Effects of Environment and Genotype on Phenolic Acids in Wheat in the HEALTHGRAIN Diversity Screen

Abstract

Phenolic acid content and composition have been determined in 26 wheat genotypes grown in Hungary over three consecutive years and at three additional locations (France, United Kingdom, and Poland) during the third year. Fractions comprising free, soluble conjugated, and bound phenolic acids were analyzed using HPLC with measurements being made for individual phenolic acids in each fraction. Statistically significant differences in phenolic acid content occurred across the different growing locations with the average total phenolic acid content being highest in the genotypes grown in Hungary. The growth year in Hungary also had a large impact, especially on the free and conjugated phenolic acid contents. Certain genotypes were more resistant to environmental impacts than others. Of the genotypes with high levels of total phenolic acids, Lynx, Riband, Tommi, and Cadenza were most stable with respect to their total contents, whereas Valoris, Herzog, and Malacca, also high in phenolic acid content, were least stable. Of the three fractions analyzed, the free and conjugated phenolic acids were most variable and were also susceptible to the effect of environment, whereas bound phenolic acids, which comprised the greatest proportion of the total phenolic acids, were the most stable.

Variation of total antioxidant activity and of phenolic acid, total phenolics and yellow coloured pigments in durum wheat (Triticum turgidum L. var. durum) as a function of genotype, crop year and growing area

“…Lastly, for the free form Duilio had the highest content (6.7 ± 3.6 mg/ kg dm) and Dylan the lowest (3.1 ± 1.3 mg/kg dm). In agreement with previous data (Fernandez-Orozco et al, 2010;Li et al, 2008;Martini et al, 2014), the free form showed the highest variability (RSD ¼ 56%), followed by the conjugated form (17%) and by the bound form, which showed the lowest variability (RSD ¼ 14%).…”

“…growing temperature and rainfall from anthesis to maturity). More recently, a study within the HEALTHGRAIN Project reported that environment affects PA content (especially the free and conjugated forms) in common wheat, observing that rainfall level before heading period may be a more relevant factor than total precipitation (Fernandez-Orozco et al, 2010). Regarding specifically durum wheat, Menga et al (2010) observed that TPC was mainly influenced by the growing area and secondly by genotype and growing area  genotype interaction.…”

“…sugars, sterols) and PAs bound to cell wall polysaccharides such as arabinoxylans (Adom et al, 2003;Fernandez-Orozco et al, 2010;Li et al, 2008). The bound form has been widely recognized as the most abundant one in wheat, accounting for over 80% of total PAs, followed by the conjugated and lastly by the free form, generally representing 1e2% of total PAs (Fernandez-Orozco et al, 2010;Li et al, 2008).…”

Spring, einkorn and emmer wheat species - potential rich sources of free ferulic acid and other phenolic compounds

“…Statistically significant year-to-year differences -higher FFA amounts in 2009 in comparison with 2010 in emmer and spring wheat species (Figure 2) -may be affected by lower sum of precipitation and higher average temperatures in 2009 (Table 1). Shewry et al (2010) reported for free phenolic acids r = 0.899, P = 0.015 for average temperature and r = -0.706, P = 0.0117 for precipitation heading to harvest. The respective data for conjugated phenolic acids were r = 0.753, P = 0.084 for average temperature and r = -0.744, P = 0.090 for precipitation heading to harvest.…”

“…The antioxidant activity of wheat and its different fractions usually depends on the variety examined (Yu et al 2002a,b), and the location where it is grown . Environmental factors (such as temperature stress, solar radiation and irrigation), and the interactions between environmental factors and genotype can modulate the antioxidant activity of wheat (Moore et al 2006, FernandezOrozco et al 2010, Shewry et al 2010.…”