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ARS Home » Pacific West Area » Albany, California » Western Regional Research Center » Healthy Processed Foods Research » Research » Publications at this Location » Publication #404485
Research Project: New Sustainable Processes, Preservation Technologies, and Product Concepts for Specialty Crops and Their Co-Products

Location: Healthy Processed Foods Research

Title: Convective hot air drying of red cabbage (Brassica oleracea var. capitata rubra): Mathematical modeling, energy consumption and microstructure

Author
item VEGA-GALVEZ, ANTONIO - University Of La Serena
item GOMEZ-PEREZ, LUIS - University Of La Serena
item ZEPEDA, FRANCISCA - University Of La Serena
item SEGOVIA-GARCIA, PURIFICACION - Valencia University
item Bilbao-Sainz, Cristina
item MEJIAS, NICOL - University Of La Serena
item PASTEN, ALEXIS - University Of La Serena

Submitted to: Processes
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/27/2024
Publication Date: 2/29/2024
Citation: Vega-Galvez, A., Gomez-Perez, L.S., Zepeda, F., Segovia-Garcia, P., Bilbao-Sainz, C., Mejias, N., Pasten, A. 2024. Convective hot air drying of red cabbage (Brassica oleracea var. capitata rubra): Mathematical modeling, energy consumption and microstructure. Processes. 12(3). Article 509. https://doi.org/10.3390/pr12030509.
DOI: https://doi.org/10.3390/pr12030509

Interpretive Summary: Red cabbage (Brassica oleracea var. capitata rubra) is one of the most produced edible vegetables around the world due its low production costs and beneficial health properties. However, red cabbage has a brief shelf-life. Drying is an effective preservation technology widely used by the food industry. However, drying is a highly energy-intensive process. The present work evaluated drying kinetics, energy consumption, rehydration process and product quality of rehydrated cabbage dried at different temperatures (50, 60, 70, 80, and 90 °C). We found that drying at 90 °C reduced energy cost due to shorter drying times. Also, the cellular microstructure of the cabbage was better preserved at 90 °C, which resulted in a faster rehydration process and higher water holding capacity when compared with drying at lower temperatures.

Technical Abstract: This study examined the convective drying of red cabbage by evaluating the desorption isotherms, drying kinetics and rehydration behavior through mathematical modeling. The effects of process conditions on energy consumption and microstructure were also evaluated. Fresh red cabbage was dehydrated at different temperatures. Desorption isotherms at 50 and 70 °C were predicted by mathematical models and the equilibrium moisture was determined. Drying kinetics and rehydration processes were evaluated with mathematical models solved by iterative methods. The energy consumption was determined and microstructure was observed by scanning electron microscopy. Desorption isotherms showed a type II curve. The Halsey model had the best fit to experimental data and equilibrium moisture contents were determined to be 0.0672, 0.0490, 0.0379, 0.0324 and 0.0279 g water/g d.m. at 50, 60, 70, 80, and 90 °C, respectively. Drying kinetics had a decreasing exponential behavior and was described most accurately by the Midilli & Kucuk model. Also, the diffusion coefficient values increased with the process temperature. Lower energy consumption was noted at 90 °C and the rehydration process was described by the Weibull model. High water holding capacity and maintenance of microstructure was observed in samples dehydrated at 90 °C. These results could be used to optimize dehydration conditions for red cabbage.