Carvone Containing Essential Oils as Sprout Suppressants in Potato (Solanum tuberosum L.) Tubers at Different Storage Temperatures

Sprout suppressant capacities of caraway ( Carum carvi L.), dill ( Anethum graveolens L.), and spearmint ( Mentha spicata L.) essential oils containing high levels of carvone were studied at different storage temperatures (5, 10, and 15 °C) and compared to two chemical sprout inhibitors chlorpropham (CIPC) and S-(+)-carvone. Amongst the essential oils tested, caraway oil was the most effective sprout inhibitor and prevented sprouting up to 180 days at all storage temperatures. CIPC treatment in preventing sprouting was very effective only at low-temperature conditions, while its effect diminished at 15 °C and sprouting began after 120 days of storage. Dill oil prevented sprouting effectively at 15 °C for more than 135 days, and less than 20% of tubers exhibited sprouting. Sprout inhibitory effects of peppermint oil and S-(+)-carvone decreased with increasing storage temperature. All treatments significantly decreased weight loss as compared to the control. The weight loss of caraway oil treated tubers was 36.1%, 46.2%, and 49.6% at 5, 10, and 15 °C, respectively, being lower than that of the control. The peelings of tubers treated with essential oils showed lower carvone residue levels than those of S-(+)-carvone applied tubers. The CIPC residue levels of tubers stored at 5 °C were 16 ppm, being greater than the allowed threshold levels in European countries. It was concluded that using caraway and dill oils decreased weight losses substantially and prevented sprouting for long-term storage at up to 15 °C.