“Effect Of Pretreatments And Drying Methods Of Cocoyam Flour On The Physiochemical And Sensory Properties Of Its Biscuits:- Unamba, Chidiebube E

ABSTRACT

This study evaluated the effect of pretreatment (soaking, blanching, drying oven and solar) of cocoyam flour of on the physicochemical, phytochemical, antioxidant, and sensory properties of biscuits. Five formulations were produced from flour content obtained as follows: control from dried cocoyam, soaked-oven-dried, soaked-solar-dried, blanchedoven-dried, and blanched-solar-dried. Standard methods were used for biscuit production to give CT (biscuit from dried cocoyam; control), SO (biscuit from soaked-oven-dried cocoyam), SS (biscuit from soaked-solar-dried cocoyam), BO (biscuit from blanchedoven-dried cocoyam), and BS (biscuit from blanched-solar-dried cocoyam); results were analyzed by one-way ANOVA and means separated with Duncan’s multiple range test (p < 0.05). Proximate composition ranged as follows: moisture 5.06 % to 7.16 %, protein 5.86 % to 9.66 %, crude fibre 2.03 to 2.47 %, fat 4.03 % (SO) to 4.62 %, ash 2.32 % to 2.89 %, carbohydrate 75.32 % to 79.54 %, and energy 373.63 kcal/100 g to 381.44 kcal/100 g, with significant differences across all parameters. Physical properties showed weight 11.43 g to 15.24 g, thickness 7.41 cm to 12.89 cm, diameter 4.65 cm to 5.07 cm, spread ratio 0.371 to 0.683, and break strength 2.85 to 3.47 kg; blanching increased spread while soaking produced thicker, less spread biscuits. Phytochemicals differed significantly (p < 0.05): phytate 0.38 to 0.73 mg/100 g, total phenols 0.03 to 0.11 mg/100 g, tannins 0.29 to 0.47 mg/100 g, and oxalate 4.93 to 6.33 mg/100 g; soaking most effectively reduced antinutrients, whereas the control retained the highest phenolics. Antioxidant capacity followed the order control > blanched > soaked for all assays, with DPPH 2.65 to 4.13 %, FRAP 0.42 to 0.64 mg TE/g, and ABTS 5.06 to 6.50 pmol TE/g (p < 0.05). Sensory evaluation revealed significant differences (p < 0.05) for appearance (5.68 to 7.20), texture (4.12 to 6.80), taste (5.44 to 7.16), mouthfeel (4.72 to 7.08), and overall acceptability (5.20 to 7.20), while aroma (5.68 to 6.52) did not differ significantly (p < 0.05). Overall, blanching (with oven or solar drying) yielded the best balance of geometry, texture, taste, mouthfeel, and acceptability, while soaking reduced protein, ash, fat, phenolics, and antioxidant activity but lowered phytate and oxalate. The control had the highest protein and antioxidant indices but slightly higher antinutrients. These findings provide practical guidance on selecting pretreatment-drying combinations to optimize nutritional quality, functional performance, and consumer acceptability of cocoyam-based biscuits