Location: Food Quality LaboratoryTitle: Compressive strength of Super Soft wheat endosperm
Submitted to: Journal of Cereal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/2/2019
Publication Date: 12/3/2019
Citation: Delwiche, S.R., Morris, C.F., Kiszonas, A. 2019. Compressive strength of Super Soft wheat endosperm. Journal of Cereal Science. https://doi.org/10.1016/j.jcs.2019.102894.
Interpretive Summary: Wheat kernel texture is an important factor in milling of wheat to produce flour. In practice, wheat kernel texture or hardness is evaluated in wheat quality programs by use of a device called the single kernel classification system (SKCS). Although the SKCS hardness index has been substantiated by classical laboratory force-displacement measurements that determine kernel hardness across a spectrum of ordinary soft and hard wheat, the newly developed very soft wheats know as 'Super Soft' have not undergone such evaluation, until now. Using genetically related lines of wheat whose texture ranges from traditional soft down to very soft, we have corroborated that the relationships between SKCS hardness index and mechanical compressive strength properties continue to hold true. Knowledge of this finding will give confidence in wheat quality evaluation programs to use the SKCS in evaluating Super Soft wheats, and in commercial milling operations that will eventually process newly released Super Soft varieties.
Technical Abstract: Wheat endosperm texture (hardness) largely determines end-product suitability. Since its development 25 years ago, the single kernel classification system (SKCS, a mechanical instrument that measures, among other properties, the force imparted on a kernel during crushing) has been used in breeding programs to differentiate soft wheats from hard wheats. Nominally, these have a soft to hard SKCS hardness index (HI) range of 25 to 75 (dimensionless units). However, in recent years, breeders have developed extremely soft ('Super Soft') lines having SKCS HI < 0. Until now, these very low SKCS HIs have not been corroborated with traditional methodologies that characterize mechanical strength. Herein, we report on the relationships between SKCS HI and three compressive strength properties (maximum stress, Young's modulus, and work) in Super Soft wheat. With respective correlation coefficients of 0.76, 0.66, and 0.75, we have found that the relationships between SKCS HI and compressive strength agree with prior research involving ordinary soft and hard wheats.