Effects of gamma‐irradiation on cotyledon cell separation and pectin solubilisation in hard‐to‐cook cowpeas

Abstract

As the cell wall changes brought about by gamma-irradiation were associated with pectin solubilisation, this supports the phytate-phytase-pectin theory as a major cause of the HTC defect. However, the non-reversal of the defect in HTC susceptible cowpeas and the absence of an effect on CSP indicate that other mechanisms are involved in HTC defect development in cowpeas, possibly the formation of alkali-soluble, ester bonded pectins. © 2017 Society of Chemical Industry.

Polyphenols in Common Beans (Phaseolus vulgaris L.): Chemistry, Analysis, and Factors Affecting Composition

“…This phenomenon might be attributed to hard-to-cook defect (Coelho et al, 2007;Jombo, Minnaar, & Taylor, 2017;Martín-Cabrejas et al, 1997). Several theories have been proposed to explain the hard-to-cook phenomenon, including phytase-phytate-pectin theory, lignification theory, protein and starch interactions, and a multiple mechanism theory, but the "phytase-phytate-pectin" theory is the most widely accepted (Jombo et al, 2017). According to the "phytasephytate-pectin" theory, water-soluble pectin permits water uptake by legume seeds.…”

“…() reported that the TPC of different pinto bean genotypes varied during storage, and the kaempferol content of CDC Pentium cultivar seed coats was reduced by almost half, whereas the kaempferol content of 1533‐15 cultivar seed coats did not change significantly. This phenomenon might be attributed to hard‐to‐cook defect (Coelho et al., ; Jombo, Minnaar, & Taylor, ; Martín‐Cabrejas et al., ). Several theories have been proposed to explain the hard‐to‐cook phenomenon, including phytase–phytate–pectin theory, lignification theory, protein and starch interactions, and a multiple mechanism theory, but the “phytase–phytate–pectin” theory is the most widely accepted (Jombo et al., ).…”

“…If the phytate is crosslinked with calcium or magnesium ions, legume seeds appear to be easy‐to‐cook. However, phytate may be hydrolyzed by phytase during storage so that the chelating potential of phytate vanishes, and then the calcium or magnesium ions can crosslink with pectin to form insoluble calcium and magnesium pectates, which are not dissolved readily when heated, thus restricting cell separation, inhibiting water uptake, and resulting in hard‐to‐cook defect (Galiotou‐Panayotou et al., ; Jombo et al., ).…”

Understanding the Relations Among the Storage, Soaking, and Cooking Behavior of Pulses: A Scientific Basis for Innovations in Sustainable Foods for the Future

“…Development of both defects in pulses can be hereditary, that is, dependent on variety/cultivar as demonstrated for beans (Njoroge et al., ; Nyakuni et al., ), cowpeas (Jombo, Minnaar, & Taylor, ), and chickpeas (Reyes‐Moreno, Okamura‐Esparza, Armienta‐Rodelo, Gomez‐Garza, & Milan‐Carrillo, ). It can also be dependent on seed size, with smaller seeds being more prone to HTC as demonstrated for beans (De J. Berrios, Swanson, & Cheong, ; Nyakuni et al., ).…”

“…In addition, phytic acid content was related to susceptibility to HTC development in chickpeas (Reyes-Moreno et al, 2000) but not in beans (Martin-Cabrejas, Esteban, Perez, Maina, & Waldron, 1997). Irradiation of HTC cowpeas leading to reduced cooking time was associated with changes in pectin solubility (Jombo et al, 2018).…”