Changes in antioxidant capacity and colour associated with the formation of beta-carotene epoxides and oxidative cleavage derivatives

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)In this study HPLC-DAD-MS/MS was applied for the identification of compounds derived from (all-E)-beta-carotene following epoxidation and oxidative cleavage. The consequences on the CIELAB colour parameters and antioxidant capacity (AC) were also evaluated. Five apocarotenoids, three secocarotenoids, seven Z isomers and two epoxides were detected as a result of the oxidative cleavage. Four epoxides and three Z isomers were detected as a consequence of the epoxidation reaction. Some compounds were detected for the first time as a result of oxidation reactions. Both treatments led to a marked decrease in b* and C-ab* values, indicating that these colour parameters can be used for the rapid assessment of beta-carotene oxidation. The oxidative cleavage of beta-carotene resulted in increased capacity to both scavenge ABTS(+) and quench singlet oxygen. These results suggest that the study of the AC of these oxidative derivatives and their possible usefulness as food ingredients deserves further attention. (C) 2013 Elsevier Ltd. All rights reserved.147160169Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)European Union [FP7-224789]Spanish program Ramon y. Cajal [RYC-2010-07115]Spanish program Ramon Juan de la Cierva [JCI-2008-1767]CYTED [112RT0445]Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)European Union [FP7-224789]Spanish program Ramon y. Cajal [RYC-2010-07115]Spanish program Ramon Juan de la Cierva [JCI-2008-1767]CYTED [112RT0445

Schwankungen im Gesamtgehalt an phenolischen-Verbindungen, Anthocyanen und Monoterpenen bei der Tafeltraubensorte (V. vinifera L.) ‘Muscat Hamburg’ als Ergebnis der Ausdünnung des Traubenbehanges und des frühen und späten Entfernens der basalen Blätter

Cluster thinning (CT) and basal leaf removal (BLR) are common canopy management practices used in grape growing. In recent years, novel viticultural techniques have been evolved all around the world to decrease costs of yield management, causing improvement in grape quality. The purpose of this study was to evaluate the effects of CT and early and late period BLR treatments on yield and quality components of cv. 'Muscat Hamburg'. While BLR treatments were performing at pre-bloom (PB, early), berry set (BS), berries with pea size (PS), verasion (V), CT treatment was conducted at verasion period. Compared to Control, while the total phenolic compounds content, total anthocyanin content, free volatile terpenes content and potentially volatile terpenes content were made better by CT treatment and BLR treatments applied from berry set to verasion period gradually raised all these quality components. As a result, BLR-PB treatment from BLR treatments, which was alternative to usual cluster thinning treatment in yield controlling grapevines was especially determined as powerful tool for improving quality characteristics of cv. 'Muscat Hamburg'