Reinventing Southern Thai dessert ‘Khanom-La’ via starch-phenolic complex-induced resistant starch: Physicochemical transitions and functional enhancement

Abstract

This study demonstrates the potential of starch-phenolic complexes, formed from indigenous Noui Khuea brown rice starch (NBS) and crude Mon-Pu (Glochidion wallichianum Muell Arg) leaf extract (MP), as a source of resistant starch (RS) for enhancing the nutritional value of traditional Southern Thai Khanom-La. Physicochemical analysis was conducted on native NBS partially substituted with the NBS-MP complex (0–30 %, w/w), followed by the preparation of Khanom-La, which was subsequently evaluated for in vitro starch digestibility, physicochemical characteristics, and sensory attributes. The FTIR spectra confirmed the success of the starch-phenolic complex formation. The rheological and thermal properties of the starch mixture varied with the amount of substituted NBS-MP complex, with decreasing G′, G″, and thermal parameters (particularly T_p and ΔH) as the amount of NBS-MP complex substituted increased. Higher amounts of substituted NBS-MP complex exhibited significantly increased DPPH radical scavenging activity (p < 0.05). The formulation containing 30 % NBS-MP complex exhibited the highest RS content (p < 0.05). Khanom-La with 20 % NBS-MP complex had the highest overall acceptability (p < 0.05), combining increased nutritional benefits with positive sensory attributes. These findings underscore the potential of the optimally substituted NBS-MP complex as a functional food ingredient in traditional Thai desserts.