Evaluation of CMC-based coatings with thyme extract)Thymus vulgaris(on physiochemical reactions of fresh hazelnut

In recent years, extensive researches has been done on use of edible coating in food packaging. Edible coatings can increase the shelf life of coated foods and they are suitable alternative for synthetic packaging. In this research, the effect of carboxy methyle cellulose based edible coatings with thyme extract on reducing moisture absorption and decreasing lipid oxidation productions have been evaluated. The edible coatings were prepared at different concentration levels of carboxy methyle cellulose (0.0, 0.5, and 1.5% W/V) and thyme extracts (0.0, 0.5 and 1% V/V). The moisture content, peroxide, thiobarbituric acid and acid number changes were determined for samples. The experiment was performed by Dunnett statistical tests in three replications using factorial design based on completely random design. The results indicated that the coating containig of 1.5% W/V of carboxy methyle cellulose and 1% V/V of thyme extract showed better results in reduction of peroxide value in fresh hazelnut. Carboxy methyl cellulose coating can delay the lipid oxidation of fresh hazelnut by providing a barrier against moisture and oxygen permiability to the texture of hazelnut. Adding of thyme extract into coating formulation, in addition to increasing the shelf life of hazelnut, is important regarding functional aspects of hazelnut. This coatings have both edible and environmentally friendly properties and preferable to synthetic packaging.