EFFECT OF HARVESTING PERIODS AND PROCESSING METHODS ON CAROTENOID PROFILE OF YELLOW TRIFOLIATE YAM FLOUR
No Thumbnail Available
Date
2015-11
Journal Title
Journal ISSN
Volume Title
Publisher
JARD
Abstract
Trifoliate yam (Dioscorea dumetorum) unlike other yam tubers are not harvested
immediately after maturity but are left in the ground until needed as food due to hardening
process which occurs few hours after harvesting. Yellow trifoliate yam pigment contains
high carotenoids which are of benefit in human diet. Storage of trifoliate yam in the ground
after maturity and processing of the tuber could have effect on the carotenoid contents of
the tuber. Therefore, carotenoid profiles of yellow trifoliate yam flour as affected by
periods of harvesting within four months of consecutives farming season and different
processing methods was assessed. Freshly harvested yellow trifoliate yam was made into
four treatments flour using four processing methods as follow: Raw Flour (oven dried at
60oC), Soaked Flour (water deep at 29±2oC) and dried (oven dried at 60oC), Blanched
Flour (water deep at 60oC) and dried (oven dried at 60oC), Parboiled Flour (water deep at
100±2oC) and dried (oven dried at 60oC). The treated flour samples were subjected to
carotenoid profile using gas chromatography (model no HP6890 powered with HP
ChemStation Rev. A 09.01 [1206] software). The major carotenoids detected in yellow
trifoliate cultivar were carotene (31.61-81.03 μg/100 g) and β-cryptoxanthin (29.03-35.72
μg/100 g). Other carotenoids detected were viola-xanthin, lycopene, astaxanthin and
antheraxanthin. Total carotenoids content (129.69 μg/100 g) of parboiled flour sample
harvested at 7 months was higher than other samples. Harvesting of trifoliate yam tubers
at 11 months provided yam with high concentration of carotenoids coupled with parboiling
processing methods.
Description
Utilisation of trifoliate yam
Keywords
Carotenoids, Harvesting periods, Processing methods, Yellow trifoliate yam