Antibacterial and physical effects of modified chitosan based-coating containing nanoemulsion of mandarin essential oil and three non-thermal treatments against Listeria innocua in green beans

• Published in: International journal of food microbiology Vol. 191; pp. 82 - 88
• Main Authors: Severino, Renato, Vu, Khanh Dang, Donsì, Francesco, Salmieri, Stephane, Ferrari, Giovanna, Lacroix, Monique
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 17.11.2014; Elsevier
• Subjects: Anti-Bacterial Agents - pharmacology; Antimicrobial coating; Bacteriology; Biological and medical sciences; Chitosan - pharmacology; Colony Count, Microbial; Emulsions; Fabaceae - drug effects; Fabaceae - microbiology; Food industries; Food microbiology; Food Microbiology - methods; Food Preservation - methods; Fundamental and applied biological sciences. Psychology; Life Sciences; Listeria - drug effects; Listeria innocua; Microbiology and Parasitology; Nanoemulsion of mandarin oil; Oils, Volatile - pharmacology; Ozonated water; Phaseolus vulgaris; UV-C; Vegetables - drug effects; Vegetables - microbiology; Vegetables - standards; γ-Irradiation; UV-C; Antimicrobial coating; Ozonated water; Nanoemulsion of mandarin oil; γ-Irradiation; Listeria innocua; Water; Heat treatment; Vegetables; Fruit; Citrus fruit; Antimicrobial agent; Bean; Gamma irradiation; Bacteria; Essential oil; Chitosan; Coating; Mandarin; Antibacterial agent
• ISSN: 0168-1605; 1879-3460
• DOI: 10.1016/j.ijfoodmicro.2014.09.007

The antimicrobial activity against Listeria innocua of three different combined non-thermal treatments, along with the impact on color and texture on green bean samples, was evaluated. In this study a bioactive coating formulation based on modified chitosan containing 0.05% nanoemulsion of mandarin essential oil was tested in combination with γ-irradiation, UV-C and ozonated water treatments, and the results in terms of antimicrobial activity, color and texture changes, were evaluated during 14days storage. The combined coating and γ-irradiation treatment gave promising results, showing 3.3 log CFU/g initial microbial reduction, and exhibiting a strong synergistic antimicrobial effect. The treatment based on UV-C and coating formulation allowed a 3 log CFU/g reduction of initial L. innocua population on samples, showing a good residual antimicrobial activity and preventing loss of firmness and color changes during storage. The combined treatment of coating and ozonated water did not show any synergistic or additive antimicrobial effect, but they showed an impact on firmness and color. In conclusion UV-C and γ-irradiation treatments, in combination with the bioactive coating, represent an effective approach to control the growth of L. innocua on vegetable foods. •Modified chitosan containing mandarin essential oil nanoemulsion was used as coating.•Coating was effective against Listeria innocua in green beans.•UV-C or γ-irradiation and ozonated water was also tested in combination with coating.•UV-C or γ-irradiation plus coating ensured bacterial and physical properties of beans.•γ-Irradiation plus coating showed a synergistic antibacterial effect during storage.