Key tips to improve processes in the olive oil sector

Virgin olive oil, as its name indicates in an olive juice, which is obtained by exclusively physical procedures. Its production process is subject to a series of critical points, which, as we work on them, the quality of the final product will be affected. The knowledge and control of these critical points are decisive to achieve a quality product.

It is necessary to start from the base of a quality raw material, the olive must have a correct sanitary state as well as a good point of maturity. We are going to see the production process of the olive, until it becomes an Extra Virgin Olive Oil (EVOO).  Step by step from the olive in the field to its placing on the shelf, we will go through the processes that influence the quality of the final product.

In the olive oil sector, one of the most pronounced phrases is that “quality improvement begins in the field”, in the olive grove.

1.- The plantation

2.- The collection

3.- The reception in the patio

4.- Washing the fruit

5.- Storage hopers in patio

6.- The mill

7.- The shake

8.- The decanter or horizontal centrifuge

9.- Vertical centrifuge

10.- Decanter

11.- Deposits in the warehouse

1.- THE PLANTATION

A correct sanitary state of the plantation, for example, will prevent the proliferation of diseases and pests that will undoubtedly affect the quality of the fruit. The olive fly is the pest that decisively affects the quality of the oil.

Olive grove pruning ESAO P.A.O. ESAPO image bank.

Among other things, the olive fly causes a massive fall of the fruit, with the consequent loss in quality and quantity of oil, and many of the fruits that remain on the tree are chopped, being a gateway to fungi and other pests.

Another disease, caused in this case by a fungus, and that affects the deterioration of the quality of the oil is the soapy olive or anthracnose.

It can cause, especially in rainy autumns, significant damage to fruits. Necrotic spots, depressed, rounded, and ocher or brown in color are observed on the fruit; the affected olives become dehydrated, wrinkled and many of them fall prematurely, while others remain on the tree. The oils obtained from soapy olives may have greater turbidity, high acidity and a reddish color.

Both one and the other will be reflected in the chemical analysis of olive oil.

To improve the process in the plantation:

• Carry out a good control of the olive fly and soapy olive, as well as all those pests or diseases to which our olive grove is susceptible
• Carry out a correct fertilization program to achieve the maximum development and fat yield of the fruit. We will avoid closed and rigid calendars and we will analyze with the help of a technician the evolution and health status of the olive grove.
• Take care of the pruning of the olive tree in a suitable time and manner.

2.- THE COLLECTION

It is of vital importance, and already well known by those who wish to produce quality, that when harvesting the olive, you must have a clear separation from the flight or olive that is on the tree to the olive that is already fallen and is found on the ground.

Soil olives will normally be attacked by fungi and will produce highly acidic and flawed oils.

To improve the harvesting process:

• Make a good separation of the olive according to the flight or ground procedure
• Always respect the safety terms of the phytosanitary products, if this is not the case, you may find traces of insecticide, herbicide and fungicide in the oil. These analytics are becoming more and more common.
• The transport must be in the smallest consignments that we are allowed, in rigid and well ventilated boxes. Avoid crushing and heating the olive.
• Pick the olives at the optimum moment of maturation, depending on the variety in question. In any case, avoid overripening in the backyard

3.- THE RECEPTION IN THE PATIO

The reception of the olives in the patio is a key point in the production system and it is becoming more and more careful, especially when it comes to quality production of olive oils.

The reception of the olives in the patio is a key point in the production system and it is becoming more and more careful, especially when it comes to quality production of olive oils.

To improve the process at the reception:

• First of all, it is necessary to have differentiated lines that allow the separation of the fruits by quality.
• It is important to ensure that there is no contamination of the olives with mineral oils used in the machinery, to prevent tractors from passing over safety grates when unloading the olives.
• The olive reception hopper must be made of stainless steel.

In any case, regarding the material, the objective is to avoid direct contamination of the olive, since it will be reflected in the physicochemical analysis of the virgin olive oil that we analyze, and therefore will affect the quality.

The reception hopper, if any, must be in a correct state of cleanliness.

The olive conveyor belts must be approved, they must be food belts.

4.- WASHING THE FRUIT

The indiscriminate washing of the fruit is no longer a common practice in the olive sector. In olive oil courses, it is a repeated message, that for quality production, it will be done depending on the state of the batch that we are going to process.

To improve the washing process:

• We will use the washing machine, in those items that are dirty, or with adhering dirt or mud, especially if they come from the ground.
• For consignments of olives from flight, a "shower" with clean water will be recommended to eliminate the remains of phytosanitary treatments that may be present or to avoid dust and so on.
• The washing water must be clean, avoiding possible contamination that may be dissolved. If we wash with dirty water, we will be dirtying instead of cleaning.
• Drinking water from the network or well must be used to prevent contamination.

5.- STORAGE HOPPERS IN PATIO

Avoiding storage hoppers as much as possible is the best proposition. However, when it comes to large productions, this is sometimes necessary.

A taster is able to detect possible defects caused in these hoppers.

Storage hopper. ESAO image bank

To improve the process in yard storage:

• The crowding or piling of olives in patios must be avoided at all costs.
• This practice is becoming less frequent, however it is still carried out.
• Shrinking or crowding must be avoided, both due to the proliferation of fungi and the increase in defects, producing a seriousverdes decrease in the quality of the oil.
• The lung or storage hoppers, if their use is necessary, must be made of stainless steel and it is recommended that they are always covered or covered.
• Take special care of the start of the lung hopper, a periodic review must be carried out to verify its cleanliness and avoid mass in the corners.
• To facilitate the work in the quality of the oil mill, you must have sufficient grinding capacity for all the olives that can enter us daily, you must plan the campaign and the entry of olives as far as possible.
• The storage hoppers, if necessary, will also be separated according to whether it is ground or flight.

6.- THE MILL

The Mill is the first machine where the olives begin to be worked, after the patio. The most common mills are hammer mills. The objective of the mill is to crush the olives to create a paste that will later go to the blender.

Mill. ESAO  image bank

To improve the storage process in the Mill:

• We will have the Mill in a perfect state of cleanliness.
• We will try to have the maximum possible control over the revolutions, to adapt it to our needs.
• We will avoid heating the dough as much as possible.
• We will ensure that the mill has a dough cooler.

7.- THE SHAKE

After the olives are crushed by the mill, the next machine that we come across is the mixer or thermablator, also called a kneader.

High temperatures will produce defects in the olive oil and that the taster will perceive

Shaker. ESAO image bank

To improve the process in the mixer:

• Keep the blender in a perfect state of cleanliness
• Avoid, as far as possible, an increase in both unnecessary time and temperature.
• Continuously control the temperature of the dough. High temperatures will decrease the quality of the oil
• The use of permitted and authorized adjuvants will be used with an automatic dispenser and whenever the mass demands it.
• There are dough preparation systems such as the protoreactor or high voltage electrical pulses, which will help us to reduce the mixing time as much as possible.

8.- THE DECANTER OR HORIZONTAL CENTRIFUGE

The decanter or horizontal centrifuge is the machine that goes after the mixer and that will be in charge of, by means of centrifugation, separating the solids from the liquids. Normally the two-phase system is used, where there is a separation between vegetation water, oil and pomace.

Decanter or Horizontal Centrifuge . ESAO image bank

To improve the process in the decanter:

• As in general all machinery, it is not convenient to take them to maximum capacity.
• To work in quality, we can use between 50% and 75% of its capacity.
• Cleanliness is essential when we want the resulting virgin olive oil to have the highest quality.

9.- THE VERTICAL CENTRIFUGE

Once we have extracted the oil through the decanter, we will pass it through the vertical centrifuge, with the aim of cleaning the virgin olive oil of moisture and impurities as much as possible.

Different studies and chemical analyzes have been made of olive oil passed through a vertical centrifuge and those passed through natural decantation where some differences are appreciated.

Vertical Centrifuge. ESAO  image bank

To improve the process in the vertical centrifuge:

• We have to maintain a continuous cleaning of the vertical. If possible with automatic cleaning much better. Otherwise they will be manual and constant.
• The temperature must be well controlled, avoiding increases.
• The virgin olive oil that comes out of the centrifuge must have a “milky appearance” and green when it comes to quality. This helps us confirm that we are not losing oil.

10.- DECANTERS

The purpose of the decanters is to purge the moisture or impurities that the freshly produced virgin olive oil may carry.

Decanters. ESAO image bank

To improve the process in decanters:

• It is important that the bottoms are tapered.
• The cleaning like the rest of the machinery the more thorough the better
• The purges will be continuous, whether they are mechanical or automatic.

We will have the oil for the necessary time where the bleeding comes out clean in order to take it to the winery in the best possible state.

11.- DEPOSITS IN THE WAREHOUSE

The deposits will be where the virgin olive oil is kept once classified. The objective is to keep the oil as clean and at the best constant temperature as possible while waiting for its packaging and sale.

In the tanks and in the cellar we want the oil to maintain its sensory and nutritional characteristics as much as possible, protecting it from fermentation, oxidation, since all this will cause defects.

Deposits. ESAO image bank

To improve the process in warehouses:

• Use conical bottom tanks.
• Use nitrogen in case of consignments that go towards quality or we are going to have a time in the cellar. Above all, use it according to the class, type or quality of olive oil that you have in the tank in question.
• The cleaning of the tanks, as well as of the cellar in general, is of special importance, the automated purging system is ideal especially for flat bottoms, even if they are inclined.

Keep the cellar at a constant temperature of between 18 and 20ºC, as odorless and aseptic as possible, isolated from the production body.