TITLE:
Chemical Composition of the Marc of a Wild Tropical Plant Tacca involucrata (Schumach and Thonn, 1827)
AUTHORS:
Joel Aondohulugh Bosha, Aruh Ottoh Anaga, Isaac Uzoma Asuzu
KEYWORDS:
Elements, Phytochemicals, Proximate, Tacca involucrata, Vitamins
JOURNAL NAME:
Food and Nutrition Sciences,
Vol.6 No.1,
January
13,
2015
ABSTRACT: Tacca involucrata (Batflower or Polynesian arrowroot) tubers are a
stable food in tropics where it occurs. In central Nigeria, it is processed
locally after digging it from the ground by peeling with sharp sand, grating
and soaking in fresh water after which it is filtered and the filtrate is dried
and is cooked with other ingredients. The marc, said to be bitter, is usually
discarded by deep burial as it is considered poisonous to livestock and humans.
All parts of the plant are used in folk medicine to treat various diseases. The
aim of this work was to analyze quantitatively the phytochemical, elemental,
vitamin and proximate composition of the marc of the tubers with a view of
assessing its pharmacological and nutritional potentials. The marc was obtained
from Jandeikyura Village in Wukari LGA of Taraba State, Nigeria, and was
extracted with 80% methanol for 72 hr to give a yield of 10.1% w/w and was
whitish in colour. Phytochemical analysis showed the presence of reducing
sugars, tannins, flavonoids, steroids, glycosides and hydrogen cyanide at
195.65 ± 0.5, 3.44 ± 0.2, 1.29 ± 0.5, 0.83 ± 0.4, 1.36 ± 1.0 and 0.00985 ± 0.3
(mg/100g), respectively. The elemental analysis showed the presence of
potassium, sodium, magnesium, selenium, manganese, vanadium and some heavy
metals like lead, aluminium, arsenic and mercury at 36.45 ± 0.1, 44.04 ± 0.1,
1.52 ± 0.2, 0.80 ± 0.9, 0.52 ± 0.7, 0.27 ± 0.7, 0.07 ± 0.6, 0.008 ± 0.05, 0.085
± 0.6 and 0.026 ± 0.6 (mg/100g), respectively. Vitamin analysis showed the
presence of vitamins A, B1, B2, B3, C and E in various amount as 2.26 ± 0.8 μg,
0.83 ± 0.8 mg/100g, 0.58 ± 0.4 mg/100g, 0.33 ± 0.6 mg/100g, 9.80 ± 0.4 mg/100g
and 6.86 ± 0.9 mg/100g, respectively. The proximate analysis showed the marc to
contain moisture, ash, fats, fibre, crude protein and carbohydrate in the range
of 10.83% ± 0.3%, 1.93% ± 0.6%, 1.06% ± 0.5%, 4.42% ± 0.4%, 6.12% ± 0.6% and
86.07% ± 0.3%, respectively. This shows that
despite the presence of hydrogen cyanide and some heavy metals in traces amount which are considered poisonous to livestock and humans, the marc contains some
elements, vitamins, phytochemical and nutrients which are pharmacologically and
nutritionally important.