Study of carboxymethyl cellulose-based edible coatings containing nanoliposomes, free Rosemarinus officinalis essential oil on the microbial, chemical properties of rainbow trout

Abstract

In this study, we examined the effects of free and microencapsulated liposomes containing rosemary essential oil (REO) on the microbiological and physicochemical properties of rainbow trout meat coated with carboxymethyl cellulose (CMC). The essential oil was extracted using a Clevenger, and nanoliposomes of the essential oil were produced through a combination of thin-layer hydration and ultrasound waves. Gas chromatography-mass spectrometry analysis revealed that the main components of REO were compounds 1-8, cineole (30.03%), and alpha-pinene (13.09%). Antioxidant activities measured by the DPPH method were 72.21% for free REO and 71.8% for microencapsulated REO. Both types of REO nanoliposomes were separately applied with CMC to create an edible coating for rainbow trout meat, which was stored at 4°C for 15 days. Our findings on the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of REO and its nanoliposomes against Escherichia coli and Staphylococcus aureus showed that REO nanoliposomes had a significantly lower effect compared to free REO (p< 0.05). Moreover, the growth of live bacteria, psychotropic bacteria, lactic acid bacteria, and enteric bacteria in samples coated with CMC and REO nanoliposomes was significantly reduced compared to other samples and was lower than in samples with free essential oil (p<0.05). Overall, using CMC with either free REO or REO nanoliposomes effectively reduces the microbial and chemical deterioration of rainbow trout during storage.

Keywords

• rosemary essential oil
• nanoliposome
• rainbow trout
• length of storage period
• quality