3.6. Color
Color is one of the most vital attributes of any food product due to consumer acceptability considerations. The color of extruded productswas measured in terms of Hunter L (lightness), a (redness), and b (yellowness) values. The values of L, a, and b under different designed experimental conditions are given in Table 2. The results indicated that the L values of extrudates varied between 74.2 and 87.4, a-values ranged from 0.12 to 3.47 and b values varied from 23.1 to 35.4. L value increased with decreasing soy protein isolate content and increasing processing temperature. The a-value increased with increasing protein content and process temperature. The highest b value was found while processing was done at 180 C with 60 g/ 100 g (dry basis) soy protein isolate and 35 g/100 g (wet basis) moisture content