| Full text | |
| Author(s): |
Total Authors: 3
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| Affiliation: | [1] Univ Sao Paulo, Dept Chem Engn, Escola Politecn, Sao Paulo, SP - Brazil
[2] Univ Sao Paulo, Food Res Ctr FoRC, Sao Paulo, SP - Brazil
[3] Sastry, Sudhir K., Ohio State Univ OSU, Dept Food Agr \& Biol Engn FABE, Columbus, OH USA.Funcia, Eduardo S., Univ Sao Paulo, Dept Chem Engn, Escola Politecn, Sao Paulo, SP - Brazil
[4] Ohio State Univ OSU, Dept Food Agr & Biol Engn FABE, Columbus, OH - USA
Total Affiliations: 4
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| Document type: | Journal article |
| Source: | Food and Bioprocess Technology; v. 13, n. 7 JUN 2020. |
| Web of Science Citations: | 2 |
| Abstract | |
This study evaluated effect of alternating electric field on pectinesterase activity in 5-mL Navel orange juice samples subject to ohmic pasteurization. An empirical Weibull kinetic model for enzyme inactivation was fitted to data from conventional and ohmic heating runs. Discretization of time-dependent inactivation rates allowed accounting for a nonisothermal process, with similar equivalent times between paired runs indicating comparable time-temperature profiles across heating methods. Conditions were 60 Hz, 32-36 V/cm, holding temperatures 60-90 degrees C, holding times 0-200 s in a custom cell with stirring, and two Ti-Pt electrodes. Residual pectinesterase activity was assayed with a traditional titration method at pH 7.5 and 30 degrees C. The stochastic Monte Carlo resampling method of smoothed bootstrap estimated the parameter populations to propagate experimental uncertainty on enzyme activity. Joint parameter populations and confidence regions agree with least squares estimates, and indicate that kinetic parameters depend on heating technology. This difference is evidence of electric field effects on pectinesterase activity, which is more evident at lower heat process intensities; however, the thermal denaturation seems to overcome other effects at higher processing times and temperatures. The finding that there are conditions where electric fields significantly affect enzyme inactivation highlights the importance of thoroughly assessing effects of alternative processing technologies on targets and indicators in food processing. (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: | 17/24163-7 - Inactivation kinetics of enzymes in green coconut water and orange juice by ohmic and conventional heating |
| Grantee: | Eduardo dos Santos Funcia |
| Support Opportunities: | Scholarships abroad - Research Internship - Doctorate (Direct) |
| FAPESP's process: | 16/24265-1 - Study and modelling of enzyme inactivation in the processing of green coconut water and orange juice by ohmic and dielectric heating |
| Grantee: | Eduardo dos Santos Funcia |
| Support Opportunities: | Scholarships in Brazil - Doctorate (Direct) |
| 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: | 14/25179-6 - Study of enzyme inactivation in the processing of green coconut water by focused microwave technology |
| Grantee: | Eduardo dos Santos Funcia |
| Support Opportunities: | Scholarships in Brazil - Master |