Combined effect of antimicrobial edible coatings with reduction of initial microbial load on the shelf‐life of fresh hake (Merluccius merluccius) medallions

• Published in: International journal of food science & technology Vol. 54; no. 3; pp. 835 - 843
• Main Authors: Otero‐Tuárez, Víctor, Carrión‐Granda, Ximena, Fernández‐Pan, Idoya, Fernández, Teresa, Maté, Juan I.
• Format: Journal Article
• Language: English
• Published: Oxford Wiley Subscription Services, Inc 01-03-2019
• Subjects: Antiinfectives and antibacterials; Antimicrobial edible coating; Bacteria; Carvacrol; Coating effects; Coatings; Enterobacteriaceae; Essential oils; Evolution; Fish; Hake; Hydrogen sulfide; initial microbial load; Lactic acid; Lactic acid bacteria; Merluccius merluccius; Microorganisms; NaOCl; Oregano; oregano essential oil; Pseudomonas; Reduction; refrigerated hake; Refrigeration; Shelf life; Sodium; Sodium hypochlorite; whey protein isolate
• ISSN: 0950-5423; 1365-2621
• DOI: 10.1111/ijfs.14003

Summary
Two distinct strategies were combined to preserve fresh fish (Merluccius merluccius) under refrigeration at 4 °C for 12 days: (i) the application of an antimicrobial edible coating enriched with oregano essential oil (OEO) or carvacrol (CV) and (ii) the reduction of initial microbial load by good handling practise and the use of sodium hypochlorite (NaOCl). The action of antimicrobial coatings alone retarded the growth of Enterobacteriaceae, lactic acid bacteria (LAB) and H2S producing bacteria on fish samples. The reduction of initial microbial load by itself only affected the evolution of LAB, but not the rest of the bacterial groups. When using both techniques combined, edible antimicrobial coatings were significantly more effective with additional and significant delays in the growth of mesophilic, psychrotrophic and Pseudomonas bacteria. Thus, the use of both strategies combined resulted in a reduction of the counts of all bacterial groups after 12 days of storage which ranged from 1.5 log and 8 log, in Pseudomonas and H2S producing bacteria, respectively. Moreover, no significant differences were observed when comparing the microbiological evolution of samples treated with OEO compared to those only treated with CV.
Effect of NAOCl and/or antimicrobial coating treatments on the evolution of the microbial quality in refrigerated fresh hake medallions