A new insight into the impact of high hydrostatic pressure (HHP) on the changes of physicochemical, morphological and in-vitro digestibility of sago starch
Muhammad Ezzudin Ramli, Musfirah Zulkurnain, Nor Shariffa Yussof, Abdorreza Mohammadi Nafchi, Fazleen Izzany Abu Bakar, Uthumporn Utra
Abstract
High hydrostatic pressure (HHP) has proven to be an effective method for starch modification, offering benefits through its environmentally friendly approach and minimal processing on food systems during modifications. In this study, sago starch slurry (20%, w/v) was treated with high hydrostatic pressure 100, 200, 300, 400, 500 and 600 MPa for 10 min. Comprehensive characterization techniques including spectroscopy, microscopy and digestibility have been employed to compare with native sago and treated samples. The results revealed that treatment at 600 MPa caused to a reduction in amylose content and relative crystallinity of starch granules, resulting in greater affinity for water and oil absorption compared to native starch. Regardless of the pressure level, solubility and swelling power increased significantly after incubation at 70 °C for 30 minutes, accompanied by morphological damage, including granule gelatinization and complete disappearance of the Maltese cross structure. In vitro digestibility analysis revealed a significant ( p <0.05) decrease in resistant starch (RS) and increase in rapid digestibility starch (RDS) across all treated samples, without compromised with pressure levels. Therefore, these findings provide valuable insights into the application of HHP as a promising technology with potential applications in the food industry.