Understanding the mechanics of wheat grain fractionation and the impact of puroindolines on milling and product quality

Authors: LULLIEN-PELLERIN, V - Inra, Génétique Animale Et Biologie Intégrative , Jouy-En-josas, France; HARASZI, R - Campden Bri; ANDERSSON, R - Commonwealth Scientific And Industrial Research Organisation (CSIRO); Morris, Craig

Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: 6/17/2019
Publication Date: 4/14/2020
Citation: Lullien-Pellerin, V., Haraszi, R., Andersson, R.S., Morris, C.F. 2020. Understanding the mechanics of wheat grain fractionation and the impact of puroindolines on milling and product quality. In: Igrejas, G., Ikeda, T.M., and Guzmán, C., editors. Wheat Quality for Improving Processing and Human Health. Switzerland: Springer Nature. p. 369-385. https://doi.org/10.1007/978-3-030-34163-3.
DOI: https://doi.org/10.1007/978-3-030-34163-3

Interpretive Summary: Mechanical properties play a major role in wheat grain fractionation behavior as grinding and sieving are the main steps required in milling to isolate smaller endosperm particles from the larger particles comprised of the outer layers of the grain. Indeed, grain mechanical resistance has an impact on the energy required to fracture, the particle size of the resulting product, and its biochemical composition. Mechanical properties thus affect both the process durability and the quality of the obtained products. Genetics, and more precisely the key role of the Hardness (Ha) locus in the D genome of common wheat (T. aestivum), are well established as contributing to the grain mechanical behavior. However, environmental factors are also known to influence grain mechanical properties. Recently, the respective role of genetics and environmental factors on grain mechanical properties were investigated. Involvement of genes encoding the so-called puroindolines has been extensively analyzed thanks to the use of mutants or genetic manipulation and the key role of these proteins was confirmed. Classical measurement methods (e.g. PSI, NIRS, SKCS) used to characterize grain hardness have to be reconsidered taking into account that both genetics and environmental factors contribute to the differences in grain mechanical resistance. Moreover, methods to acquire data on the mechanical resistance of each of the grain tissue or respective components were developed. Finally, the interest of numerical modelling approach to better understand and predict the effect of changes in the wheat starchy endosperm composition will be discussed.

Technical Abstract: Mechanical properties play a major role in wheat grain fractionation behavior as grinding and sieving are the main steps required in milling to isolate smaller endosperm particles from the larger particles comprised of the outer layers of the grain. Indeed, grain mechanical resistance has an impact on the energy required to fracture, the particle size of the resulting product, and its biochemical composition. Mechanical properties thus affect both the process durability and the quality of the obtained products. Genetics, and more precisely the key role of the Hardness (Ha) locus in the D genome of common wheat (T. aestivum), are well established as contributing to the grain mechanical behavior. However, environmental factors are also known to influence grain mechanical properties. Recently, the respective role of genetics and environmental factors on grain mechanical properties were investigated. Involvement of genes encoding the so-called puroindolines has been extensively analyzed thanks to the use of mutants or genetic manipulation and the key role of these proteins was confirmed. Classical measurement methods (e.g. PSI, NIRS, SKCS) used to characterize grain hardness have to be reconsidered taking into account that both genetics and environmental factors contribute to the differences in grain mechanical resistance. Moreover, methods to acquire data on the mechanical resistance of each of the grain tissue or respective components were developed. Finally, the interest of numerical modelling approach to better understand and predict the effect of changes in the wheat starchy endosperm composition will be discussed.