Physicochemical and Sensory Properties, and <i>In-Vitro</i> Digestibility of Biscuits Made from Blends of Tigernut (<i>Cyperus esculentus</i>) and Pigeon Pea (<i>Cajanus cajan</i>)

Abstract

Objective: The study explored the potential of tigernut and pigeon pea flour blends in the preparation of biscuits.
Materials and methods: Tigernut and Pigeon pea seeds were processed into flour and formulated into blends. The chemical composition of the flours and biscuits prepared from the flour blends as well as in-vitro (starch and protein) digestibility, physical and sensory properties of the biscuits were evaluated using standard methods.
Results: The chemical composition such as protein, moisture, fat, ash, crude fiber, ash, energy, iron, calcium, zinc and phosphorus contents of composite biscuits ranged from (11.64 to 17.81%), (4.11 to 6.03%), (12.80 to 18.40%), (2.43 to 3.63%), (3.81 to 4.95%), (437.84to 453.36kcal) , (3.18 to 3.81mg/100g), (60.15 to 87.69mg/100g), (0.50 to 1.27mg/100g) and (223.19 to 248.17mg/100g) respectively and were significantly (p. 0.05) higher than 100 % wheat biscuit. The composite biscuits had poor starch digestibility (25.43 to 44.18 %) than 100 % wheat flour biscuit (57.25 %) as well as high protein digestibility (60.20 to 71.57 %). Biscuits prepared from tigernut and pigeon pea flour blends were significantly (p. 0.05) higher in width and spread ratio than control samples while their break strength decreased with increase in pigeon pea flour addition. There were no significant (p.0.05) differences in appearance, flavour, crust colour and overall acceptability between composite biscuits and control.
Conclusion: This study reveals that tigernut and pigeon pea flour could be used in the production of nutritious biscuit and confirms their potential as a functional food especially for diabetic and obese patients due to their low starch and high protein digestibility.