Sucralose Hydrogels: Peering into the Reactivity of Sucralose versus Sucrose Using Lipase Catalyzed Trans-Esterification

Abstract

Sucralose differs from sucrose only by virtue of having three Cl groups instead of OH groups. Its intriguing features include being noncaloric, noncariogenic, 600 times sweeter than sucrose, stable at high temperatures/acidic pH's, and void of disagreeable aftertastes. These properties are attractive as food additive, one of which is as hydrogel obtainable via the technique of molecular gelation using a sucralose-derived low-molecular weight gelator (LMWG). The process of molecular gelation entails using specially designed lipid-like amphiphilic molecules capable of self-assembling in a liquid solvent to form a 3D-network. A rational molecular design would involve appending lipophilic alkyl chain to sucralose to afford sucralose-based amphiphiles. Our preliminary study has shown that sucralose, unlike sucrose, is unreactive under biocatalytic conditions using lipase enzyme, which is consistent with its reported lack of reactivity by hydrolytic enzymes in the body. Hence, the aim of this work was (i) to use computation and simulations to further understand sucralose's lack of enzymatic reactivity and (ii) to synthesize the sucralose-based amphiphiles using conventional chemical synthesis and systematically study their tendency towards hydrogelation. Three of the sucralose-based amphiphiles (SL-5, SL-6 and SL-7) proved to be successful hydrogelators. The gelators also showed the ability to gel selected beverages. The LMWGs gelled quantities of water and beverage up to 71 and 55 times their weight, respectively, and remain thermally stable up to 144 °C.