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Relatively small spherical protein bodies (approximately 5 μm) form a matrix that supports embedded starch granules of varied size and oblong shapes (Uebersax et al. 1989), as shown in ssss1, with an expanded view of this matrix presented in ssss1. Zimmermann et al. (1967) demonstrated partitioning of nutrients within the cotyledons with greater levels of protein and trypsin inhibitor present in the outer layers compared to the inner layers of the tissue.

Processed texture and nutrient availability of beans are influenced by the dimensions and arrangement of the cotyledonary cells. The outermost cells are an epidermal layer with an inner and outer portion. The innermost cells are elongated, and the outer layer cells are cubical. The next layer is the hypodermis, which has larger elliptically shaped cells. Both the epidermal and hypodermis layers appear granular, which is characteristic of protein.

The remaining and largest portion of the cotyledon parenchyma cells are bound by a distinct cell wall and middle lamella with a few vascular bundles. The parenchyma cells have thick walls that give rigidity to the cotyledon. Within each parenchyma cell, starch granules are imbedded within a protein matrix. The secondary walls found only in mature parenchyma cells are very thick and contain pits that facilitate the diffusion of water during soaking. The middle lamella is composed mainly of pectic substances that serve to hold cells together while giving rigidity and strength to the total tissue. Pectic substances (complex polygalacturonic acid residues that possess various degrees of methyl side groups) actively cross‐link with divalent cations to form cohesive structures that significantly affect the texture of the plant tissues (Gooneratne et al. 1994; Njoroge et al. 2015). This commonly observed mechanism in beans is discussed in ssss1.