Heat pretreatment reduces decay and chilling injury in sweet basil.
Aharoni N., Chalupowicz D., Faure-Mlinski M., Aharon Z., Maurer D., Lers A.
5th International Postharvest Symposium . Volume of Abstract . Verona, Italy 6-11 June 2004,p42.
2004
บทคัดย่อ
Heat pretreatment reduces decay and chilling injury in sweet basil.
Exposure of harvested sweet basil (Ocimum basilicum L.) to storage temperatures below 12 °C resulted in chilling injury expressed as leaf browning, necrosis, and abscission.Storing the basil at temperatures above 12 °C might result in soft rot, caused by Botrytis cinerea and Erwinia carotovora, followed by increased leaf abscission.Basil harvested early in the morning and stored at 12 °C was found to be very susceptible to both chilling injury and decay.Delaying the harvest, at least 4 hours after sunrise, but preferably to afternoon or evening, markedly reduced this susceptibility.Previous experiments revealed that exposure of morning harvested basil bunches to 38 °C for 16 hours, markedly reduced development of soft rot on the leaves and stems but caused slight leaf browning, wilting, and increased leaf abscission.The same heat treatment to afternoon or evening harvested basil, was much more efficient in inducing chilling resistance resulting in less decay and only slight physiological side effects.
Recent experiments revealed, that reducing the length of the heat treatment to only 8 hours for afternoon or evening harvested basil, controlled efficiently both decay and chilling injury.Heat treatment under these conditions enables to store some basil cultivars even at 9 °C which otherwise results in substantial injuries.Basil harvested before noon should be preheated for only 4 hours at 38 °C for achieving the best efficacy.Basil cuttings from multiple-harvested plants were more susceptible to both chilling injury and decay than those from first or second harvest.This susceptibility can be markedly reduced by the heat treatment applied to afternoon or evening harvested basil.Mode of action of the heat treatment will be discussed.