Abstract:
Recently, several techniques have been developed to extract anthocyanin
pigments from Dandila (Dioscorea alata) yams, due to their proven health
benefits and applicability as a natural colorant for several food items. However,
these studies have not focused on the utilization of the residual starchy portion of
yams created after the pigment extraction. This leads to the wastage of yam
residues. As a matter of un-attended, only a limited number of studies are
available on this residual yam portion and their nutritional quality is still
unknown. Therefore, this study aimed to convert the residual Dandila yam from
microwave-assisted extraction of anthocyanin into flour and to analyse the
nutritional and physical properties of the flour to minimize the wastage of yams
during the pigment extraction. The residual Dandila yam portion remaining after
the microwave-assisted anthocyanin extraction process was converted to flour by
drying in a hot air oven below 40 0C. The standard procedures were used to
determine the proximate composition and the physical properties of the flour. The
mineral composition was analyzed with Atomic Absorption Spectrophotometry.
Starch was the major nutrient component found in this flour, accounting for
70.89±0.71 % of the weight and the most abundant mineral was Potassium
(12.98±0.00 mg/g) followed by phosphorus, magnesium, sodium, calcium, and
zinc. The physical properties were as desired for flour. Therefore, the Dandila
yam residue, remaining after the extraction of anthocyanin, can be successfully
converted into flour which contains essential nutrients. Further, 100 g of flour is
sufficient to meet the Recommended Daily Intake of sodium and zinc. The
observed physical properties ensure the utilization of this flour in a variety of
food formulations including, infant food formulations, soups, gravies, sausage,
dough, processed cheese, bakery products and whipped toppings. However, the
applicability of the flour in these formulations is required to be studied.