Research Journal of Food Science and Nutrition
Volume 6(3), pages 22-29, October 2021
Article Number: CABE43681
ISSN: 2536-7080
https://doi.org/10.31248/RJFSN2021.122
https://integrityresjournals.org/journal/RJFSN
Full Length Research
Effects of orange-fleshed sweet potato supplementation
on the phytochemical composition, physicochemical,
and sensory properties of sorghum-based kunu-zaki
A. G. Ibrahim, J. A. Ayo* and H. M. Joseph
Department of Food Science and Technology, Federal University Wukari, Nigeria.
*Corresponding author. Email: jeromeayo@gmail.com; Tel: +234 802 420 3245.
Copyright © 2021 Ibrahim et al. This article remains permanently open access under the terms of the Creative Commons Attribution License 4.0,
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited
Received 20th September, 2021; Accepted 8th October, 2021
ABSTRACT: The phytochemical, physicochemical, and sensory properties of the blended kunun-zaki were determined.
The fermented sorghum paste was substituted for orange-fleshed sweet potato puree at 0, 5, 10, 15, 20, 25 and 50% to
produce orange-fleshed sweet potato-sorghum blended kunun-zaki. The phytochemical composition: carotenoids,
flavonoids, and vitamin A content of the blended kunun-zaki increased from 0 to 28.14 mg/100g, 0 to 191.50 mg/100g and
0.44 to 7.74 mg/100g respectively, while the tannin content decreased from 4.97 to 1.51 mg/100g, with an increase in
added orange-fleshed sweet potato puree. The effects were significant (p = 0.05). The physicochemical properties: pH,
total soluble solids, total solid and specific gravity increased from 3.97 to 4.10, 4.95 to 8.25°Brix, 1.55 to 2.80 g/100g and
5.65 to 13.70 g/100g respectively, while the acidity decreased from 39.21 to 12.00 g/100g, with increase in the added
orange-fleshed sweet potato puree (0-50%). The average mean scores for sensory quality; flavour, colour and taste
increased from 6.70 to 7.06, 6.70 to 7.41 and 6.43 to7.40 respectively, whereas odour, mouth feel and appearance
decreased with increasing inclusion level of oranged-fleshed sweet potato puree from 7.90 to 6.93, 7.40 to 6.40 and 7.26
to 6.72 respectively. Overall results show that the beverage formulated were generally acceptable of which the sample
containing 20% orange-fleshed sweet puree was most preferred. The addition of oranged-fleshed sweet potato puree
improved the phytochemical content and the sensory quality [taste, flavour and colour] of the sorghum-based kunun-zaki.
Keywords: Kunun-zaki, orange-fleshed sweet potato, sensory properties, sorghum.
INTRODUCTION
Cereal beverage products are one of the main thirst
quenchers of an average individual in North-Eastern
Nigeria and Africa as a whole (Agarry et al., 2000). Several
methods in cereals preparation give rise to different
beverage food products (Gaffa and Ayo, 2002). These
techniques could be as a result of culture, tradition, and
individual taste, with or without combining other
ingredients to make up the beverage food product
(Aderinola and Oluwamukomi, 2021). Locally made
beverages of cereal origin include Machacha, Burukutu,
Pito, Busa, Kafir, and Kunu among others.
Kunu is a Hausa name for unfermented beverages.
Kunun-zaki is a local fermented beverage made from
ungerminated cereal grains (Oluwajoba et al., 2013). It is
among the widely consumed cereal-based non-alcoholic,
non-carbonated beverages in Northern Nigeria (Aderinola
and Oluwamukomi, 2021). Kunu occurs differently and
their names are obtained based on the type of raw material
used in its production, sensory attribute, locality, or any
other ingredient that is introduced (Aderinola and
Oluwamukomi, 2021). Some of these local beverages may
include kunun-gyada having groundnut seed paste,
kunun-tsamiya having tamarind fruit pulp, kunun burukuru
having fermented cow milk, and kunun-zaki having sugar