title: Industrial scale microwave processing of tomato juice using a novel continuous microwave system.
abstract: This study evaluated the effect of an industrial scale continuous flow microwave volumetric heating system in comparison to conventional commercial scale pasteurisation for the processing of tomato juice in terms of physicochemical properties, microbial characteristics and antioxidant capacity. The effect against oxidative stress in Caco-2 cells, after in vitro digestion was also investigated. Physicochemical and colour characteristics of juices were very similar between technologies and during storage. Both conventional and microwave pasteurisation inactivated microorganisms and kept them in low levels throughout storage. ABTS[Symbol: see text](+) values, but not ORAC, were higher for the microwave pasteurised juice at day 0 however no significant differences between juices were observed during storage. Juice processed with the microwave system showed an increased cytoprotective effect against H2O2 induced oxidation in Caco-2 cells. Organoleptic analysis revealed that the two tomato juices were very similar. The continuous microwave volumetric heating system appears to be a viable alternative to conventional pasteurisation.
authors.affiliation: Queen's University Belfast, Institute for Global Food Security, Belfast, Northern Ireland, UK.
authors.forename: Alexandros Ch
authors.initials: AC
authors.lastname: Stratakos
authors.affiliation: Queen's University Belfast, Institute for Global Food Security, Belfast, Northern Ireland, UK.
authors.forename: Gonzalo
authors.initials: G
authors.lastname: Delgado-Pando
authors.affiliation: Agri-Food & Biosciences Institute, Belfast, Northern Ireland, UK.
authors.forename: Mark
authors.initials: M
authors.lastname: Linton
authors.affiliation: Agri-Food & Biosciences Institute, Belfast, Northern Ireland, UK.
authors.forename: Margaret F
authors.initials: MF
authors.lastname: Patterson
authors.affiliation: Queen's University Belfast, Institute for Global Food Security, Belfast, Northern Ireland, UK. Electronic address: t.koidis@qub.ac.uk.
authors.forename: Anastasios
authors.initials: A
authors.lastname: Koidis
mesh_terms: D000975:Antioxidants / Q000032:analysis; D001628:Beverages / Q000032:analysis*; D006358:Hot Temperature; D018551:Solanum lycopersicum / Q000737:chemistry*; D008872:Microwaves
chemical_list: D000975:Antioxidants
keywords: Antioxidant; Caco-2 cells; Continuous; In vitro digestion; Microwave; Processing; Tomato juice