Authorized talcum powder acts as an adjuvant.
We understand adjuvants as: different substances which are added to industrial processes in order to improve them, obtaining better work conditions and/or performance and quality of the final product, removing it during the process and remaining only in the final product the technically inevitable quantity.
For virgin olive oil extractions, only food additives which doesn’t contain any biological or chemical action can be used during the process.
Micronized natural talcum powder and kaolinitic clay are the only authorized adjuvants by the European Union for virgin olive oil extraction.
One of the most used technological adjuvants during the elaboration process of olive oil is the ‘MTN’ or ‘Microtalco Natural’ (natural micro talcum powder), which is a hydrated magnesium silicate.
Its use is authorized by the spanish legislation since 1986, always for food purposes and when it doesn’t produce any change in the olive oil physical or organoleptic properties.
Its acting principle is through physical absorption phenomena, which produces no chemical processes against the definition of virgin olive oil.
Its use is recommended when we can observe the called ‘pastas difíciles’, recognized by showing up as a very fluid and non consistent dough, which doesn’t allow a clear separation of the oil during the blend.
This paste produces, during the solid-liquid separation, very dirty oils with a pap excess; this excess forces to sieve the oil through a vertical centrifuge, action that involves much more difficulties.
As a consequence of this situation, the obtained subproducts have a high concentration of fat, that means a big loss of performance during the process.
In order to avoid this situation as much as possible, talcum powder is often used in order to allow the improvement of the physical structure of the paste, so the centrifuge and shake operations are more effective.
The clarification of the olive oil by the horizontal centrifuge decanter and a decrease of fat level in subproducts are the most visible signs of talcum powder use.
It must only be used when the olive paste demands it as if it is used in non needed conditions, the obtained effect will be the contrary, increasing the fat levels. Also, it demands a continuous analytical control, which allow us to regulate the talcum powder dosis that it’s adequate to the type of paste that you are processing, which can variate from 0,5% to 2% of olive weight.
Most commonly, the higher water content on the olive (beginning of the season), the more amount of talcum powder dose is used, decreasing as the season goes on.
The early olive grind, certain olive varieties suchs as ‘Picual’ or ‘Hojiblanca’ and olives coming out from olive trees who have entered in sap out of the winter, are the most typical situations for MTN use.
Talcum powder dosage must be done through dispensers, which can be programmed to add constant doses of MTN related the mass in process.
The use of a dipper is totally inadvisable as it doesn’t allow the uniform addition of the MTN. The point where to do the talcum powder dosage depends on the blender tipe.
In general, for the three bodies horizontal blenders the dosage must be done in the central body and in the discharge point of the superior body blended paste; in two bodies blenders, it will be done in the lowest body, and in the further point of the suction area of the dough pump.
With talcum powder use, different studies reveal that there is no significant changes in olive oil quality parameters; however, above average dosage can induce to taste loses.
In rare occasions, wastes of the talcum powder or from its derivatives can be found in the final product, but they are no harm neither for health or the environment; due to having a bigger density, they might not dissolve in olive oil.
Diverse studies also confirmed that the use of adjuvants didn’t affect the olive quality or its sensory evaluation.
Way different it’s the use of talcum powders which are very rich in calcium carbonate, as it involves a change in the chemical composition of the olive oil eliminating acidity, which is totally prohibited. Also, the use of this kind of products can be harmful for the machinery.
As a way of conclusion, the Olive Oil School of Spain recommends the use ‘MTN’, always in a controlled and moderated way and doesn’t support the systematic use of adjuvants. Use must be done always when the past needs it and when the extraction requires it.