Effect of microwave-assisted processing on polyphenol oxidase and peroxidase inactivation kinetics of acai-berry (Euterpe oleracea) pulp

Author(s)

de Barcelos Costa, Henrique Coutinho ; Siguemoto, Erica Sayuri ; Bulhoes Bezerra Cavalcante, Tiago Augusto ; Silva, Danylo de Oliveira ; Martins Vieira, Luiz Gustavo ; Wilhelms Gut, Jorge Andrey

• Document type: Journal article
• Source: Food Chemistry; v. 341, p. 9-pg., 2021-03-30.

Abstract

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 acai-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 degrees 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 acai-berry pulp were evaluated at 915 and 2,450 MHz for temperatures up to 120 degrees 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). (AU)

• FAPESP's process: 14/06026-4 - Study of continuous-flow microwave thermal processing of cloudy apple juice
• Grantee: Érica Sayuri Siguemoto
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 13/07914-8 - FoRC - Food Research Center
• Grantee: Bernadette Dora Gombossy de Melo Franco
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC
• FAPESP's process: 12/04073-0 - Experimental determination of the dielectric properties of liquid and pasty foods considering the continuous heat treatment using microwave technology
• Grantee: Carmen Cecilia Tadini
• Support Opportunities: Regular Research Grants
• FAPESP's process: 14/17534-0 - Evaluation of the effects of focused microwave processing on liquid foods
• Grantee: Jorge Andrey Wilhelms Gut
• Support Opportunities: Regular Research Grants
• FAPESP's process: 14/25041-4 - Investigation of thermal and non-thermal effects of focused microwaves on the activity of enzymes of interest in the processing of fruit-based products
• Grantee: Tiago Augusto Bulhões Bezerra Cavalcante
• Support Opportunities: Scholarships in Brazil - Master