life and acquire the dried produce. Jujube slices were dried with hot air combined with radio frequency (RF) at different drying stages, namely, early (0–2 h, E-HA + RF), middle (2–4 h, M-HA + RF), later (4–6 h, L-HA + RF), and whole (0–6 h, W-HA + RF) stages. This study aimed to investigate the effects of different RF application stages on the microstructure, moisture absorption rate, color, and ascorbic acid of jujube slices. Compared with the hot air drying (HA) group, the E-HA + RF group obtained the best results among the experimental groups because it reduced the cells with a roundness of less than 0.4 by 5%. Moreover, the M-HA + RF group showed better results than those of other groups, with an 18.6% and 48.8% reduction in cells for a cross-sectional area less than 200 µm2 and a perimeter less than 25 µm, respectively. The minimum total color difference (ΔE = 9.21 ± 0.31) and maximum retention of ascorbic acid (285.06 mg/100 g) were also observed in this group. Therefore, the method of hot air drying assisted by phased RF is viable in the drying industry to improve the quality of dried agricultural products and reduce energy consumption.
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Impact of radio frequency treatment on textural properties of food products: An updated review. Trends Food Sci Technol 2022. [DOI: 10.1016/j.tifs.2022.04.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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8
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Lombardi SJ, Pannella G, Tremonte P, Mercurio I, Vergalito F, Caturano C, Maiuro L, Iorizzo M, Succi M, Sorrentino E, Coppola R. Fungi Occurrence in Ready-to-Eat Hazelnuts ( Corylus avellana) From Different Boreal Hemisphere Areas. Front Microbiol 2022; 13:900876. [PMID: 35558107 PMCID: PMC9087596 DOI: 10.3389/fmicb.2022.900876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Accepted: 03/28/2022] [Indexed: 11/24/2022] Open
Abstract
The present study evaluated the fungal contamination of ready-to-eat dried hazelnuts considering for the first time the application of the same condition drying process of several hazelnut cultivars from different boreal hemisphere areas. Fifty lots of hazelnuts (Corylus avellana), belonging to eight cultivars from seven regions in four countries, were analyzed for fungal microbiota, describing both load levels and species diversity. For this purpose, a polyphasic approach consisting of morphological examination (optical and scanning electron microscope observation) and molecular characterization [PCR-DGGE analysis and sequence analyses of the internal transcribed spacer (ITS)] was performed. The results show that different fungal populations occur in dried hazelnuts regardless of their geographical area of production. Although some varieties appear to be relatively less susceptible, species related to Aspergillus, such as A. commune and A. ochraceus, Penicillium, including P. commune, P. solitum, and P. expansum, and Rhizopus, for instance, R. stolonifer and R. oryzae, have generally been found. A related character “hazelnut cultivar—fungi” was found for species related to the genera Trichoderma and Fusarium, including F. oxyxporum, F. solani, and F. falciforme. All 14 species found are known to host pathogenic strains. Therefore, their presence in a ready-to-eat product, such as dried hazelnuts, can pose a real danger to the consumer. Based on these considerations, the development of new protective strategies seems highly desirable. The species-level description of the contaminating fungal community acquired through this study is the starting point for the development of tailor-made protective biotechnologies.
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Affiliation(s)
- Silvia Jane Lombardi
- Department of Agricultural, Environmental and Food Sciences, University of Molise, Campobasso, Italy
| | - Gianfranco Pannella
- Department of Agricultural, Environmental and Food Sciences, University of Molise, Campobasso, Italy
| | - Patrizio Tremonte
- Department of Agricultural, Environmental and Food Sciences, University of Molise, Campobasso, Italy
| | - Ida Mercurio
- Department of Agricultural, Environmental and Food Sciences, University of Molise, Campobasso, Italy
| | - Franca Vergalito
- Department of Agricultural, Environmental and Food Sciences, University of Molise, Campobasso, Italy
| | - Costantino Caturano
- Department of Agricultural, Environmental and Food Sciences, University of Molise, Campobasso, Italy
| | - Lucia Maiuro
- Department of Agricultural, Environmental and Food Sciences, University of Molise, Campobasso, Italy
| | - Massimo Iorizzo
- Department of Agricultural, Environmental and Food Sciences, University of Molise, Campobasso, Italy
| | - Mariantonietta Succi
- Department of Agricultural, Environmental and Food Sciences, University of Molise, Campobasso, Italy
| | - Elena Sorrentino
- Department of Agricultural, Environmental and Food Sciences, University of Molise, Campobasso, Italy
| | - Raffaele Coppola
- Department of Agricultural, Environmental and Food Sciences, University of Molise, Campobasso, Italy
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Zeng S, Li M, Li G, Lv W, Liao X, Wang L. Innovative applications, limitations and prospects of energy-carrying infrared radiation, microwave and radio frequency in agricultural products processing. Trends Food Sci Technol 2022. [DOI: 10.1016/j.tifs.2022.01.032] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Zuo Y, Zhou B, Wang S, Hou L. Heating uniformity in radio frequency treated walnut kernels with different size and density. INNOV FOOD SCI EMERG 2022. [DOI: 10.1016/j.ifset.2021.102899] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Zhu R, Jiang S, Li D, Law CL, Han Y, Tao Y, Kiani H, Liu D. Dehydration of apple slices by sequential drying pretreatments and airborne ultrasound-assisted air drying: Study on mass transfer, profiles of phenolics and organic acids and PPO activity. INNOV FOOD SCI EMERG 2022. [DOI: 10.1016/j.ifset.2021.102871] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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12
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Simultaneous hot-air assisted radio frequency drying and disinfestation for in-shell walnuts using a two-stage strategy. Lebensm Wiss Technol 2021. [DOI: 10.1016/j.lwt.2021.112134] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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13
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Elik A. Hot air-assisted radio frequency drying of black carrot pomace: Kinetics and product quality. INNOV FOOD SCI EMERG 2021. [DOI: 10.1016/j.ifset.2021.102800] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Predictive models of the top electrode voltage of radio frequency heating systems for low moisture foods. INNOV FOOD SCI EMERG 2021. [DOI: 10.1016/j.ifset.2021.102788] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Mao Y, Wang S. Recent developments in radio frequency drying for food and agricultural products using a multi-stage strategy: a review. Crit Rev Food Sci Nutr 2021; 63:2654-2671. [PMID: 34583556 DOI: 10.1080/10408398.2021.1978925] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Radio frequency (RF) drying is an emerging technology for food and agricultural products, holding features of rapid, uniform, stable, and volumetric heating, high energy efficiency, and moisture leveling. However, the RF drying with a single stage commonly has drawbacks of unexpected product quality, non-uniform moisture distribution, and prolonged drying time. The multi-stage drying approach could overcome the shortcomings of one-stage strategy accordingly by applying different drying methods or operating parameter values in each phase separately. This review describes the principle of RF heating, presents the typical systems and superiorities of RF drying, and provides a comprehensive overview on recent development in applications of both the one-stage and the multi-stage RF drying, and analysis of drying characteristics and merits for different types of the two-stage strategy. This review finally proposes recommendations for future studies in improving and optimizing the existing RF drying protocols and scaling up them to industrial applications.
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Affiliation(s)
- Yuxiao Mao
- College of Mechanical and Electronic Engineering, Northwest A&F University, Yangling, Shaanxi, China
| | - Shaojin Wang
- College of Mechanical and Electronic Engineering, Northwest A&F University, Yangling, Shaanxi, China.,Department of Biological Systems Engineering, Washington State University, Pullman, Washington, USA
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Wei X, Agarwal S, Subbiah J. Heating of milk powders at low water activity to 95°C for 15 minutes using hot air-assisted radio frequency processing achieved pasteurization. J Dairy Sci 2021; 104:9607-9616. [PMID: 34176627 DOI: 10.3168/jds.2021-20449] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2021] [Accepted: 05/13/2021] [Indexed: 11/19/2022]
Abstract
Salmonella persistence in milk powders has caused several multistate foodborne disease outbreaks. Therefore, ways to deliver effective thermal treatment need to be identified and validated to ensure the microbial safety of milk powders. In this study, a process of hot air-assisted radio frequency (HARF) followed by holding at high temperatures in a convective oven was developed for pasteurization of milk powders. Heating times were compared between HARF and a convection oven for heating milk powders to a pasteurization temperature, and HARF has been shown to considerably reduce the come-up time. Whole milk powder (WMP) and nonfat dry milk (NFDM) were inoculated with a 5-serotype Salmonella cocktail and equilibrated to a water activity of 0.10 to simulate the worst case for the microbial challenge study. After heating the sample to 95°C using HARF, followed by 10 and 15 min of holding in the oven, more than 5 log reduction of Salmonella was achieved in WMP and NFDM. This study validated a HARF-assisted thermal process for pasteurization of milk powder based on previously collected microbial inactivation kinetics data and provides valuable insights to process developers to ensure microbial safety of milk powder. This HARF process may be implemented in the dairy industry to enhance the microbial safety of milk powders.
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Affiliation(s)
- Xinyao Wei
- Department of Food Science and Technology, University of Nebraska, Lincoln 68588
| | | | - Jeyamkondan Subbiah
- Department of Food Science and Technology, University of Nebraska, Lincoln 68588; Department of Food Science, University of Arkansas System Division of Agriculture, Fayetteville 72704.
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