The effect of controlled atmospheres on the composition and quality of dill (Anethum graveolens L. cv. Ducat) cultivated in spring and stored at two temperatures

Abstract

This study was performed to evaluate four atmospheres varying in CO2 and N2 concentrations on the composition and quality of dill (Anethum graveolens L. cv. Ducat) during storage. Seeds were sown directly in the soil on 16/01/2010 and the plants harvested 93 days after sowing. The leaves (lamina and petiole) were weighed at harvest and immediately transferred to airtight plastic bags within which the atmospheres were modified by injection of O2, CO2 and N2. The treatments that were applied (O2-CO2-N2) were: (1): 20-0-80, (2): 20-5-75, (3): 20-10-70, (4): 20-15-65. All samples were stored for 14 days at 2 or 5°C and the gas composition within the bags maintained at the desired levels. From the results, it was found that weight loss during storage varied between 7 and 12% at 2oC and 13 and 17% at 5oC irrespective of the gas composition. Vitamin C concentration decreased during storage, but at both storage temperatures the decrease was less at the highest CO2 level. The concentration of total phenolics decreased during storage, irrespective of the composition of the storage atmosphere. There was a loss of chlorophyll during storage, which tended to be greater at 5oC than at 2oC, but was prevented at both temperatures by the highest CO2 concentration. In consequence, leaves stored under a gas composition of 20-15-65 (O2-CO2-N2) were greener at the end of storage. This, in conjunction with the relatively higher vitamin C concentration in this treatment, indicates that 15% CO2 was the most suitable storage atmosphere for quality retention in dill, while the preferred temperature was 2oC due to lower weight loss.