Protein Enhancement and Consumer Acceptability of Cassava-Based Biscuits Fortified with Soybean: Development and Evaluation in a Ghanaian Context

Cassava (Manihot esculenta), Ghana’s most widely cultivated staple, has low protein content (1–2% dry basis), limiting its nutritional value. This study developed cassava-soybean composite biscuits at three formulation levels: 100:0 (S1, control), 80:20 (S2), and 70:30 (S3) cassava-to-soybean ratios, using Afisiafi cassava and Jenguma soybean varieties. Biscuits were assessed for proximate composition, mineral content, and sensory acceptability using a 50-member panel. Soybean fortification progressively increased protein from 2.85 ± 0.08% (S1) to 8.44 ± 0.14% (S3), a 196% enhancement (p < 0.001). Calcium, potassium, and iron increased by 176%, 101%, and 121%, respectively, in S3 relative to the control. The 70:30 formulation achieved the highest nutritional and sensory performance among the three formulations evaluated (overall acceptability 8.08 ± 0.15/9.00). Positive associations between protein and sensory attributes (r = 0.92–0.96) were observed, though these should be interpreted cautiously given only three formulation levels were assessed. These findings support further investigation of cassava-soybean composite flour technology to address protein malnutrition in Ghana.