Abstract
Cowpeas are an inexpensive source of quality protein but their utilisation is limited by long seed cooking time. This is exacerbated by development of the hard-to-cook (HTC) defect, which also adversely affects starch and protein functionality. Gamma-irradiation can eliminate cowpea seed insect infestation and affects seed functional properties, including reducing cooking time. Hence, the potential of γ-irradiation to modify the starch- and protein-related functionalities of HTC cowpeas was investigated. Gamma-irradiation at approximately 11 kGy was applied to the seeds of two cowpea varieties, differing in HTC susceptibility, where HTC had been induced by high-temperature, high-humidity (HTHH) storage. HTHH storage increased flour pasting peak viscosity by up to 40% in the less susceptible variety and by more than 100% in the more susceptible variety. Gamma-irradiation at least completely reversed this effect, due to starch depolymerisation and debranching. Gamma-irradiation also positively impacted on some protein-related properties adversely affected by HTC; partially reversing the reduction in flour and cooked paste nitrogen solubility index of the HTC-susceptible cowpea, as a result of protein depolymerisation. The multiple benefits of γ-irradiation: disinfection, cooking time reduction and reversing some adverse effects of HTC on functional properties could make it a viable process for improving HTC cowpea quality.
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Abbreviations
- BV:
-
Breakdown viscosity
- HTC:
-
Hard-to-cook
- HTHH:
-
High temperature, high humidity
- NSI:
-
Nitrogen solubility index
- PV:
-
Pasting viscosity
- SP:
-
Swelling power
- SV:
-
Setback viscosity
- WAC:
-
Water absorption capacity
- WSI:
-
Water solubility index
References
Abu JO, Minnaar A (2009) Gamma-irradiation of cowpea (Vigna unguiculata L. Walp) seeds: effect on colour, cooking quality and pasting characteristics. Int J Food Sci Technol 44:2335–2341
Abu JO, Muller K, Duodu KG, Minnaar A (2005) Functional properties of cowpea (Vigna unguiculata L. Walp) flours and pastes as affected by gamma-irradiation. Food Chem 93:103–111
American Association of Cereal Chemists (2000) Approved methods of the AACC, 10th edn. AACC, St. Paul
Chung HJ, Liu Q (2010) Molecular structure and physicochemical properties of potato and bean starches as affected by gamma-irradiation. Int J Biol Macromol 47:214–222
Cieśla K, Eliasson AC (2007) DSC studies of retrogradation and amylose–lipid complex transition taking place in gamma irradiated wheat starch. Nucl Instr Methods Phys Res B 265(265):399–405
Darfour B, Ocloo FCK, Wilson DD (2012a) Effects of irradiation on the cowpea weevil (Callosobruchus maculates F.) and moisture sorption isotherm of cowpea seed (Vigna unguiculata L. Walp). Arthropods 1:24–34
Darfour B, Wilson DD, Ofosu DO, Ocloo FCK (2012b) Physical, proximate, functional and pasting properties of flour produced from gamma irradiated cowpea (Vigna unguiculata L. Walp). Rad Phys Chem 81:450–457
Dogan H, Karwe MV (2003) Physicochemical properties of quinoa extrudates. Food Sci Technol Int 9:101–114
Du SK, Jiang H, Yu X, Jane JL (2014) Physicochemical and functional properties of whole legume flour. LWT Food Sci Technol 55:308–313
Falade KO, Kolawole TA (2013) Effect of irradiation dose on physical, functional and pasting properties of cowpea (Vigna unguiculata L. Walp) cultivars. J Food Process Eng 36:147–159
Fu JT, Rao MA (2001) Rheology and structure development during gelation of low-methoxyl pectin gels: the effect of sucrose. Food Hydrocoll 15:93–100
Galiotou-Panayotou M, Kyriakidis BN, Margaris I (2008) Phytase-phytate-pectin hypothesis and quality of legumes cooked in calcium solutions. J Sci Food Agric 88:355–361
Garcia E, Lajolo FM (1994) Starch alterations in hard-to-cook beans. J Agric Food Chem 42:612–615
Hincks MJ, Stanley DW (1987) Lignification: evidence for a role in hard-to-cook beans. J Food Biochem 11:41–58
Jombo TZ, Minnaar A, Taylor JRN (2018) Effects of γ-irradiation on cotyledon cell separation and pectin solubilisation in hard-to-cook cowpeas. J Sci Food Agric 98:1725–1731
Kaur A, Singh N, Ezekiel R, Guraya HS (2007) Physicochemical, thermal and pasting properties of starches separated from different potato cultivars grown at different locations. Food Chem 101:643–651
Kuan Y, Bhat R, Patras A, Karim AA (2013) Radiation processing of food proteins—a review on the recent developments. Trends Food Sci Technol 30:105–120
Kyei-Boahen S, Savala CEN, Chikoye D, Abaidoo R (2017) Growth and yield responses of cowpea to inoculation and phosphorus fertilization in different environments. Front Plant Sci 8:646
Liu K (1997) Storage proteins and hard-to-cook phenomenon in legume seeds. Food Technol 51(5):58–61
Liu K, McWatters KH, Phillips RD (1992) Protein insolubilization, thermal destabilization during storage as related to hard-to-cook defect in cowpeas. J Agric Food Chem 40:2403–2407
Moorthy S (1985) Effect of different types of surfactants on cassava starch properties. J Agric Food Chem 35:1227–1232
Mwangwela AM, Waniska RD, McDonough C, Minnaar A (2007) Cowpea cooking characteristics as affected by micronisation temperature: a study of the physicochemical and functional properties of starch. J Sci Food Agric 87:399–410
Ocloo FCK, Minnaar A, Emmambux MN (2014) Effects of gamma-irradiation and stearic acid, alone and in combination, on functional, structural, and molecular characteristics of high amylose maize starch. Starch-Stärke 66:624–635
Ogundele OM, Minnaar A, Emmambux MN (2017) Effects of micronisation and dehulling of pre-soaked bambara groundnut seeds on microstructure and functionality of the resulting flours. Food Chem 214:655–663
Olopade AA, Akingbala JO, Oguntunde AO, Falade KO (2003) Effect of processing method on the quality of cowpea (Vigna unguiculata) flour for akara preparation. Plant Food Hum Nutr 58:1–10
Paredes-López O, Maza-Calviño EC, Montes-Rivera R (1988) Effect of the hard-to-cook phenomenon on some physicochemical properties of bean starch. Starch-Stärke 40:205–210
Parmar N, Singh N, Kaur A, Virdi AS, Shevkani K (2017) Protein and microstructure evaluation of harder-to-cook and easy-to-cook grains from different kidney bean accessions. LWT Food Sci Technol 79:487–495
Rombo GO, Taylor JRN, Minnaar A (2004) Irradiation of maize and bean flours: effects on starch physicochemical properties. J Sci Food Agric 84:350–356
Shelton DR, Lee WJ (2000) Cereals. In: Kulp K, Ponte JG (eds) Handbook of cereal science and technology, 2nd edn. Marcel Dekker, New York, pp 385–415
Shimelis E, Meaza M, Rakishit S (2006) Physicochemical properties, pasting behaviour and functional characteristics of flours and starches from improved bean (Phaseolus vulgaris L.) varieties grown in East Africa. CIGR E J 8:1–18
Singh U (2001) Functional properties of grain legume flour. J Food Sci Technol 38:191–199
Tester RF, Morrison WR (1990) Starch: The polysaccharide fraction. In: Frazier PJ, Donald AM, Richmond P (eds) Starch structure and functionality. The Royal Society of Chemistry, London, pp 147–163
Wadchararat C, Thongngam M, Naivikul O (2006) Characterization of pregelatinized and heat moisture treated rice flours. Kasetsart J 40:144–153
Whistler RL, BeMiller JN (1997) Carbohydrate chemistry for food scientists. Eagan Press, St. Paul
Yousif AM, Kato J, Deeth HC (2007) Effect of storage on the biochemical structure and processing quality of Adzuki bean (Vigna angularis). Food Rev Int 23:1–33
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The authors thank the University of Pretoria for a post-graduate bursary for TZ Jombo.
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Jombo, T.Z., Emmambux, M.N. & Taylor, J.R.N. Modification of the functional properties of hard-to-cook cowpea seed flours and cooked prepared pastes by γ-irradiation. J Food Sci Technol 58, 22–33 (2021). https://doi.org/10.1007/s13197-020-04509-z
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DOI: https://doi.org/10.1007/s13197-020-04509-z