The Effects of Nanoemulsion Film Coatings Containing Essential Oils on the Storage Quality of Sugar Beets (Beta vulgaris L.)

This study was carried out under controlled conditions to determine the effects of chitosan-based nanoemulsion film coating formulations, formed using different essential oils, on storage quality of sugar beet roots during storage period. In the study, roots of Conviso Smart (KWS) sugar beet variety were coated with nanoemulsion film formulations containing thyme (Thymus vulgaris), clove (Szygium aromaticum), ginger (Zingiber officinale) and tea tree (Melaleuca alternifolia) essential oils doses of 250, 500 and 1000 ppm immediately after harvest. The roots were stored in plastic cases under controlled conditions (+ 8-10°C, 85-90% relative humidity) for 90 days. Weight loss in beet roots was determined at 30-day intervals from the start of the storage period, and at the end of the storage period, firmness, dry matter ratio, brix value, polar sugar, reducing sugar, alpha amino nitrogen and glycine betaine contents and fungal infection developments in beet roots were also evaluated. The film coating applications significantly affected postharvest weight and quality losses in sugar beet roots. The applications significantly reduced roots weight loss during storage compared to the control. Although the polar sugar ratios were higher in film coated roots compared to the control, alpha-amino nitrogen, glycine betaine, and reducing sugar contents showed significant decreases. White mold and green mold infections on the roots were significantly decreased, especially with high dose film coating applications. The highest dry matter ratio, brix values and firmness were obtained from film coatings containing 1000 ppm cinnamon and thyme essential oils. While polar sugar ratio was higher in root which film coated compared to the control, alpha amino nitrogen, glycine betaine and reducing sugar contents showed significant decreases. White mold and green mold infections developing on root showed significant decreases especially with film coating applications applied at high doses. The study concluded that coating sugar beet roots with nanoemulsion film formulations containing essential oils can significantly reduce, weight and quality losses, as well as fungal disease development, during the storage period.