Enhancing brown seaweed Sargassum muticum drying using pulsed electric fields and dehydration pretreatments

• Published in: Drying technology Vol. 42; no. 11; pp. 1766 - 1777
• Main Authors: Le Loeuff, Jeanne, Boy, Virginie, Morançais, Pascal, Bourgougnon, Nathalie, Lanoisellé, Jean-Louis
• Format: Journal Article
• Language: English
• Published: Philadelphia Taylor & Francis 12-08-2024; Taylor & Francis Ltd
• Subjects: Air jets; Algae; Convection; Dehydration; Disintegration; Drying ovens; Electric fields; Free convection; Freeze drying; Life Sciences; Moisture; moisture diffusion coefficient; Pressing; Pretreatment; pretreatments; Sargassum muticum; Seaweeds
• ISSN: 0737-3937; 1532-2300
• DOI: 10.1080/07373937.2024.2388307

The present study on the brown seaweeds Sargassum muticum focused on the application of dehydration by pressing or pulsed electric fields (PEF) pretreatment before three drying processes, namely freeze-drying, air impingement drying, and natural convection in an oven. Both pretreatments permitted to reduce significantly the initial moisture of the seaweeds with a reduction up to 50 %. The structural modifications induced by these pretreatments had a direct impact on the mechanisms of moisture retention and distribution within the seaweeds, which consequently exerted an influence on drying kinetics. The apparent moisture diffusivity for freeze-drying was significantly improved by PEF passing from 2.98 10
−9
m
2
s
−1
to 3.62 10
−9
m
2
s
−1
after a total disintegration. Concerning oven drying by natural convection, a dehydration by pressing will be preferred because the drying time to reach 0.45 kg kg
−1
in dry basis was reduced by 61 min with this pretreatment.