NUTRITIONAL AND PHYSIOCHEMICAL PROPERTIES OF TIGER NUT (CYPERUS ESCULENTUS) AND ORANGE FLESH SWEET POTATO (IPOMOEA BATATAS) COMPOSITE FLOUR

Abstract

Cereals have been the main source of flour utilized in the food industry for the production of various processed foods across the globe. However, in this study, the nutritional and physiochemical properties of various formulations of tiger nut and orange flesh flour were tested. Orange flesh sweet potato and the yellow type of tiger nut used were processed for the various flour formulations and quality assessment. The tiger nuts and orange flesh were dried using a solar drier and milled into flour. The flour from the tiger nut and the potato were formulated into three forms including; 1 100% tiger nut, 2 90% tiger nut: 10% orange flesh sweet potato, and 3 60% tiger nut: 40% orange flesh sweet potato. The mean proximate results of the three composite flour formulations (respectively) were carbohydrate (62.3%, 63.9% and 68.1%), crude fat (13.9%, 19.2% and 20.9%), protein (5.3%, 6.3% and 6.8%), fibre (3.6%, 3.7% and 3. 8%), ash (1.4%, 1.7% and 2.5%), and moisture (5.0%, 5.2% and 6.5%) as against mean percentages of 11.60-20.0%, 1.10-2.95%, 4.5-9.87%, 4.43%, 44.60-69.60%, and 2.10-26.70% for moisture, ash, protein, fat, carbohydrate and fibre respectively on maize. The energy value of the samples ranged from 418.7 - 464.8 Kcal making samples suitable for contributing to the daily energy requirements of consumers. The physiochemical properties ranged from 0.432-0.448 g/ml for loose density and 0.607-0.607 g/ml for tapped density, 26.26-29.66 for compressibility and 1.36-1.42 as hausner ratio. The water activity ranged from 0.55-0.56 and 202.11-172.43 were recorded for water absorption. In terms of nutritional quality, the 60% tiger nut: 40% orange flesh sweet potato flour was superior. However, the means scores for consumer acceptability of the porridge prepared from the formulated samples were not significantly different. Therefore, tiger nut and orange flesh sweet potato can be processed into flour for use in the food industry to supplement or replace the use of flour from cereals.