Free asparagine concentrations in Canadian hard red spring wheat cultivars

Abstract

The amino acid asparagine is considered the rate limiting precursor in the formation of acrylamide in cereal based baked foods. However, there are no data on the quantity of this precursor in Canadian wheat. Wholemeal and white flour samples obtained from 30 Canadian Hard Red Spring (Canada HRS) wheat grown in the Prairie Provinces were analysed for asparagine content by liquid chromatography. The asparagine content varied from 302 to 965 and 116 to 336 µg/ g for wholemeal and white flour, respectively. Therefore, wheat grown in Canada has similar asparagine levels to wheat grown in other parts of the world. Analysis of variance suggested that asparagine content is significantly affected by genotype (p < 0.001), suggesting that breeding strategies could be investigated to produce cultivars with lower levels of this amino acid. Few significant correlations were observed between wheat and flour quality parameters and asparagine content, although there was a tendency towards weaker dough strength indices with increasing asparagine content.

Effects of growing environment, genotype, and commercial fertilization levels on free asparagine concentration in Western Canadian wheat

“…Similar findings were obtained by Malunga et al. (2019) among 30 Canadian hard red spring wheat cultivars: Of these, Glenn had the lowest free ASN concentration in both wholemeal (302.2 µg/g) and white flour (116.1 µg/g), whereas AAC Elie yielded the highest free ASN concentration in wholemeal (700.3 µg/g) and AC Muchmore in white flour (335.5 µg/g) (Malunga et al., 2019).…”

“…The moisture content of whole‐wheat flour was determined according to AACCI Method 44–15.02 prior to free ASN analysis. The free amino acids from whole‐wheat flour (200 mg) were extracted with 0.01 M hydrochloric acid solution and derivatized with a AccQ•Tag Ultra Precolumn Derivatization Amino Acid Kit to form stable urea for UPLC analysis as previously reported (Malunga et al., 2019). The internal standard L‐norvaline (250 µM) was added into the 0.01 M hydrochloric acid solution and incorporated into each sample during extraction to improve the precision of free ASN quantification.…”

“…UPLC analyses were performed using a Waters H class ultrahigh‐pressure liquid chromatography system, equipped with quaternary solvent manager, sample manager, heated column compartment, and photodiode array detector (Waters, Mississauga, ON, Canada) as per Malunga et al. (2019). A Waters AccQ•Tag Ultra C 18 column (2.1 × 100 mm) was used for the UPLC separation of extracted components.…”

“…Numerous research studies have been conducted worldwide on the free ASN concentration in wheat to investigate effective strategies for reducing free asparagine formation in wheat (Corol et al., 2016; Curtis et al., 2009; Malunga et al., 2019; Navrotskyi et al., 2018; Ohm et al., 2017). Selecting the correct wheat genotype, a suitable growing environment with sufficient precipitation and low heat stress, and a proper ratio of nitrogen and sulfur fertilization are three effective approaches to control free ASN concentration in wheat (Corol et al., 2016; Curtis et al., 2009; Granvogl et al., 2007; Malunga et al., 2019; Navrotskyi et al., 2018; Ohm et al., 2018; Stockmann et al., 2018; Yadav et al., 2019).…”

“…The study of factors affecting free ASN concentration in wheat commercially grown in North America is still very limited (Malunga et al., 2019, in press; Navrotskyi et al., 2018; Ohm et al., 2017; Wilson et al., 2020). Therefore, the objective of this study was to evaluate the variation of free ASN concentration in select Canadian wheat genotypes grown in different environments under commercially relevant fertilization treatments.…”