Suppression of the tert-butylhydroquinone toxicity by its grafting onto chitosan and further cross-linking to agavin toward a novel antioxidant and prebiotic material

•TBHQ toxicity is suppressed by grafting into chitosan and further cross-linking to agavin.•The novel compound displays prebiotic effect as it promotes lactic acid bacteria growth.•FRAP and ORAC tests demonstrate that the antioxidant power in TBHQ is preserved.•The novel compound has potential application in foods as antioxidant and prebiotic dietary fiber. The enzyme-mediated grafting of tert-butylhydroquinone (TBHQ) onto chitosan and further crosslinking to agave inulin (agavin) has been successfully achieved in a mild and non-toxic two-step route. The resulting products were characterized by nuclear magnetic resonance (NMR) and Infra-red spectroscopies to assess the molecular structure. The study of acute oral toxicity in mice revealed no adverse short-term effects of consumption in the synthesized materials with non-toxicity evidence until 2000mg/kg through an oral acute administration. Importantly, this study proves that the compound maintains the radical scavenging capacity of the phenolic antioxidant upon ferric-reducing antioxidant power (FRAP) and oxygen radical absorbance capacity (ORAC) assays with a measured half-maximal inhibitory concentration (IC50) for the best case of 1.54g/L based on inhibition of 2,2′-azino-bis(3-ethylbenzothiazoline)-6-sulfonic acid diammonium salt (ABTS). Additionally, the novel compound presented high prebiotic activities as ascertained in the presence of lactic acid bacteria (LAB).