Microwave flow and conventional heating effects on the physicochemical 1 properties, bioactive compounds and enzymatic activity of tomato puree

BACKGROUND Thermal processing causes a number of undesirable changes in physicochemical and bioactive properties of tomato products. Microwave (MW) technology is an emergent thermal industrial process that offers a rapid and uniform heating, high energy efficiency and high overall quality of the fin...

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Bibliographic Details
Authors: Arjmandi, Mitra, Otón Alcaraz, Mariano, Artés Calero, Francisco, Artés Hernández, Francisco de Asís, Gómez di Marco, Perla Azucena, Aguayo Giménez, Encarna
Format: article
Status:Versión aceptada para publicación
Publication Date:2016
Country:España
Institution:Universidad Politécnica de Cartagena(UPCT)
Repository:Repositorio Digital UPCT
OAI Identifier:oai:repositorio.upct.es:10317/5813
Online Access:http://hdl.handle.net/10317/5813
Access Level:Embargoed access
Keyword:Carotenoids
Viscosity
Vitamin C
Thermal treatment
Smoothie
Producción Vegetal
3309.13 Conservación de Alimentos
Description
Summary:BACKGROUND Thermal processing causes a number of undesirable changes in physicochemical and bioactive properties of tomato products. Microwave (MW) technology is an emergent thermal industrial process that offers a rapid and uniform heating, high energy efficiency and high overall quality of the final product. The main quality changes of tomato puree after pasteurization at 96 ± 2 °C for 35 s, provided by a semi-industrial continuous microwave oven (MWP) under different doses (low power/long time to high power/short time) or by conventional method (CP) were studied. RESULTS All heat treatments reduced colour quality, total antioxidant capacity and vitamin C, with a greater reduction in CP than in MWP. On the other hand, use of an MWP, in particular high power/short time (1900 W/180 s, 2700 W/160 s and 3150 W/150 s) enhanced the viscosity and lycopene extraction and decreased the enzyme residual activity better than with CP samples. For tomato puree, polygalacturonase was the more thermo-resistant enzyme, and could be used as an indicator of pasteurization efficiency. CONCLUSION MWP was an excellent pasteurization technique that provided tomato puree with improved nutritional quality, reducing process times compared to the standard pasteurization process. © 2016 Society of Chemical Industry