DESCRIPTION

Technical field

This invention relates to a filter element for the filtration of food and beverages, in particular for the filtration of olive oil and a related method for making a filtration agent.

Background art

Extra virgin olive oil, obtained by pressing olives, must be filtered so that it can be stored for longer.

The filtration of olive oil, which is the step immediately prior to bottling, is based on the use of agents which make the processing possible in the raw state.

The filtration is a physical-mechanical operation by which a moving liquid, under the action of a pressure gradient, separates from the solid particles dispersed therein by the effect of their retention by porous filtering means, also known as a filtration agent, through which the liquid is passed. Currently, three types of filtration agents are used basically in mills and in the oil industry: fossil flour, cellulose flour and perlite, that is to say, substances based on fossil flours and cellulose.

The filtration agents guarantee a solid connection with the filtration support and easy detachment of the deposit from the support at the end of the operation.

The main limitations of the current method, based on the use of the above- mentioned filtration agents, is the sustainability of the process in the long term.

Firstly, the fossil flour, which consists of silicon, comes from the deposits of diatoms, which are fossilised algae which constitute deposits which are still present in some countries of the world, but are running out.

In the same way, the perlite is also extracted from natural “quarries" and represent a non-renewable resource over time, which sooner or later could become scarce they are also used for other purposes.

In addition, fossil flour is not very easy to handle; it is a source of harmful substances, which may also lead to risks for operators who handle it, mainly due to the presence of crystalline silica, which is a harmful substance that causes silicosis.

On the other hand, cellulose flour, which is also a renewable product as it is obtained from the processing of cellulose extracted from plants, is produced in many countries around the world by the chopping down of forests, with all the consequences of an ethical and environmental nature that the deforestation of the world results in.

Summary of the Invention

The aim of the invention is to overcome the above-mentioned drawbacks of prior art types of filter elements for the filtration of food and beverages, in particular for the filtration of olive oil and a relative method for making a filtration agent which allows the above-mentioned environmental problems to be overcome, avoiding the environmental impacts which the current production of cellulose results in for the making of filter elements intended for food and beverages.

In the context of the above-mentioned purpose, an aim of the invention is to provide a filter element for the filtration of food and beverages, in particular for the filtration of olive oil which does not use fossil flour, but renewable resources.

Another aim of the invention is to avoid the use of substances classified as harmful products.

Another aim of the invention is to obtain a filtration waste which can be easily disposed of or which can be recycled in a compatible manner with respect to the environment.

Another aim of the invention is to encourage innovative actions to support and improve the olive oil production process, increasing and improving the distinctive capacity of the oil production system, optimising environmental sustainability and technological modernisation.

Yet another aim of the invention is to provide a method for making a filtration agent, particularly for the filtration of olive oil, which can be easily implemented and is economically competitive.

This purpose, as well as these and other aims, which are described in more detail below, are achieved by a filter element for the filtration of food and beverages, in particular for the filtration of olive oil and a related method for making a filtration agent according to the invention, comprising the technical features described in one or more of the appended claims. The dependent claims correspond to possible different embodiments of the invention.

In particular, according to a first aspect, this invention relates to a filter element for the filtration of food and beverages, in particular for the filtration of olive oil, comprising a by-product of the processing of olives. Advantageously, the by-product is a panel made of cellulose-based powdery material deriving from the stones of the olives.

The Applicant has concluded that cellulose present in the stone of the olive can be used to replace filtration agents which are at risk of poor availability, are harmful to human health, or whose production has a high environmental impact.

The fruit of the olive is in fact a drupe, with an oval or rounded shape, which has an epicarp (or skin) on the outer part, a mesocarp (or pulp) containing the endocarp (or stone). The latter part is the innermost part which also comprises the seed: it is fibrous and woody and is referred to with the term “drupe” assigned to the category of fruit.

The use of olive stones as a by-product does not represent a novelty.

In fact, in the countries where extra virgin olive oil is produced (Spain, Portugal, Italy and Greece), the olive is often pitted and a by-product known as pellets is obtained from the stone which, once crushed, is used as a fuel biomass in the energy chain. This use, however, is highly polluting as a source of heat. Another aspect of the invention consists in the method for making a filtration agent, in particular for the filtration of olive oil, which comprises the succession of steps consisting of:

- pitting the olives in such a way as to extract the stones,

- crushing the stones,

- dehydrating the crushed stones to remove the moist component from them,

- grinding the dehydrated stones in such a way as to obtain powdery material,

- forming the cellulosic material in the form of a powdery material, that is to say, forming the agent made of cellulose powder coming from the stones, with a soft appearance and white in colour.

Alternatively, a technical equivalent of this method could be that of dehydrating after the grinding, however this would result in less effective dehydration.

The alternative and equivalent method would comprise the following sequence of steps:

- pitting the olives in such a way as to extract the stones,

- crushing these stones,

- grinding the stones in such a way as to obtain powdery material,

- dehydrating the powdery material to remove the moist component from the stones,

- forming the cellulosic material in the form of a powdery material, that is, forming the above-mentioned agent.

Advantageously, the stones are crushed by milling devices.

The recent growth on the market of biomass stoves and boilers has, consequently, increased the demand for olive pellets, resulting in many mills adopting technologies useful for pitting the olives. The new technologies, introduced in the sector, thanks to the dedication and interest of machine manufacturers and research technicians, foresee the use of machines which are able to easily recover the stone from the olives. The Applicant has therefore perceived that the stone could be used for other purposes, that is to say, the Applicant has understood that the pellets after being subjected to crushing/grinding (and drying) until reaching the grain size of the current filtration agents used in the oil sector, can be used as cellulose-based fibre.

Another aspect of the invention relates to the process for the filtration of olive oil, of known type, using a filter element obtained according to the method according to the invention and which allows an oil and cellulose- based filtration by-product to be obtained.

Advantageously, the Applicant understood that this filtration by-product, rich in oils and fibres, can be used in the production of skin care products.

Detailed description

Further features and advantages of the invention are more apparent in the detailed description below, with reference to a preferred, non-limiting embodiment of the filter element for the filtration of food and beverages, in particular for the filtration of olive oil and a related method for making a filtration agent.

Described below is a preferred embodiment of a filter element for the filtration of food and beverages, in particular for the filtration of olive oil and a relative method for making a filtration agent, according to the invention, which comprises a by-product of the processing of the olives in a powder form and which has cellulose deriving from the stones of the olives.

The powdery material preferably has a grain size of between 50 and 350 microns/m, preferably between 80 and 200 microns/m, even more preferably between 90 and 150 microns/m, so as to allow an optimum filtration of the oil.

Preferably, the stone in the form of powdery material has a moisture content at least less than 10%, preferably at least less than 8%, even more preferably at least less than 7%.

The powdery material has ash in a maximum quantity of substantially 1%, with a pH substantially between 5 and 7. Moreover, it does not have preservatives nor toxic substances.

The maximum apparent density of the powdery material is substantially 220 g/litre, whilst its filtering porosity is between 1.6 and 3.6 Darcy in a scale C.P. 100 - 260.

The method for making a filtration agent, in particular for the filtration of olive oil, that is, for making the filter element, comprises the following sequence of steps.

Firstly, the olives are pitted in such a way as to extract the stones. Currently, in order to be able to recover the pellets from the olives, use is made of machines for pitting the olives which allows extraction of the whole stone from the fruit, corresponding in terms of weight to approximately 18-20 kg per 100 kg of olives, starting the extraction of a paste from just the pulp of the olive.

These pellets are then crushed and then ground in such a way as to obtain the powdery material just described, with a grain size preferably between 80 and 200 microns/m, even more preferably between 90 and 150 microns/m, in such a way as to allow an optimum filtration of the oil.

In practice, a finer fibre (with the same weight) allows a greater contact surface between the filter material and the oil.

However, a finer fibre tends to compact itself more, thus reducing the service life of the filtering panel and the quantity of olive oil filtered per cycle.

It will therefore be necessary, during production, to provide commercially a format with a "spaghetti” shape, that is to say, extruded, and therefore to bring on the market a thread-like rather than granular fibre.

It will be necessary to adjust the aim during the experimental and implementation phases, possibly by calibrating the grinding of the raw material also into mixtures comprising bran, middlings, by-products of processing of the cereals and pellets.

During the filtration, the oil, stored in large silos, travels in steel pipes to reach the press filter. Inside the latter, the oil is pressurised even more against the walls of the filtering panel which can reach work surfaces of from 20 sq.m up to 150 sq.m (and above).

The aim of the industrial filtration of the olive oil is to remove the impurities present in the form of wax, mucilage, etc., and especially moisture.

The latter greatly affects the storage of the oil also in a bottle. In this context, a fundamental prerequisite is that the cellulose fibre in turn complies with the required moisture content so that it can be a specific agent in the formation of the filter panel.

The crushed material is dehydrated in suitable drying cabinets, for removing the damp component away from the stones until reaching a moisture content of at least less than 10%, preferably at least less than 8%, even more preferably at least less than 7%.

Drying cabinets are of per se known type and are used for the drying of biomasses. There are various models available on the market, with different production capacities for small, medium and large production.

The drying may be performed using systems for generating hot air produced in various ways or by using a cold technology which is based on cooling systems which cool the air, dehydrate and heat it to reach temperatures of approximately 35/40°C leaving a maximum residual moisture content equal to approximately 6%.

Lastly, cellulose agents are formed in a powder form, thus constituting the cellulosic material in the form of powdery material.

At this point, the filter element may be used to filter the oil, in particular olive oil, for example extra virgin olive oil, thus providing an oil and cellulose-based filtration by-product.

The oil and cellulose-based filtration by-product may advantageously be used in the cosmetics sector and, in particular, may be used for making skin care products.

In practice, a pitted extra virgin olive oil is obtained, of per se known type, obtained by immediate and preventive separation of the stones from the pulp of the olive.

If this process allowed the simultaneous pressing of the olives and extraction of the crushed stones (pellets), immediately ready for use as fuel in pellet boilers and stoves, the solution according to the invention aims to use the crushed stones which are a source of cellulose flour as agents/material for the filtration of liquid foods.

From the above description it may be seen how the invention achieves the preset purpose and aims and in particular it should be noted that a filter element is made for the filtration of food and beverages, in particular for the filtration of olive oil and a related method for making a filtration agent, which is environmentally sustainable, avoiding the chopping down of forests.

In particular, the use of cellulose from the same source of extraction of the oil, that is to say, from the olives which have been pressed, allows the practical production of the chosen model of circular economy, for example virtuous.

Another advantage of the invention is due to the fact that the exclusive use of fibre, as flour and/or cellulose agent, instead of the fossil flours which are currently used, for the process of filtration of the extra virgin olive oil, results in an improvement in terms of environmental sustainability and economy, since, unlike the waste consisting of fossil-oil flour, which must be treated as waste and disposed of in landfill, the residue consisting of cellulose-oil may, on the other hand, constitute a resource, for example by means of its use for skin care purposes. Another advantage of the invention is due to the fact that this circular economy model allows the reduction of the oil filtration costs, reducing the costs for the filtration agents, unlike current circumstances, where the only interest of the large oil mills is to use the filtering panel as much as possible and to obtain the greatest profit in terms of the greatest extraction of oil from the entire filtering panel. For this reason, the used agents which remain after the filtration are not recovered and their end is often dictated by their disposal cost.

Another advantage of the invention is to avoid the use of fossil flour and perlite which are harmful to the operator.

Lastly, the method for making a filtration agent, particularly for the filtration of olive oil, can be easily implemented, is economically competitive and allows the re-use of the pellets, avoiding, however, the combustion.

The invention can be modified and adapted in several ways without thereby departing from the scope of the inventive concept.

Moreover, all the details of the invention may be substituted by other technically equivalent elements.

In practice, the materials used, as well as the dimensions, may be of any type, depending on requirements, provided that they are consistent with their production purposes.