JPH10117747A - Production of sweet potato juice having flavor of roasted sweet potato - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain as sweet potato juice high in the content of a pigment originated from the raw material and in a sugar content, low in a pulp content, having the flavor of roasted sweet potato by treating sweet potato having a high pigment content under specific conditions, squeezing the treated sweet potato and cooking the juice at a prescribed temperature. SOLUTION: Sweet potato having a high pigment content, such as high carotene content sweet potato containing β-carotene in an amount of >=1.0wt.%, is thermally treated under such conditions as substantially inactivating a polyphenol oxydase contained therein but activating an amylase so as to given a maltose content of 1.0-10wt.%, preferably 3.0-8.0wt.%, and subsequently press- squeezed with a press type squeezer, followed by cooking the squeezed juice at a material temperature of >=100 deg.C to obtain the sweet potato juice. The thermally treated sweet potato is preferably press-squeezed by the use of a press type squeezer equipped with a screw and a screen surrounding the screw under conditions satisfying the inequality [P is the exit pressure (kgf/cm<2> ) of the press type squeezer in a value of 0.01-20; S is a screen hole diameter (mm) of 0.050-1.0].

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing sweet potato juice, and more particularly, to a method for producing sweet potato juice which has a high pigment content and a high sugar content derived from raw materials and is suitable for drinking having a roasted sweet potato flavor with good yield. .

[0002]

2. Description of the Related Art Conventionally, as a method for producing sweet potato juice,
A method has been proposed in which sweet potatoes are peeled, heat-treated, cut, and squeezed with a juicer (Journal of Nagoya Women's University Vol. 41, pp. 93-100, 1995). Recently, various sweet potatoes having a high pigment content have been provided, and even in the above-described conventional method,
Sweet potatoes with a high pigment content have been studied. However,
This conventional method has the drawback that, even when a sweet potato having a high pigment content is used as a raw material, the pigment content and sugar content derived from the raw material of the sweet potato juice obtained are low, and there is no baked sweet potato flavor, and the yield is particularly poor. On the other hand, as a method for producing a sweet potato juice having a baked sweet potato flavor, a method of grinding a baked sweet potato, adding water to the ground product, and then squeezing the juice is performed. However, in this conventional method, since starch is gelatinized when baking sweet potatoes to make roasted potatoes, it is not possible to extract juice as it is as a matter of fact, so it is squeezed after adding water, so that a high pigment content as a raw material Even when sweet potatoes are used, there are drawbacks in that the content of pigment derived from the raw material of the sweet potato juice obtained is low and the flavor is inferior.

[0003]

The problem to be solved by the present invention is that, in the conventional method, even if a sweet potato having a high pigment content is used as a raw material, the pigment content and sugar content derived from the raw material of the obtained sweet potato juice are low, In addition, the sweet potato juice obtained does not have a roasted sweet potato flavor and has a particularly low yield, or has a correspondingly roasted sweet potato flavor, but has a low pigment content derived from raw materials and is inferior in flavor.

[0004]

Means for Solving the Problems Thus, the present inventors have
As a result of research to solve the above problems, after subjecting a sweet potato having a high pigment content to a specific heat treatment, pressing and squeezing the juice under specific conditions, the pigment content derived from the raw material and It has been found that a sweet potato juice having a high sugar content and having a baked potato flavor and suitable for drinking can be produced with good yield.

That is, the present invention provides a sweet potato having a high pigment content,
The polyphenol oxidase contained therein is substantially inactivated, but under the conditions for activating amylase, the mixture is subjected to a heat treatment so that the maltose content is 1.0 to 10% by weight. The present invention relates to a method for producing sweet potato juice, comprising squeezing and squeezing the juice at a temperature of 100 ° C. or higher.

In the present invention, the sweet potato used as a raw material is a sweet potato having a high pigment content containing pigments such as carotene and anthocyanin at a high concentration. Among them, β-carotene is used for 1.
A sweet potato having a high carotene content containing 0 mg% or more and a sweet potato having a high anthocyanin content containing a colorant of 0.10 or more anthocyanin in a portion excluding the perimeter of the sweet potato are preferable. Healthy Red, Higashiyama, Kyushu No. 120 and the like, and such sweet potatoes with a high anthocyanin content, commonly known as Yamakawa purple, Chiran purple, Tanegashima purple, Kyushu 109, Kyushu 113,
Nakamurasaki and the like. In the present invention, the color value is, when it is a raw sweet potato, peels and grinds the sweet potato,
The milled material is diluted 10 times by weight with distilled water, centrifuged, and then the absorbance of the supernatant at the maximum absorption wavelength of 500 to 600 nm is measured. When it is the sweet potato juice produced, the sweet potato juice is diluted 10 times by weight with distilled water, centrifuged, and then the absorbance measured in the same manner as above is set to 1
It is a value multiplied by 0.

In the present invention, sweet potatoes having a high pigment content as described above are heat-treated. The heat treatment substantially inactivates the polyphenol oxidase contained in the sweet potato, but has a maltose content of 1.
It is carried out so as to be 0 to 10% by weight, preferably 3.0 to 8.0% by weight. Polyphenol oxidase has a lower inactivation temperature than amylase, and most of its substrate, polyphenol, is concentrated in the surface layer of sweet potatoes.Therefore, by selecting the temperature and time of the heat treatment, polyphenol oxidase can be substantially lost. While active, amylase can be activated. By inactivating polyphenol oxidase, sweet potato juice having a good color can be produced, and by activating amylase, saccharification of starch can be promoted to produce sweet potato juice having a high sugar content.

According to the present invention, as described above, a sweet potato having a high pigment content can substantially inactivate the polyphenol oxidase contained therein, but has a maltose content of 1.0 under the conditions for activating amylase. Heat treatment is performed so as to be 10 to 10% by weight, preferably 3.0 to 8.0% by weight.
A heat treatment to substantially inactivate polyphenol oxidase and to reduce the maltose content produced by saccharification of starch to less than 1.0% by weight under the action of amylase even under conditions that activate amylase. Can produce only sweet potato juice with low sugar content. Conversely, in the heat treatment in which the maltose content exceeds 10% by weight, it is presumed that the starch is gelatinized, but it becomes difficult to squeeze the juice and the yield decreases. As the heat treatment itself, known methods such as a method of dipping sweet potatoes in hot water and a method of spraying steam on sweet potatoes can be applied.
Although a method of immersing the sweet potato in hot water of 0 ° C. for 10 to 20 minutes can be applied, a method of immersing sweet potatoes in hot water of 80 to 100 ° C. for 5 to 20 minutes is preferably applied.

In the present invention, the sweet potato subjected to the heat treatment is squeezed and squeezed by a squeezing juicer. Juice extractors include a centrifugal type such as a pulper, a ginger and a decanter, and a press type such as a filter press, a screw press, and a twin-screw rotary extruder for juice. Squeezing type is used. Among them, it is preferable to use a squeezing press equipped with a screw and a screen surrounding the screw, and it is particularly preferable to use a screw press or a twin-screw rotary extruder for squeezing. This is because a sweet potato juice having a high pigment content derived from raw materials and suitable for drinking can be produced with good yield.

When the heat-treated sweet potato is squeezed and squeezed with a squeezing press equipped with a screw and a screen surrounding the screw, the squeezed squeezed juice under the condition satisfying the following equation 1 is A sweet potato juice with a high pigment content and a good pulp content and good throat can be produced with good yield.

[Formula 1] 0.10 ≦ log (P / S) ≦ 2.0 に お い て In the formula 1, P is an outlet pressure (kgf / cm ² ) of a squeezing type juicer,
Numerical value in the range of 0.10 to 20 S: hole diameter (mm) of the screen mounted on the squeeze type juicer, numerical value in the range of 0.050 to 1.0

[0011] In the present invention, the squeezed squeezed juice is treated at a product temperature of 1
Cook above 00 ° C. Such cooking can be performed by open heating using a closed-system tube or plate heater, a retort, or a tank, whereby an appropriate roasted sweet potato flavor can be imparted to the juice.

Although the present invention has been described above, in the present invention, the stage before the squeezed juice, specifically, the stage before the heat treatment or after the heat treatment and before the squeezed juice, is also described. It is preferable to peel the sweet potatoes. This is because sweet potato juice having a better color tone and less bitterness can be produced. As the peeling method, known peeling methods such as mechanical peeling method, chemical peeling method, and peeling method combining these methods can be applied, but mechanical peeling method without heating is suitably used, for example, peeling with a peeler. Is preferred. In addition, it is preferable to crush or cut the heat-treated sweet potato at a stage before the squeezed juice. Squeeze juice smoothly to increase the juice rate,
This is because the yield can be improved.

[0013] Further, in the case where the squeezed juice is carried out by a squeezing type juicer equipped with a screw and a screen surrounding the screw, in the above formula 1, 0.30 ≦ lo
g (P / S) ≦ 1.5 is preferably performed, and the clearance between the screw and the screen mounted on the squeezing press (the radial outer peripheral end face of the screw and the radial inner surface of the screen) Gap between the peripheral end face) and 1.0
It is preferable to set it to be equal to or less than mm. This is because the squeezing rate can be increased to improve the yield. Also, in the case where the squeezed juice is performed by any squeezed juicer, it is preferable to perform the squeezed juice at a product temperature of 75 ° C. or less. This is because starch gelatinization can be prevented, the squeezing rate can be increased, and the yield can be improved.

The cooking is preferably carried out after adjusting the pH of the squeezed squeezed juice to a pH of 3.5 to 4.5, preferably at a product temperature of 100 to 125 ° C. and a maximum temperature of 5 minutes. This is because a suitable roasted sweet potato flavor can be imparted by the juice.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention include the following 1) to 5). 1) A so-called healthy red containing 3.7 mg% of β-carotene is immersed in hot water at 90 ° C for 10 minutes to activate polyamylase while substantially inactivating polyphenol oxidase, thereby converting maltose to 5.0. A heat-treated product containing a weight percent is obtained. The heat-treated product is peeled with a peeler, crushed with a micro grader, and squeezed and squeezed with a screw press. The squeezed juice at this time is discharged at an outlet pressure P = 5.0 kgf.
/ Cm ² , screen pore size S = 0.40 mm, log (P /
S) = 1.1, clearance = 0.50 mm, product temperature = 70
Perform under the condition of ° C. The squeezed juice thus squeezed and squeezed is cooked at 105 ° C. for 3 minutes to produce a sweet potato juice having a baked sweet potato flavor.

2) A so-called Kyushu 120 containing 10 mg% of β-carotene is immersed in hot water at 95 ° C. for 10 minutes to activate polyamylase while substantially inactivating polyphenol oxidase, thereby reducing maltose to 6%. A heat-treated product containing 0.0% by weight is obtained. The heat-treated product is peeled with a peeler, crushed with a crusher, and squeezed and squeezed with a biaxially differently rotating extruder. The squeezed juice at this time was subjected to outlet pressure P = 6.3 kgf / cm ² , screen pore size S = 0.2
0 mm, log (P / S) = 1.5, clearance = 0.
It is carried out under the conditions of 50 mm, product temperature = 70 ° C. The juice thus squeezed and squeezed is cooked at a product temperature of 100 ° C. (attained temperature) to produce a sweet potato juice having a baked sweet potato flavor.

3) A so-called Benihayato containing 12 mg% of β-carotene is immersed in hot water at 80 ° C. for 20 minutes to activate polyamylase while substantially inactivating polyphenol oxidase, thereby reducing maltose to 7% by weight. A heat-treated product is obtained. This heat-treated product is peeled with a peeler, crushed with a micro grader, and then squeezed and squeezed with a biaxially different-direction rotating type extruder. The squeezed juice at this time was subjected to outlet pressure P = 1.0 kgf / cm ² , screen pore size S = 0.50.
mm, log (P / S) = 0.30, clearance = 0.
It is carried out under the conditions of 50 mm, product temperature = 70 ° C. The juice thus squeezed and squeezed is adjusted to pH 3.9 by adding lemon juice, and then cooked at a product temperature of 121 ° C. (attained temperature) to produce a squeezed sweet potato juice having a baked potato flavor.

4) A so-called Yamakawa purple containing 3.2 in color value of anthocyanin is immersed in hot water at 90 ° C. for 10 minutes to activate polyamylase while substantially inactivating polyphenol oxidase, thereby reducing maltose. A heat-treated product containing 5.0% by weight is obtained. The heat-treated product is peeled with a peeler, crushed with a micro grader, and squeezed and squeezed with a screw press. The squeezed juice at this time is converted to an outlet pressure P =
5.0 kgf / cm ² , screen hole diameter S = 0.40 mm, lo
g (P / S) = 1.1, clearance = 0.50 mm, and temperature = 70 ° C. The squeezed juice thus squeezed and squeezed is cooked at 105 ° C. for 3 minutes to produce a sweet potato juice having a baked sweet potato flavor.

5) So-called Chiran purple containing 1.5 of anthocyanin in color value is immersed in hot water at 90 ° C. for 10 minutes to activate polyamylase while substantially inactivating polyphenol oxidase, thereby converting maltose. A heat-treated product containing 5.0% by weight is obtained. The heat-treated product is peeled with a peeler, crushed with a crusher, and then squeezed and squeezed with a biaxially different direction rotating type extruder for squeezing. At this time, the squeezed juice was subjected to outlet pressure P = 5.0 kgf / cm ² , screen pore size S =
The test is performed under the conditions of 0.30 mm, log (P / S) = 1.2, clearance = 0.50 mm, and product temperature = 70 ° C. The juice thus squeezed and squeezed is cooked at a product temperature of 100 ° C. (attained temperature) to produce a squeezed sweet potato juice having a baked sweet potato flavor.

[0020]

【Example】

Example 1 A so-called healthy red containing 3.7 mg% of β-carotene was immersed in hot water of 80 ° C. for 8 minutes to activate polyamylase while substantially inactivating polyphenol oxidase, thereby reducing maltose to 3.%. A heat-treated product containing 0% by weight was obtained. The heat-treated product was peeled with a peeler, crushed with a micro grader, and squeezed and squeezed with a biaxially different direction rotating type extruder for squeezing. The squeezed juice at this time was subjected to outlet pressure P = 5.0 kgf / cm ² , screen pore diameter S = 0.40 m.
m, log (P / S) = 1.1, clearance = 0.5
The test was performed under the conditions of 0 mm and the product temperature = 70 ° C. Then, the squeezed juice is supplied to a retort, and the product temperature is 100 ° C. (attained temperature).
To make sweet potato juice. 2.6mg% β-carotene in sweet potato juice, sugar content 12% by weight,
The SV amount (the amount of sedimentation used as an index of the pulp content) is 19
The sweet potato juice had a volume% and a yield of 61% by weight, and had a vivid color tone and a good taste as desired, and was suitable for drinking having a baked potato flavor.

Comparative Example 1 The same well-known Healthy Red as in Example 1 was immersed in hot water of 80 ° C. for 20 seconds to obtain a heat-treated product. After peeling the heat-treated product with a peeler and crushing with a micro grader,
Squeezed with a juicer to produce sweet potato juice. Β-carotene of sweet potato juice is 1.5 mg%, sugar content is 9.0% by weight, SV amount is 20% by volume, yield is 40% by weight, it is inferior in color tone and flavor, sweet potato juice without baked potato flavor. there were.

Comparative Example 2 The same healthy red as in Example 1 was placed in an oven,
I made baked sweet potato. The roasted potatoes were peeled, ground, mixed with the same amount of water, mixed well, and squeezed with a juicer to produce sweet potato juice. The sweet potato juice has a β-carotene content of 0.70 mg%, a sugar content of 9.0% by weight, and an SV content of 2%.
The sweet potato juice had a volume of 2% by volume and a yield of 37% by weight, and had a roasted sweet potato flavor but a poor color tone and flavor.

Examples 2 and 3 and Comparative Examples 3 and 4 The procedure was the same as in Example 1, except that the heat treatment conditions were changed as shown in Table 1 to produce sweet potato juice. The production conditions of each example, including the cases of Example 1, Comparative Examples 1 and 2, and the results of the sweet potato juice produced in each example are shown in Table 1.

[0024]

[Table 1]

In Table 1, maltose was measured by liquid chromatography. β-carotene: measured by liquid chromatography. Sugar content: Measured with a refractometer. SV amount: 10 ml of sweet potato juice was centrifuged into a sedimentation tube (length 105
mm) and centrifuged (rotation radius 14.5 mm, rotation speed 3)
000 rpm, time 10 minutes) and the scale (ml) of the precipitate immediately after being left to stand naturally is multiplied by 10 times. Yield: Yield on raw material. Sensory evaluation: The sweet potato juice of each example and the sweet potato juice of Comparative Example 2 were compared at two points by a total of 50 men, 25 men and 25 women, and the flavor, color tone, and throat of baked sweet potato flavor and sweetness were comprehensively evaluated. And the number of persons who preferred the sweet potato juice of each example was described (note that the * mark in the table indicates a significance level of 5% or less, and * The asterisk indicates a significance level of 1% or less).

EXAMPLE 4 A so-called Kyushu No. 120 containing 10 mg% of β-carotene
It was immersed in hot water at 0 ° C. for 10 minutes to activate the amylase while substantially inactivating polyphenol oxidase, to obtain a heat-treated product containing maltose at 5.0% by weight. The heat-treated product was peeled with a peeler, crushed with a micro grader, and squeezed and squeezed with a biaxially different direction rotating type extruder for squeezing. The squeezed juice was mixed with the outlet pressure P = 1.
0 kgf / cm ² , screen hole diameter S = 0.50 mm, log
(P / S) = 0.30, clearance = 0.50 mm, and product temperature = 70 ° C. Then, the squeezed juice was provided to a retort and cooked at a product temperature of 100 ° C. (attained temperature) to produce sweet potato juice. Β of sweet potato juice
-5.5 mg% of carotene, 17% by weight of sugar, 21% by volume of SV, 52% by weight of yield, sweet potato juice suitable for drinking with baked sweet potato flavor, vivid color and good taste as desired Met.

Comparative Example 5 The same Kyushu 120 as in Example 4 was placed in hot water at 80 ° C.
It was immersed for 0 seconds to obtain a heat-treated product. The heat-treated product was peeled with a peeler, crushed with a micro grader, and squeezed with a juicer to produce sweet potato juice. Β-carotene of sweet potato juice is 2.5 mg%, sugar content is 9.0% by weight, SV amount is 21% by volume, yield is 40% by weight, it is inferior in color tone and flavor, sweet potato juice having no baked potato flavor. there were.

Comparative Example 6 The same Kyushu No. 120 as in Example 4 was placed in an oven to make a baked sweet potato. The roasted potatoes were peeled, ground, mixed with the same amount of water, mixed well, and squeezed with a juicer to produce sweet potato juice. The sweet potato juice has β-carotene of 1.6 mg%, sugar content of 9.0% by weight and SV of 22%.
The sweet potato juice had a volume% and a yield of 37% by weight, and had a correspondingly baked potato flavor, but was inferior in color tone and flavor.

Examples 5 to 7 and Comparative Example 7 The procedure was the same as in Example 4, except that the pressing and squeezing conditions and the cooking conditions were changed as shown in Table 2 to produce sweet potato juice. Example 4, Comparative Example 5, and Comparative Example 6
Table 2 summarizes the production conditions of each example, including the case of the above, and the results of the sweet potato juice produced in each example.

[0030]

[Table 2]

In Table 2, Example 7: Lemon juice was added to the squeezed juice and p
It was cooked after adjusting to H3.9. Maltose,
β-carotene, sugar content, SV amount, yield: the same as in Table 1. Sensory evaluation: Notation was performed in the same manner as in Table 1 except that the sweet potato juice of each example and the sweet potato juice of Comparative Example 6 were compared at two points.

Example 8 A so-called Yamakawa purple containing 3.2 of anthocyanin by a color value of 8 was used.
It was immersed in hot water at 0 ° C. for 8 minutes to activate the amylase while substantially inactivating polyphenol oxidase, to obtain a heat-treated product containing 3.0% by weight of maltose. The heat-treated product was peeled with a peeler, crushed with a micro grader, and squeezed and squeezed with a biaxially different direction rotating type extruder for squeezing. The squeezed juice is discharged at an outlet pressure P = 5.
0 kgf / cm ² , screen hole diameter S = 0.40 mm, log
(P / S) = 1.1, clearance = 0.50 mm, product temperature = 70 ° C. Then, the squeezed juice was provided to a retort and cooked at a product temperature of 100 ° C. (attained temperature) to produce sweet potato juice. The sweet potato juice anthocyanin has a color value of 3.7, a sugar content of 13% by weight, an SV amount of 18% by volume, and a yield of 60% by weight. It was a suitable sweet potato juice.

Comparative Example 8 The same so-called Yamakawa purple as in Example 8 was placed in an oven to prepare a baked sweet potato. The roasted potatoes were peeled, ground, mixed with the same amount of water, mixed well, and squeezed with a juicer to produce sweet potato juice. Sweet potato juice has an anthocyanin color value of 1.5, a sugar content of 9.2% by weight, an SV amount of 21% by volume, and a yield of 39% by weight. Although it has a roasted sweet potato flavor, it has poor color tone and flavor. It was juice.

Examples 9 and 10 The procedure was the same as in Example 8, except that the heat treatment conditions and cooking conditions were changed as shown in Table 3 to produce sweet potato juice. Table 3 summarizes the production conditions of each example, including the case of Example 8 and Comparative Example 8, and the results of the sweet potato juice produced in each example.

Example 11 A so-called chiran purple containing 1.5 anthocyanins at a color value of 9
It was immersed in hot water at 0 ° C. for 10 minutes to activate the amylase while substantially inactivating polyphenol oxidase, to obtain a heat-treated product containing maltose at 5.0% by weight. The heat-treated product was peeled with a peeler, crushed with a micro grader, and squeezed and squeezed with a biaxially different direction rotating type extruder for squeezing. The squeezed juice was mixed with the outlet pressure P = 1.
0 kgf / cm ² , screen hole diameter S = 0.50 mm, log
(P / S) = 0.30, clearance = 0.50 mm, and product temperature = 70 ° C. Then, the squeezed juice was provided to a retort and cooked at a product temperature of 100 ° C. (attained temperature) to produce sweet potato juice. Sweet potato juice anthocyanin has a color value of 1.7, sugar content of 16% by weight, SV
The amount was 21% by volume, the yield was 51% by weight, and it was a sweet potato juice having a brilliant color and a good taste of roasted potato having a roasted sweet potato flavor as desired.

Comparative Example 10 The same so-called Chiran purple as in Example 10 was placed in an oven to prepare a baked sweet potato. The roasted potatoes were peeled, ground, mixed with the same amount of water, mixed well, and squeezed with a juicer to produce sweet potato juice. The sweet potato juice has an anthocyanin color value of 0.7, a sugar content of 8.5% by weight, an SV content of 24% by volume, and a yield of 37% by weight. Although it has a roasted sweet potato flavor, it has a poor color tone and flavor. It was juice.

Examples 12 and 13 The procedure was the same as in Example 11, except that the pressing and squeezing conditions and the cooking conditions were changed as shown in Table 3 to produce sweet potato juice. Table 3 summarizes the production conditions of each example, including the case of Example 11 and Comparative Example 10, and the results of the sweet potato juice produced in each example.

[0038]

[Table 3]

In Table 3, maltose, sugar content, SV amount, and yield: the same as in Table 1. Color value of anthocyanin: Measured by the method described above. Sensory evaluation: For Examples 8 to 10, the sweet potato juice of each example was compared with the sweet potato juice of Comparative Example 8 at two points, and for Examples 11 to 13, the sweet potato juice of each example and Comparative Example 9 were compared.
And the sweet potato juice was compared in the same manner as in Table 1 except that it was compared at two points.

[0040]

As is clear from the above description, the present invention described above can produce sweet potato juice having a roasted sweet potato flavor, which has a high pigment content and a high sugar content and a low pulp content, and is suitable for drinking with a good yield. effective.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Akitaka Muraoka 17 Kagome Co., Ltd.

Claims (13)

[Claims] 1. A high-pigmented sweet potato which substantially inactivates polyphenol oxidase contained therein, but has a maltose content of 1.0 to 10% by weight under conditions for activating amylase. After the heat treatment, the juice is squeezed and squeezed with a squeeze-type squeezing machine, and the squeezed liquid is heated to 100 ° C
A method for producing a sweet potato juice having a baked sweet potato flavor, characterized by cooking as described above. 2. The production of sweet potato juice having a roasted sweet potato flavor according to claim 1, wherein the juice is squeezed and squeezed by a squeezing type juicer equipped with a screw and a screen surrounding the screw under the following condition: Method. [Formula 1] 0.10 ≦ log (P / S) ≦ 2.0 に お い て In the formula 1, P is an outlet pressure (kgf / cm ² ) of a squeezing type juicer,
Numerical value in the range of 0.10 to 20 S: hole diameter (mm) of the screen mounted on the squeeze type juicer, numerical value in the range of 0.050 to 1.0 3. A sweet potato with a high pigment content comprising β-carotene.
The method for producing sweet potato juice having a baked sweet potato flavor according to claim 1 or 2, which is a sweet potato having a high carotene content containing 0 mg% or more. 4. The sweet potato juice having a baked sweet potato flavor according to claim 1 or 2, wherein the sweet potato having a high pigment content is a sweet potato having a high anthocyanin content of 0.10 or more in color value except an outer skin of the sweet potato. Manufacturing method. 5. A maltose content of 3.0 to 8.0% by weight.
5. The method for producing a sweet potato juice having a baked sweet potato flavor according to claim 1, wherein the heat treatment is carried out so as to be as follows. 6. The squeezing type juicer is a screw press or a twin-screw rotary extruder for squeezing.
A method for producing a sweet potato juice having the baked sweet potato flavor according to 3, 4 or 5. 7. The method for producing a sweet potato juice having a baked sweet potato flavor according to claim 1, wherein the sweet potato having a high pigment content is peeled before the pressing and squeezing. 8. The heat-treated sweet potato having a high pigment content is crushed or cut and then squeezed and squeezed.
A method for producing a sweet potato juice having a baked sweet potato flavor according to 5, 6, or 7. 9. The squeezed juice under a condition satisfying 0.30 ≦ log (P / S) ≦ 1.5.
A method for producing a sweet potato juice having the baked sweet potato flavor according to 6, 7, or 8. 10. The squeezing and squeezing by a squeezing type squeezing machine in which a clearance between a screw and a screen is set to 1.0 mm or less.
A method for producing a sweet potato juice having the baked sweet potato flavor as described. 11. The method for producing sweet potato juice having a baked sweet potato flavor according to claim 1, wherein the juice is squeezed at a product temperature of 75 ° C. or lower. 12. The method according to claim 1, wherein the juice is adjusted to pH 3.5 to 4.5 before cooking.
A method for producing a sweet potato juice having the baked sweet potato flavor according to 7, 8, 9, 10 or 11. 13. The method according to claim 1, wherein the juice is cooked at a temperature of 100 to 125 ° C. for a maximum temperature of 5 to 5 minutes.
6. A method for producing a sweet potato juice having a baked potato flavor according to 6, 7, 8, 9, 10, 11 or 12.