Third generation snacks are amongst the most widely consumed in México. These occupy 15.4% of the national market. Chia is an important source of omega-3 fatty acids fiber and proteins. Resistant starch type IV (RS4) had physiological effects similar to soluble fiber. RS4 derivatized starches can be produced by chemical modifications, as conversion, substitution or cross linking, or by retrograde amylose during processing. The aim of this study was to develop and characterize third generation (3G) snacks obtained by extrusion process and using acetylated corn starch blended with defatted chia flour. We evaluated the effects that barrel temperatures (BT) (60 - 140°C), content of defatted chia flour (DCHF) (2.5-15%) and (MC) moisture content (25-35%) had on the physical, chemical and nutritional characteristics of 3G snacks during the extrusion process.
The optimal expansion time of the extruded pellets by microwave energy was 23 s. Their highest expansion index was >6.24 and the lowest apparent density was <99.19 kgm3 for 3G snacks extruded at 30 % MC and 130°C BT. Decreasing DCHF (<2.57%) content in the blends gradually decreased penetration force (<5.30 N) and increased luminosity (>90%) of 3G snacks. We conclude that 3G snacks with DCHF and derivatized corn starch can get good expansion and texture, and increased nutritional value due to the greater content of resistant starch type IV, protein and fiber.