title: Mechanical and thermal pretreatments of crushed tomatoes: effects on consistency and in vitro accessibility of lycopene.
abstract: The effects of mechanical and thermal treatments on the consistency and in vitro lycopene accessibility of crushed tomatoes were evaluated. Different crushing intensities and a subsequent heat treatment carried out as a heat shock (95 degrees C for 8 min) or a boiling step (100 degrees C for 20 min) were examined. Additional homogenization was compared with milder crushing regarding the effect on lycopene content and in vitro accessibility. Textural properties, polygalacturonase and pectinmethylesterase activity, pectin degree of methoxylation, lycopene content, and in vitro lycopene accessibility were evaluated. Microstructure was studied using both light and transmission electron microscopy. Crushing and subsequent heating affected the pectin degree of methoxylation and the consistency of the crushed tomatoes. The mechanical and thermal treatments did not affect the lycopene content to any great extent; however, in vitro accessibility seemed to improve with extensive crushing followed by heating. Crushing or homogenization in itself was not enough to increase in vitro lycopene accessibility.
authors.affiliation: SIK-The Swedish Inst for Food and Biotechnology, Structure and Material Design, Box 5401, 402 29 Göteborg, Sweden.
authors.forename: Evelina A
authors.initials: EA
authors.lastname: Tibäck
authors.forename: Cecilia A
authors.initials: CA
authors.lastname: Svelander
authors.forename: Ines J P
authors.initials: IJ
authors.lastname: Colle
authors.forename: Annika I
authors.initials: AI
authors.lastname: Altskär
authors.forename: Marie A G
authors.initials: MA
authors.lastname: Alminger
authors.forename: Marc E G
authors.initials: ME
authors.lastname: Hendrickx
authors.forename: Lília M
authors.initials: LM
authors.lastname: Ahrné
authors.forename: Maud I B C
authors.initials: MI
authors.lastname: Langton
mesh_terms: D002265:Carboxylic Ester Hydrolases / Q000378:metabolism; D002338:Carotenoids / Q000302:isolation & purification / Q000378:metabolism*; D055598:Chemical Phenomena; D004063:Digestion; D005511:Food Handling / Q000379:methods*; D005638:Fruit / Q000737:chemistry / Q000201:enzymology / Q000648:ultrastructure; D006358:Hot Temperature; D000077276:Lycopene; D018551:Solanum lycopersicum / Q000737:chemistry* / Q000201:enzymology / Q000648:ultrastructure; D055595:Mechanical Phenomena; D008745:Methylation; D010368:Pectins / Q000737:chemistry / Q000302:isolation & purification; D011096:Polygalacturonase / Q000378:metabolism; D011786:Quality Control; D013237:Stereoisomerism; D013997:Time Factors
chemical_list: D002338:Carotenoids; D010368:Pectins; D002265:Carboxylic Ester Hydrolases; C022323:pectinesterase; D011096:Polygalacturonase; D000077276:Lycopene