Disinsectization and Sanitation of Dates
Like most of the fruits, dates are exposed to the risk of contamination by parasites, and in particular moths, beetles, yeasts, and molds.
The treatment of the product is currently done chemically by fumigation of methyl bromide or phosphine.
However, these gases are highly toxic, difficult to handle, and are not compatible with organic farming. Methyl bromide is banned in more and more countries because it destroys the ozone layer, and phosphine may be forbidden as well in the future due to its potential toxicity for the workers. Industrials are therefore looking to replace them with another method.
Dates are not a particularly fragile food. However, their high sugar rate makes them particularly vulnerable to mold and yeast, in addition to moths and beetles’ larvae.
The main difficulty therefore consists in killing the insects and deactivating the microorganisms, while preserving the organoleptic properties of the dates: appearance, taste, and texture of the fruit.
The gentle treatment offered by the microwave helps to keep the taste while getting rid of parasites.
SAIREM has conducted a comprehensive study (available on request) to ensure that the microwave treatment is effective on mold and insects, while preserving the integrity and taste of the dates.
By testing different wavelength (915 MHz and 2450 MHz), power adjustment, and treatment duration, our company has established the most suitable cycle in order to obtain an effective treatment against parasites and micro-organisms, and the preservation of the organoleptic properties of the fruits (specifically to avoid the stickiness due to the high sugar rate).
Microwave have the ability to heat thanks the dielectric loss properties of materials. This phenomenon is caused by the vibration and rotation of polarized molecules inside the material, induced by the quick polarity reversal of the electromagnetic field (a million times per second).
The heat generation is almost instantaneous and allows for a perfectly controlled process thanks to rapid, uniform heating. Moreover, almost all the energy is transferred to the treated product, drastically reducing energy losses.
Unlike conventional solutions, where heat is transferred by convection or conduction from the outside to the product through its surface, microwave and RF heat the entire product mass directly and homogeneously. It is called “volumetric heating”.
We have proposed a microwave tunnel at 915 MHz who can treat up to 1200 kg/h of product, without the use of any chemical. The temperature of the dates reaches around 75 °C for few minutes, which is sufficient to kill mold and pest.
Organic farming compatible process
Microwave are already in use in several countries for the treatment of organic food as it avoids the use of chemicals and only operate by thermal process. It has been approved in France for the treatment of organic products.
Although microwave technology has a thermal effect only, the high power used requires certain precautions. This is why all our equipment is equipped with redundant sensors and interlocks, as well as a microwave leak detector, which will immediately cut the power if necessary.
Treatment in the final packaging !
By using the volumetric heating properties of the microwaves, our equipment is able to raise quickly and homogeneously the temperature of the dates, from core to surface.
The speed of the process, who last less than 10 minutes, allow a perfect sanitation of the dates, while preserving their organoleptic properties.
Finally, for an optimized logistic, the fruits can be treated directly in their final packaging!
For more info contact Deléne Boshoff from PHT – 0861 777 993