Evaluation of Food Potentials of Tiger Nut Tubers and Its Product

ABSTRACT The food potentials of tigernut tubers (Cyperus esculentus) locally know as “aki awusa” in Igbo, ”aya” in Hausa and “ofio” in Yoruba were evaluated. The proximate composition of 100g of raw and processed tigernuts showed that moisture content of tigernuts ranged from 4.19 – 51.93 %, crude protein 2.61 – 10.12 %, ash 0.70 – 1.77 %, crude fibre 7.48 – 13.97 %, crude fat 10.79 – 32.06 %, and carbohydrate 22.73 – 56.85 %. Energy values ranged from 232.31- 487.15 Kcal. Tigernuts contain significant amounts of Mg (95.32 -140.96 mg), K (106.44 – 427.92 mg), P (121.78 – 195.95 mg), Fe (1.60 – 4.03 mg), Cu (0.08 – 0.99 mg), Zn (0.32 - 2.46mg), vitamin C (30.90 – 84.66 mg), vitamin E (2.22 – 5.26 mg), moderate Ca (24.42 – 62.29 mg) and low Na (15.77 – 18.27 mg) content. Processing of tigernuts generally increased carbohydrate but decreased magnesium and sodium values. Malting significantly increased calcium content (85 %) and drying and roasting increased Zn and Cu by 100 %. Physico-chemical and functional properties showed that tigernuts and its products are acidic while viscosity of the products per 100 ml was between 88 – 90 cP, specific gravity 1.01 – 1.07, reducing sugar 0.30 – 0.44 g , foaming capacity 18 %. Foaming stability 5.35 %, emulsion capacity 21.88 %, and emulsion stability 49.38 %. Alcohol content of tigernut wine was between 3.17 – 7.13 %. Fresh tigernuts were utilized in the development of tigernut products (milk, coffee and wine) using household methods such as soaking, drying, roasting, malting, fermentation and freezing. Organoleptic and acceptability assessment of the developed tigernut products showed that there was no significant difference (P > 0.05) between tiegrnut products and their controls in most of the parameters tested. All then products were highly acceptable. Tigernuts products (milk extract and wine) evaluation per 100 ml showed high ascorbic acid (6.18 – 7.8 mg), thiamin (0.80 – 1.25 mg), riboflavin (0.35 – 0.59 mg), vitamin E (0.22 – 0.75 mg) and cyanocobalamin (0.03 – 0.05 ug) content. The result of the microbial count of tigernut products (milk and wine) showed values between 3.0 x 102 – 8.0 x 102 cfu / ml and keeping quality ranged from 6 hours to 10 months.