Ohmic heating as a novel approach for enhancing the techno-functional properties of sesame protein isolate
Shaghayegh Samadi Saeedabad, Hoda Shahiri Tabarestani, Mohammad Ghorbani, Aman Mohammad Ziaiifar
Abstract
Plant proteins are increasingly valued for their environmental benefits and role in food diversification. However, their lower bioavailability and performance require innovative enhancement techniques. This study examines the effects of ohmic heating (OH) and conventional water bath heating (CWH) on the physicochemical, functional, and structural properties of sesame protein isolate (SesPI). Results showed that CWH produced a more negative zeta potential, while OH led to positive values, significantly enhancing dispersion stability. Both treatments reduced particle size and improved uniformity, with OH resulting in increased turbidity due to higher protein aggregation. Surface hydrophobicity increased after both treatments, showing a negative correlation with particle size. FTIR analysis indicated structural changes, with CWH promoting β-sheet formation and OH yielding a more ordered structure influenced by electric field intensity (EFI). OH treatment significantly increased free sulfhydryl groups, while CWH enhanced overall solubility more than OH. Both treatments improved water and oil holding capacities, emulsifying properties, and foaming characteristics, although excessive EFI diminished some functionalities. These findings highlight the importance of thermal processing conditions in modifying the functional properties of SesPI, which is essential for food formulation and processing applications. • FTIR showed OH restructured SesPI, favoring ordered α-helix and β-turn at high EFI. • OH boosted zeta potential, achieving maximum stability at 10 V/cm EFI. • Increasing EFI during OH reduced hydrophobicity and sulfhydryl groups. • CWH achieved higher overall solubility and improved interface properties.