Vacuum cooler for fresh cut flowers

Floriculture is an agricultural sector of worldwide importance and of paramount social and economical influence. Roses account to a large percentage of all flowers grown. After flowers are harvested, temperature is the one factor affecting them the most. This is the time to evaluate different cooling methods used in the postharvest of roses, by measuring their effects over floral longevity and other quality variables. The residual effects of passive, forced air and vacuum cooling methods were evaluated, after transport simulation. The test was performed at a flower-exporting farm. It was found that those flowers exposed to vacuum cooling showed the longest longevity while those that took forced air had the lowest.

The main cause of elimination of flowers was the presence of Botrytis (44%) and dormancy (35%). No significant differences in such causes were found among the various cooling treatments; however it was observed that those flowers that went through the passive and forced air cooling methods showed presence of Botrytis much sooner than those exposed to vacuum cooling. Furthermore bent neck in vacuum cooled flowers only were observed after day 12 while in the other treatments that happened within the first five days of the test. With regard to the quantity of stems affected by dehydration, no differences were found among all treatments, which refutes the common belief that vacuum cooling accelerates dehydration of flower stems.

The main problems related to the quality of flowers during the production phase are inappropriate harvest in length of stalks and opening cut stage, bent stems, mechanical damage and sanitation problems. Those related to post harvest are classification and bunch forming, deterioration, hydration and cold chain.

Fresh cut flowers are still live material and metabolically active and therefore subject to the same physiological processes as the plant. However, after being cut they deteriorate faster, under similar environmental conditions.

Thus, longevity of cut flowers is determined by the same factors that affect the growth of plants, such as temperature, humidity, water, light and availability of nutrients.

Post time: Jun-17-2023