title: Characterisation of onion (Allium cepa L.) by-products as food ingredients with antioxidant and antibrowning properties.
abstract: Processing and stabilising onion wastes (residues and surpluses of onion) could solve the environmental problem derived from a great onion wastes disposal. Moreover, obtaining stabilised onion by-products as natural antioxidant food ingredients could be advantageous to food industry, not only to improve the use of onion wastes but also to obtain new natural and functional ingredients. The aim of this study was to characterise onion by-products - juice, paste and bagasse - from two Spanish onion cultivars - 'Figueres' and 'Recas' - that have been stabilised by thermal treatments - freezing, pasteurisation and sterilisation - in order to evaluate the effect of the processing and stabilisation treatment on the bioactive composition, antioxidant activity and polyphenol oxidase (PPO) enzyme inhibition capacity. The results obtained triggered to choose one onion by-product offering better characteristics for its potential development as a food ingredient: source of antioxidant and antibrowning bioactive compounds. In this study it was shown that processing of 'Recas' onion wastes to obtain a paste (mixture content) and applying a mild pasteurisation were the best alternatives to obtain an interesting stabilised onion by-product with good antioxidant properties that made useful its use as functional food ingredient.
authors.affiliation: Department of Plant Foods Science and Technology, Instituto del Frío, Consejo Superior de Investigaciones Científicas (CSIC), C/ José Antonio Novais 10, Ciudad Universitaria, E-28040 Madrid, Spain.
authors.forename: Eduvigis
authors.initials: E
authors.lastname: Roldán
authors.affiliation: Department of Plant Foods Science and Technology, Instituto del Frío, Consejo Superior de Investigaciones Científicas (CSIC), C/ José Antonio Novais 10, Ciudad Universitaria, E-28040 Madrid, Spain. Electronic address: csanchezm@if.csic.es.
authors.forename: Concepción
authors.initials: C
authors.lastname: Sánchez-Moreno
authors.affiliation: Department of Plant Foods Science and Technology, Instituto del Frío, Consejo Superior de Investigaciones Científicas (CSIC), C/ José Antonio Novais 10, Ciudad Universitaria, E-28040 Madrid, Spain.
authors.forename: Begoña
authors.initials: B
authors.lastname: de Ancos
authors.affiliation: Department of Plant Foods Science and Technology, Instituto del Frío, Consejo Superior de Investigaciones Científicas (CSIC), C/ José Antonio Novais 10, Ciudad Universitaria, E-28040 Madrid, Spain.
authors.forename: M Pilar
authors.initials: MP
authors.lastname: Cano
keywords: Antioxidant; Bioactive compounds; Enzymatic browning; Freezing; Functional food ingredient; Onion by-products; Pasteurisation; Stabilisation treatments; Sterilisation