Potential of Propolis Extract as a Natural Antioxidant and Antimicrobial in Gelatin Films Applied to Rainbow Trout (Oncorhynchus mykiss) Fillets

Abstract

Usage of edible films and coatings alone or incorporated with natural extracts are a new approach to preservation and packaging of food. In this study, therefore, the microbiological, chemical quality, and sensorial changes of rainbow trout fillets coated with gelatin films supplemented with propolis extract (PE) (2, 8, 16%), as a source of polyphenols, were determined during 15 days of refrigerated storage (4 ± 1 °C). According to peroxide value (PV) and thiobarbituric acid reactive substances (TBARS) assays, lipid oxidation was delayed in the fillets coated with gelatin films incorporated with PE comparing with the control and gelatin-coated (without PE) fillets. The total volatile basic nitrogen (TVB-N) value of rainbow trout fillets showed an increase in all groups at the end of storage, observing the lowest values in the fillets coated with gelatin films prepared with 16% PE. Gelatin films enriched with PE had great inhibitory effects on the microbial growth in rainbow trout fillets. The addition of PE enhanced the effectiveness of gelatin films and delayed the lipid oxidation and sensory and microbial deterioration in trout fillets coated with these films. Thus, PE can be recommended to be used as a natural antioxidant and antimicrobial additive with gelatin films to maintain rainbow trout fillet quality.

Effectiveness of chitosan/propolis extract emulsion coating on refrigerated storage quality of crayfish meat (Astacus leptodactylus)

“…Similar results were found in studies for chitosan/cinnamon oil and fish gelatine/GL-βCDcurcumin for fresh fish protection (Jouki et al, 2014;Sun et al, 2019). Ucak et al (2020) reported that during the storage period, PB of fillets coated with gelatin films containing propolis were lower than those of the gelatin film coated samples and control samples. The varieties of H 2 S-producing bacteria (Figure 3c), yeast and mold bacteria (Figure 3d), and Pseudomonas spp.…”

“…Spinelli et al (2015) reported that the sensory quality of fresh fish burgers containing microencapsulated propolis improved. Ucak et al (2020) found similar results. They reported that combining PE with gelatin films had a positive effect on trout fillet.…”

“…This count was greater than the maximal admissible limit of ICMSF. Ucak et al (2020) reported lower TMAB numbers in gelatin-coated trout fillets containing propolis. The lower TVC of samples may be attributed to the antimicrobial activity of propolis.…”

Antioxidant and antimicrobial effects of gelatin films incorporated with citrus seed extract on the shelf life of sea bass ( Dicentrarchus labrax ) fillets

“…(2020), who found that chitosan coating enriched with lemon peel extract had positive effects on the sensory properties of fillets, and the shelf life extended for 6 days compared with the control. In many studies, it was reported that edible films and coatings incorporated with natural extracts or essential oils could improve the sensory characteristics of fish fillets (Mayeli et al., 2019; Ucak, 2019; Ucak et al., 2020).…”

Determination of microbiological quality and histamine levels in rainbow trouts (Oncorhynchus mykiss)

“…is higher than the findings of the researchers. Ucak et al (2020) reported the numbers of initial total viable, psychrotrophic bacteria, yeastmold and Enterobacteriaceae as 1.543, 1.932, 1.194 and3.390log 10 cfu/g respectively. The findings of the researchers are quite low compared to our findings in terms of total viable, total psychrotrophic bacteria and yeast and mold numbers.…”