Submitted to: Journal of Hazardous Materials
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 2, 2011
Publication Date: March 15, 2011
Citation: Appell, M.D., Jackson, M.A., Dombrink Kurtzman, M. 2011. Removal of patulin from aqueous solutions by propylthiol functionalized SBA-15. Journal of Hazardous Materials. 187(1-3):150-156. Interpretive Summary: This research determined that potable liquids contaminated with the toxin patulin could be detoxified by using a specially designed, chemically modified solid silica material. Patulin is a natural contaminant of agricultural commodities, with potential to contaminate fruit juices used in products for children. We evaluated a new approach to detoxify patulin contaminated commodities. A material was designed, synthesized, and evaluated for its ability to remove the contaminant patulin from solutions including juices. Molecular modeling was applied to elucidate the mechanism of the material. This work demonstrates that synthetically modified materials can reduce patulin levels. The report will be valuable to food scientists looking for new approaches to remove toxins from agricultural commodities.
Technical Abstract: The goal of this study is to investigate the ability of functionalized silicas to detoxify aqueous solutions including apple juice contaminated with the regulated mycotoxin patulin. Micelle templated silicas with a specific pore size were synthetically modified to possess propanethiol groups, a functional group known to form Michael reaction products with the highly conjugated double bond system of patulin. BET Surface area analysis indicated the SBA-15 functionalized silica possessed channels with the pore size of 5.4 nm and a surface area of 345 m2/g. B3LYP/GIAO calculations matched experimentally observed NMR signals. Elemental analysis indicates that silicon/sulfur ratio to be 10:1, inferring one propanethiol substituent for every ten silica residue. Performance of the material is pH dependent, with improved capacity at pH 7.0 at room temperature. Efficacy of the material was significantly reduced at pH 4.0, however heating low pH solutions and apple juice to 60 'C in the presence of the propanethiol functionalized SBA-15 significantly reduced patulin concentrations in contaminated samples. A composite model based on previously reported studies and PM3 semi-empirical and force field calculations supports patulin permeation of the mesoporous propanethiol functionalized SBA-15. These findings indicate that solid materials containing thiols are capable of reducing patulin levels in contaminated apple juice.