Nutritional, physical and sensory properties of extruded products from high-amylose corn grits

Abstract

To investigate the applicability of high-amylose corn grits (HACG) to the process for extruded products, a single screw extruder was used to produce extrudates under feed rate of 220 g/min, barrel temperature of 120°C, and screw rotational speed of 150 rpm. The nutritional, physical and sensory properties were investigated in the HACG extrudate and normal corn grits (NCG) extrudate acting as control. The results indicated that the HACG extrudate had higher (P≤ 0.05) protein (7.07%), fiber (5.41%), lipid (1.48%), ash (0.76%), resistant starch (2.89%), zein (4.65%), calcium (22.34 mg/kg), magnesium (718.63 mg/kg), iron (19.47 mg/kg), zinc (22.73 mg/kg) contents and 16 of 17 types of amino acids compared to the NCG extrudate. In regards to physical properties, the bulk density (BD), radial expansion index (REI) and water solubility index (WSI) values of the HACG extrudate, which were 57.94 mg/ml, 45.47 and 43.25, respectively, were significantly lower (P≤ 0.05) than those of the NCG extrudate. However, the HACG extrudate had a higher special length (SL), indicating a higher axial expansion, water absorption index (WAI), frangibility and cohesiveness (7.34 cm/g, 3.69, 68.79 and 0.32, respectively), and a more sponge-like structure. A sensory analysis indicated that the HACG extrudate had higher values for frangibility, cohesiveness, chewiness and overall taste with a lower coarseness and adhesiveness (to teeth).

Effects of formulation and process conditions on chemical composition, color parameters, and acceptability of extruded insect‐rich snack

“…The range of lipid content found in this investigation was within the range reported by Liu et al. (2017) at 1.42 g/100 g, that by Gumul et al. (2015) at 1.77–3.35 g/100 g. These differences are due to the raw materials used to obtain the extruded product and its lipid content.…”

“…Therefore, the values observed in this work suggest that the extrusion process reduced the final moisture contents of the extrudates to a level that supported their stability, and for the range of moisture contents found, the extrudates were classified as intermediate-moisture foods (10-50 g/100 g)(Rodríguez-Miranda et al, 2011). These results are in agreement with those reported in other investigations Liu et al (2017). reported 5.43 g/100 g moisture in extruded (120°C) corn grains with high amylose content Navarro- Cortez et al (2016).…”

“…This result was due to the loss in lipids as a result of impregnation in the barrel and the screw, as well as to the degradation of lipids due to the high processing temperatures; this complexation depends on both the starch and the type of lipid present in a food, which reduces the efficacy of some lipid extraction procedures (such as the use of petroleum ether or hexane), producing the apparent disappearance of lipids during processing (Sobukola et al, 2013). The range of lipid content found in this investigation was within the range reported by Liu et al (2017) at 1.42 g/100 g, that by Gumul et al (2015) at 1.77-3.35 g/100 g. These differences are due to the raw materials used to obtain the extruded product and its lipid content. Raksakantong et al (2010) note that edible insects are a good source of healthy and beneficial fatty acids such as longchain omega-3 fatty acids, such as alpha-linolenic acid; eicosapentaenoic acid; and other polyunsaturated fatty acids, considering them as good sources of lipids and proteins.…”

“…James and Nwabueze (2013) noted that extrusion cooking significantly (p < .05) increased ash in extrudates from 2.85 to 5.15 g/100 g, which was attributed to the high temperature of the barrel and the high cutting speed involved during the process of cooking. The ash content found in this research (1.67-7.88 g/100 g) was higher than that (0.58-2.5 g/100 g) reported by other authors (Gumul et al, 2015;Liu et al, 2017;Navarro-Cortez et al, 2016).…”

“…Liu et al. (2017) reported 5.43 g/100 g moisture in extruded (120°C) corn grains with high amylose content. Navarro‐Cortez et al.…”