Gradients in compositions in the starchy endosperm of wheat have implications for milling and processing

Publication date: December 2018Source: Trends in Food Science & Technology, Volume 82Author(s): Paola Tosi, Jibin He, Alison Lovegrove, Irene Gonzáles-Thuillier, Simon Penson, Peter R. ShewryAbstractBackgroundWheat is the major food grain consumed in temperate countries. Most wheat is consumed after milling to produce white flour, which corresponds to the endosperm storage tissue of the grain. Because the starchy endosperm accounts for about 80% of the grain dry weight, the miller aims to achieve flour yields approaching this value.Scope and approachBioimaging can be combined with biochemical analysis of fractions produced by sequential pearling of whole grains to determine the distributions of components within the endosperm tissue.Key findings and conclusionsThis reveals that endosperm is not homogeneous, but exhibits gradients in composition from the outer to the inner part. These include gradients in both amount and composition. For example, the content of gluten proteins decreases but the proportion of glutenin polymers increases from the outside to the centre of the tissue. However, the content of starch increases with changes in the granule size distribution, the proportions of amylose and amylopectin, and their thermal properties. Hence these parts of the endosperm differ in the functional properties for food processing. Gradients also exist in minor components which may affect health and processing, such as dietary fibre and lipids. The gradients in grain compositio...

Source: Trends in Food Science and Technology - October 5, 2018 Category: Food Science Source Type: research