Pink discolouration in canned banana (Musa paradisiaca) and field bean (Dolichos lablab var. Lignosus prain). II. Chemical changes in leucoanthocyanidins during processing.

Ranganna, S. and Parpia, H. A. B. (1974) Pink discolouration in canned banana (Musa paradisiaca) and field bean (Dolichos lablab var. Lignosus prain). II. Chemical changes in leucoanthocyanidins during processing. Lebensmittel Wissenschaft und Technologie, 7. pp. 111-119. ISSN 0023-6438

PDF Food Science + Technology, Volume-7( (1974) 111-119.pdf - Published Version Restricted to Registered users only Download (447kB)

Abstract

The chromogen formed on processing in frnits and vegetables containing leucoanthocyanidins, which had been hitheno found inextradable, could be isolated in the present study. Solublility, chromatographic and absorption characteristics of the chromogen failed to support the anthocyanidin nature although reflectance spectra ofthe processed pulp so indicated. Posi~ tive test with reagents and formation of anthocyanidins on heating with mineral acids showed the chromogen to be still leucoanthocyanidin in nature. Processing caused polymerization of the leucoanthQCJIanidins, the extent of which increased with the duration of heating and the concentration of acid(s). Irrespedive of the degree 0/ polymerization, tin predpi~ toted the leucoanthocyanidins in the cold which turned bright purple on processing. Based on chemical and spectral studies, conversion of colourless leucoantkocyanidins into the CQloured form on heat processing is considered to be due -to the formation of phlobaphene like polymer having conjugated qUinonoid rings and xanthylium nuclei in them. A tentarilie structure is proposed/or the chromogenic/orm ofthe leucoanthocyanidin in the processed product.

Item Type:	Article
Uncontrolled Keywords:	pink discolouration, leucoanthocyanidins, canned banana, field bean
Subjects:	600 Technology > 08 Food technology > 14 Physical properties > 01 Colours 600 Technology > 08 Food technology > 24 Fruits > 02 Banana 600 Technology > 08 Food technology > 06 Preservation and Storage > 01 Canning
Divisions:	Fruit and Vegetable Technology
Depositing User:	Food Sci. & Technol. Information Services
Date Deposited:	20 Sep 2013 08:56
Last Modified:	20 Sep 2013 08:56
URI:	http://ir.cftri.res.in/id/eprint/4860

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