BACKGROUND: High moisture before harvest can cause sprouting of the wheat kernel, which is termed pre-harvest sprouting (PHS). The aim of this study was to examine the variation in physicochemical properties of proteins in PHS-damaged (sprouted) hard red and white spring wheat genotypes. Specifically, protein content, enzyme activity and degradation of proteins were evaluated in sound and PHS-damaged wheat. RESULTS: Protein contents of sprouted wheat samples were lower than that of non-sprouted samples; however, their differences were not significantly (P > 0.05) correlated with sprouting score. Sodium dodecyl sulfate (SDS) buffer extractable proteins (EXP) and unextractable proteins (UNP) were analyzed by high-performance size exclusion chromatography. PHS damage elevated endoprotease activity and consequently increased the degradation of polymeric UNP and free asparagine concentration in wheat samples. Free asparagine is known to be a precursor for formation of carcinogenic acrylamide during high heat treatment, such as baking bread. Free asparagine content had significant correlations (P < 0.01) with sprouting score, endoprotease activity and protein degradation. CONCLUSIONS: Genotypes with higher endoprotease activity tend to exhibit a larger degree of degradation of UNP and higher free asparagine concentration in sprouted wheat samples.
BACKGROUND: High moisture before harvest can cause sprouting of the wheat kernel, which is termed pre-harvest sprouting (PHS). The aim of this study was to examine the variation in physicochemical properties of proteins in PHS-damaged (sprouted) hard red and white spring wheat genotypes. Specifically, protein content, enzyme activity and degradation of proteins were evaluated in sound and PHS-damaged wheat. RESULTS: Protein contents of sprouted wheat samples were lower than that of non-sprouted samples; however, their differences were not significantly (P > 0.05) correlated with sprouting score. Sodium dodecyl sulfate (SDS) buffer extractable proteins (EXP) and unextractable proteins (UNP) were analyzed by high-performance size exclusion chromatography. PHS damage elevated endoprotease activity and consequently increased the degradation of polymeric UNP and free asparagine concentration in wheat samples. Free asparagine is known to be a precursor for formation of carcinogenic acrylamide during high heat treatment, such as baking bread. Free asparagine content had significant correlations (P < 0.01) with sprouting score, endoprotease activity and protein degradation. CONCLUSIONS: Genotypes with higher endoprotease activity tend to exhibit a larger degree of degradation of UNP and higher free asparagine concentration in sprouted wheat samples.
Authors: Joseph Oddy; Rocío Alarcón-Reverte; Mark Wilkinson; Karl Ravet; Sarah Raffan; Andrea Minter; Andrew Mead; J Stephen Elmore; Isabel Moreira de Almeida; Nicholas C Cryer; Nigel G Halford; Stephen Pearce Journal: BMC Plant Biol Date: 2021-06-29 Impact factor: 4.215
Authors: Marcus Newberry; Alexander B Zwart; Alex Whan; Jos C Mieog; May Sun; Emmett Leyne; Jenifer Pritchard; Sergio Nicolas Daneri-Castro; Kutty Ibrahim; Dean Diepeveen; Crispin A Howitt; Jean-Philippe F Ral Journal: Front Plant Sci Date: 2018-09-07 Impact factor: 5.753