Inactivation kinetics of pectin methyl esterase in the microwave-assisted pasteurization of orange juice

Author(s)

Brugos, Ana F. O. ^[1] ; Gut, Jorge A. W. ^{[1, 2]} ; Tadini, Carmen C. ^{[1, 2]}

Affiliation

^[1] Univ Sao Paulo, Escola Politecn, Dept Chem Engn, Main Campus, BR-05508010 Sao Paulo, SP - Brazil

^[2] Univ Sao Paulo, FoRC NAPAN Food Res Ctr, Sao Paulo, SP - Brazil

• Document type: Journal article
• Source: LWT-FOOD SCIENCE AND TECHNOLOGY; v. 97, p. 603-609, NOV 2018.
• Web of Science Citations: 0

Abstract

The enzyme pectin methyl esterase (PME) kinetic inactivation study in orange juice was performed by conventional heat treatment (thermal bath) and focused microwave heating (synthesis microwave reactor). Experiments have been performed in batch, with temperatures ranging between 50 degrees C and 95 degrees C for time between 0 and 60 s for both processes. Non-isothermal processes were considered and histories of time-temperature have been acquired. The kinetic model adjusted considered two fractions of PME (thermosensitive and thermoresistant), and the kinetic parameters to microwave processes at T-ref = 90 degrees C were z(1) = 13.7 degrees C, z(2) = 20.3 degrees C, D-1 = 0.231 s and D-2 = 130.8 s with alpha = 0.95. Comparative analysis of processes was performed graphically by residual enzymatic activity versus lethality. The results demonstrated the microwave-assisted thermal process was more effective than conventional one under the same conditions, indicating the possibility for some additive non-thermal effects. Innovative conditions of inactivation were achieved: i.e. 90% at 60 degrees C after 10 s and 99% at 80 degrees C after 20 s. (AU)

• 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: 14/17534-0 - Evaluation of the effects of focused microwave processing on liquid foods
• Grantee: Jorge Andrey Wilhelms Gut
• Support Opportunities: Regular Research Grants