JP2002238490A - Method for producing processed fruit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing processed fruit capable of making pectic substances in fruits have low molecule weight without using highly concentrated common salt. SOLUTION: This method for producing processed fruit comprises the steps of impregnating such fruit as plum or apricot with pectic decomposition enzyme to soften the tissue of fruits. Foods made of plum, apricot or the like obtained through this method are provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a processed fruit comprising impregnating a fruit of a plum or apricot with a pectolytic enzyme to soften the fruit tissue, a plum or apricot obtained by this method, and a method for producing the processed fruit. Containing foods.

[0002]

[Prior Art] Umeboshi is a salted product made by processing plum fruits.
Most of them contain about 20% of salt, but in recent years, products with salt content of about 5 to 10% are becoming mainstream in response to consumers' low salt tendency. For example, as a method for producing reduced salt plums, a technique of desalinating (secondarily processing) fruits that have been salted (primarily processed) with high-concentration salt and used with water is widely used. However, in this method, wastewater containing a large amount of salt is generated from the manufacturing process, and depending on the treatment, it may develop into an environmental problem. Further, in this desalting step, the active ingredients in the plum fruit such as citric acid are also washed away, so that the preservative properties and the like that are originally possessed by the plum may be impaired.

[0003] On the other hand, the softness of the pulp of dried plum is greatly affected by the ripeness of the fruit as a raw material. That is, in order to stably produce a product having a soft pulp and high palatability, it is necessary to use a moderately matured fruit of a constant ripeness as a raw material. For example, when an overripe fruit is used as a raw material, the surface of the pericarp is easily damaged in the processing step, and when an unripe fruit is used, the flesh shrinks and loses commercial value. As long as fruits with a certain degree of ripeness are used as raw materials, it is inevitable that the work will be concentrated at one time, but especially when harvesting,
If unripe fruits, which can be easily sorted and used, can be used as raw materials, the work can be decentralized and contribute to improvement in production efficiency. Under such circumstances, plum fruit can be pickled with a small amount of salt from the beginning without desalting after primary processing, and it has the same taste, texture and characteristics as immature fruits as conventional products There is a strong demand for the development of techniques for producing plums.

[0004]

The salt plays an important role not only in preserving the fruit but also in softening the fruit tissue in the production of dried plums. Therefore, the present inventors further examined the role of such salt, and tissue softening was performed by calcium chelating between pectin chains in fruits,
Solubilization of pectic substances generated by dissociation of chelate bonds by replacement of divalent metal ions such as magnesium with sodium ions derived from salt, and pectin substances activated by pectinolytic enzymes in fruits that are activated accordingly Was considered to be due to the low molecular weight of. From these facts, if the pectic substance in plum fruit can be reduced in molecular weight by a method other than sodium replacement with salt, it will be possible to produce reduced salt plum without using high concentration of salt. Conceivable. It is also known that in the process of maturation of fruits, pectic substances are reduced in molecular weight by pectinolytic enzymes possessed by the fruits themselves, and the flesh is softened. Even for unripe fruits with insufficient pectin molecular weight reduction, it is possible to produce umeboshi with the same quality as when using ripe fruits by reducing the molecular weight of pectin substance by some method. it is conceivable that.

[0005]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies based on the above presumption, and found that (1) fruit tissues are softened by impregnating the fruits with pectin-degrading enzymes; (2) Impregnation is promoted by placing the fruits under reduced pressure or pressurized conditions and then returning to normal pressure. (3) Although the permeability of the enzyme decreases with time after harvesting the fruits, Immersing the fruit in a solution containing a water-soluble calcium salt, storing the fruit, storing the fruit under reduced pressure or pressurized conditions, or finding that a combination thereof can prevent a decrease in the permeability of the enzyme. It was completed. Therefore, according to the present invention, a method for producing a processed fruit comprising impregnating ume or apricot fruit with a pectolytic enzyme to soften fruit tissue, a plum or apricot obtained by this method, and a food containing the same Is provided.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Plum and apricot to which the method of the present invention is applied are each Prunusmume SIEB.
et ZACC and the fruits of the plant known by the scientific name of Prunus armeniaca, if it is used for food, plums are Nanko, Yoro, Shirokaga, Akebono, Bungo, etc., apricot is Peace, Niigata Daimi, etc. It may be of any kind.

The pectolytic enzyme used in the present invention may be any of those derived from microorganisms or those obtained by synthesis, as long as it is an enzyme capable of decomposing insoluble pectic substances. More than one kind may be used in combination. Examples of pectinolytic enzymes include protopectinases derived from yeasts such as Trichosporon penicillatum and microorganisms closely related to yeast (M
ethods in Enzymology, 161, 335, 1988), polygalacturonases from Aspergillus awamori (Biochem.Biophys.Biotech.,
64, 1337 and 1729, 2000), Trichosporone
Polymethoxygalacturonases from penicillata
(FEBS Letters, 414, 439, 1997). Protopectinase-S (Methods in Enzymology, 161 produced by Trichosporone penicillatum SNO3 strain).
Vol. 335, 1988).

[0008] These enzymes may be in the form of either liquid or solid, but are used as an enzyme-containing aqueous solution in which the enzyme is dissolved in a solution that does not affect the enzyme action, such as water, a buffer, or preferably distilled water. By immersing the fruit of plum or apricot at room temperature, preferably at a temperature of 25-37 ° C. for a certain period of time, and impregnating the fruit with the enzyme,
Fruit tissue can be softened. Pectinolytic enzyme depends on the enzyme and the type of target fruit, etc.
100,000-500,000U (international unit) per kg, 200,000-400,000U
The concentration of the enzyme-containing aqueous solution is preferably in this range as a whole, and it is preferable that all the fruits are soaked.

[0009] The procedure, immersion time and the like are arbitrary as long as the fruit can be impregnated with the pectolytic enzyme. For example, the enzyme-containing aqueous solution may be added to the container containing the fruit, or the fruit may be added to the container previously containing the enzyme-containing aqueous solution. The immersion time is not particularly limited, and is usually 10 minutes to 1 hour, preferably 10 to 20 minutes. The enzyme is 0
The fruit can be efficiently impregnated by placing the fruit under reduced pressure such as 4040 mmHg or pressurized conditions such as 770-800 mmHg, and then returning to normal pressure. In a state of being immersed in the aqueous solution, it is placed in a vacuum container at room temperature, the pressure in the container is kept under a reduced pressure condition of 20 to 30 mmHg, and then the pressure is rapidly returned to normal pressure. The time for maintaining the pressure or pressure is not particularly limited, and is usually 10
Minutes to 1 hour, preferably 10 to 20 minutes. Such a pressure change can be performed, for example, using a pressure transducer in a state where the fruit and the enzyme-containing aqueous solution are placed in a known pressure vessel.

[0010] In order to impregnate the fruit with the pectinolytic enzyme as described above, it is necessary to use the fruit within 24 hours from the time of harvest, ie, at the time of harvesting from a tree.
This is because the permeation of the enzyme into the fruit decreases with time after the harvest of the fruit, and it is almost impossible to impregnate the fruit, for example, 48 hours after the harvest with the enzyme. However, according to the study of the present inventors, this decrease in enzyme permeability over time after harvesting can be attained by storing fruits by immersing them in an aqueous solution containing a water-soluble calcium salt, or by storing fruits under reduced pressure. Alternatively, it can be prevented by storing under a pressurized condition.

[0011] When the fruit is stored by immersing it in an aqueous solution containing a water-soluble calcium salt, water-soluble calcium such as calcium chloride, calcium lactate, calcium gluconate, calcium nitrate and calcium acetate is used.
An aqueous solution having a calcium ion concentration of ~ 2.0% is prepared, and the fruit is immersed in the aqueous solution. Of the above, calcium chloride or calcium gluconate is particularly preferred, and fruits immersed in a calcium solution can be stored at room temperature for several days. When the fruit is stored under reduced pressure or under pressure, it can be performed by the above-described pressure and method. For example, it is preferable that the fruit is vacuum-packaged in a polyethylene multilayer film bag or the like and stored at room temperature. Therefore, after harvesting, the fruits to which this method is applied should be immersed in a solution containing a water-soluble calcium salt or subjected to reduced pressure or pressurized conditions while the enzyme permeability does not decrease (preferably within several hours after harvest). Placing it underneath or storing by a combination of these methods allows the enzyme to be effectively impregnated several days after collection.

The ume or apricot obtained by the method of the present invention may be used as it is as a food or may be further processed to produce various foods such as bean jam, jelly and yokan, especially plum in the case of ume, It can be manufactured in pickled plums. Seasonings such as sugar and salt, coloring agents, preservatives, preservatives and the like necessary for the production of the final product can be impregnated with the enzyme together with the enzyme, or added to the fruit after the enzyme has been impregnated. For example, when the salt content is about 5
% Umeboshi can be obtained by dissolving sodium chloride in an aqueous solution containing an enzyme to a concentration of 10% and impregnating the fruit, or after impregnating the enzyme with 10% by weight of a salt for 2 hours to 1 day. By pickling, a fruit impregnated with enzyme and salt is obtained, then dried for 3 days to 1 week in the sun, and processed by adding reddish leaves to produce a product.

As described above, according to the method of the present invention, processing which conventionally takes a long time can be performed in a short time, and the processing time can be reduced and the process can be simplified. In the case of producing a salted product such as umeboshi, it is possible to obtain the same taste and characteristics as a conventional product with a small amount of salt, and to suppress the amount of salt-containing wastewater to a small amount. In addition, since unripe fruits, which have conventionally been difficult to use as raw materials, can be used, the production rate of foods containing the same can be improved. Furthermore, since pectin-degrading enzymes produce more pectin oligosaccharides in fruit tissues than in the conventional method, by ingesting plums or apricots obtained by the method of the present invention and foods containing them, the pectin oligosaccharides Effects such as suppression of cancer cell development are also expected.

[0014]

Hereinafter, the present invention will be described with reference to examples.
The present invention is not limited to these examples. Example 1 Protopectinase-S produced by Trichosporone penicillatum SNO3 strain was dissolved in 1,000 ml of distilled water in a plastic container to obtain a 0.1% enzyme-containing aqueous solution (150,000 U). 800g). This vessel was evacuated to 20 mmHg with a pressure transducer (manufactured by Tokyo Rika) at room temperature, kept for 15 minutes, quickly returned to normal pressure, and left still for 15 minutes. After that, keep the processed fruit in a frozen state for 1-3 mm
Slices, and dehydrated with 70% and 90% ethanol to prepare ultrathin section specimens.
ase) buffer (pH 7.0) using an anti-protopectinase-S rabbit antibody (Agric. Biol. Chem., 46, 667, 1982) and an anti-rabbit IgG goat antibody (ICN Pharmaceuticals, Inc.). Enzyme immunostaining was performed to observe the state of enzyme impregnation. As a result, it was confirmed that protopectinase had permeated deep into the fruits in the fruits treated within 2 hours from the harvest. On the other hand, fruits more than 48 hours after harvest were comparable to control fruits without enzyme impregnation,
Protopectinase was hardly impregnated (FIGS. 1A-C).

Example 2 In order to examine the action of the pectolytic enzyme impregnated in the fruit, plum fruit (A) treated in the same manner as in Example 1 was dissolved in an aqueous solution containing the enzyme by dissolving 10% by weight of sodium chloride. The plum fruit (B) treated in the same manner as in Example 1, the plum fruit (C) salted with 10% by weight of sodium chloride by a conventional method, and the plum fruit (D) salted with 20% by weight of salt, were distilled water from the fruit. The extracted water-soluble pectin fraction was subjected to a gel filtration method (Amersham Pharmacia Biotech, HiLoad 16/60 Superdex 75 p
rep grade column). Condition is Vo
40 ml; Vt 120 ml; eluent water; flow rate 1 ml / min; fractionation 2 ml / fraction; detection was performed by the carbazole sulfate method. Samples (A) to (C) had the same amount of 0.1 g / ml, and sample (D)
Five volumes were used. As a result, the pectic substance was degraded better in the sample (A) than in the sample (C) and the sample (D), and in particular, in the sample (B) impregnated with the salt simultaneously with the enzyme, the decomposition of the pectic substance was accelerated, and the enzyme was degraded. Was shown to work well in fruit tissue (FIG. 2). In addition, when the pectic substances decomposed in each sample were analyzed by chromatography under the same conditions as above, high molecular sugars were found in samples (C) and (D), but samples (A) and ( In B), the presence of oligosaccharides was confirmed.

Example 3 Immediately after harvesting, immersed in an aqueous solution containing various water-soluble calcium salts and stored at room temperature for 2 days. Were compared in the state of impregnation into the fruit. As a result, it was confirmed that immersion in an aqueous solution containing a water-soluble calcium salt maintained the enzyme-permeability of the fruit (FIG. 3).

Example 4 500 g of plum fruits immediately after harvesting were stored in a plastic laminate bag for 2 days under room temperature conditions without packaging or in vacuum packaging (20 mmHg) atmosphere. Similarly, the enzyme impregnation ability was examined. As a result, when the fruits are vacuum-packaged and stored at room temperature, the fruits maintain the same enzyme impregnation ability as immediately after harvesting, and when stored under such conditions, the enzymes are impregnated into the fruits efficiently. It turned out that it could be done (FIG. 4).

Example 5 Minami Takashi plum fruit 50 stored at room temperature for 24 hours after harvest
0 g of sucrose (manufactured by Wako Pure Chemical Industries) 20%, red No. 102 dye (manufactured by San-Ei Gen FFI, absorbance at 520 nm of 5.0) and calcium chloride (sum) were added to the enzyme-containing aqueous solution described in Example 1. A solution in which 5% (Kako Pure Chemical Industries, Ltd.) was dissolved was impregnated under the conditions described in Example 1. Next, 5 g of the pulp of this fruit was collected, suspended in 20 ml of distilled water at room temperature, and thoroughly stirred, and then centrifuged.
The supernatant was collected at (15 minutes, 10,000 rpm, 5 ° C.), and the absorbance and sucrose (manufactured by Elmo, using a saccharimeter) concentration were measured. As a result, the absorbance at a wavelength of 520 nm was 1.2, and sucrose 10%
Was impregnated, indicating that the desired product could be easily produced by impregnating the fruits with the seasonings and colorings required for the final product together with the enzyme.

Example 6 Immediately after harvesting, 1000 g of unripe plum fruits of the southern high variety were immersed in 2 L of a 2% aqueous calcium chloride solution and stored at room temperature for 2 days.
Each group was divided into two groups of 0 g. One group was impregnated with the enzyme under the conditions described in Example 2. That is, Trichosporon
Protopectinase-S produced by penicillatum SNO3
Dissolve it in 1000 mL of 10% saline solution to make 0.1% (150,0
00U), the pressure was reduced to 20 mmHg by a pressure transducer (manufactured by Tokyo Rika) at room temperature, and the pressure was maintained for 15 minutes. Then, the pressure was quickly returned to normal pressure, and the mixture was left still for 15 minutes (section A). Another group was not subjected to the enzyme impregnation treatment (section B). In both A-section and B-section, the fruits were washed with water and dried, then salted with 55.6 g of salt (final salt content: 10%), dropped by a conventional method, and covered with a lid.
A 50 g weight was placed and stored at room temperature for 5 weeks. Thereafter, sun drying was performed for three days to prepare plum dried.

The umeboshi in section B had a texture that was significantly different from that of umeboshi produced by using normal ripe fruits, with the flesh atrophy and hardening. And had a comparable texture. Each physical property was evaluated using a food physical property measuring device (manufactured by Sun Kagaku Co., Ltd., rheometer CR-200D type). That is, one side of umeboshi in each section was cut at a section in contact with the seed, and the cut side was placed on a measuring table of the apparatus with the cut side down. The maximum load was measured when a metal tooth profile pressure-sensitive shaft (No. 34 tooth profile A, manufactured by Sun Kagaku Co., Ltd.) was brought into contact with the sample surface from above the sample, and 3 mm was entered at a speed of 20 mm / min. . The maximum load for section B was 214.1 gf on the average of seven randomly selected pieces, whereas A
In the ward, a large difference of 24.9 gf was observed. When this value was compared with a load value of 23.3 gf obtained in the same manner for a standard product prepared by a conventional method using high-concentration sodium salt as a raw material, no significant difference was observed (Table 1). 1).

[Table 1]

[0021]

Industrial Applicability According to the present invention, a method for producing a processed fruit comprising impregnating ume or apricot fruit with a pectolytic enzyme to soften fruit tissue, a plum or apricot obtained by this method, A food is provided.
According to this method, it is possible to shorten the processing time and simplify the process, which are conventionally required, and to use immature fruits which have not been used conventionally for processing. In addition, when manufacturing salted products such as conventional umeboshi, it is possible to obtain foods with the same taste and characteristics as conventional products with a small amount of salt, and it is also possible to reduce the amount of salt-containing wastewater to a small amount. , Environmental and production efficiency.

[0022]

[Brief description of the drawings]

FIG. 1A shows enzyme immunostaining of plum fruits impregnated with enzymes immediately after harvest. The fruit impregnated with the enzyme is stained.

FIG. 1B shows enzyme immunostaining of control plum fruit not impregnated with enzyme.

FIG. 1C shows enzyme immunostaining of plum fruits impregnated with enzymes 48 hours or more after harvest.

FIG. 2 shows the molecular weight distribution of pectin in plum fruit. Sample A: Fruit impregnated with protopectinase-S, Sample B:
Fruit impregnated by dissolving 10% by weight of salt in an aqueous solution containing an enzyme, Sample C: Fruit salted with 10% by weight of salt, Sample D:
Fruit pickled with 20% by weight of salt.

FIG. 3 shows changes in enzyme impregnation ability by immersion in various calcium salt solutions.

FIG. 4 shows a change in enzyme impregnation ability according to storage conditions.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Michiyo Nakauchi 242-7 Kano, Wakayama City, Wakayama Prefecture (72) Inventor Shigeaki Ikemoto 158 Nogaminaka, Kainan City, Wakayama Prefecture Ichi Fujishiro 17 (72) Inventor Takuo Sakai 4-13-6 Harayamadai, Sakai City, Osaka (72) Inventor Hajime Yoshisu 2-950-68, Nakamachi Nishi, Nara City, Nara Prefecture (72) Inventor Tetsuo Murakami Nara, Nara Prefecture 2-3-34, Chiyogaoka, Nishi-shi F term (reference) 4B016 LG01 LG03 LK18 LP13 4B069 DA05 HA15

Claims (7)

[Claims] 1. A method for producing a processed fruit, comprising impregnating ume or apricot fruit with a pectolytic enzyme to soften the fruit tissue. 2. The method according to claim 1, wherein the pectinolytic enzyme is used at a concentration of 100,000 to 500,000 U (international unit) per kg of fruit. 3. The method according to claim 1, wherein the impregnation is carried out by keeping the fruits in the aqueous solution containing pectinolytic enzymes under reduced pressure and then returning to normal pressure. 4. The method according to claim 1, wherein the fruit is previously stored in an aqueous solution containing a water-soluble calcium salt. 5. The method according to claim 1, wherein the fruit has been previously stored under reduced pressure. 6. A plum or apricot obtained by the method according to claim 1. 7. A food containing the plum or apricot according to claim 6.