Red rice starch modification - Combination of the non-thermal method with a pulsed electric field (PEF) and enzymatic method using α-amylase

Raphael Lucas Jacinto Almeida; Newton Carlos Santos; Cecilia Elisa Sousa Muniz; Raphael da Silva Eduardo; Rebeca de Almeida Silva; Celene Ataíde Cordeiro Ribeiro; Gilsandro Alves da Costa; Maria José de Figueiredo; Pablícia Oliveira Galdino; Everaldo Silvino Dos Santos

doi:10.1016/j.ijbiomac.2023.127030

Red rice starch modification - Combination of the non-thermal method with a pulsed electric field (PEF) and enzymatic method using α-amylase

Int J Biol Macromol. 2023 Dec 31;253(Pt 5):127030. doi: 10.1016/j.ijbiomac.2023.127030. Epub 2023 Sep 23.

Affiliations

¹ Department of Chemical Engineering, Federal University of Rio Grande do Norte, Natal, RN, Brazil.
² Department of Chemical Engineering, Federal University of Campina Grande, Campina Grande, PB, Brazil.
³ Department of Engineering, Mauricio de Nassau University Center, Campina Grande, PB, Brazil.
⁴ Department of Nutrition, Federal University of Paraiba, João Pessoa, PB, Brazil.
⁵ Department of Food Engineering, Federal University of Paraiba, João Pessoa, PB, Brazil.
⁶ Department of Agro-industrial Management and Technology, Federal University of Paraiba, Bananeiras, PB, Brazil.
⁷ Department of Chemistry, State University of Paraiba, Campina Grande, PB, Brazil.
⁸ Department of Chemical Engineering, Federal University of Rio Grande do Norte, Natal, RN, Brazil. Electronic address: everaldo.santos@ufrn.br.

PMID: 37742893
DOI: 10.1016/j.ijbiomac.2023.127030

Abstract

The objective of this study was to investigate the dual modification of red rice starch using pulsed electric field (PEF) and α-amylase, focusing on morpho-structural, thermal, and viscoamylographic properties. Native starch (Control) underwent various treatments: PEF at 30 kV cm^-1 (PEF30), α-amylase at 9.0 U mg^-1 (AA0), and a combination of both (PEF30 + α and α + PEF30). The PEF30 + α treatment exhibited the highest degree of digestion (10.66 %) and resulted in morphological changes in the starch granules, which became elongated and curved, with an increased average diameter of 50.49 μm compared to the control. The starch was classified as type A, with a maximum reduction in crystallinity of up to 21.17 % for PEF30. The deconvolution of FT-IR bands indicated an increase in the double helix degree (DDH) for PEF30 and AA0, while the degree of order (DO) was reduced for PEF30, AA0, and PEF30 + α. DSC analysis revealed significant modifications in gelatinization temperatures, particularly for PEF30, and these changes were supported by a reduction in gelatinization enthalpy (ΔH) of up to 28.05 % for AA0. These findings indicate that both individual and combined treatments promote a decrease in starch gelatinization and facilitate the process, requiring less energy. Differences were observed between the formulations subjected to single and alternating dual treatments, highlighting the influence of the order of PEF application on the structural characteristics of starch, especially when applied before the enzymatic treatment (PEF + α). Regarding the viscoamylographic parameters, it was observed that AA0 presented higher values than the control, indicating that α-amylase enhances the firmness of the paste. The double modification with PEF + α was more effective in reducing syneresis and starch retrogradation, leading to improvements in paste properties. This study provided significant insights into the modification of red rice starch using an efficient and environmentally friendly approach.

Keywords: Dual modification; Enzymatic hydrolysis; Green chemistry; Thermal and pasting properties.

MeSH terms

Oryza* / chemistry
Spectroscopy, Fourier Transform Infrared
Starch* / chemistry
Temperature
alpha-Amylases / chemistry

Substances

Starch
alpha-Amylases