Development and characterisation of protein films derived from dried distillers’ grains with solubles and in-process samples

Abstract

Polymer films were developed utilising proteins extracted from wheat distillers' dried grains with solubles (DDGS) and in-process samples (wet solids), both by-products of bioethanol production process. Structural characterisation of DDGS and wet solids films indicated a change in the secondary structure of the proteins, reflecting the impact of DDGS production process such as effect of enzyme on protein properties and consequently on the film properties; whereas the developed films exhibited a rough surface with voids.Determination of moisture sensitivity indicated that DDGS films exhibited more hydrophilicity than wet solids films, with the same trend being observed for their water solubility and water uptake. The moisture content and solubility of DDGS films ranged from 10.2-14.2 % and 32.3-41.8 % respectively whereas those for wet solids' film ranged from 18.9-19.8 % and 23.8-24.2 % respectively. The mechanical properties of DDGS and wet solids (ranging from 0.27-0.32 MPa) were comparatively lower than commercial wheat gluten film (0.6 MPa). The poor mechanical properties and high water vapour permeability of DDGS and the wet solids films limit their application as biodegradable packaging materials.However, based on their hydrophilicity, the developed films have potential applications in agriculture and horticulture as controlled release matrices and soil conditioners.

Ultrasound‐assisted fractionation of dried distillers' grains with solubles (DDGS) at mild temperature for co‐production of xylan and protein feed

“…The wide range of protein and fat content is mainly caused by the particular ethanol production process (dry‐grinding or wet‐milling processes), including the steps of fat and protein extraction from corn prior to fermentation . The utilization of DDGS for high value‐added products of biodegraded thermoplastics, electrode materials, food additives and biofuels have been widely studied . However, most researches focused on extraction and utilization of a single component of DDGS, such as zein, protein, cellulose and hemicellulose, leading to a waste of the other high value components.…”

Proteins in dried distillers' grains with solubles: A review of animal feed value and potential non‐food uses

“…In particular, wheat‐DDGS proteins (mainly gliadin and glutenin) have remarkable viscoelastic characteristics, enabling carbon dioxide holding properties during dough fermentation (Coltelli et al, 2016). The developed film exhibited a rough surface with voids and high water vapor permeability but excellent hydrophilicity (Prabhakumari et al, 2018). Generally, plasticizers should be added to improve the flexibility and extensibility of wheat‐protein films (Sánchez et al, 1998).…”

Extrusion modification of prolamins from distiller's grains to facilitate the construction of biopolymer films

“…DGs are developed in the following ways: being used as animal feed and for energy and biofuel generation. [4][5][6] Prolamins from DGs (PDGs) are a good and low-cost source of cereal prolamins, since the concentration of ethanol in the fermentation environment of liquor is not sufficient to dissolve PDGs, resulting in a large number of unutilized PDGs. 3 The low essential amino acid contents and unbalanced amino acid composition of PDGs mean that they are at a disadvantage in terms of nutritional value and food processing.…”

“…3 The low essential amino acid contents and unbalanced amino acid composition of PDGs mean that they are at a disadvantage in terms of nutritional value and food processing. 6 But the selfassembly ability, biocompatibility and high crosslinking property of prolamins mean that they have received increasing attention in the field of biomaterials, 2 such as films for active ingredients (curcumin, eugenol and resveratrol) packaging 6,7 and stabilizers for Pickering emulsions. 8 Moreover, prolamins and their derivatives can be used in medical research, such as that concerning ⊍-glucosidase inhibitory peptides.…”