TECHNICAL FIELD AND BACKGROUND ART.

The present invention relates to a method for extracting juice from food products, in particular for clear and/or turbid fruit and/or vegetable juices, of the type comprising at least the phases of cold trituration of the product, extracting the product puree and extracting the juice from the puree.

Currently, the method for extracting juices or purees from food products generally comprise a first phase of washing and verifying the quality of the products, typically fruit and/or vegetables, and a subsequent phase of cold trituration of the product with simultaneous administration of anti-oxidising agents, preferably ascorbic acid. Thereafter, the triturated product is heated to inhibit the enzymatic activity that is responsible for chemical degradation (such as colour or viscosity changes). Subsequently, the triturated and heated product ends in a strainer or refiner which separates the puree and/or the juice from the scrap (peels, seeds, petioles,...). The puree and the juice are then obtained by means of heat pressing and are subsequently pasteurised.

The method continues with the separation of the solid phases suspended in the juice, the concentration of the juice and final storage of the product thereby obtained.

A particularly acute problem in the sector of the production of food juices and/or purees pertains to the treatments required to inhibit the enzymatic

activity that develops in the puree and/or in the juice following trituration and that is responsible for the chemical degradation of the product, such as colour and/or viscosity changes. In particular, the enzymes responsible for the change are known by the term of peroxidase, whilst those responsible for viscosity change are called polyesterase.

Currently, the inhibition of the enzymatic activity, operation technically called enzymatic deactivation, takes place by heating the triturated product at a product that varies according to the product and generally falls within a temperature range between 80°C and 95°C. The temperatures used must be sufficiently high to guarantee the deactivation of the most heat-resistant enzymes.

As regards the trituration phase, the prevention and/or reduction of the enzymatic activity responsible for the oxidation occurs by the administration of ascorbic acid.

The method briefly described above has some drawbacks.

First of all, ascorbic acid, if present in large quantities, can give rise to chemical degradation during the storage of the juice or of the puree, such as colour changes or separation of the solid phase from the liquid phase, especially in turbid juices.

In the second place, the enzymatic deactivation by heating the triturated product inevitably entails a worsening in the quality of the puree and/or of the juice.

Another drawback is represented by the fact that extraction, with heat, of the puree or of the juice by means of a strainer entails significant product wastage, since scrap, such as peels, seeds or petioles, are always associated

to parts of pulp.

Studies and research work performed by the Applicant have shown that the concentration of the enzymes responsible for the chemical degradation of the product is considerably higher in scrap, in particular in peels and in seeds, than in the pulp. In particular, for the Golden apple the elimination without heating of peel, seeds and petioles allows to reduce by about eight times the activity of the peroxidase and to eliminate the most heat-resistant forms of polyesterase.

DISCLOSURE OF INVENTION.

The aim of the present invention is to eliminate the aforesaid drawbacks making available a method for extracting juice from food products, in particular for clear and/or turbid fruit and/or vegetable juices, which allows to reduce the enzymatic activity responsible for the chemical degradation of the puree and/or of the juice, such as colour and viscosity changes.

Another aim of the present invention is to propose a method for extracting juice that allows a pasteurisation at lower temperatures than those currently used in known processes, improving the quality of the product. In particular, an aim of the invention is also to obtain juices with fresh flavour and without aftertaste.

An additional aim of the present invention is to obtain a method that allows to obtain stable turbid juices, i. e. juices in which, during storage, there is no separation of the liquid phase from the solid phase.

Another aim of the present invention is to propose a method that allows to reduce the presence of pulp in the scraps.

Said aims are fully achieved by the method for extracting juice from food

products, in particular for clear and/or turbid fruit and/or vegetable juices, of the present invention, that is characterised by the contents of the claims set out below and in particular in that it comprises, during the trituration phase, a phase of separating peels and/or seeds and/or other scraps from the pulp of the product, said trituration phase being simultaneous with the phase of extracting the product puree.

BEST MODE FOR CARRYING OUT THE INVENTION.

These and other aims shall become more readily apparent from the detailed description that follows of a preferred embodiment illustrated, purely by way of non limiting example.

The method for extracting juice from food products of the present invention is of the type comprising at least the phase of triturating the product without heating, extracting the product puree and extracting the juice from the puree.

The method originally comprises, during the trituration phase, a phase of separating peels and/or seeds and/or petioles and/or other scrap from the pulp of the product. In particular, said trituration phase is substantially simultaneous with the phase of extracting the product puree and preferably takes place inside a known turbo-extractor.

Subsequently to the trituration and puree extraction phases, the method comprises a phase of pasteurising the puree, in order to deactivate the enzymes responsible for the chemical degradation mentioned in the present description.

The pasteurisation phase takes place within a range of temperatures that varies according to the processed product, although, by effect of eliminating the peel, the seeds and the petioles, the temperatures used are lower by a few

tens of degrees from those currently employed in processes according to the prior art. In particular, in the extraction of the apple juice, the complete enzymatic deactivation is achieved at a temperature lower by about 10°C- 15°C than the one required to deactivate the puree with the peel present.

The elimination of the peel, of the seeds and of the petioles allows considerably to reduce the enzymatic concentration, eliminating in particular the most heat-resistant enzymes.

The method of the invention further comprises a phase of administering at least anti-oxidising agent during the trituration phase. In the example described herein, said anti-oxidising agent is ascorbic acid that is administered in a quantity that generally does not exceed 500 milligrams for each kilogram of product processed.

The juice extraction phase comprises at least a decantation phase, during which the juice is separated from the solid puree.

The method further comprises a phase of removing solid particulate present in suspension in the juice, a phase of concentrating the juice and lastly a phase of sterilising the juice. In particular, the phase of removing the solid particulate is preferably accomplished by means of centrifuging.

The method of the invention achieves important advantages.

First of all, eliminating the peel and/or the seeds and/or the petioles during the cold trituration phase allows to reduce the quantity of ascorbic acid required to inhibit the oxidation of the puree. In this way, the juice obtained at the end of the method is more stable and does not tend to separate into liquid phase and solid phases, or to change colour. This is particularly appreciated in the manufacture of turbid juices.

Secondly, a pasteurisation carried out at temperatures lower by a few tens of degree than those commonly used in the prior art, in addition to allowing considerable energy savings, improves the quality of the product, since it reduce the heat stresses whereto the product is subjected. Moreover, since the puree is obtained without pressing the scraps, the extracted juice has a fresher flavour without aftertaste.

Advantageously, the elimination of peels, seeds and petioles without heating allows to reduce the presence of pulp in the scraps, with consequent economic savings.