Effect of barrel temperature and feed moisture on the physical properties of chickpea–sorghum and chickpea–maize extrudates, and the functionality and nutritional value of their resultant flours—Part II

Abstract

Background and objectives The effect of barrel temperature (120 and 150°C, held constant in zones 4–6) and feed moisture (20% and 24%) on the physical properties of chickpea–sorghum (CS) and chickpea–maize (CM) extrudates, and the functional and nutritional properties (protein quality) of their flours were examined. Findings Temperature had a greater effect on the physical properties than moisture for both blends, where, in general, extrusion at 150°C resulted in greater expansion, less hardness, and lower bulk density than at 120°C. Extrusion also increased the water‐holding capacity relative to the raw CS and CM blends, but had an adverse effect on oil‐holding capacity, foaming, and emulsifying properties. Pasting viscosities of precooked flours were also lowered by 8 to 37 times due to the pregelatinization of the starch. Although in vitro protein digestibility increased after extrusion, the in vitro protein digestibility‐corrected amino acid score (PDCAAS) showed an overall reduction relative to the raw blended flours due to the reduction of the primary limiting amino acid lysine during extrusion. Conclusions Only the chickpea–maize blend extruded at 120°C at either 20% or 24% moisture had higher in vitro PDCAAS than the raw blend, with only the one with 24% moisture having a value >0.70. Significance and novelty A balance between functionality and protein quality needs to be considered when using extruded pulse–cereal blends.

Development of Cellular High-Protein Foods: Third-Generation Yellow Pea and Red Lentil Puffed Snacks

“…In the literature, EI values of extrusion cooked products at similar DT (i.e., 120 °C) have been reported as high as 2.2 for 60% chickpea and 40% sorghum blends (protein content of 16.9% d.b.) [ 1 ], which is higher than those obtained in our study. Not surprisingly, when raw materials with lower protein content are extruded, the EI values of extrusion cooked products display larger values.…”

“…Plant protein-rich foods, such as those from pulses (e.g., peas, lentils, etc. ), offer environmentally less resource-intensive and more humane alternatives to animal protein-rich foods [ 1 ]. In addition, processing pulses into appealing snack foods can provide healthier food options, and facilitate increased consumption of foods rich in plant proteins, as recommended by several health organizations, e.g., Health Canada [ 2 ].…”

Oxidizing agent‐assisted extrusion cooking of yellow peas and the techno‐functionality of the resulting extrudate flours

“…With increasing die temperature from 95℃ to 155℃ the final viscosity of extrudates increased (Table 2) due to the reassociation and retrogradation of starch polymers (Wani & Kumar, 2019). The increase in final viscosity with increasing temperature has been also reported by Wang, Nosworthy, et al (2019) for extrudates made from chickpea/sorghum and chickpea/corn flours at die temperatures of 120℃ and 150℃.…”

Influence of chickpea flour and yellow pea concentrate additive amount and in‐barrel moisture content on the physiochemical properties of extruded extrudates

“…During extrusion, starch granules are hydrated with the added moisture and heated as it is mixed within the barrel. Starch granules then swell, and amylose chains and some amylopectin within the granule become amorphous and migrate outside of the granule (known as pasting) (Wang, Nosworthy, et al., 2019). In general, under higher in‐barrel moisture, a lower degree of starch degradation occurs possibly caused by a decrease in frictional damage during the extrusion cooking process, as also reflected by the relatively lower SME values of higher moisture extrudates, which also induced to the pasting time delayed in RVA curves (Figure 5d,f).…”