COPING WITH POSTHARVEST PHYSIOLOGY OF FRESH CULINARY HERBS
Fresh green herbs (Labiatae family) are vulnerable to accelerated senescence due to a high rate of metabolism which is increased further following harvesting and handling procedures. Most of the herbs keep better at low temperatures close as possible to 0°C. Prevention of water loss in the harvested herbs and storage at their optimal temperature are prime factors in the maintenance of their culinary quality. Excessive water loss can be eliminated by keeping the produce at high humidity. Most fresh herbs of the Labiatae family are kept well when packed in cartons lined with folded perforated polyethylene (PE), in which water loss, leaf abscission and decay are minimal. Perforation of the PE liner reduces the undesirable accumulation of ethylene and CO2. Nevertheless, the perforated film is not effective enough to delay the senescence of yellowing-susceptible herbs such as coriander, dill, chervil, sorrel, parsley, chives, and watercress. Packing these species in cartons with non-perforated PE liners results in the creation of a moderate modified atmosphere (MA) capable of retarding yellowing and decay. Elevated concentrations of CO2 inhibited the senescence-inducive effect of accumulated ethylene in the package, especially when combined with a decreased level of O2. Packing these herbs in sealed PE-lined cartons exhibited more marked changes in the respiratory gases, especially oxygen. Extreme temperature fluctuations during shipment may result in anaerobic respiration in sealed film, that can be eliminated by using microperforated (MP) film. In MP packages, CO2 concentrations never exceeded 10% and O2 concentrations never dropped below 5%. Spraying of yellowing-susceptible herbs with gibberellic acid (GA3) immediately prior to harvest retarded senescence and decay. Optimal results were achieved when the GA3-treated herbs were packed in film with MA.
Aharoni, N., Dvir, O., Chalupowicz, D. and Aharon, Z. (1993). COPING WITH POSTHARVEST PHYSIOLOGY OF FRESH CULINARY HERBS. Acta Hortic. 344, 69-78
modified atmosphere, film packaging, gibberellic acid, cold storage