CN112898249A

CN112898249A - Method for extracting vitamin C from kiwi fruits, vitamin C obtained by extraction method and application of vitamin C

Info

Publication number: CN112898249A
Application number: CN202110087364.8A
Authority: CN
Inventors: 李永军
Original assignee: Nanjing Strong Food Co ltd
Current assignee: Nanjing Strong Food Co ltd
Priority date: 2021-01-22
Filing date: 2021-01-22
Publication date: 2021-06-04

Abstract

The invention provides a method for extracting vitamin C from kiwi fruits, vitamin C obtained by the extraction method and application of the vitamin C; the method for extracting vitamin C from kiwi fruits comprises the following steps: mixing and pulping the peeled kiwi fruit with a first acidic solution to obtain kiwi fruit pulp; freeze-drying the kiwi fruit slurry for the first time, and then crushing to obtain kiwi fruit powder; and mixing the kiwi fruit powder with a second acidic solution, then carrying out first solid-liquid separation, and carrying out second freeze drying on the obtained first liquid to obtain the kiwi fruit vitamin C. The extraction method is simple, efficient, safe, low in cost, suitable for industrial production and application, and high in vitamin C extraction rate.

Description

Method for extracting vitamin C from kiwi fruits, vitamin C obtained by extraction method and application of vitamin C

Technical Field

The invention relates to the technical field of food, in particular to an extraction method of vitamin C from kiwi fruits, vitamin C obtained by the extraction method and application of the vitamin C.

Background

The kiwi fruit is commonly called as Actinidia chinensis, wild peach, Hiyan peach, wild pear and the like, is a fruit with fresh and tender quality, rich nutrition and delicious flavor, contains rich vitamins besides microelements such as calcium, potassium, selenium, zinc, germanium and the like and 17 amino acids required by human body, and is known as 'fruit king'; the content of vitamin C in the kiwi fruits is 5-10 times of that of oranges and 11-13 times of that of lemons. Vitamin C is one of the most important vitamins in human nutrition, and is also called ascorbic acid because of its deficiency to produce scurvy. Vitamin C not only has important effect on regulating metabolism, but also can enhance the resistance of organism to tumor, and has the effect of blocking chemical carcinogen.

Besides being directly eaten, the kiwi fruit is mainly used for making canned fruits and kiwi fruit juice, and the deep processing such as extraction of vitamin from the kiwi fruit is less. In the prior art, in the process of extracting vitamin C from kiwi fruits, the vitamin C is easy to oxidize and lose, and the extraction rate of the obtained vitamin C product is low.

Disclosure of Invention

The invention aims to provide a method for extracting vitamin C from kiwi fruits, vitamin C obtained by the extraction method and application of the vitamin C, wherein the method is high in production efficiency, low in cost, suitable for industrial production and application, and high in vitamin C extraction rate.

In order to achieve the above purpose, the invention provides the following technical scheme:

a method for extracting vitamin C from kiwi fruits comprises the following steps:

mixing and pulping the peeled kiwi fruit with a first acidic solution to obtain kiwi fruit pulp;

freeze-drying the kiwi fruit slurry for the first time, and then crushing to obtain kiwi fruit powder;

and mixing the kiwi fruit powder with a second acidic solution, then carrying out first solid-liquid separation, and carrying out second freeze drying on the obtained first liquid to obtain the kiwi fruit vitamin C.

As a further improvement of the above technical solution, the first acidic solution includes an oxalic acid solution;

preferably, the mass fraction of the first acidic solution is 1-5%;

preferably, a filter screen of 80-120 meshes is further included after pulping;

preferably, the mass ratio of the peeled kiwi fruit to the first acidic solution is 1: (3-5).

As a further improvement of the technical scheme, the particle size of the kiwi fruit powder is 40-60 meshes;

preferably, the first freeze-drying further comprises: flatly paving the kiwi fruit slurry in a container to enable the thickness of the kiwi fruit slurry to be 1-3 cm;

preferably, the temperature of the first freeze drying is-55 to-50 ℃, and the time is 6 to 10 hours;

preferably, the moisture content of the kiwifruit powder is less than 5 wt%.

As a further improvement of the above technical solution, the second acidic solution comprises a metaphosphoric acid solution;

preferably, the mass fraction of the second acidic solution is 3-5%;

preferably, the mass ratio of the kiwi fruit powder to the second acidic solution is 1: (5-8);

preferably, the step of standing is further included after the kiwi fruit powder and the second acidic solution are mixed; optionally, the standing time is 1-3 h.

As a further improvement of the above technical solution, before the second freeze-drying, the method further comprises: mixing the solid obtained by the first solid-liquid separation with a third acidic solution, then carrying out second solid-liquid separation, and mixing the obtained second liquid with the first liquid to obtain a mixed liquid;

preferably, the third acidic solution comprises a metaphosphoric acid solution;

preferably, the mass fraction of the third acidic solution is 3-5%;

preferably, the mass ratio of the solid to the third acidic solution is 1: (5-8).

As a further improvement of the above technical solution, the method further comprises the steps of before the second freeze-drying; mixing the mixed liquid with a fourth acidic solution;

preferably, the fourth acidic solution comprises an oxalic acid solution;

preferably, the mass fraction of the fourth acidic solution is 3-5%;

preferably, the pH value of a mixed solution obtained by mixing the mixed solution and the fourth acidic solution is 5-6;

preferably, the step of mixing the mixed liquid and the fourth acidic solution further comprises the step of filtering the obtained mixed liquid through a 120-160-mesh filter screen.

As a further improvement of the above technical solution, the first solid-liquid separation and the second solid-liquid separation each include at least one of filtration and centrifugation.

As a further improvement of the above technical solution, before the second freeze-drying, the method further comprises: flatly paving the kiwi fruit slurry in a container to enable the thickness of the kiwi fruit slurry to be 1-3 cm;

preferably, the temperature of the second freeze drying is-55 to-50 ℃, and the time is 6 to 10 hours.

The invention also provides kiwi fruit vitamin C which is prepared by the extraction method.

The invention also provides application of the kiwi fruit vitamin C in food, medicines or cosmetics.

The invention has the beneficial effects that:

mixing and pulping the peeled kiwi fruit with a first acidic solution, freeze-drying, mixing with a second acidic solution, carrying out solid-liquid separation, and freeze-drying to obtain vitamin C of the kiwi fruit; the method for extracting vitamin C from kiwi fruits is simple, efficient, safe, low in cost and suitable for industrial production and application; and the extraction rate of the vitamin C is high, and the vitamin C is stable and is stored.

Detailed Description

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention.

This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein, but rather should be construed as broadly as the present invention is capable of modification in various respects, all without departing from the spirit and scope of the present invention.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In case of conflict, the present specification, including definitions, will control.

The terms as used herein:

"prepared from … …" is synonymous with "comprising". The terms "comprises," "comprising," "includes," "including," "has," "having," "contains," "containing," or any other variation thereof, as used herein, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.

The conjunction "consisting of … …" excludes any unspecified elements, steps or components. If used in a claim, the phrase is intended to claim as closed, meaning that it does not contain materials other than those described, except for the conventional impurities associated therewith. When the phrase "consisting of … …" appears in a clause of the subject matter of the claims rather than immediately after the subject matter, it defines only the elements described in the clause; other elements are not excluded from the claims as a whole.

When an amount, concentration, or other value or parameter is expressed as a range, preferred range, or as a range of upper preferable values and lower preferable values, this is to be understood as specifically disclosing all ranges formed from any pair of any upper range limit or preferred value and any lower range limit or preferred value, regardless of whether ranges are separately disclosed. For example, when the range "1 ~ 5" is disclosed, the ranges described should be construed to include the ranges "1 ~ 4", "1 ~ 3", "1 ~ 2 and 4 ~ 5", "1 ~ 3 and 5", and the like. When a range of values is described herein, unless otherwise stated, the range is intended to include the endpoints thereof and all integers and fractions within the range.

In these examples, the parts and percentages are by mass unless otherwise indicated.

"part by mass" means a basic unit of measure indicating a mass ratio of a plurality of components, and 1 part may represent any unit mass, for example, 1g or 2.689 g. If we say that the part by mass of the component A is a part by mass and the part by mass of the component B is B part by mass, the ratio of the part by mass of the component A to the part by mass of the component B is a: b. alternatively, the mass of the A component is aK and the mass of the B component is bK (K is an arbitrary number, and represents a multiple factor). It is unmistakable that, unlike the parts by mass, the sum of the parts by mass of all the components is not limited to 100 parts.

"and/or" is used to indicate that one or both of the illustrated conditions may occur, e.g., a and/or B includes (a and B) and (a or B).

s10, mixing and pulping the peeled kiwi fruit with the first acidic solution to obtain kiwi fruit pulp.

The first acidic solution is oxalic acid solution; preferably, the mass fraction of the first acidic solution is 1-5%.

Preferably, the method further comprises the step of filtering the kiwi fruit pulp through a filter screen of 80-120 meshes so as to filter out kiwi fruit pulp residues after pulping.

S20, carrying out primary freeze drying on the kiwi fruit slurry, and then crushing to obtain kiwi fruit powder.

In some embodiments, the first freeze-drying further comprises: the kiwi fruit pulp is spread in a container to enable the thickness of the kiwi fruit pulp to be 1-3 cm, so that quick, uniform and sufficient freeze drying is facilitated; the temperature of the first freeze drying is preferably-55 to-50 ℃, the time is 6 to 10 hours, the freeze drying effect is best, and the water content of the kiwi fruit powder can be less than 5 wt%.

Preferably, the particle size of the kiwi fruit powder is 40-60 meshes.

S30, mixing the kiwi fruit powder with a second acidic solution, then carrying out first solid-liquid separation, and carrying out second freeze drying on the obtained first liquid to obtain the kiwi fruit vitamin C.

Preferably, the step of mixing the kiwi fruit powder with the second acidic solution further comprises standing; optionally, the standing time is 1-3 h.

The second acidic solution is a metaphosphoric acid solution; preferably, the mass fraction of the second acidic solution is 3-5%.

Preferably, the mass ratio of the kiwi fruit powder to the second acidic solution is 1: (5-8).

In some embodiments, the second freeze-drying further comprises: mixing the solid obtained by the first solid-liquid separation with a third acidic solution, then carrying out second solid-liquid separation, and mixing the obtained second liquid with the first liquid to obtain a mixed liquid; so as to further extract the vitamin C in the solid obtained by the first solid-liquid separation, and further improve the yield of the vitamin C in the kiwi fruit.

The third acidic solution is a metaphosphoric acid solution; preferably, the third acidic solution has a mass fraction of 3-5%.

In some embodiments, the second freeze-drying further comprises; mixing the mixed liquid with a fourth acidic solution; the fourth acidic solution is oxalic acid solution, and the mass fraction of the fourth acidic solution is 3-5%.

Preferably, the pH value of the mixed liquid obtained by mixing the mixed liquid and the fourth acidic solution is 5-6, so as to ensure that the mixed liquid also keeps subacidity and prevent the vitamin C from being oxidized.

Preferably, the step of mixing the mixed liquid with the fourth acidic solution further comprises passing the obtained mixed liquid through a 120-mesh sieve.

The above-mentioned first solid-liquid separation and the second solid-liquid separation each include at least one of filtration and centrifugation.

In some embodiments, the second freeze-drying further comprises, prior to: the kiwi fruit pulp is spread in a container to enable the thickness of the kiwi fruit pulp to be 1-3 cm, so that rapid, uniform and sufficient freeze drying is facilitated; preferably, the temperature of the second freeze drying is-55 to-50 ℃, and the time is 6 to 10 hours.

It should be noted that the above acidic solutions are all used to keep vitamin C in the kiwi fruits under acidic conditions, so as to reduce the oxidation loss of the vitamin C effective components.

The method for extracting vitamin C from kiwi fruits is simple, efficient, safe, low in cost and suitable for industrial production and application; and the extraction rate of the vitamin C is high, and the vitamin C is stable and storable after freeze drying.

Embodiments of the present invention will be described in detail below with reference to specific examples, but those skilled in the art will appreciate that the following examples are only illustrative of the present invention and should not be construed as limiting the scope of the present invention. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.

Example 1

(1) Cleaning and peeling 10kg of kiwi fruit, soaking the kiwi fruit in 10kg of oxalic acid solution with the mass fraction of 3%, and pulping the mixture of the peeled kiwi fruit and the oxalic acid solution by using a colloid mill until the pulp can completely pass through a filter screen of 80 meshes to obtain the kiwi fruit pulp.

(2) And (2) flatly paving the kiwi fruit slurry obtained in the step (1) in a porcelain plate, wherein the thickness of the slurry is 3cm, then putting the kiwi fruit slurry into a freezing chamber at the temperature of 50 ℃ below zero for freezing for 5 hours, detecting that the water content of freeze-dried kiwi fruit blocks is less than 8 wt%, and then crushing the freeze-dried kiwi fruit blocks by using a crusher until the powder can completely pass through a 40-mesh screen to obtain kiwi fruit powder.

(3) Adding a metaphosphoric acid solution with the mass fraction of 3% into the kiwi fruit powder obtained in the step (2), so that the mass ratio of the kiwi fruit powder to the metaphosphoric acid solution is 1: and 5, uniformly stirring, standing for 1h at normal temperature, and filtering by using a 120-mesh filter screen to obtain a filtrate.

(4) And (4) flatly paving the filtrate obtained in the step (3) in a porcelain plate, freezing the porcelain plate in a freezing chamber at the temperature of 50 ℃ below zero for 10 hours, and detecting that the water content of the freeze-dried kiwi fruit is less than 5 wt% to obtain the kiwi fruit vitamin C dry powder.

Example 2

(1) Cleaning and peeling 10kg of kiwi fruit, soaking the kiwi fruit in 10kg of oxalic acid solution with the mass fraction of 5%, and pulping the mixture of the peeled kiwi fruit and the oxalic acid solution by using a colloid mill until the pulp can completely pass through a filter screen of 80 meshes to obtain the kiwi fruit pulp.

(2) And (2) flatly paving the kiwi fruit slurry obtained in the step (1) in a porcelain plate, wherein the thickness of the slurry is 2cm, then putting the kiwi fruit slurry into a freezing chamber at the temperature of-55 ℃ for freezing for 3h, detecting that the water content of freeze-dried kiwi fruit blocks is less than 8 wt%, and then crushing the freeze-dried kiwi fruit blocks by using a crusher until the powder can completely pass through a 40-mesh screen to obtain kiwi fruit powder.

(3) Adding a metaphosphoric acid solution with the mass fraction of 4% into the kiwi fruit powder obtained in the step (2), so that the mass ratio of the kiwi fruit powder to the metaphosphoric acid solution is 1: 6.5, stirring uniformly, standing for 1h at normal temperature, and filtering by using a 120-mesh filter screen to obtain a filtrate.

(4) And (4) flatly paving the filtrate obtained in the step (3) in a porcelain plate, freezing the filtrate in a freezing chamber at the temperature of minus 55 ℃ for 6 hours, and detecting that the water content of the freeze-dried filtrate is less than 5 wt% to obtain the vitamin C dry powder of the kiwi fruit.

Example 3

(1) Cleaning and peeling 10kg of kiwi fruit, soaking the kiwi fruit in 10kg of oxalic acid solution with the mass fraction of 1%, and pulping the mixture of the peeled kiwi fruit and the oxalic acid solution by using a colloid mill until the pulp can completely pass through a filter screen of 80 meshes to obtain the kiwi fruit pulp.

(2) And (2) flatly paving the kiwi fruit slurry obtained in the step (1) in a porcelain plate, wherein the thickness of the slurry is 1cm, then putting the kiwi fruit slurry into a freezing chamber at the temperature of-52 ℃ for freezing for 4 hours, detecting that the water content of freeze-dried kiwi fruit blocks is less than 8 wt%, and then crushing the freeze-dried kiwi fruit blocks by using a crusher until the powder can completely pass through a 40-mesh screen to obtain kiwi fruit powder.

(3) Adding a metaphosphoric acid solution with the mass fraction of 5% into the kiwi fruit powder obtained in the step (2), so that the mass ratio of the kiwi fruit powder to the metaphosphoric acid solution is 1: and 8, uniformly stirring, standing for 1h at normal temperature, and filtering by using a 120-mesh filter screen to obtain a filtrate.

Example 4

(3) Adding a metaphosphoric acid solution with the mass fraction of 3% into the kiwi fruit powder obtained in the step (2), so that the mass ratio of the kiwi fruit powder to the metaphosphoric acid solution is 1: and 5, uniformly stirring, standing for 1h at normal temperature, and filtering by using a 120-mesh filter screen to obtain a first liquid and a solid.

(4) Adding a metaphosphoric acid solution with the mass fraction of 3% into the solid obtained in the step (3) to ensure that the mass ratio of the solid to the metaphosphoric acid solution is 1: 2, stirring uniformly, standing for 1h, and then filtering by using a 120-mesh filter screen to obtain a second liquid.

(5) And uniformly mixing the first liquid and the second liquid to obtain a mixed liquid, adjusting the pH value of the mixed liquid to 5 by using an oxalic acid solution with the mass fraction of 3%, and filtering by using a 120-mesh filter screen to remove impurities in the mixed liquid.

(6) And (3) flatly paving the mixed liquid treated in the step (5) in a porcelain plate, freezing the mixed liquid in a freezing chamber at the temperature of 50 ℃ below zero for 10 hours, and detecting that the water content of the freeze-dried mixed liquid is less than 5 wt% to obtain the kiwi fruit vitamin C dry powder.

Example 5

(3) Adding a metaphosphoric acid solution with the mass fraction of 4% into the kiwi fruit powder obtained in the step (2), so that the mass ratio of the kiwi fruit powder to the metaphosphoric acid solution is 1: 6.5, stirring uniformly, standing for 1h at normal temperature, and filtering by using a 120-mesh filter screen to obtain a first liquid and a solid.

(4) Adding a metaphosphoric acid solution with the mass fraction of 4% into the solid obtained in the step (3), wherein the mass ratio of the solid to the metaphosphoric acid solution is 1: and 3, uniformly stirring, standing for 1h, and filtering by using a 120-mesh filter screen to obtain a second liquid.

(5) And uniformly mixing the first liquid and the second liquid to obtain a mixed liquid, adjusting the pH value of the mixed liquid to 6 by using an oxalic acid solution with the mass fraction of 4%, and filtering by using a 120-mesh filter screen to remove impurities in the mixed liquid.

(6) And (3) flatly paving the mixed liquid treated in the step (5) in a porcelain plate, wherein the thickness is 2cm, putting the porcelain plate into a freezing chamber at the temperature of minus 55 ℃ for freezing for 6 hours, and detecting that the water content after freeze-drying is less than 5 wt% to obtain the kiwi fruit vitamin C dry powder.

Example 6

(3) Adding a metaphosphoric acid solution with the mass fraction of 5% into the kiwi fruit powder obtained in the step (2), so that the mass ratio of the kiwi fruit powder to the metaphosphoric acid solution is 1: and 8, uniformly stirring, standing for 1h at normal temperature, and filtering by using a 120-mesh filter screen to obtain a first liquid and a solid.

(4) Adding a metaphosphoric acid solution with the mass fraction of 2% into the solid obtained in the step (3), wherein the mass ratio of the solid to the metaphosphoric acid solution is 1: and 4, uniformly stirring, standing for 1h, and filtering by using a 120-mesh filter screen to obtain a second liquid.

(5) And uniformly mixing the first liquid and the second liquid to obtain a mixed liquid, adjusting the pH value of the mixed liquid to 5.5 by using an oxalic acid solution with the mass fraction of 5%, and filtering by using a 120-mesh filter screen to remove impurities in the mixed liquid.

Comparative example 1

Comparative example 1 differs from example 1 in that: removing the oxalic acid solution in the step (1), and directly pulping the peeled kiwi fruit; otherwise, the same procedure as in example 1 was repeated.

Comparative example 2

Comparative example 2 differs from example 1 in that: replacing the mass fraction of the oxalic acid solution in the step (1) with 8 percent; otherwise, the same procedure as in example 1 was repeated.

Comparative example 3

Comparative example 3 differs from example 1 in that: replacing the mass fraction of the oxalic acid solution in the step (1) with 0.1%; otherwise, the same procedure as in example 1 was repeated.

Comparative example 4

Comparative example 4 differs from example 1 in that: replacing the freeze drying in the step (2) and the step (4) with direct oven drying; otherwise, the same procedure as in example 1 was repeated.

Comparative example 5

Comparative example 5 differs from example 1 in that: replacing the mass fraction of the metaphosphoric acid solution in the step (3) with 1 percent; otherwise, the same procedure as in example 1 was repeated.

Comparative example 6

Comparative example 6 differs from example 1 in that: replacing the mass fraction of the metaphosphoric acid solution in the step (3) with 8 percent; otherwise, the same procedure as in example 1 was repeated.

Detecting the content of vitamin C in the dry powder obtained in the above examples 1-6 and comparative examples 1-6, and extracting rate and storage period of vitamin C in kiwi fruit; specific results are shown in table 1 below.

In addition, 1, the content of the vitamin C in the dry powder and the content of the vitamin C in the kiwi fruit are detected according to a first method (high performance liquid chromatography) in GB 5009.86-2016;

2. the extraction rate of vitamin C in the kiwi fruit is equal to the content of the vitamin C in the dry powder/the content of the vitamin C in the kiwi fruit is multiplied by 100 percent.

TABLE 1

In conclusion, the extraction rate of vitamin C in kiwi fruits obtained by the extraction method is higher.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Furthermore, those skilled in the art will appreciate that while some embodiments herein include some features included in other embodiments, rather than other features, combinations of features of different embodiments are meant to be within the scope of the invention and form different embodiments. For example, in the claims above, any of the claimed embodiments may be used in any combination. The information disclosed in this background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

Claims

1. The extraction method of vitamin C from kiwi fruits is characterized by comprising the following steps:

2. The method of claim 1, wherein the first acidic solution comprises an oxalic acid solution;

preferably, the mass fraction of the first acidic solution is 1-5%;

preferably, a filter screen of 80-120 meshes is further included after pulping;

3. The method for extracting vitamin C from kiwi fruits according to claim 1, wherein the particle size of the kiwi fruit powder is 40-60 meshes;

preferably, the temperature of the first freeze drying is-55 to-50 ℃, and the time is 6 to 10 hours.

4. The method of claim 1, wherein the second acidic solution comprises a metaphosphoric acid solution;

preferably, the mass fraction of the second acidic solution is 3-5%;

5. The method for extracting vitamin C from kiwi fruit according to claim 1, further comprising, before said second freeze-drying: mixing the solid obtained by the first solid-liquid separation with a third acidic solution, then carrying out second solid-liquid separation, and mixing the obtained second liquid with the first liquid to obtain a mixed liquid;

preferably, the third acidic solution comprises a metaphosphoric acid solution;

preferably, the mass fraction of the third acidic solution is 3-5%;

preferably, the mass ratio of the solid to the third acidic solution is 1: (2-4).

6. The method for extracting vitamin C from kiwi fruits according to claim 5, further comprising, before said second freeze-drying; mixing the mixed liquid with a fourth acidic solution;

preferably, the fourth acidic solution comprises an oxalic acid solution;

preferably, the mass fraction of the fourth acidic solution is 3-5%;

7. The kiwi vitamin C extraction process of claim 5, wherein said first solid-liquid separation and said second solid-liquid separation each comprise at least one of filtration and centrifugation.

8. The method for extracting vitamin C from kiwi fruits according to any one of claims 1-7, further comprising, before the second freeze-drying: flatly paving the kiwi fruit slurry in a container to enable the thickness of the kiwi fruit slurry to be 1-3 cm;

9. Kiwi fruit vitamin C, characterized in that, prepared by the extraction method of any one of claims 1 to 8.

10. Use of kiwifruit vitamin C as claimed in claim 9 in food, pharmaceutical or cosmetic products.