Coloured wheat — known for its blue, purple or black grains — has emerged as a promising source of antioxidants, B vitamins and essential minerals.Unlike traditional white wheat, these pigmented grains are rich in flavonoids and anthocyanins, compounds associated with anti-inflammatory, antidiabetic and antioxidant effects.
Furthermore, minerals such as zinc and iron, critical for neurological development and oxygen transport, are more concentrated in coloured wheat.
Owing to these health benefits and persistent “hidden hunger” in parts of the world, detailed studies of micronutrient dynamics in wheat grains are urgently needed.
A study published in Seed Biology on by Wei Chen’s team at the Huazhong Agricultural University offers promising strategies for breeding nutritionally enhanced wheat and developing health-oriented food products.
In this study, researchers applied comprehensive ionomic and metabolomic profiling to mature grains of blue, purple and white wheat varieties, identifying 501 distinct nutrients, including ten essential mineral elements.
The comparative analysis revealed striking variability in nutrient accumulation among varieties, with anthocyanins, phenolamides and flavonoids showing the highest coefficients of variation, whereas mineral content remained relatively stable, likely because of ion homeostasis mechanisms.
Coloured wheat grains exhibited significantly elevated levels of health-promoting compounds such as anthocyanins, flavonoids, B vitamins and essential minerals such as iron and zinc, compared with white wheat.
Blue wheat was particularly rich in glycosylated anthocyanins (delphinidin, malvidin), whereas purple wheat contained more acylated anthocyanins, explaining their distinct pigmentation.
Further, developmental-stage analysis from 7–35 days after flowering (DAF) showed nutrient levels were highest in early grain filling but declined as grains matured, whereas anthocyanin content increased after 21 DAF, peaking during the mid-filling stage and then decreasing.
K-means clustering identified nine distinct nutrient accumulation patterns, highlighting that most nutrients — especially amino acids, polyphenols and vitamins — declined toward maturity.
Notably, "green wheat kernels" at mid-filling stages were found to be richer in more than 200 nutrients compared with mature grains.
Transcriptome sequencing at 14 and 21 DAF identified gene clusters and transcription factors (mainly MYB and bHLH families) responsible for anthocyanin biosynthesis, with 21 candidate genes strongly correlated with pigment accumulation.
These findings provide valuable insights into the metabolic and genetic underpinnings of nutrient dynamics and grain colouration in wheat, laying the groundwork for biofortification, improved harvest timing and functional food development.
The study's findings offer immediate applications in both agriculture and the functional food industry.
Green wheat kernels, especially from coloured varieties, can serve as nutrient-dense ingredients for whole-grain products, health snacks and natural pigment sources.
Their antioxidant-rich profiles make them suitable for consumers with lifestyle-related health risks, such as diabetes and cardiovascular disease.
From a breeding perspective, the identified genes and transcription factors offer markers for selecting varieties with enhanced nutritional content, contributing to biofortification efforts in wheat.