Blanching and long‐term freezing affect various bioactive compounds of vegetables in different ways
Source: Journal of the Science of Food and Agriculture, Volume 83, Number 14, November 2003 , pp. 1389-1402(14)
Publisher: John Wiley & Sons, Ltd.
Abstract:An extensive study on the effects of blanching/freezing and long‐term freezer storage on various bioactive compounds of more than 20 commonly used vegetables was performed. Effects were strongly plant species‐dependent. Contents of dietary fibre components either were not affected or increased slightly. Minerals in general were also stable, but some losses of soluble minerals by leaching were observed. Phenolic antioxidants and vitamins were clearly more sensitive. Significant losses (20–30%) of antioxidant activity and total phenolics were detected in many vegetables. A qualitative HPLC profiling method for phenolic antioxidants was developed which proved to be very useful when evaluating the complex behaviour of phenolics during food processing. Up to one‐third of vitamin C contents were lost during blanching, and further slight losses were detected during storage. Folic acid turned out to be very sensitive to blanching, with more than half of the vitamin being lost, but was stable during freezer storage. Carotenoids and sterols were not affected by blanching or freezer storage. The usefulness of the applied screening methods for evaluation of the effects of processing on vegetables is shown. Copyright © 2003 Society of Chemical Industry
Document Type: Research Article
Affiliations: 1: VTT Biotechnology, PO Box 1500 (Tietotie), FIN-02044 VTT, Finland 2: Department of Applied Chemistry and Microbiology, PO Box 27 (Latokartanonkaari 11), FIN-00014 University of Helsinki, Finland 3: MTT, Agrifood Research Finland, Chemistry Laboratory, FIN-31600 Jokioinen, Finland
Publication date: November 1, 2003