Thesis Abstract

Abstract
Instant kunun zaki is a popular Nigerian beverage made from millet and legume malts with potential health benefits. This study aimed to investigate the changes in physicochemical properties of instant kunun zaki flours produced from millet, cowpea, and soybean during storage. Millet, cowpea, and soybean were malted and processed into instant kunun zaki flours which were then stored under ambient conditions for up to 12 weeks. The pH, titratable acidity, total soluble solids, water absorption capacity, and pasting properties of the flours were analyzed at 0, 4, 8, and 12 weeks of storage. Results showed that the pH of the instant kunun zaki flours decreased significantly (p < 0.05) during storage, indicating possible fermentation processes. Titratable acidity increased significantly (p < 0.05) in all the flours, suggesting the accumulation of organic acids over time. Total soluble solids content also increased significantly (p < 0.05) during storage, indicating possible changes in the carbohydrate content of the flours. Water absorption capacity decreased significantly (p < 0.05) in all the flours, possibly due to changes in the structure of the flours during storage. Pasting properties of the instant kunun zaki flours showed variations during storage, with peak viscosity, trough, and final viscosity generally increasing while breakdown viscosity decreased over time. These changes in pasting properties could be attributed to enzymatic activities or structural modifications in the flours during storage. Overall, the physicochemical properties of the instant kunun zaki flours produced from millet, cowpea, and soybean were affected by storage conditions, with notable changes in pH, titratable acidity, total soluble solids, water absorption capacity, and pasting properties observed over the 12-week storage period. In conclusion, the study highlights the importance of monitoring the physicochemical properties of instant kunun zaki flours during storage to ensure product quality and safety. Further research is needed to elucidate the specific mechanisms underlying the observed changes and to develop strategies for optimizing the storage stability of instant kunun zaki flours for commercial production and consumption.

Thesis Overview

1. INTRODUCTION

       Kunun zaki is a traditional, non-alcoholic and non-carbonated beverage widely  consumed in Northern Nigeria and is becoming popular in the South .It is consumed at any time of the day by both adults and children, as breakfast drink. It an appetizer and it is commonly served at social gatherings. The ingredients used in its manufacture include, millet (Pennisetum typhoideum), sorghum (Sorghum vulgare), maize (Zea mays), rice (Oryza sativa), spices [ginger (Zingiber officinale), garlic (Allium sativum), red peeper (Capsicum annuum), black pepper (Piper nigrum), clove (Syzygium aromaticum)]. Also Cadaba farinosa, potatoes (Ipomea batatas)(Efiuvwevwere and Akoma, 1995). Tiger nuts (Cyperus esculentus) and groundnut (Arachis hypogea) may be added to sweeten and enrich protein content.

Kunun zaki is rich in carbohydrates, vitamins and minerals but it is low in protein (Ayo and Okaka, 1998). Sugar may be added instead of pepper to meet the demands of some consumers (Onuorah et al, 1987; Akoma et al 2006). Some consumers consume kunun zaki without sugar or pepper (Adeyemi and Umar, 1994). Kunun zaki is accepted based on its colour (cream) and flavour (millet mixed with ginger flavour).

Traditionally, kunun zaki is produced by steeping the grains in water, wet milling with spices and sieving, the overall process taking 24 hours (Adeyemi and Umar, 1994). This traditional method has been improved by shortening the processing time to 12 hours by steeping the grains in warm water containing 15% sodium metabisulphate, wet-milling, liquefication and saccharification with enzymes in the grain, filtering, bottling and pasteurization at 80oC for 30 minutes before refrigeration at 4-8 oC (Gaffa and Ayo, 2002). Traditionally produced kunun zaki has a shelf life of about 24 hours (Adeyemi and Umar, 1994) at ambient temperature. The improved method can however extend the shelf life to 8 days after pasteurization followed by refrigeration storage (Osuntogun and Aboada, 2004) which can last for 90 days when chemical preservation is applied as has been achieved by FIIRO, Nigeria (Haard, 1998). Also instant kunun zaki flour has been produced by Dala Foods Limited Kano, Nigeria and commercialized Kunun Tsamiya, the product being made only from millet. Further work was done by Amazikwu (2007) where she produced instant kunun zaki flours from millet-cowpea malt and millet-soybean malt to enhance protein content and sensory quality. She also carried out sensory evaluation and the samples were rated acceptable by consumers.  However no packaging or storage studies have been carried out on the instant powders and shelf life is also largely dependent upon the storage conditions and packaging materials used. This work is therefore a follow up of the work done by Amazikwu (2007). Against this background, this project was designed to produce instant kunun zaki flours from millet-cowpea malt and millet-soybean malt combinations and store in good flexible packaging material. Specific attention was therefore directed at;

(i) producing instant kunun zaki powders from millet-cowpea malt and millet-soybean malt by steam heating.

(ii) studying the changes in physicochemical and functional properties of the packaged flours during storage.