Differences between easy- and difficult-to-mill chickpea ('Cicer arietinum' L.) genotypes. Part II: Protein, lipid and mineral composition

Background: Ease of milling is an important quality trait for chickpeas ('Cicer arietinum' L.) and involves two separate processes: removal of the seed coat and splitting of cotyledons. Four chickpea genotypes (two desi types, one kabuli type and one interspecific hybrid with 'wild' 'C. echinospermum' parentage) of differing ease of milling were examined to identify associated seed composition differences in the seed coat, cotyledons and their junctions (abaxial and adaxial). Results: Several components in different fractions were associated with ease of milling chickpea seeds: primarily soluble and insoluble non-starch polysaccharides (including pectins) and protein at the seed coat and cotyledon junctions, and the lignin content of the seed coat. Conclusion: This study shows that the chemical composition of chickpea does vary with seed type (desi and kabuli) and within desi genotypes in ways that are consistent with physical explanations of how seed structure and properties relate to milling behaviour.