Abstract: This research explored the use of immobilized lipase Novozym 435 to catalyze selective synthesis of 6,6’-O-acyltrehalose diesters through the transesterification of trehalose with fatty acid vinyl esters of different carbon chain lengths (C6–C18) at a molar ratio of 1:4 in a mixed solvent of tert-butanol and pyridine (11:9, V/V). The chemical structures of the products were identified by nuclear magnetic resonance (NMR) and mass spectrometry (MS), the hydrophilic lipophilic balance (HLB), foaming properties and thermostability were determined, and the cytotoxicity was evaluated by the methyl thiazolyl tetrazolium (MTT) assay. It turned out that a series of trehalose fatty acid diesters were formed, with a yield between 43% and 75%. The trehalose didecanoate and trehalose dilaurate had good foaming properties (foamability of 101.00% and 142.67%, and foam stability (within 80 min) of 40%–60% and 50%–70%, respectively). The trehalose dioleate had the best thermal stability with a retention rate of 60.58% at 350 ℃. Moreover, it was found that these trehalose fatty acid esters were safe and lowly toxic. To conclude, this study may point out a new direction for the development of new types of value-added, non-ionic surfactants for the food industry.

Key words: immobilized lipase; transesterification; foaming properties; thermal stability; cytotoxicity