Physico-Chemical Characteristics of Turmeric Genotypes Cultivated in Nigeria as Potential Sources of Commercial Colourants

摘要

Powdered dried rhizomes of the major turmeric genotypes (Cl-1, Cl-2) cultivated in Nigeria were physico-chemically analysed (with the aid of laboratory methods and local consumers) for their potential as sources of commercial colourants. Results showed that the colour of the dilute (0.5%) liquid extracts of the dried (at 50, 60 and 70°C) turmeric samples was generally yellow, yellow-orange, lemon-yellow and orange with cold water, hot water, acetone and ethanol, respectively. The organoleptic analysis with local food consumers showed that the experimental turmeric powder samples were generally liked. At the ratio of 1:2000 (turmeric powder: rice w/w), the yellowish cooked rice, coloured by the pigments in some turmeric powder samples was liked much by these local consumers. Furthermore, the commercial oleoresin content of the dehydrated curcuminoid rich turmeric rhizome samples was found to be 14.80 and 14.00% for NCl-1 and NCl-2 genotypes, respectively.