Effect of microwave-assisted processing on polyphenol oxidase and peroxidase inactivation kinetics of açai-berry (Euterpe oleracea) pulp
•Dielectric properties evaluated at 915 and 2,450 MHz up to 120 °C.•Penetration depth decreases with temperature at 915 MHz but constant at 2450 MHz.•PPO and POD inactivation described with first order two-component model.•POD was more thermally resistant than PPO.•The inactivation rate depended on...
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Published in | Food chemistry Vol. 341; no. Pt 2; p. 128287 |
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Main Authors | , , , , , |
Format | Journal Article |
Language | English |
Published |
England
Elsevier Ltd
30.03.2021
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Subjects | |
Online Access | Get full text |
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Summary: | •Dielectric properties evaluated at 915 and 2,450 MHz up to 120 °C.•Penetration depth decreases with temperature at 915 MHz but constant at 2450 MHz.•PPO and POD inactivation described with first order two-component model.•POD was more thermally resistant than PPO.•The inactivation rate depended on the heating technology.
Microwave heating has been considered a promising technology for continuous flow thermal processing of fluid foods due to better retention of quality. Considering the importance of açai-berry pulp and its perishability, the inactivation kinetics of peroxidase (POD) and polyphenol oxidase (PPO) were investigated under conventional and microwave heating. First-order two-component model was well fitted to the data, indicating the presence of at least two fractions with different resistances. POD was more thermally resistant (90% inactivation for 40 s at 89 °C) and could be considered as a processing target. Inactivation curves dependency on heating technology suggests specific effects of microwaves on the protein structure. Additionally, the dielectric properties of açai-berry pulp were evaluated at 915 and 2,450 MHz for temperatures up to 120 °C. Power penetration depth dropped with temperature at 915 MHz (from 29 to 11 mm), but was less affected at 2,450 MHz (between 8 and 11 mm). |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0308-8146 1873-7072 |
DOI: | 10.1016/j.foodchem.2020.128287 |