Physicochemical properties of extruded germinated wheat and barley as modified by CO₂ injection and difference extrusion conditions

Abstract

Summary Germinated wheat and barley were extruded with a pilot‐scale corotating twin‐screw extruder under different barrel temperatures (100 and 120 °C), feed moisture content (30 and 35%) and CO2 injection. The effect of germination, barrel temperature, feed moisture content and CO2 injection on physical properties, proximate composition, γ‐aminobutyric acid, β‐glucan, phytic acid and protease activity was investigated. Results indicated that the barrel temperature, moisture content and CO2 injection significantly affected water absorption index (WAI), water‐soluble solid index (WSI), specific length, expansion ratio, bulk density, mechanical properties and colour of all extruded products (P < 0.05). Extrusion process significantly decreased γ‐aminobutyric acid and protease activity in extruded germinated wheat (EGW) and barley (EGB) products (with and without CO2 injection). However, extrusion process (with and without CO2 injection) increased β‐glucan in EGB and decreased phytic acid in EGW. The content of proximate composition, γ‐aminobutyric acid, β‐glucan, phytic acid and protease activity was slightly affected by CO2 injection.

Whole faba bean flour exhibits unique expansion characteristics relative to the whole flours of lima, pinto, and red kidney beans during extrusion

“…This is because the ER is related to the molecular breakdown and molecular transformation. These factors influence the degree of melting, the viscosity of material, and the pressure drop with vaporization of water at the end of die (Ganjyal & Hanna, ; Singh, Sekhon, et al., ; Singkhornart et al., ). The lower moisture content could promote the degradation or deformation of starch, protein, and fiber, reconstructing the structure of materials with an improvement in the ER compared to higher moisture content since excess water as a lubricant may inhibit the degradation and deformation (Gu et al., ; Kowalski, Hause, Joyner, & Ganjyal, ; Singh, Sekhon, et al., ).…”

“…Extrusion processing is a continuous and rapid process that is commonly used in food industries for various applications, such as pastas, puffed snacks, breakfast cereals, texturized proteins, and others because of low cost and high efficiency (Aluwi et al, 2016;Singkhornart, Gu, & Ryu, 2013). Grains and seeds typically in their flour forms are utilized as a feed material are used in extrusion processing (Gu, Kowalski, & Ganjyal, 2017;Serge, Gu, Kim, & Ryu, 2011).…”

“…Raw materials in the extruder are subjected to high temperature, shear, and pressure, which result in the physicochemical transformation of the materials (Gu, Dhumal, Wolcott, & Ganjyal, 2019;Masli, Gu, Rasco, & Ganjyal, 2018;Norajit, Gu, & Ryu, 2011). The process conditions during extrusion process lead to an increase in the bioavailability of nutrients in beans, reduction of the antinutrient activity, and an increase in the digestibility of proteins (Gulati & Rose, 2018;Nosworthy et al, 2018;Singkhornart et al, 2013).…”

Sprouting of oats: A new approach to quantify compositional changes

“…Consequently, the use of sprouted grain to produce bread, pasta, breakfast cereals, biscuits, and porridge was studied and discussed (Richter, Christiansen, & Guo, 2014;Singkhornart, Gu, & Ryu, 2013). Consequently, the use of sprouted grain to produce bread, pasta, breakfast cereals, biscuits, and porridge was studied and discussed (Richter, Christiansen, & Guo, 2014;Singkhornart, Gu, & Ryu, 2013).…”

“…During the past years, many food products containing sprouted grains appeared on the market. Consequently, the use of sprouted grain to produce bread, pasta, breakfast cereals, biscuits, and porridge was studied and discussed (Richter, Christiansen, & Guo, 2014;Singkhornart, Gu, & Ryu, 2013). In order to achieve this desired incorporation in a controlled manner, it is important to understand how the raw material changes during the sprouting process.…”