Instrumental and Sensory Properties of Cowpea and Whey Protein Concentrate-Fortified Extruded Rice Snacks

Consumers are being encouraged to increase their protein and fibre consumption through convenient and healthy food products. Six samples of extruded rice snacks were developed by substituting rice flour with cowpea flour and whey protein concentrate (WPC). Texture and colour were assessed instrumentally, and sensory analysis was conducted by an untrained panel (N = 70) who rated overall liking using the nine-point hedonic scale, and a check-all-that-apply (CATA) question with 37 attributes and emotions. Hedonic scores of the texture, taste and overall liking were significantly different across samples (p < 0.05). The crispy and crunchy CATA attributes were associated with 10-15% cowpea and 5% WPC. Correlations between mechanical and sensory texture and colour were non-significant (p > 0.05). A principal component analysis (PCA) revealed the positive associations between the groups, crispiness and L* value, and hardness b* and a* values, respectively. The results of the present study will help to guide innovative high-protein and high-fibre plant food designs and formulations.