Micromorphological and elemental characteristics of chickpea, faba bean, field pea, and lentil cotyledon topographies

Background and objectives Micromorphological and elemental information on pulse cotyledon topographies is an essential aspect in identifying grain physiological and structural interactions at cotyledon-seed coat (abaxial) and cotyledon-cotyledon (adaxial) interfaces, which can influence grain quality and processing behavior in food industry applications. The objective of this study was to characterize the topographies of the abaxial and adaxial surfaces of two cultivars each of faba bean, chickpea, field pea, and lentil via micromorphological and elemental analyses. Findings Scanning electron microscopic imaging of the abaxial and adaxial cotyledon surfaces showed gentle undulation of either tabular- or polygonal-shaped epidermal cells that were projected as flat or rugose. They were covered by epicuticular wax films, which had smooth, striate, or granular micromorphology. Elemental results confirmed the presence of C, O, K, Ca, and Mg as the key elements on both cotyledon abaxial and adaxial surfaces. Conclusions Abaxial and adaxial cotyledon topographies of all the cultivars confirmed varietal differences associated with their micromorphological characteristics. It can be concluded that both abaxial and adaxial surfaces are cemented by a complex cuticle layer of similar elemental composition with a few significant (p < .05) variations. The ease of milling/pearling of pulses could be directly associated with the species, cultivar, architecture, micromorphology, and elemental composition of the pulse cotyledon abaxial and adaxial surfaces. Significance and novelty These findings will not only assist in interpreting the differences observed in the processing behavior of different pulse species and cultivars but will also enhance our understanding of the process design, targeting pearling of pulses for value-added food applications.