Finding a Needle in a Haystack: Producing Antimicrobial Cutin-Derived Oligomers from Tomato Pomace

Area of Science:

• Agricultural Science and Technology
• Biomaterials Science
• Food Chemistry

Background:

• Agro-industrial residues, rich in plant polymers like cutin, are valuable resources for novel materials and supplements.
• Fruit pomaces, particularly tomato pomace, contain abundant cutin in their peels, offering a sustainable source for bioproducts.
• Previous research has explored fruit pomaces for cutin-derived materials, but specific antimicrobial applications require further investigation.

Purpose of the Study:

• To establish proof of concept for producing antimicrobial oligomers from cutin-rich materials isolated from tomato pomaces.
• To analyze the chemical characteristics of cutin-rich materials and their derived oligomers.
• To screen the bactericidal activity of these oligomers against common foodborne pathogens, *Escherichia coli* and *Staphylococcus aureus*.

Main Methods:

• Isolation of cutin-rich materials from tomato pomaces using a single-step ionic liquid extraction.
• Chemical characterization of pomace and isolated materials using nuclear magnetic resonance (NMR) and gas chromatography-mass spectrometry (GC-MS).
• Mild hydrolysis of cutin-rich materials to produce oligomers, followed by chemical analysis and screening for antimicrobial activity.

Main Results:

• The chemical signature of the isolated cutin-rich material correlated with the original pomace composition.
• Antimicrobial activity against *Escherichia coli* was linked to the presence of esterified, linear/branched structures, potentially including dioic acids.
• *Staphylococcus aureus* exhibited susceptibility to both oligomers and monomers, indicating a broader activity spectrum.

Conclusions:

• Tomato pomace cutin can be processed into antimicrobial oligomers, validating its potential as a source for bioactive compounds.
• The structural characteristics of the derived oligomers influence their specific antibacterial efficacy.
• Further research is needed to optimize the production of broad-spectrum antimicrobial oligomers for circular economy applications.