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http://hdl.handle.net/10773/36885
Title: | Blanching impact on pigments, glucosinolates, and phenolics of dehydrated broccoli by-products |
Author: | Ferreira, Sónia S. Monteiro, Filipa Passos, Cláudia P. Silva, Artur M. S. Wessel, Dulcenia Ferreira Coimbra, Manuel A. Cardoso, Susana M. |
Keywords: | Brassica by-products Valorisation Microwave hydrodiffusion and gravity Food ingredients Ultra-high efficiency liquid chromatography Glucoraphanin |
Issue Date: | Jun-2020 |
Publisher: | Elsevier |
Abstract: | Because of high water content, the valorisation of broccoli by-products requires dehydration that can preserve bioactive compounds. Blanching pre-treatment has been reported to improve the drying rate of broccoli. As a thermal treatment, it promotes also enzyme inactivation. Therefore, in this study, the impact of pre-dehydration blanching step, freeze-drying, air-drying at 40 °C, and microwave hydrodiffusion and gravity (MHG) dehydration on the levels of pigments, glucosinolates, and phenolics, was evaluated by UHPLC-DAD-ESI/MSn. When compared to freeze-drying, a technique known to preserve compounds, a pre-blanching step increased the extractability of both pigments and phenolics, while air-drying only retained 49% of the pigments and 70% of phenolics, both without affecting glucosinolates. However, when air-drying was preceded by blanching, less than 50% of compounds were retained. On the other hand, MHG dehydration increased the phenolics extractability by 26%, particularly that of kaempferol derivatives while also retaining the amount of the glucosinolate glucoraphanin, when compared to freeze-drying. Nevertheless, only 23% of indole glucosinolates were recovered and pigments were severely reduced, with lutein accounting only for 32% and only chlorophyll b was observed in trace amounts after MHG dehydration. Therefore, to valorise broccoli by-products as ingredients, different drying technologies may be used when targeting different composition richness: freeze-drying is suitable for pigments and glucosinolates, air-drying is suitable for glucosinolates, while MHG promotes the extractability of phenolic compounds. |
Peer review: | yes |
URI: | http://hdl.handle.net/10773/36885 |
DOI: | 10.1016/j.foodres.2020.109055 |
ISSN: | 0963-9969 |
Appears in Collections: | DQ - Artigos REQUIMTE - Artigos |
Files in This Item:
File | Description | Size | Format | |
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Blanching impact on pigments, glucosinolates, and phenolics of dehydrated.pdf | 1.52 MB | Adobe PDF | View/Open |
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