Physiological postharvest responses of marjoram (Majorana hortensis Moench)
Horst Bottcher, Ingeborg Gunther and Ulrike Bauermann
Postharvest Biology and Technology Vol: 15 Issue: 1 Pages: 41-52.
1999
บทคัดย่อ
Freshly harvested marjoram is characterized by an unusually high respiration
rate (average at 10°C, 632 W t-1; at 20°C,
1409 W t-1, and at 30°C, 2625 W t-1).
These comparatively high levels were maintained throughout a postharvest period
of 72¯80 h. The values declined only to 49, 39 and
42% of the initial rate for each temperature range, and even at 30°C
there was no respiratory collapse despite notable senescence and wilting. The
greatest decrease in the rates occurred during the first 18 h after cutting.
The ensuing dry matter loss was relatively high, as was transpiration (at 10°C,
1.53% of the fresh matter was lost in 24 h). The essential oil balance measured
over the postharvest period at 10 and 20°C increased slightly (10%).
At 30°C,
majoram herbs (1st cut) which had been harvested near the optimal date (10¯30%
flowering) contained 22% more essential oils than dried, freshly harvested
material; physiologically younger plants (2nd cut) showed even a 35% increase.
In some cases the proportion of cis-sabinenic hydrate and sabinenic
hydrate-acetate increased slightly at 20 and 30°C, while there was only a
minor influence on -
and
-terpinenes
and 4-terpineol. Colour and exterior quality were best maintained, as in dried
material, when the herbs were held at 10°C throughout the postharvest
period.