Quaternized chitosan as a biopolymer sanitizer for leafy vegetables: synthesis, characteristics, and traditional vs. dry nano-aerosol applications

Yael Cohen; Esther Mwangi; Nimrod Tish; Jie Xu; Nachiket D Vaze; Tal Klingbell; Elazar Fallik; Yaguang Luo; Philip Demokritou; Victor Rodov; Elena Poverenov

doi:10.1016/j.foodchem.2022.132056

Quaternized chitosan as a biopolymer sanitizer for leafy vegetables: synthesis, characteristics, and traditional vs. dry nano-aerosol applications

Food Chem. 2022 Jun 1:378:132056. doi: 10.1016/j.foodchem.2022.132056. Epub 2022 Jan 6.

Authors

Yael Cohen¹, Esther Mwangi², Nimrod Tish³, Jie Xu⁴, Nachiket D Vaze⁴, Tal Klingbell¹, Elazar Fallik⁵, Yaguang Luo⁶, Philip Demokritou⁴, Victor Rodov⁵, Elena Poverenov⁷

Affiliations

¹ Agro-Nanotechnology and Advanced Materials Center, Department of Food Science, Agricultural Research Organization, The Volcani Institute, 68 HaMaccabim Road, P.O. Box 15159, Rishon LeZion 7505101, Israel; Institute of Biochemistry, Food Science and Nutrition, The Robert H. Smith, Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Herzl Street P.O. Box 12, Rehovot 7610001, Israel.
² Institute of Biochemistry, Food Science and Nutrition, The Robert H. Smith, Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Herzl Street P.O. Box 12, Rehovot 7610001, Israel; Department of Postharvest Science, Agricultural Research Organization, The Volcani Institute, 68 HaMaccabim Road, P.O. Box 15159, Rishon LeZion 7505101, Israel.
³ Department of Postharvest Science, Agricultural Research Organization, The Volcani Institute, 68 HaMaccabim Road, P.O. Box 15159, Rishon LeZion 7505101, Israel; Department of Life Sciences, Bar-Ilan University, Ramat Gan, Max ve-Anna Webb, 5290002, Israel.
⁴ Center for Nanotechnology and Nanotoxicology. Department of Environmental Health, T.H. Chan School of Public Health, Harvard University, 665 Huntington Avenue, Boston, MA 02115, USA.
⁵ Department of Postharvest Science, Agricultural Research Organization, The Volcani Institute, 68 HaMaccabim Road, P.O. Box 15159, Rishon LeZion 7505101, Israel.
⁶ Environmental Microbial and Food Safety Laboratory, U. S. Department of Agriculture, Agricultural Research Service, Beltsville Agricultural Research Center, 10300 Baltimore Ave, Beltsville, MD 20705, USA.
⁷ Agro-Nanotechnology and Advanced Materials Center, Department of Food Science, Agricultural Research Organization, The Volcani Institute, 68 HaMaccabim Road, P.O. Box 15159, Rishon LeZion 7505101, Israel. Electronic address: elenap@volcani.agri.gov.il.

PMID: 35030463
DOI: 10.1016/j.foodchem.2022.132056

Abstract

A series of quaternary dimethyl-(alkyl)-ammonium chitosan derivatives (QACs) was synthesized and studied for physicochemical properties and bioactivity. The QACs tended to spontaneously self-assembly into nanoaggregates. Antimicrobial activity was examined in vitro on Gram-negative Escherichia coli (E. coli) and Gram-positive Listeria innocua (L. innocua) bacteria as well as phytopathogenic fungus Botrytis cinerea. The hexyl chain-substituted QAC-6 demonstrated the highest potency causing 3.0- and 4.5-log CFU mL-1 reduction of E. coli and L. innocua, respectively. QAC-6 was tested for antimicrobial activity on stainless steel coupons and fresh spinach leaves. A traditional 'wet' application (spray) and dry Engineered Water Nanostructure (EWNS) approach were used for spinach decontamination. With both approaches, significant reduction of microbial load on the treated produce was achieved. The wet application showed a greater reduction of microbial load, while the advantages of EWNS were reaching the antimicrobial effect with miniscule dose of active agent leaving treated surface visibly dry.

Keywords: Botrytis cinerea; Chitosan; Engineered Water Nanostructures; Escherichia coli; Listeria innocua; Spinach.

MeSH terms

Chitosan*
Colony Count, Microbial
Escherichia coli O157*
Food Microbiology
Plant Leaves
Vegetables

Substances

Chitosan