Infrared heating under optimized conditions enhanced the pasting and swelling behaviour of cowpea starch

• Published in: International journal of biological macromolecules Vol. 184; pp. 678 - 688
• Main Authors: Oyeyinka, Samson A., Oyedeji, Ajibola B., Ogundele, Opeolu M., Adebo, Oluwafemi A., Njobeh, Patrick B., Kayitesi, Eugénie
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.08.2021
• Subjects: Cowpea starch; Infrared heating; Moisture preconditioning; Pasting properties; Thermal properties; Thermal properties; Moisture preconditioning; Pasting properties; Infrared heating; Cowpea starch
• ISSN: 0141-8130; 1879-0003
• DOI: 10.1016/j.ijbiomac.2021.06.129

Native starches are not suitable for industrial use and must be modified for improved functionality. In this study, the effect of moisture preconditioning and infrared heating time on physicochemical properties of cowpea starch was investigated using a two-factor central composite rotatable design. Factors (moisture levels:10–40 g/100 g starch and infrared heating time:10–60 min) with their corresponding α mid-point values resulted in 13 experimental runs. Selected functional and pasting properties were determined as response variables. Starch samples produced under optimized conditions were compared with corn starch and their physicochemical properties determined. Except for pasting temperature, cowpea starch prepared using the optimal conditions (moisture: 46.21 g/100 g starch, dry basis and heating time of 32.88 min) had higher functional and pasting properties compared with the native cowpea starch. Infrared heating significantly reduced the gelatinization temperatures of cowpea starch but did not significantly change that of the corn starch. The crystallinity and double-helical order structure of moisture conditioned cowpea starch also reduced after modification. Cowpea starch showed a bigger granule size, higher swelling power but lower water absorption capacities and pasting properties compared with the control. The infrared heating process is a novel and promising modification method for improving the swelling properties of starch. [Display omitted] •Optimum moisture level & heating time were 46.2 g and 32.9 min, respectively.•Infrared heated cowpea starch showed higher swelling and pasting properties.•Cowpea starch was bigger and showed higher swelling power than corn starch.•Corn starch exhibited higher water absorption capacity and pasting properties.•Modified cowpea starch had reduced crystallinity & gelatinization temperatures.