Gelatin chitosan film incorporated with clove essential oil for retaining quality of silver pomfret fish fillet

Clove (Syzgium aromaticum L.) essential oil has been reported for its potent antioxidant and antimicrobial activities. In this study, clove essential oil was incorporated with gelatin-chitosan solution to develop an edible film (CEO film) for fish preservation. The objective was to determine the effectiveness of this edible film in controlling physical, biochemical and microbial changes in fillet of silver pomfret (Pampus argenteus). The effectiveness of this film was compared with uncoated fillet (control), and gelatin-chitosan film (GC film). The formulated film was tested for water solubility and antimicrobial activity against four selected microorganisms: Escherichia coli, Pseudomonas aeroginosa, Salmonella enterica and Bacillus cereus. The effectiveness of the formulated film on the silver pomfret fillet was evaluated based on weight loss, pH, firmness, total volatile basic nitrogen (TVB-N) and total plate count (TPC) of the fish fillet. The CEO films intermediately inhibit the growth of E. coli and S. enterica. Meanwhile, GC film did not show inhibition on the growth of tested microorganisms. CEO film had lower water solubility compared to GC film. CEO film was observed to reduce weight loss (p<0.05), lower pH on day 6 (p<0.05), and increase firmness of fish fillet when compared to the control (p<0.05). Fish fillet applied with CEO film also had lower TVB-N value and microbial count. This study shows that the CEO film has antimicrobial properties which can benefit fish preservation. Improvement for developing the edible film with acceptable properties is thus important to extend the shelf life of fish fillet.