Prolamins from cereal by-products: Classification, extraction, characterization and its applications in micro- and nanofabrication

Background: Prolamins are the endosperm storage proteins of cereal grains. Currently, the agri-food industry generates large quantities of by-products, among which are those generated from wet-milling, such as Gluten Meals (GM), dry-milling, such as the Distillers Dried Grains with Solubles (DDGS) and Brewer's Spent Grain (BSG). These by-products are important biopolymer sources such as prolamins. The prolamins have low nutritional value, however can be are useful for obtaining micro- and nanomaterials Scope and approach: The main objective of this review was to make known the techniques of obtaining and its main applications in micro- and nanotechnology of prolamins obtained from cereal, and the purpose of this investigation was to promote the use of prolamins obtained from cereal by-products. Key findings and conclusions: The prolamins can be obtained of by-products cereals and due to their economic importance and high productivity, the main cereals that generate these types of by-products are wheat and corn, in addition to sorghum, which is experiencing an increasing boom. The conformational structure of prolamins render them feasible for producing various micro- and nanomaterials, particles and fibers. These micro- and nanomaterials are of interest in the food industry and medicine for protection of bioactive compounds, pickering emulsions stabilized, drug delivery system and controlled release fertilizer. There is more evidence on nano materials that micromaterials that have been obtained from prolamins: from 2014 and up to date, around 247 investigations have been published dealing with the obtention of nanoparticles and nanofibers, of which only 2.0% corresponds to materials obtained from cereals by-products. Therefore, future prolamin research in nanotechnology from the by-products of cereals is necessary, with the purpose of increase added value and decreasing environmental contamination.