Effect of ingredients on the quality characteristics of gluten free snacks

Grain-based fabricated snacks from non-wheat grains (amaranth, finger millet, sorghum and black gram) were used to prepare puffed snacks employing the method of hot air toasting. The functional characteristics and sensory attributes of the snack were determined by varying the moisture content and time of toasting. The quality attributes of the snacks like the instrumental color parameters, peak force and puff thickness of the snack correlated well with the sensory attributes (appearance/color, texture and overall acceptability). A snack made from amaranth showed a bright reddish brown colour at a moisture content of 20-40%; the product had a good puffing and high overall acceptability. The moisture content of all the snacks was around 3% and had a fat content of 1-2%; protein and dietary fiber contents were in the ranges of 22-23 and 10-11%, respectively. The principal component analysis (PCA) accounted for a total of 89.6% variation. The PCA biplot showed that sensory appearance, sensory texture and sensory overall acceptability were closely related to the puff thickness. The microstructure of the snack indicated the presence of air cells to offer a porous structure. On toasting, the flakes increased their thickness creating a porous microstructure such that the toasted snacks were crispy having a brittle texture. Popped sorghum and gelatinized starch added doughs exhibited good puffing when toasted at 20-30% moisture content while popped amaranth samples required higher moisture content (30-40%). The grain based gluten-free snacks with improved sensory and nutritional characteristics can be prepared by using different ingredients.