[5-1015-C] Postharvest/Food Technology and Process Engineering (5)

[5-1015-C-01] THE EFFECT OF DRYING METHODS ON THE QUALITY OF TIGER NUT (Cyperus esculentus lativum)

*Akindele Folarin ALONGE¹, Edikan Ufot GILBERT (1. University of Uyo(Nigeria))

Keywords:Drying methods, quality, tiger nuts, moisture content, properties

This study aimed at evaluating the effect of different drying methods on the quality of tiger nut (cyperus esculentum lativum). Three drying methods: sun drying, oven drying and microwave-oven drying were employed. Analysis of proximate, minerals, anti-nutrient and anti-oxidant composition of fresh (control) and dried tiger nut were carried out using the official method of analysis byt the association of analytical chemist (AOAC, 2010). Fresh tiger nut tubers were divided into four portions. Three of the four portions were dried to constant weight using sun, oven and micro-wave drying methods respectively. The fourth portion of the sample was not dried but serves as the control. Result showed that the proximate composition of fresh and dried tiger nut sample for moisture content ranged from (5-45%), Protein (1.04-3.50%), Ash (0.05-0.51%), fibre (3.69-5.04%). fat (23.48-24.11%). For the dried samples, microwave oven drying had the lowest moisture (5.0%), oven had the highest fibre (3.80%), oven had the highest ash (0.48%), oven had the highest fat (24.11%), and oven had the highest protein (3.50%) contents contents. These values were significantly different from (p<0.05) the control. The minerals composition of the fresh and dried tiger nut ranged from Calcium (1.97mg/g-2.41mg/g), Potassium (2.29mg/g-3,83mg/g), Magnesium (1.03mg/g-5.33mg/g), and Zinc (5.09mg/g-8.11mg/g). Anti-nutrients of dried tiger nut were significantly reduced among other drying methods when compared with the control; anti-nutrient of the fresh and dried tiger nut range from Hydrogen cyanide (HCN) (0.012mg/g-0.401mg/g), Oxalate (0.016mg/g-0.084mg/g). Phytate (0.022mg/g-0.062mg/g), Tannin (Ta) (0.029mg/-0.0364mg/g). Anti-oxidant of the fresh and dried tiger nut ranged from 1, 1-diphenyl-2-picryllydrazyl (DPPH) (0.577%-2.23%), Cupric ion reducing capacity assay (CUPRAC) (0.52%-0.44%), Ferric ion reducing anti-oxidant power assay (FRAP) (0.40%-0.68%). At the end of this study, Oven drying maintained high nutritional content among the drying methods. Microwave oven drying method had the highest retention of its mineral composition when compared with the control. Sun drying had the lowest anti-nutrient among the drying methods. Microwave oven drying was effective in its anti-oxidant activity with reference to the control.