THE ANTIFUNGAL EFFECTS OF HYDROALCOHOLIC EXTRACT OF THYME (THYMUSVULGARIS) AND CARBOXY METHYL CELLULOSE EDIBLE COATING ON THE SHELF LIFE OF FRESH HAZELNUT

Introduction: Today, biodegradable packaging is taken more consideration due to the environmental problems of the synthetic packaging materials. Edible coating is one of the important biodegradable active packaging material and is regarded as a suitable alternative for the synthetic packaging studied. In this research the effects of edible coating based on carboxy methyl cellulose containing thyme was studied with particular reference to moisture absorption, fungal growth and sensory characteristics in coated raw hazelnut. Materials and Methods: The edible coatings were prepared at different concentration levels of carboxy methyl cellulose (0.0, 0.5, & 1.5% W/V) and thyme extracts (0.0, 0.5 & 1% V/V). The mean changes in fungal growth and sensory characteristics were determined for coated and uncoated (control) hazelnut over 21 weeks. The tests were applied in three replications using factorial design based on completely random design. Results: The results of this research showed that non-coated samples had the most moisture absorption, fungal growth and mold development rates. Addition of hydroalcoholic thyme extract to coating solution significantly reduced the fungal growth in coated samples (p≤ 0.05). The results of the sensory tests of the samples indicated that the use of carboxy methyl cellulose coating delayed the softening of the tissues. Conclusion: The use of edible coatings with carboxy methyl cellulose and thyme extract reduced the moisture absorption and mold growth and increased the shelf-life of the coated hazelnuts. Carboxy methyl cellulose, a biodegradable natural biopolymer might be regarded as an alternative to the synthetic packaging.