title: Development of Metal-Organic Framework for Gaseous Plant Hormone Encapsulation To Manage Ripening of Climacteric Produce.
abstract: Controlled ripening of climacteric fruits, such as bananas and avocados, is a critical step to provide consumers with high-quality products while reducing postharvest losses. Prior to ripening, these fruits can be stored for an extended period of time but are usually not suitable for consumption. However, once ripening is initiated, they undergo irreversible changes that lead to rapid quality loss and decay if not consumed within a short window of time. Therefore, technologies to slow the ripening process after its onset or to stimulate ripening immediately before consumption are in high demand. In this study, we developed a solid porous metal-organic framework (MOF) to encapsulate gaseous ethylene for subsequent release. We evaluated the feasibility of this technology for on-demand stimulated ripening of bananas and avocados. Copper terephthalate (CuTPA) MOF was synthesized via a solvothermal method and loaded with ethylene gas. Its crystalline structure and chemical composition were characterized by X-ray diffraction crystallography, porosity by N2 and ethylene isotherms, and morphology by electron microscopy. The MOF loaded with ethylene (MOF-ethylene) was placed inside sealed containers with preclimacteric bananas and avocados and stored at 16 °C. The headspace gas composition and fruit color and texture were monitored periodically. Results showed that this CuTPA MOF is highly porous, with a total pore volume of 0.39 cm(3)/g. A 50 mg portion of MOF-ethylene can absorb and release up to 654 μL/L of ethylene in a 4 L container. MOF-ethylene significantly accelerated the ripening-related color and firmness changes of treated bananas and avocados. This result suggests that MOF-ethylene technology could be used for postharvest application to stimulate ripening just before the point of consumption.
authors.affiliation: Environmental Microbial and Food Safety Laboratory, Agricultural Research Service, ‡Food Quality Laboratory, Agricultural Research Service, and ∥Electron and Confocal Microscope Unit, Agricultural Research Service, United States Department of Agriculture , Beltsville, Maryland 20705, United States.|Department of Nutrition and Food Science, and ⊥Department of Chemistry and Biochemistry, University of Maryland , College Park, Maryland 20742, United States.
authors.forename: Boce
authors.initials: B
authors.lastname: Zhang
authors.affiliation: Environmental Microbial and Food Safety Laboratory, Agricultural Research Service, ‡Food Quality Laboratory, Agricultural Research Service, and ∥Electron and Confocal Microscope Unit, Agricultural Research Service, United States Department of Agriculture , Beltsville, Maryland 20705, United States.|Department of Nutrition and Food Science, and ⊥Department of Chemistry and Biochemistry, University of Maryland , College Park, Maryland 20742, United States.
authors.forename: Yaguang
authors.initials: Y
authors.lastname: Luo
authors.affiliation: Environmental Microbial and Food Safety Laboratory, Agricultural Research Service, ‡Food Quality Laboratory, Agricultural Research Service, and ∥Electron and Confocal Microscope Unit, Agricultural Research Service, United States Department of Agriculture , Beltsville, Maryland 20705, United States.|Department of Nutrition and Food Science, and ⊥Department of Chemistry and Biochemistry, University of Maryland , College Park, Maryland 20742, United States.
authors.forename: Kelsey
authors.initials: K
authors.lastname: Kanyuck
authors.affiliation: Environmental Microbial and Food Safety Laboratory, Agricultural Research Service, ‡Food Quality Laboratory, Agricultural Research Service, and ∥Electron and Confocal Microscope Unit, Agricultural Research Service, United States Department of Agriculture , Beltsville, Maryland 20705, United States.|Department of Nutrition and Food Science, and ⊥Department of Chemistry and Biochemistry, University of Maryland , College Park, Maryland 20742, United States.
authors.forename: Gary
authors.initials: G
authors.lastname: Bauchan
authors.affiliation: Environmental Microbial and Food Safety Laboratory, Agricultural Research Service, ‡Food Quality Laboratory, Agricultural Research Service, and ∥Electron and Confocal Microscope Unit, Agricultural Research Service, United States Department of Agriculture , Beltsville, Maryland 20705, United States.|Department of Nutrition and Food Science, and ⊥Department of Chemistry and Biochemistry, University of Maryland , College Park, Maryland 20742, United States.
authors.forename: Joseph
authors.initials: J
authors.lastname: Mowery
authors.affiliation: Environmental Microbial and Food Safety Laboratory, Agricultural Research Service, ‡Food Quality Laboratory, Agricultural Research Service, and ∥Electron and Confocal Microscope Unit, Agricultural Research Service, United States Department of Agriculture , Beltsville, Maryland 20705, United States.|Department of Nutrition and Food Science, and ⊥Department of Chemistry and Biochemistry, University of Maryland , College Park, Maryland 20742, United States.
authors.forename: Peter
authors.initials: P
authors.lastname: Zavalij
mesh_terms: D003300:Copper / Q000737:chemistry; D005030:Ethylenes / Q000737:chemistry / Q000494:pharmacology*; D005519:Food Preservation / Q000295:instrumentation / Q000379:methods*; D061353:Food Storage; D005638:Fruit / Q000187:drug effects / Q000254:growth & development; D005740:Gases / Q000737:chemistry / Q000494:pharmacology; D028521:Musa / Q000187:drug effects* / Q000254:growth & development; D027421:Persea / Q000187:drug effects* / Q000254:growth & development; D010795:Phthalic Acids / Q000737:chemistry; D010937:Plant Growth Regulators / Q000737:chemistry / Q000494:pharmacology*; D016062:Porosity; D014961:X-Ray Diffraction
chemical_list: D005030:Ethylenes; D005740:Gases; D010795:Phthalic Acids; D010937:Plant Growth Regulators; C011363:terephthalic acid; D003300:Copper; C036216:ethylene
keywords: climacteric produce; ethylene; food waste; metal−organic framework