Extraction of chitin from white shrimp (Penaeus vannamei) shells using binary ionic liquid mixtures

[Display omitted] •Binary ionic liquid mixtures were used to extract chitin from shrimp shells.•The yield of chitin was 2.04 times higher than that of acid/base method.•The extraction of chitin by [EMIM][Ac] and [BMIM][Br] has a cooperative effect.•The whiteness index of chitin was better than that of commercial chitin.•Binary ionic liquid mixtures can be used instead of acid/base to extract chitin. Binary ionic liquid mixtures (IL) were used for the first time to extract chitin from shrimp shells. Two ionic liquids, 1-ethyl-3-methylimidazole acetate ([EMIM][Ac]) and 1-butyl-3-methylimidazole bromide salt ([BMIM][Br]), were mixed at ratios of 0:1, 1:1, 3:2, 4:1, and 1:0 and the properties of the IL and the characteristics of extracted chitin were investigated. With an increase in proportion of [EMIM][Ac], the viscosity, dielectric constant, and dielectric loss of IL gradually decreased (p