FR2901963A1 - PROCESS FOR EXTRACTING AND TREATING CITRUS JUICE, AND HIGH VITAMIN C CONTENT COMPOSITION - Google Patents

Abstract

The invention relates to a method for extracting and treating a citrus juice, in particular an orange juice, in order to obtain a composition with a high vitamin C content. citrus fruits in half-citrus fruits, according to a substantially equatorial cutting plane; said half-citrus fruits are pressed to obtain a pressing product; and filtering said pressing product to draw a filtered juice. The invention is characterized in that a decantation of the filtered juice is also carried out so as to obtain a separation of the latter in three phases: an upper phase of oily consistency, a lower phase of sedimentary composition and an intermediate phase consisting of in a composition containing vitamin C. At the end of this decantation, the intermediate phase is extracted to obtain said composition with a high content of vitamin C. Also, according to the invention, all the steps of the process, of the cutting the citrus fruit until the extraction of said intermediate phase of decantation, is carried out away from natural light and at a temperature of the order of 4-10 degree C.

Description

METHOD FOR EXTRACTING AND PROCESSING CITRUS JUICE, AND COMPOSITION

  The invention relates to a method for extracting and treating a citrus juice, in particular an orange juice, in order to obtain a composition with a high content of vitamin C and in which said vitamin C exhibits high stability with respect to deterioration. Essential for the good functioning of the organism of the higher species, in particular the primates which have lost the capacity to synthesize it, the vitamin C intervenes, among others, in the elaboration of the connective tissue, the formation of the vessels, the cartilages and the bones . It also stimulates the maturation of red blood cells and intervenes in cellular respiration as an oxygen carrier.

  The daily requirements of vitamin C are, for the adult man, of the order of 75 mg and are considerably amplified during infections and / or lesions. From a chemical point of view, natural vitamin C is a levorotatory lactone, white when it is in solid form. In solution, it has a low acidity (pKa = 4,17) and is in equilibrium between two forms: an oxidized form (ascorbic acid: ASC) and a reduced form (dehydroascorbic acid: DHA); both are biologically active. But, unlike ascorbic acid, in contact with oxygen - especially air - dehydroascorbic acid undergoes irreversible and rapid denaturing oxidation, thus losing its vitamin activity. The degradation process of vitamin C is relatively complex but can be simplified as follows: ASC DHA oxidation degradation products active forms inactive forms Among the breakdown products of vitamin C, some, such as hydroxymethylfurfural (HMF), have been the subject of studies confirming their involvement in the appearance of glycotoxins which are involved in many oxidative and inflammatory cascades, particularly harmful to the proper functioning of the body.

  To meet the daily needs of vitamin C, the consumption of fruits (for example blackcurrant, strawberry, citrus, kiwi, mango, guava ...) and vegetables (for example parsley, pepper, broccoli, green cabbage, cauliflower, watercress, radish ...) is highly recommended, but is generally insufficient. The consumption of foods naturally rich in vitamin C, in transformed form (especially orange juice), or enriched in synthetic vitamin C (various juices, milk, cereals, yogurts, jams ...), and the absorption of Parapharmaceutical specialties such as dietary supplements, cachets and sachets of synthetic vitamin C are therefore also recommended.

  However, many scientific publications and recent epidemiological studies suspect a certain harmfulness of synthetic vitamin C for the body and have expressed reservations about the real benefits of foods naturally rich in vitamin C, in transformed form, for example the juices of citrus fruit, in particular orange juice, produced industrially. In particular, it is explained that, unlike natural vitamin C, of exclusively levorotatory form, synthetic vitamin C is an amphoteric mixture in which the dextrorotatory fraction shows no vitamin activity and would be potentially harmful for the organism that metabolize to compounds with pro-oxidative activity.

  Similarly, the real capacity of foods naturally rich in vitamin C, in processed form, especially industrial fruit juices, to compensate for an insufficient supply of vitamin C resulting from a consumption of fresh products, is also highly questionable. Indeed, an essential difference between the fresh product and the corresponding processed product comes from its actual content of vitamin C. Vitamin C is particularly sensitive to the processing of the product, and the mode of preservation of the processed product. It is particularly fragile because it is water-soluble, unstable by heat and sensitive to oxygen and ultraviolet light. As a result, it degrades rapidly during heat treatment pasteurization or sterilization, and then during storage. The degradation rate is proportional to the time-temperature torque applied during the treatment, then to the dissolved oxygen content passing through the packaging during storage, as well as to the transparency of this ultraviolet packaging. In the case of orange, for example, the vitamin C content of the whole fruit is very stable. It is usually 45 to 100mg / 100g, depending on the maturity and variety of the orange. In industrial juice after treatment, this content only represents 30 to 70% of the initial content according to the treatments applied. The majority of juices do not store more than 25 mg / 100 g after a few months or even weeks. In view of the 75 mg daily recommended vitamin C, this relatively low content of vitamin C has, in itself, little impact since only 30 cl of these are enough to completely offset such a need.

  Unfortunately, this low vitamin C content results from the degradation of vitamin C, and is therefore associated with a significant amount of glycotoxins, which affects the nutritional quality of the product and can make the product unfit for consumption. In this context, the invention aims to propose a new method for extracting and treating citrus juice, in particular orange juice, which preserves the vitamin C content, in particular which makes it possible to obtain compositions with a content in vitamin C close to the amount originally contained in the citrus fruits used. In particular, the object of the invention is to propose a new method for extracting and treating citrus juice and, in particular orange juice, in order to obtain compositions with a high content of vitamin C, which is particularly stable by environmental effects (ambient air, natural light, temperature 15-25 C) and time, so that said composition makes it possible to meet, at least in part, the daily requirements of vitamin C, without risk of contamination by glycotoxins.

  To this end, the invention relates to a process for extracting and treating a citrus juice-notably an orange juice-in order to obtain a composition with a high content of vitamin C, in which the following steps :

  citrus fruits are cut in half-citrus fruits, according to a cutting plane 10 at least substantially equatorially,

  said half-citrus fruits are pressed to obtain a pressing product,

  - The pressing product is filtered to obtain a filtered juice, characterized in that:

  The filtered juice is decanted so as to be able to separate it into three phases: an upper phase of oily consistency, a lower phase of sedimentary composition and an intermediate phase consisting of a composition containing vitamin C. ,

  at the end of this decantation, the intermediate phase is extracted for

  To obtain a composition with a high content of vitamin C,

  the whole of the steps, from the cutting of the citrus fruit until the extraction of said intermediate phase, is carried out sheltered from natural light and at a temperature of the order of 4-10 C.

  The invention is thus based on the finding that, in addition to the

  Temperature, oxygen, pH, ultraviolet, vitamin C also has a particular sensitivity to certain substances naturally contained in citrus fruits. Therefore, their contact with vitamin C should be limited as much as possible.

  Although the nature and location in citrus fruits of these substances have not been clearly identified, the inventor has demonstrated that after filtration and decantation carried out under the particular conditions of the the invention, after extraction of the intermediate phase, a composition rich in vitamin C is obtained; a vitamin C particularly stable compared to that contained in a fruit juice prepared with a traditional method.

  According to the invention, the filtration of the pressing product makes it possible to obtain a filtered juice, at least partially freed from pulps, pieces of albedo, pips and other unwanted solids entrained with the pressing juice and which, for at least less some of them, are sources of factors that promote the oxidative denaturation of vitamin C.

  Once filtered, the juice may have some turbidity resulting from the residual pulp and small solid particles that have not been retained by the filter used.

  According to the invention, decantation makes it possible to complete this liquid-solid separation previously initiated by filtration. It causes sedimentation of pulp and suspended particles. It also makes it possible to separate constituents of the aqueous phase, in particular vitamin C, the various oily substances (oils, essences, etc.) also identified by the inventor as detrimental to the stability of vitamin C.

  These oily substances are, at least partly, naturally present in the albedo and in the bark (or flavedo) of citrus fruits. For this reason, the fruits should not be pressed in their entirety. It is important to precut them in two, according to an equatorial cutting plane, so as to avoid / minimize, during pressing, the disruption of the albedo and the bark of the fruits, and thus to reduce as much as possible the release of oily substances in the juice of pressing.

  For the same reason, advantageously and according to the invention, the citrus fruits are pressed by means of a static type press. The pressing members of this type of press consist, essentially, a ball and a cup. Each half-citrus previously cut according to the equatorial plane of the fruit, is placed inside the cup, with the cutting plane facing the patella. The juice of the fruit is pulled under the constraint of the patella which sinks inside the endocarp of the half-citrus fruits; without there being any relative rotational movement of the ball with respect to the cup. Unlike conventional rotary spindle presses, static type presses allow "soft" extraction of the pressing juice, by a pressure effect with a minimum of friction; the ejection of the juice out of the vesicles occurs by simple bursting of their membranes (these membranes constitute the pulp of the citrus fruits). This limits the grinding of the membranes and the mixing of these membranes with the juice, and therefore the contact between vitamin C and some of the constituent compounds of the vesicle membranes, potentially harmful to vitamin C. Furthermore, In doing so, a pressing product is collected with a reduced amount of pulp.

  Advantageously and according to the invention, the operation of the press is calibrated so that the pressing takes place without causing substantial alteration of the albedo and / or citrus peel.

  At the end of a process according to the invention, a composition containing a high content of vitamin C is recovered, comprising at least about 40 mg per 100 g of composition, in particular at least of the order of 50 mg. per 100 g of composition. This composition with a high content of vitamin C differs from a traditional citrus juice, especially industrial, both by its visual appearance as its remarkable organoleptic properties.

  First, it is visually distinguishable from a traditional citrus juice, for example an orange juice-usually orange-yellow in color, opaque to light, and of a more or less thick consistency-by

  25 a visual appearance very similar to that of a rather dry white wine. Its transparency in light and its more or less pale and brilliant yellow color can be explained in particular by the elimination of a large proportion of compounds and colored materials which give traditional citrus juices their distinctive orange-yellow color. These compounds and colored materials have been largely removed

  Essentially during the decantation step of a process according to the invention. Thus, in comparison with an ordinary citrus juice, a high vitamin C composition according to the invention is visually characterized by an absence of turbidity, and possibly an absence of suspended solid material, in particular the pulp of the fruit.

  Also, a composition with a high vitamin C content, obtained by the implementation of a process according to the invention, exhibits remarkable organoleptic qualities. In the first place, it gives off a pleasant citrus scent stronger than that of a citrus juice freshly squeezed by a traditional method. On the palate, it is subtly sweet and tangy, and gives a feeling of natural freshness.

  Surprisingly, besides a vitamin C content particularly close to the amount of vitamin C initially contained in citrus fruit, especially in oranges, the inventor has found that a composition with a high content of vitamin C, prepared in accordance with invention, contains a vitamin C having a remarkable and durable resistance to degradation, even though no special precautions have been taken to keep it safe from light, oxygen from the air and at ambient temperature To carry out a process according to the invention and to obtain a composition with a high content of vitamin C, at least of the order of 40 mg per 100 g of composition, and which is particularly stable over time, when faced with exposure to natural light, ordinary ambient temperatures (15-32 C) and oxygen in the air, the following precautions should be taken: - avoid as much as possible and between the aqueous phase rich in vitamin C which is initially confined inside the multitude of vesicles that enclose each quarter of citrus, with all other substance not contained in these vesicles, - once the pressed fruits, the stages of separation, filtration and decantation, must be carried out with great diligence, - as soon as the fruit is cut and as long as the aqueous phase rich in vitamin C has not been recovered and isolated from the other elements which also constitute the filtered juice, this phase Under no circumstances should the aqueous solution be exposed to ultraviolet radiation (in natural light of the day) or to temperatures exceeding 10 ° C. In this context, advantageously and according to the invention, the filtration is carried out directly after the pressing step. . Advantageously and according to the invention, the filtered juice is decanted in the presence of an enzyme with pectolytic activity. In this respect, it is advantageous to use oenological enzymes, which are widely used in the manufacture of wine, for the settling stages.

  10 and / or clarification of grape must. In doing so, after decantation of the order of 24 hours, a good sedimentation of the solid residues is obtained, and an excellent separation of the filtered juice in three phases, sufficiently distinct from each other, to be able to extract the intermediate aqueous phase in it. which vitamin C is contained. Advantageously and according to the invention, the decantation of the filtered juice is carried out by adding therein a quantity of the order of 2-3 g.hl-1 of at least one enzyme with pectolytic activity. . Advantageously and according to the invention, the intermediate phase is collected after settling of the order of 24 hours. Advantageously and according to the invention, citrus fruits are refrigerated at a temperature of less than 10 ° C., in particular of the order of 4 ° C., before cutting and pressing them. The refrigeration time is chosen so that the temperature inside citrus fruits does not exceed 10 C. Advantageously and according to the invention, a tank is used

  25 decanted decant to collect and treat the filtered juice. Advantageously and according to the invention, for the sake of hygiene, a sterilizing filtration of the intermediate phase is carried out before proceeding to its packaging, especially for its marketing and / or consumption. For this purpose, sterilizing filters are conventionally used.

  30 known, especially from the agri-food industry.

  Also for the sake of hygiene, in a process according to the invention, the citrus fruits are washed before being cut and then pressed, and possibly before being chilled. Advantageously and according to the invention, as citrus fruits, oranges of the type without umbilicus are used. Preferably, these belong to a genus chosen from: Citrus sinensis (and in particular, the varieties Salustiana and Valencia late), Citrus deliciosa (in particular, the variety Setubalense).

  The invention also extends to a composition having a high content of vitamin C, in particular a content of at least about 40 mg per 100 g of composition, obtained by a process for extracting and treating juice. citrus according to the invention, and which can be consumed as a soft drink. Advantageously and according to the invention, a composition according to the invention comprises a vitamin C content of at least about 50 mg per 100 g of composition, and preferably 60 mg per 100 g of composition. In an alternative embodiment of the invention, an alcoholic composition having a high content of vitamin C is prepared by alcoholic fermentation. For this purpose, advantageously and according to the invention, the subtracted intermediate phase is subjected to the decantation tank. a vinification type treatment, that is to say an alcoholic fermentation carried out according to a method borrowed from the manufacture of wine. Advantageously and according to the invention, at the outlet of the settling tank, the intermediate phase rich in vitamin C is transferred to a refrigerated tank at a temperature of the order of 10 C, and is fermented with a yeast operating at room temperature. low temperature, until obtaining a title of alcohol of the order of 6 to 10% vol / vol. As a yeast operating at a temperature of the order of 10 C, vitilevide KD is known, a particular strain of Sacharomyces cerevisae, especially distributed by the company MARTIN VIALATE INOLOGY, France.

  In addition to the high stability of vitamin C and its high content, a fermented drink thus prepared has a flavor reminiscent of that of some white wines. In this context, to improve the taste quality of the product, for its preparation, we can advantageously consider a chaptalized fermentation step. Also, advantageously and according to the invention, a 13-glucosidase can be used during the fermentation to express the terpenes. The invention also relates to a process for extracting and treating a citrus juice, a composition with a high content of vitamin C, optionally vinified, characterized in combination by all or some of the characteristics mentioned above or below. . Other purposes, features and advantages of the invention

  will appear in the detailed description which follows and which relates to two examples

  embodiment of a process for extracting and treating an orange juice according to the invention, as well as for measuring the vitamin C of the various

  compositions thus prepared. EXAMPLE 1 Preparation of compositions containing a high content of vitamin C, non-alcoholic The process is carried out from whole oranges, previously washed and refrigerated at 4 ° C., so that their internal temperature does not exceed 10 ° C. Of course, the method can also be implemented from other citrus species (in particular grapefruit, lemon, mandarin, clementine). In order to be treated according to the invention, the oranges are transported in a chamber illuminated by non-emitting ultraviolet light sources. All stages of cutting oranges, pressing and filtration, is achieved by means of an industrial press type

  ZUMEX Z-450, manufactured and distributed by ZUMEX INDUSTRIAL (Spain). The use of other press models may be considered.

  Once the oranges are loaded into the machine, each orange undergoes a frank cut in half-oranges, according to its equatorial plane. The juice extraction of the half-oranges is then carried out according to a static pressing technique, by the action of a ball joint functionally associated with a cup. Each half-orange ready to be pressed is immobilized inside a cup, with the cutting plane turned towards the outside of the cup. The patella penetrates into the mass of the endocarp of the half-orange, exerting a compression with a minimum of friction effect. The compression that occurs at the level of the epicarp (which essentially corresponds to the albedo and the bark of the orange) is also minimized. The pressing juice is filtered before leaving the press. The filtered juice is somewhat cloudy because of the presence

  suspended particles (in particular orange pulp) and has a

  pectin which increases the viscosity of the juice and promotes the suspension of these particles. Quickly after extraction and filtration, the juice is quickly transferred to a stainless steel settling tank, equipped with a refrigeration device adapted to maintain the juice at a temperature of about 4-10 C.

  The interior of the settling tank was previously deaerated, for example by injection of carbon dioxide or nitrogen, and placed at a temperature of the order of 4-10 C. To accelerate the decantation, an enzyme is used. de débourbage, conventionally employed in the manufacture of wine. In particular, 2 grams of SUPRAZYM (a product of LA LITTORALE INNOLOGIE, France) per hectolitre of filtered juice are used. Other enzymes with pectolytic activity can also be used to shorten and / or improve the decantation step, for example, Klerzym (also a product of the company L'Littoralaleologie, France) after settling in the order of 24 hours, we obtain a separation of filtered juice in three phases. The intermediate phase, an aqueous phase rich in vitamin C, is then subtracted, which is then subjected to a sterilizing filtration stage in order to obtain a composition with a high content of vitamin C which is perfectly suitable for consumption. The sterilizing membranes used for this purpose are conventional and are commercially available. Table 1, below, presents the results of vitamin C assays performed on samples from different compositions prepared from orange. The vitamin C assays have been entrusted to various analysis laboratories accredited by COFRAC (French accreditation body). EXAMPLE 2 Preparation of High Vitamin C Fermented Compositions To obtain a high vitamin C fermented composition according to the invention, one begins by reproducing identically the stated preparation protocol. in Example 1. The sterilizing filtration carried out on the intermediate phase at the end of the decantation is optional at this stage of Samples Vitamin C (date of analysis) (mg / 100g) natural daylight, at the temperature (about 20 C) and ambient air, before being sent to the laboratory for analysis. • simply squeezed orange juice (oranges from batch A) then immediately stored at 4 ° C for 48 hours 65 692-_AA00- 060403-C-59 39 2 • left, for 2 hours, exposed to (03/04/2006) daylight, temperature (around 20 C) and ambient air, before being filtered and decanted i____ to the laboratory to be analyzed • comp prepared according to the invention (oranges from batch B) 61 912-_AA00-060306-C-12

s

e, pe

a 11 • t

  daily, expo ea • composition prepared according to the invention (oranges from a batch B) 60306002 59 4 • left, for 11 days, exposed to the (06/03/06) natural daylight, at the temperature 22 C, and ambient air, before being sent to the laboratory for analysis. OBSERVATIONS 67 04 AA0 - 0604 1 -

  17 - - 81.2 • left for 2 hours, exposed to the (11/04/2006) j • composition prepared according to the invention (oranges from a batch A) and then immediately kept at 4, 48 hours s in accordance with the invention, and sent (06/03/2006) 65 1 natural light of the day, at a temperature of 25 C, and to the ambient air, before being sent to the laboratory __ _____ To be analyzed ------------------------------------------------- - the preparation, because it contributes to the elimination of alcoholic yeasts naturally present in orange juice. Thus, once the intermediate phase of decantation recovered, it is transferred to a refrigerated tank at a temperature of about 10 C, to be fermented cold. To do this, we use the KD vitilevide (MARTIN VIALATE INOLOGY, France), a strain of Sacharomyces cerevisae modified, which has the distinction of being able to operate both at low temperature and high temperature, 5 C to 37 C. Also this yeast strain has the advantage of being very undemanding in terms of nutrients; it is able to ferment musts strongly decorticated, as is the case here. The composition with a high vitamin C content is

  fermentation with a yeast operating at low temperature, until obtaining a

  alcohol of the order of 6 to 10% vol / vol. Optionally, to achieve the desired alcohol content, chaptalization may be necessary.

  In order to ferment and alcoholise a composition with a high content of vitamin C according to the invention, the techniques and know-how specific to the work of the wine which are not detailed here can be used. Table 2, below, presents the results of vitamin C assays, performed on samples from different fermented compositions high in vitamin C. These compositions were stored in white glass bottles. No precautions have been taken to preserve them from natural light or the ambient temperature. -------------------------------------------------- -------------------------------------------------- -------------------------------------------------- ------- conservation) 0204150026 39.2 o (after about 6 months of 9.59 (15/04/2002) preservation) ------------------ -------------------------------------------------- -------------------------------------------------- ------------------------------------- 47 910-_AA00-051123-C-02 36.8 no (after approximately 4 years of (02/12/2005) determined conservation) 602170043 54.0 o (17/02/2006) (after 1 month of storage) 7 + 602170044 560 Table 2 Samples (date of analysis) title Vitamin C (mg / 100g) alcohol (% vol / vol) 1020415002539.8 (15/04/2002) (after approximately 6 months of 9.62 + 6 -------- •: r 602170045 57 , 4 o (17/02/2006) (after 1 month of conservation)

o 9

  0 200) (after 1 month of storage)

Claims (2)

  1 / - A process for extracting and treating a citrus juice in order to obtain a composition with a high content of vitamin C, in which the following steps are carried out: - citrus fruits are cut in half-citrus fruits, according to a cutting plane at least substantially equatorial, - said half-citrus fruit is pressed to obtain a pressing product, - said pressing product is filtered to draw a filtered juice, characterized in that: - a decantation of the juice is carried out filtered so as to be able to separate it into three phases: an upper phase of oily consistency, a lower phase of sedimentary composition and an intermediate phase consisting of a composition containing vitamin C, after which said decantation, the intermediate phase is extracted to obtain a composition with a high content of vitamin C; all the steps, from cutting the citrus fruit until the extraction of said intermediate phase, is made in the absence of natural light and at a temperature of the order of 4-10 C. 2 / - Process according to claim 1, characterized in that the semi-citrus fruits are pressed by means of a press of the static press type.  3 / - Method according to claim 2, characterized in that caliber the operation of the press so that the pressing is carried out without causing substantial alteration to the albedo and / or the bark of citrus fruits. 4 / - Method according to one of claims 1 to 3, characterized in that the decantation of the filtered juice by adding an enzyme pectolytique activity.5 / -Procédé according to one of claims 1 to 4 characterized in what is done by decanting the filtered juice by adding a quantity of the order of   2-3 g.hl "of at least one enzyme with pectolytic activity 6 / - Method according to one of Claims 1 to 5, characterized in that the intermediate phase is subtracted after decantation of the 24 hours 7 / - Process according to one of claims 1 to 6, characterized in that the citrus fruits refrigerate at a temperature not exceeding 10 C, before proceeding to cutting and pressing. / - Method according to one of claims 1 to 7, characterized in that the filtered juice is recovered inside a decantation tank previously deaerated 9. / - Method according to one of claims 1 to 8, characterized in that a sterilizing filtration of said intermediate phase is carried out before it is packaged in. 10 / - Method according to one of claims 1 to 9, characterized in that it is made from oranges 11 / -Procédé according to claim 10, characterized in that one uses Oranges of the type without umbilicus 12 / - Method according to one of claims 10 or 11, characterized in that oranges belonging to a variety selected from: Salustiana, Valencia late and Setubalense. 13 / A method according to one of claims 1 to 12, characterized in that subject the subtracted subtractive phase to the settling tank to an alcoholic fermentation according to a method borrowed from the manufacture of wine. 14 / - Method according to claim 13, characterized in that the alcoholic fermentation is carried out in a refrigerated tank at a temperature of about 10 C, by means of a vitilevide KD.15 / - Method according to one Claims 13 or 14, characterized in that the alcoholic fermentation is allowed to proceed until an alcohol content of about 6 to 10% vol / vol is obtained. 16 / liquid composition based on citrus juice, characterized in that it is visually non-turbid and free of suspended solid particles, and in that it has a vitamin C content at least of the order of 40 mg per 100 g of composition. 17 / - Composition according to claim 16, characterized in that it is prepared according to a process according to one of claims 1 10 to 15. 18 / - Composition according to one of claims 16 or 17, characterized in that it has a vitamin C content of at least about 50 mg per 100 g of composition. 19 / -position according to one of claims 16 to 18, characterized in that it is a fermented composition having an alcohol content of the order of 6 to 10% vol / vol.