Use of organic natural extracts to enhance microbiological properties of biofilms.

What is it about?

Aim: Analysing the antimicrobial activity—against food-borne microorganisms— of modified chitosan–starch films using formic and acetic acid as chitosan solvents and Melicoccus bijugatus leaves and fruit extracts. Methods and Results: The films’ antimicrobial activity against mesophilic aerobic bacteria, total coliform, and fungi were also analyzed, in accordance with the Mexican Official Norms (NOM-092-SSA1-1994, NOM-111-SSA1-1994 and NOM-113-SSA1-1994). The pH values of the films and extracts were measured, and the volatile compounds of the extracts and two films were determined by Gas Chromatography-Mass Spectrometry (GC-MS) considering the relationship among the type of compounds extracts concentration, films’ pH and the antimicrobial activity against bacteria and fungi. The best results are obtained by films with formic acid and 10% (v/v) of leaf and fruit extracts, in comparison with untreated chitosan–starch films. Conclusions: The extracts’ compounds improved the films’ antimicrobial capacity and inhibited micro-organisms' growth with no previous sterilization required. It is correlated to the media's pH, the combination of solvent/extract used, and its concentration.

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Photo by Sangga Rima Roman Selia on Unsplash

Photo by Sangga Rima Roman Selia on Unsplash

Why is it important?

Significance and Impact of the study: This is one of the few research types where the antimicrobial activity of M. bijugatus extracts is studied. It was found that the presence of these extracts is capable of improving the antimicrobial activities of chitosan–starch films. The modified films' performance suggests their potential application as novel food packaging materials and encourages further research.