title: Changes on indigenous microbiota, colour, bioactive compounds and antioxidant activity of pasteurised pomegranate juice.
abstract: Juices prepared from arils of 'Mollar' pomegranates were analysed for naturally occurring microorganisms, CIE Lab colour parameters, total phenols, anthocyanins and punicalagins, ellagic acid content and antioxidant capacity before and after low-, mild- and high-temperature pasteurisations (LTPs, MTPs and HTPs): 65, 80 and 90 °C for 30 or 60s. Mean aerobic plate count (APC), yeast and mold count (YMC), and lactic acid bacteria (LAB) for fresh juices were 5.7, 5.36 and 4.0 log CFU/mL, respectively. MTPs and HTPs were sufficiently effective to decrease APCs to nil or negligible levels. An increase in CIE a values and decrease in CIE b values were the characteristic colour changes in heat-treated juices. The effect of pasteurisations showed that total phenols, punicalagins and ellagic acid were not much affected by thermal processing. Total anthocyanin content and antioxidant capacity were substantially and significantly influenced by the heat treatment applied. A linear relationship was observed between Trolox equivalent antioxidant capacity (TEAC) values and total anthocyanins, suggesting that they contributed strongly to the antioxidant capacity of pomegranate juice.
authors.affiliation: Departamento de Ciencia y Tecnología de Alimentos, CEBAS-CSIC, P.O. Box 164, E-30100, Espinardo, Murcia, Spain.
authors.forename: Pedro
authors.initials: P
authors.lastname: Mena
authors.forename: Salud
authors.initials: S
authors.lastname: Vegara
authors.forename: Nuria
authors.initials: N
authors.lastname: Martí
authors.forename: Cristina
authors.initials: C
authors.lastname: García-Viguera
authors.forename: Domingo
authors.initials: D
authors.lastname: Saura
authors.forename: Manuel
authors.initials: M
authors.lastname: Valero
mesh_terms: D000872:Anthocyanins / Q000032:analysis; D000975:Antioxidants / Q000032:analysis*; D001628:Beverages / Q000032:analysis* / Q000382:microbiology*; D003116:Color; D004610:Ellagic Acid / Q000032:analysis; D005638:Fruit / Q000737:chemistry* / Q000382:microbiology; D006358:Hot Temperature; D047348:Hydrolyzable Tannins / Q000032:analysis; D029561:Lythraceae / Q000737:chemistry* / Q000382:microbiology; D064307:Microbiota; D061352:Pasteurization / Q000379:methods*; D010636:Phenols / Q000032:analysis
chemical_list: D000872:Anthocyanins; D000975:Antioxidants; D047348:Hydrolyzable Tannins; D010636:Phenols; D004610:Ellagic Acid; C115642:punicalagin
keywords: Anthocyanins; Antioxidant capacity; Colour parameters; Microorganisms; Pomegranate juice; Thermal pasteurisation