Nonthermal processing technologies to produce low glycemic index starch

Abstract

Background: Native starch hydrolyzes rapidly by digestive enzymes, resulting in rapid glucose release and an elevation in blood glucose level. The consistent intake of a high glycemic diet could lead to metabolic disorders (diabetes, obesity, etc.). Therefore, reducing the starch digestibility through structural modification is the priority of the research for food scientists. Traditional, thermal, or chemical treatments include various disadvantages, such as high energy consumption, degradation of active compounds, chemical residue, etc. Therefore, alternative nonthermal processing technologies have emerged as a promising option to conventional methods for modifying starch structure and reducing digestibility. Scope and approach: This review investigated the mechanisms, processing parameters, and applications of non-thermal technologies, including ultrasonication, cold plasma, high hydrostatic pressure, and pulsed electric field treatments for producing low glycemic index (GI) starch. Additionally, challenges, obstacles, and possible future perspectives of these techniques have been discussed. Key findings: These technologies alter starch structure by disrupting crystallinity, promoting molecular rearrangement, enhancing resistant starch formation, and facilitating complexation with bioactive compounds while preserving heat-sensitive components. Ultrasonication modifies granular structure and enhances amylose-lipid complex formation, while cold plasma introduces functional groups and promotes cross-linking. High hydrostatic pressure can transform crystalline structures and promote resistant starch formation under controlled conditions. On the other hand, pulsed electric field treatment affects starch granule integrity and crystallinity. Optimizing process parameters is critical as excessive treatment can reverse beneficial effects. With certain caveats, these technologies herein offer sustainable, energy-efficient alternatives for developing low-glycemic index starch for functional food development.