Selective adsorption for dimethyl trisulfide to remove fish off-odors by edible calcium-based metal-organic frameworks: Structure, adsorption behavior, and removal mechanism.

In this study, an edible calcium-based metal-organic frameworks (Ca-MOFs) were constructed to remove off-odors. The adsorption behavior and mechanisms of Ca-MOFs for various off-odors were evaluated using kinetic models, isotherms, molecular dynamics, and density functional theory. Compared with zeolite and aluminum oxide, Ca-MOFs exhibited superior adsorption capacity for fish odors, attributed to its plentiful COO- sites and unsaturated Ca2+ sites. Moreover, Ca-MOFs showed selective adsorption for dimethyl trisulfide (DMTS) with an adsorption rate of 97.3 %, surpassing other odors (42.4-84.7 %). Ca-MOFs can completely remove DMTS from surimi and also reduce the levels of aldehydes, alcohols, and heterocyclic substances. Hydrogen bonding and van der Waals forces were identified as the primary driving forces for five off-odors adsorption, with the additional involvement of weak coordination bonds in adsorption of DMTS and trimethylamine (TMA). Overall, this study offers a novel strategy for removing off-odors and broadening the potential applications of MOFs.