Review A review on the physicochemical properties and potential food applications of cowpea (Vigna unguiculata) starch Samson A. Oyeyinka, 1,2 * Eug enie Kayitesi, 3 Oluwafemi A. Adebo, 1 Ajibola B. Oyedeji, 1 Opeolu M. Ogundele, 1 Anthony O. Obilana 4 & Patrick B. Njobeh 1 * 1 Department of Biotechnology and Food Technology, University of Johannesburg, Doornfontein Campus, Gauteng, South Africa 2 School of Agriculture and Food Technology, Alafua Campus, University of the South Pacific, Suva, Fiji 3 Department of Consumer and Food Sciences, University of Pretoria, Pretoria, South Africa 4 Department of Food Technology, Cape Peninsula University of Technology,Bellville Campus, Cape Town, South Africa (Received 28 March 2020; Accepted in revised form 21 April 2020) Abstract Cowpea is a food legume with high protein and carbohydrate contents, which could be explored in addressing food and nutritional challenges in many parts of the world. However, some cowpea varieties are difficult to cook, resulting in high energy requirements and greater loss of nutrients. Since the bulk of carbohydrate in cowpea is starch, this component may be explored as an alternative starch source for var- ious industrial applications, especially because cowpea starch is rich in resistant starch with several benefi- cial physiological effects. Hence, this review summarises the present knowledge on the isolation, composition, physicochemical properties and modification methods of cowpea starch. Future studies that are required to produce cowpea starch with novel properties were highlighted and the need to apply mod- ified cowpea starch in food systems were also noted. Keywords Cowpea starch, legumes, modification, physicochemical properties. Introduction Cowpea is an important legume that is cultivated in many parts of the world (Oyeyinka et al., 2013). It is a good and cheap source of protein (16%–31%) and car- bohydrate (50%–66%) (Giami, 2005; Oyeyinka et al., 2013; Anjos et al., 2016; Rengadu et al., 2020a, b). Cow- peas are also good sources of fibre, iron, zinc and con- tain substantial amounts of bioactive compounds (Adjei-Fremah et al., 2019). Nevertheless, cowpea utili- sation has been mainly limited to traditional uses (Oyeyinka et al., 2018) and more recently for texture improvements in comminuted fish and meat products (Adjei-Fremah et al., 2019). The underutilisation of cow- pea in food applications has been attributed to its beany flavour, high levels of antinutrients and the hard-to- cook defect that prolongs cooking time (Giami, 2005). Cowpeas are a rich source of starch with potential industrial applications (Chinma et al., 2012; Ashogbon & Akintayo, 2013; Kaptso et al., 2016; Ratnaningsih et al., 2016; Kim et al., 2018). Cowpea starch (CS) is rich in resistant starch (RS) fraction (9.42%–32.14%) (Ratnaningsih et al., 2020; Rengadu et al., 2020a, b). The RS fraction has a wide range of health benefits including improved absorption of minerals, prevention of colon cancer and as prebiotics (Hoover et al., 2010; Rengadu et al., 2020a, b). Cowpea starch is also a suit- able texture modifier in various food applications due to its resistance to enzyme and acid hydrolysis and a higher rate of retrogradation (Ratnaningsih et al., 2016), especially after modification (Huang et al., 2007; Huang et al., 2007). With the surge in demand for alternative starch sources with novel functionality, cowpea is well-positioned for use as a starch source for different industrial applications. Furthermore, accord- ing to Kim et al. (2018), the food industry is increas- ingly interested in the use of legume starches in food formulations due to their high amylose content, fast retrogradation and resistance to shear thinning. Hence, this review presents the current level of research on CS with regard to its composition, microstructure, func- tionality, physicochemical properties and modification with the view to open up future researches that should still be explored to improve its industrial use. Starch isolation methods, yield and chemical composition Starch isolation from cowpea is similar to methods reported for legume starches, which include the wet and dry milling (Hoover et al., 2010). However, the *Correspondent: E-mails: sartf2001@yahoo.com (S. A. O); pnjobeh@uj.ac.za (P. B. N) International Journal of Food Science and Technology 2020 doi:10.1111/ijfs.14604 © 2020 Institute of Food Science and Technology The peer review history for this article is available at https://publons.com/publon/10.1111/ijfs.14604 1