Lime essential oil helps extend fillet shelf life
Scientists in Iran have extended the shelf life of refrigerated trout fillets for between 10 and 15 days by coating the fish in a chitosan-gelatin glaze made with Persian lime peel essential oil.
An increasing demand for non-frozen products has made it necessary to improve shelf life with storage technologies without undesirable effects on their acceptance by the consumer.
Currently, “active packaging” is an effective way to reduce microbial and chemical deterioration by increasing the shelf life of foods. Protein, polysaccharide or lipid biopolymers can be used.
Better preservation
It has been shown that a glaze composed of chitosan-gelatin (Ch-Gl) has better preservation characteristics compared to single-component glazes. It is also known that the incorporation of essential oils in this type of glaze can result in prolonged maintenance of food.
The essential oil of Citrus latifolia, the Persian lime (LEO), contains more than 50 active and aromatic substances such as phenols and terpenes, which have antimicrobial and antioxidant properties.
Therefore, scientists from the University of Shahrekord decided to use the coating of Ch-Gl and incorporate LEO to create a layer on rainbow trout fillets, with the aim of storing them under super-chilled conditions, at temperatures above the point of freezing, for evaluation as a method of conservation of fillets.
To do this, the fillets were coated with distilled water (control), Ch-Gl, Ch-Gl plus 1% LEO and Ch-Gl plus 2% LEO and stored at -1.4 ° C for 30 days.
10 to 15 days
Evaluating microbiological, physicochemical and sensorial quality parameters, the researchers showed that all the treatments delayed the growth of total mesophilic bacteria, total psychrotrophic bacteria, enterobacteria and lactic acid bacteria compared to the control.
As for the physicochemical parameters, the treatments also delayed the increase in the total volatile nitrogen content, conjugated dienes, thiobarbituric acid reactive substances, pH and electrical conductivity.
“The use of Ch-Gl and Ch-Gl + 1% or 2% of LEO prolonged the useful life of the fillets between 10 and 15 days, respectively, and also improved the microbiological, physicochemical and sensory characteristics during refrigeration,” indicated the authors of the study in their results.
Better with lime oil
In addition, they added that the combined treatments (Ch-Gl + 1% or 2% LEO) were more effective than Ch-Gl alone in terms of the evaluated properties.
Finally, they concluded that the method based on Ch-Gl + LEO was effective in improving the quality and shelf life of rainbow trout fillets.
Read the abstract of the study entitled “Impact of glazing based on chitosan-gelatin incorporated with Persian lime (Citrus latifolia) peel essential oil on quality of rainbow trout fillets stored at superchilled condition” here.
