Method for producing jam containing fruit pulp

Abstract

To provide a technology for efficiently producing jam that contains at least a part of fruit pulp in an original shape and has excellent texture.SOLUTION: A jam according to the present invention is produced by processing a fruit-containing raw material with pectinase under reduced pressure.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to jam containing pulp and a method for producing the same.

Background Art

[0002] Jam is a food product obtained by heating and concentrating raw materials such as fruits with sugar, honey, etc. It is widely loved, not only for spreading on bread, crackers, etc. and eating, but also for pouring over yogurt and eating, or using as a raw material for cakes and confectioneries.

[0003] Generally, jam is obtained by heating fruits, etc. together with sugars, sugar alcohols or honey until they gel. Among them, jam containing fruits of a certain size or more is called "preserve style" jam and has been gaining popularity in recent years.

[0004] Regarding jam containing at least a part of the pulp in a state where the original form is retained, such as "preserve style" jam, Patent Document 1 proposes a technique for weakening the sweet smell with a stewed feeling while strengthening the smell of fresh fruits. That is, Patent Document 1 describes that after subjecting the charged material to vacuum heating and concentration at 65°C or lower, heat sterilization is performed at 90°C or higher for 10 minutes or more, and then cooling is performed to 70 - 85°C within 2 minutes from the heat sterilization.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] Regarding jam made from fruits, like preserve style jam, the popularity of jam where pulp can be felt when eaten is increasing. However, for jams containing pulp of a certain size or larger while maintaining its shape, it is difficult to strengthen conditions such as heating and stirring to maintain the shape of the pulp, and there is a problem that the production efficiency decreases particularly in industrial production.

[0007] Particularly when using cut fruits rather than whole fruits as raw materials, since the pulp is likely to break away from the cut surface during the jam manufacturing process, it has been difficult to efficiently manufacture jams containing the pulp while maintaining its original shape.

[0008] In view of such a situation, an object of the present invention is to develop a technique for efficiently manufacturing a jam that contains at least a part of the pulp while maintaining its original shape and has an excellent texture.

Means for Solving the Problems

[0009] As a result of intensive studies on the above problems, the present inventors have found that by subjecting the raw material of jam to enzymatic treatment using pectinase under reduced pressure, it is possible to efficiently manufacture a jam that contains at least a part of the pulp while maintaining its original shape and has an excellent texture, and have thus completed the present invention.

[0010] The present invention includes, but is not limited to, the following aspects. [1] A method for manufacturing a jam containing fruits, which includes treating a raw material containing fruits with pectinase under reduced pressure. [2] The method according to [1], wherein the fruits include frozen fruits. [3] The method according to [1] or [2], wherein in the pectinase treatment under reduced pressure, 3% by weight or more of the moisture in the raw material is removed. [4] The method according to [1] or [2], wherein the pectinase includes pectin methyl esterase.

Effects of the Invention

[0011] According to the present invention, at least a part of the pulp is contained while maintaining its original shape, and jam with excellent texture can be efficiently produced. Generally, although jam can be efficiently produced by heating raw materials at a high temperature when manufacturing jam, when the pulp softens due to heating and the pulp collapses, according to the present invention, by treating with pectinase under reduced pressure, it is possible to suppress the collapse of the shape of the pulp and produce jam with excellent texture.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Modes for Carrying Out the Invention

[0013] The present invention relates to jam containing pulp and a method for producing the same. The jam according to the present invention only needs to contain at least a part of the pulp while maintaining its original shape, and it naturally includes preserve-style jam, and also includes jam containing smaller pulp. That is, in the quality display standards according to Japanese Agricultural Standards (JAS standards), for preserve-style jam, (a) when berries (excluding strawberries) are used as raw materials, whole fruits, (b) when strawberries are used as raw materials, whole or halved fruits, (c) when fruits other than berries are used as raw materials, pieces of pulp or the like with a thickness of 5 mm or more are used as raw materials and are made to maintain their original shape. However, the jam according to the present invention does not have to correspond to the preserve-style jam defined by the JAS standards as long as at least a part of the pulp is contained while maintaining its original shape. Also, in the JAS standards, the fruit content rate of jam is considered "standard" when it is 33% by weight or more, but the fruit content rate of the jam according to the present invention may be less than 33% by weight. The fruit content rate of the jam according to the present invention is, for example, 10% by weight or more, 20% by weight or more, and may also be 33% by weight or more, 45% by weight or more.

[0014] Regarding jam containing pulp, for example, when mass-producing bread, confectionery products, etc., it is necessary to squeeze out the jam using a squeeze bag or a depositor. However, the discharge port may be blocked by the pulp in a state where the original shape is maintained, or the weight of the squeezed jam may vary due to variations in the size of the pulp. Therefore, depending on the application, it may be preferable to use fruits cut to a certain size instead of whole fruits, and the present invention can be suitably applied in such cases. That is, in the manufacturing process of jam, the pulp is likely to collapse from the cut surface of the cut fruit, and it is difficult to efficiently manufacture jam containing the pulp while maintaining its original shape. However, according to the present invention, it is possible to efficiently manufacture jam even when using cut fruits as raw materials.

[0015] The fruit used as a raw material in the present invention may be a whole fruit or a cut fruit. When cutting the fruit used as a raw material, the size and shape of the cut are not particularly limited, but the thickness can be, for example, 3 mm or more, and may be 5 - 35 mm or 7 - 30 mm. When cutting into dice shape, for example, one side can be 3 mm or more, and may be 5 - 35 mm or 7 - 30 mm. Depending on the fruit, it may be divided not only into two parts but also into three or four parts.

[0016] The fruit used as a raw material in the present invention may be a frozen fruit or a non - frozen fruit. When using a frozen fruit as a raw material, the shape is likely to collapse in the jam manufacturing process. According to the present invention, it becomes possible to efficiently manufacture jam while maintaining the shape of the pulp. Especially when the fruit used for jam is frozen, since the cell structure of the frozen fruit is weakened by freezing, when the frozen fruit is made into small fruit pieces, the physical structure becomes even weaker, and it becomes difficult to maintain the original shape of the fruit when boiling down the jam. However, according to the present invention, it is possible to efficiently manufacture jam while maintaining the original shape of such fruit.

[0017] The jam according to the present invention uses fruit as a raw material. In the present invention, the type of fruit is not particularly limited, but in the present invention, vegetables such as rhubarb and tomato are considered to be included in fruits. As the fruit used for jam, for example, berries such as strawberry, blueberry, raspberry, blackberry, bilberry, pome fruits such as quince, pear, apple, stone fruits such as plum, peach, ume, apricot, cherry, citrus fruits such as mandarin orange, orange, lemon, hassaku, and also mango, pineapple, grape, fig, banana, etc. can be used without limitation. The fruit used in the present invention may be one type or a plurality of types. Also, the jam according to the present invention may use petals as a raw material in addition to the fruit.

[0018] The sugar content of the jam according to the present invention is not particularly limited and may be appropriately adjusted according to the intended use. However, the Brix value is preferably 18 to 70 degrees, more preferably 25 to 55 degrees. When the sugar content is too low, bacteria are likely to grow. Therefore, it is preferable to adjust the sugar content in consideration of not only the flavor of the jam but also its storage stability.

[0019] Regarding the jam according to the present invention, the gel strength is not particularly limited, and it may be finished so that syneresis and the like are less likely to occur. That is, it may be finished so that the jam has an appropriate gel strength according to the intended use, and it may be adjusted in consideration of the mouthfeel and aroma. In the present invention, a gelling agent may be used as necessary, and examples of the gelling agent include pectin.

[0020] In the present invention, in addition to fruits, for example, fruit juice, gelling agent, starch, modified starch, acidulant, flavoring, thickener, alcoholic beverages, etc. may be added as raw materials. The type of fruit juice is not particularly limited, and examples thereof include fruit juices such as strawberry, apple, grape, pear, and orange. The fruit juice may be concentrated juice or straight juice, and may be clear juice or cloudy juice. The acidulant and thickener are also not particularly limited, and examples of the thickener include xanthan gum and guar gum, and examples of the acidulant include lemon juice and citric acid. In addition, known food additives such as antioxidants may be appropriately blended.

[0021] The jam according to the present invention can be used without limitation for various purposes. Since the jam according to the present invention can fully feel the texture of the pulp and the freshness of the fruit, for example, it can be used for bread, crackers, yogurt, beverages, etc., and of course, it can be eaten alone as jam, and it can also be preferably used as a confectionery raw material. In a preferred embodiment, the jam according to the present invention can be used, for example, as an accompaniment to chilled cakes (sandwiches, toppings), jam bread, pancake sandwiches, chiffon cakes, or as a dessert with whipped cream and strawberry jam on top of pudding, etc., or as a fruit sandwich with a mixture of whipped cream and strawberry jam sandwiched between bread.

[0022] Pectinase treatment under reduced pressure The jam according to the present invention is produced by heating after adding raw materials such as saccharides to the fruit, and at least a part of the pulp is contained in a state where the original form remains. The jam according to the present invention is produced by subjecting the raw material containing the fruit to enzymatic treatment under reduced pressure using pectinase.

[0023] The enzymatic treatment using pectinase may be carried out in a container (kettle) capable of adjusting the pressure and temperature. The pressure can be, for example, -0.060 to -0.098 MPa, preferably -0.075 to -0.095 MPa, and more preferably -0.080 to -0.095 MPa. By performing the enzymatic treatment under reduced pressure, the moisture of the raw material can be efficiently removed, and jam can be produced in a relatively short time.

[0024] In addition, the temperature of the enzymatic treatment using pectinase can be, for example, 35 to 75°C, more preferably 40 to 70°C, and even more preferably 43 to 65°C or 46 to 60°C. In the present invention, in the enzymatic treatment under reduced pressure, the moisture contained in the raw material is distilled off as vapor, and the raw material is concentrated. The degree of concentration in the enzymatic treatment step according to the present invention is not particularly limited, but for example, it is preferable that 3 to 30% by weight is distilled off from the weight of the charged raw material, and it is more preferable to perform the treatment so that 4 to 25% by weight or 5 to 20% by weight is distilled off. The time of the enzymatic treatment is also not particularly limited, but for example, it can be 5 to 60 minutes, more preferably 8 to 30 minutes, and even more preferably 10 to 20 minutes.

[0025] General jams are produced by heating and concentrating raw materials containing fruits at normal pressure. In that case, the enzyme is inactivated by heating and concentrating at a high temperature of 90°C or higher. Therefore, when heating and concentrating at normal pressure, in order to exert the effect of the enzyme, the raw material of the jam must be enzymatically treated at the optimum temperature and for the optimum time before heating and concentrating. However, the enzymatic treatment and concentration are carried out separately, which requires a long time for the production of jam. On the other hand, according to the present invention, since the enzymatic treatment is carried out under reduced pressure, it becomes possible to carry out the enzymatic treatment and concentration simultaneously in parallel, and the production time of jam is shortened. That is, in the present invention, since the enzymatic treatment is carried out under reduced pressure, the moisture contained in the raw material can be efficiently distilled off as vapor at a temperature at which the enzyme is not inactivated, and the enzymatic treatment of fruits and the concentration of jam raw materials can be carried out simultaneously. Particularly in the industrial production of jam, according to the present invention, since the enzymatic treatment of fruits and the concentration of jam raw materials can be carried out simultaneously, the production time of jam can be significantly shortened.

[0026] In the present invention, a raw material containing fruits is enzymatically treated with pectinase under reduced pressure. This makes the pulp less likely to break down in the jam manufacturing process, prevents the pulp from softening too much, and can maintain a preferable texture of the pulp. In a general jam manufacturing method, the raw material of jam is concentrated by heating at a high temperature of 90 °C or higher for a long time. In that case, decomposition of sucrose occurs, which has an unfavorable effect on the quality of sweetness, a Maillard reaction generates the aroma of Maillard products, and furthermore, the fruity aroma components of the fruits volatilize due to long-time heating, so that the commercial value of the jam is ultimately impaired.

[0027] In the present invention, pectinase is used as the enzyme. Pectinase is an enzyme that decomposes pectin, and examples thereof include polygalacturonase, pectin lyase, pectin esterase, pectin methyl esterase and the like. The pectinase according to the present invention may be derived from plants, microorganisms, or prepared by genetic recombination, and may be purified or a crude product. Further, in the present invention, other enzymes may be used in combination as long as pectinase is used. For example, some commercially available enzyme preparations may contain other enzymes in addition to pectinase, but such commercially available enzyme preparations may be used as pectinase.

[0028] In the present invention, the amount of pectinase used is, for example, about 0.01 to 1% by weight, preferably 0.02 to 0.1% by weight in terms of protein contained in the enzyme, per 100 g of fruits. When expressed in terms of the enzyme titer, it is, for example, 50 to 5000 U, preferably 75 to 2000 U or 100 to 500 U.

[0029] When performing the enzymatic treatment using pectinase, it is preferable to adjust the pH to the range of 3.0 to 6.0, more preferably to 3.2 to 5.5, in consideration of the optimum pH of the enzyme.

[0030] Further, when performing the enzymatic treatment using pectinase, Ca 2+Leaving a divalent cation such as calcium ion present is preferable because it makes the fruit flesh less likely to break down during the jam manufacturing process. The divalent cation may be calcium ion contained in the fruit, etc., and sufficient in some cases, but a divalent cation may be added as needed. The concentration of the divalent cation is not particularly limited. For example, it may be prepared to be 0.01 to 0.1% by weight, preferably 0.02 to 0.05% by weight, as the amount of Ca, based on 100 g of the fruit. Adding an excessive amount of the divalent cation salt may impart a bitter taste to the fruit.

[0031] Examples of the divalent cation to be added include calcium chloride, calcium acetate, fermented L - calcium lactate, synthetic calcium lactate, calcium gluconate, monocalcium phosphate, calcium malate, calcium sulfate, calcium hydroxide, calcium citrate, dicalcium phosphate, tricalcium phosphate, bone meal, calcium carbonate, shell powder, eggshell powder, etc. Calcium chloride, calcium lactate, and tricalcium phosphate are preferable.

[0032] The present invention may have a filling step. That is, in the filling step, the jam obtained in the enzyme treatment step is filled into a container and sealed. The material of the container is not particularly limited. For example, glass, pottery, metal, resin, paper, etc. can be appropriately used. However, from the viewpoint of ease of handling, etc., it is preferable to fill it into a resin container, particularly a flexible resin container.

[0033] When filling the jam into the container, it is preferably filled so as to reduce the headspace. If necessary, the inside of the container may be made into a deoxygenated atmosphere or nitrogen - substituted.

[0034] In one aspect, the present invention may have a sterilization step. The conditions of the sterilization step are not particularly limited. For example, the preferred temperature is 60 to 92°C, more preferably 64 to 88°C. This is because if sterilization is carried out at too high a temperature, the pulp contained in the jam will soften, making it difficult to enjoy the texture of the pulp. In the sterilization step, it may be carried out batchwise or continuously, or it may be carried out statically as long as the product can be heated to the center.

Examples

[0035] Hereinafter, the present invention will be described in more detail with specific examples, but the present invention is not limited to the following specific examples. Also, in this specification, unless otherwise specified, concentrations and the like are based on weight (mass), numerical ranges include their endpoints, and pressures are described with the unit as gauge pressure, that is, atmospheric pressure = 0.000 MPa.

[0036] Experiment 1. Production and evaluation of jam containing strawberry pulp 1-1. Manufacture of Jam Based on the formulation shown in the following table, the raw materials were mixed and enzyme-treated with pectinase to produce jam. Frozen strawberries cut into dice with a size of 15 mm were used as the raw fruit, and pectin methyl esterase (Sumiteam PME, Shin Nippon Chemical Industry) was used as the pectinase.

[0037]

Table 1-1

[0038] (Example) The above raw materials were enzyme-treated under reduced pressure at -0.090 MPa and about 60°C for about 10 minutes. By the enzyme treatment under reduced pressure, the moisture contained in the raw materials was distilled off as steam (moisture distilled off as steam: about 5.2%), and finally about 1 kg of jam was obtained. Next, 1 kg of the obtained jam was filled into bags and sterilized statically batchwise using a water bath apparatus at 87°C for 50 minutes. The Brix value of the obtained jam was about 40 and the pH was about 3.4. (Comparative Example) The same raw materials as in the examples were used, but the jam was produced by heating to about 90 °C so that the enzyme pectinase did not work. Specifically, the above raw materials were treated at about 90 °C for about 15 minutes under normal pressure to produce jam (water distilled off as steam: about 5.2%). Subsequently, 1 kg of the obtained jam was hermetically filled into a resin container while still hot. The Brix value of the obtained jam was about 40 and the pH was about 3.4.

[0039] 1-2. Evaluation of Jam After storing the jam produced as described above in the refrigerator for 3 days, the following evaluations were carried out. (1) Appearance Evaluation The pulp contained in the obtained jam was taken out, and the shape of the pulp was visually evaluated. Although Figure 1 shows a photograph of the appearance of the pulp, in the jam produced based on the present invention, the corners of the pulp remained firm and the thickness of the pulp was sufficiently maintained, while in the jam of the comparative example, the corners of the pulp were broken and the pulp had become thin.

[0040] Also, the state of the pulp tissue was observed using an optical microscope. The results are shown in Figure 2. The pulp contained in the jam of the present invention maintained the state of the cell tissue, while in the comparative example, the cell tissue had collapsed (left in Figure 2: example, right in Figure 2: comparative example). (2) Sensory Evaluation Regarding the obtained jam, the texture and freshness of the pulp were evaluated. Thirty-two panelists evaluated it on a 7-point scale, with the best case being 7 points and the worst case being 1 point, and then the average value of the evaluation points of each panelist was calculated.

[0041] The evaluation results are shown in the table below. The jam produced according to the present invention had a strong texture of the pulp and was significantly better in the texture of the pulp compared to the jam of the comparative example. Also, the jam according to the present invention had a strong flavor reminiscent of fresh strawberries and was superior in freshness compared to the jam of the comparative example.

[0042]

Table 1-2

[0043] Experiment 2. Production and evaluation of jam containing strawberry pulp 2-1. Jam was produced in the same manner as in the example of Experiment 1, except that the temperature of the enzyme treatment was changed to 40°C. That is, for the raw materials mixed based on the following table, using pectinase (pectin methyl esterase, Sumiteam PME, Shin Nippon Chemical Industry Co., Ltd.), under the conditions of -0.090 MPa and about 40°C for about 15 minutes, the enzyme treatment was carried out while reducing the pressure. By the enzyme treatment under reduced pressure, the moisture contained in the raw materials was distilled off as steam (moisture distilled off as steam: about 5.2%), and finally about 1 kg of jam was obtained (Brix value of jam: about 40, pH: about 3.4).

[0044] When the produced jam was evaluated, the texture of the pulp was felt and it was excellent in freshness.

[0045]

Table 2-1

[0046] 2-2. Jam was produced in the same manner as in the example of Experiment 1, except that a part of the strawberry fruit was replaced with strawberry juice (fruit content rate of jam: 27.1%). That is, for the raw materials mixed based on the following table, using pectinase (pectin methyl esterase, Sumiteam PME, Shin Nippon Chemical Industry Co., Ltd.), under the conditions of -0.090 MPa and about 60°C for about 10 minutes, the enzyme treatment was carried out while reducing the pressure. By the enzyme treatment under reduced pressure, the moisture contained in the raw materials was distilled off as steam (moisture distilled off as steam: about 4.3%), and finally about 1 kg of jam was obtained (Brix of jam: about 50, pH: about 3.4). Note that the strawberry juice used was a puree-like product produced from frozen strawberries used as fruits.

[0047] When the produced jam was evaluated, the texture of the pulp was felt and it was excellent in freshness.

[0048]

Table 2-2

[0049] Experiment 3. Production of jam containing various types of fruits Based on the following table, the raw materials were mixed, and in the same manner as in the examples of Experiment 1, jams containing blueberry, apple, or peach pulp were prepared (Brix: approximately 40, pH: approximately 3.4). However, for blueberries, whole fruits that were not diced were used as raw materials.

[0050]

Table 3-1

[0051]

Table 3-2

[0052]

Table 3-3

Claims

1. A method for producing jam containing fruit, comprising treating a raw material containing fruit with pectinase under reduced pressure.

2. The method according to claim 1, wherein the fruit includes frozen fruit.

3. The method according to claim 1 or 2, wherein in the pectinase treatment under reduced pressure, 3% by weight or more of the moisture in the raw material is distilled off.

4. The method according to claim 1 or 2, wherein the pectinase includes pectin methyl esterase.

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