Phenolic nutrient composition and grain morphology of winter spelt wheat (Triticum aestivum ssp spelta) cultivated in Poland

This study analysed the genotypic variation in the physical features of kernels and accumulation of phenolic acids and alkylresorcinols in the grain of 16 spelt wheat genotypes grown under the same environmental conditions in Poland. The average values of 1000-kernel weight, kernel length, width and specific density were 49.9 g, 8.08 mm, 3.32 mm and 1.24 g/cm(3), respectively, with variation between genotypes ranging from 4.03 to 7.70%. The average values of colour attributes hue, saturation and intensity were 35.5 degrees, 32.7% and 58.4%, respectively. The lowest variation of these features was noted for surface hue (1.6%), while the highest was for saturation (5.4%). The content of so-called 'free' phenolic acids ranged from 16.0 to 27.3 mg/kg, with a predominant share of ferulic (ca. 45.8%) and p-coumaric acids (circa 18.6%). The total content of phenolic acids was between 206 and 557 mg/kg (345 mg/kg on average). Ferulic acid share was between 86.6 and 91.6% of the total. The average content of alkylresorcinols was 723 mg/kg, and ranged from 561 to 919 mg/kg. The main homologues were heneicosylresorcinol (circa 58%), nonadecylresorcinol (circa 30%), and tricosylresorcinol (circa 6%). The intra-species variation was approximately 3-fold higher for phenolic acids than for alkylresorcinols (37.2 and 13.0%, respectively).