Couscous sans gluten

Abstract

The implementation of a gluten-free diet involves a variety of gluten-free foods, Thus, the aim of this work is to study the technological feasibility of rolled and extruded gluten-free couscous based on the supplementation of rice with legumes ( faba bean, chickpea and lentil) (90/10 and 70/30) g/g. The various couscous produced were characterised by determining yield, technological qualities, icrostructure, textural profile and sensory acceptability. The lightness of rolled couscous (between 59,93 et 69,19) decreased with increasing levels of supplementation (p<0,05). Rolled gluten-free couscous yields ranged from 79,46% to 85,53%. The majority of gluten-free rolled couscous were characterised by the dominance of small agglomerates (<530 µm) and their low bulk density (0,65g/cm3). Couscous enriched with chickpea (10% et 30%) or faba bean (30%) have the best water absorption capacities and swelling indices. The disintegration degrees of rolled gluten-free couscous varied between 8,89% and 10,94% and the hardness values between 151,88 N and 194,16 N. The cohesion ranges from 0,26 to 0,33. The rolled couscous enriched with faba bean (6,77 and 6,31) are ranked after the control couscous (7,54), followed by those enriched with chickpea (5,62 and 6,23) and lentil (5,62 and 4,85) respectively. Yields of extruded gluten-free couscous vary between 89,98% and 92,01%. The lightness of extruded gluten-free couscous (between 49,22 et 63,70) decreased as a function of faba bean or lentil content (p<0,05), the yellowness index (between 64,81 and 71,06) increased and the expansion ratio (between 0,90 and 0,94) decreased as a function of legumes content (p<0,05). Extruded couscous enriched with lentil has the lowest water absorption capacities (291,21% and 276,86%) and swelling indices. The disintegration degrees of extruded gluten-free couscous (between 10,15 and 16,40%) increased with the rate of legumes addition (p<0,05). The general acceptability ranking remained the same as for the rolled couscous. The final objective focused on the impact of manufacture process type (rolling or extrusion) on the properties of the couscous to be offered to the consumer. The extrusion yields (89,98 to 92,01%) are higher than those of manual rolling (79,46 to 88,91%) (p<0,05). In addition, the yellowness indexes of the extruded gluten-free couscous (64,81 to 71,06) are higher than those rolled (between 56,78 and 67,52). The highest bulk density values (0,65 and 0,67g/cm3) are attributed to rolled couscous, while the best water absorption capacities to extruded couscous (276,86 to 341,01%). Rolled couscous enriched with chickpea (10% and 30%) and those enriched with faba bean or lentil at 30% disintegrated less than extruded couscous of the same formula (p<0,05). The jury members gave a score above 5 and below 7 for all gluten-free couscous except for those enriched with 30% lentil, which obtained a score lower than 5.