ASSESSMENT OF GLUTEN-FREE COOKIES MADE FROM RICE AND SOY PROTEIN ISOLATE BLENDS

The chemical composition, physical characteristics, and sensory attributes of gluten-free cookies made from blends of rice and soy protein flour were evaluated. Nerica 7 and Faro 44 rice were separately blended with soy protein isolate, to produce five formulations with ratio (100:0, 95:5, 90:10, 85:15 and 80:20) of rice to soy protein isolate flour respectively for cookies production. The functional and pasting properties of the composite flour formulations were analysed. The bulk density and the least gelation concentration of the flour blends decreased with increasing percentage of soy protein isolate, while other functional attributes increased. Pasting properties varied significantly (p≤0.05), with whole rice flours having the highest pasting characteristics. Nerica 7 flour blend and its composite blends exhibited better pasting properties than their Faro 44 rice counterpart. Cookies made from Nerica 7 rice flour supplemented with 10% soy protein isolates had the highest spread ratio. The moisture content, protein and crude fibre content of the cookies ranged from 3.28-5.33 g/100g, 3.96-17.76 g/100g, and 3.09-4.22 g/100g respectively. The results of sensory evaluation showed that the cookies produced from flour blends were scored significantly higher in all the quality attributes compared to whole rice flours (control). Nerica 7 and Faro 44 rice flour composited with soy protein isolate could serve as functional ingredients in food formulation, especially in the production of gluten-free cookies.