JP3171564B2 - Production method of sweet potato juice - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing sweet potato juice, and more particularly to a method for producing sweet potato juice having a high pigment content and a low pulp content from raw materials, and thus having a vivid color tone and suitable for drinking. The present invention relates to a method for producing sweet potato juice.

[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,
The above-mentioned conventional method has a drawback that, even when a sweet potato having a high pigment content is used as a raw material, the pigment content and the sugar content derived from the raw material of the obtained sweet potato juice are low, and the yield is particularly poor.

[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, Especially, the yield is bad.

[0004]

Means for Solving the Problems Thus, the present inventors have
As a result of research to solve the above-mentioned problems, when a specific heat treatment and a squeezed juice are applied to sweet potatoes having a high pigment content in combination, the pigment content and the sugar content derived from the raw materials are high and the pulp content is low, and thus a vivid color tone It has been found that sweet potato juice suitable for drinking with good throat 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 is heated under a condition for activating amylase so that the maltose content becomes 1.0 to 10% by weight, and then the screw and the screw are surrounded. The present invention relates to a method for producing sweet potato juice, comprising squeezing and squeezing under a condition satisfying the following expression 1 by a squeezing type squeezing machine equipped with a screen to be processed.

[0006]

[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

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 a heat treatment in which the maltose content exceeds 10% by weight, it is presumed that the starch swells, but it becomes difficult to extract juice and the yield is reduced. 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 thus heat-treated is squeezed and squeezed by a squeezing press equipped with a screw and a screen surrounding the screw. The juicer has
There is a centrifugal type such as pulper, guinea, decanter, etc., and a press type such as a filter press, a screw press, a twin-screw rotary extruder for squeezing,
In the present invention, of the latter squeezing methods, squeezing and squeezing is performed by an squeezing machine equipped with a screw and a screen surrounding the screw. Among them, it is preferable to press and squeeze with a screw press or a twin-screw rotary extruder for squeezing. This is because a sweet potato juice which has a high pigment content and a high sugar content and a low pulp content derived from the raw material and is suitable for drinking with a vivid color tone and good taste can be produced with good yield.

In the present invention, when the heat-treated sweet potato is squeezed and squeezed by the above-mentioned squeezing type squeezing machine, the squeezed juice is squeezed under the condition satisfying the above-mentioned formula (1). As described above, P in Formula 1 is the outlet pressure (kgf / cm ² ) of the squeezing press,
Is a numerical value in the range of 0.10 to 20, and S is the hole diameter (mm) of the screen mounted on the squeezing type juicer,
It is a numerical value in the range of 0.050 to 1.0. If the condition of the squeezed juice does not satisfy the formula 1, or if P or S in the formula 1 is out of the above range even if the formula 1 is satisfied, the pigment content or the pulp content derived from the raw material may have an appropriate value. A problem arises in the light of the object of the present invention of producing sweet potato juices with good yields that are deviating and therefore vibrant and suitable for drinking.

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 to improve the yield. Furthermore, squeezed juice is
It is preferably performed under a condition satisfying 0.30 ≦ log (P / S) ≦ 1.5, 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 screen) (A gap between the inner peripheral end face in the radial direction) and 1.0 mm or less.
This is for increasing the squeezing rate and improving the yield. Furthermore, it is preferable to perform the pressed juice at a product temperature (the central temperature of the heat-treated sweet potato subjected to the pressed juice) of 75 ° C. or less. This is for preventing gelatinization of the starch, thereby increasing the squeezing rate, and improving the yield.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention include the following 1) to 6). 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 reducing maltose to 5% by weight. A heat-treated product 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 was subjected to outlet pressure P = 5.0 kgf / cm ² , screen pore size S = 0.40 mm, log (P / S) = 1.1,
The production is performed under the conditions of clearance = 0.50 mm and product temperature = 70 ° C. to produce sweet potato juice.

2) A so-called Kyushu 120 containing 10.2 mg% of β-carotene is immersed in hot water of 95 ° C. for 10 minutes,
While the polyphenol oxidase is substantially inactivated, the amylase is activated to obtain a heat-treated product containing 6% by weight of maltose. 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. The squeezed juice is subjected to an outlet pressure P = 6.3 kgf / cm ² , a screen pore diameter S = 0.20.
mm, log (P / S) = 1.5, clearance = 0.5
It is performed under the conditions of 0 mm and the temperature of the product = 70 ° C to produce sweet potato juice.

3) A so-called benihayato containing β-carotene in an amount of 12 mg% is immersed in hot water at 80 ° C. for 20 minutes to substantially inactivate polyphenol oxidase while activating amylase to reduce maltose to 7% by weight. A heat-treated product is obtained. The heat-treated product is peeled with a peeler, crushed with a micro grader, and then squeezed with a biaxially different direction rotating type extruder for juice. Press the squeezed juice to the outlet pressure P
= 1.0 kgf / cm ² , screen hole diameter S = 0.50 mm, l
og (P / S) = 0.30, clearance = 0.50m
m, product temperature = 70 ° C to produce sweet potato juice.

4) A so-called Yamakawa purple containing 3.2 of anthocyanin in a color value 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% by weight is obtained. Peel this heat-treated product with a peeler,
After crushing with a micro grader, press and squeeze with a screw press. The squeezed juice is discharged at an outlet pressure P = 5.0 kgf / c.
m ² , screen hole diameter S = 0.40 mm, log (P / S)
= 1.1, clearance = 0.50 mm, product temperature = 70 ° C to produce sweet potato juice.

5) A so-called Chiran purple containing anthocyanin at a color value of 1.5 is immersed in hot water at 95 ° C for 10 minutes to activate polyamylase while substantially inactivating polyphenol oxidase, thereby reducing maltose. A heat-treated product containing 6% by weight is obtained. Peel this heat-treated product with a peeler,
After crushing with a crusher, the juice is squeezed and squeezed with a biaxially different direction rotating type extruder. The squeezed juice was subjected to an outlet pressure P = 6.3 kgf / cm ² , a screen hole diameter S = 0.20 mm,
log (P / S) = 1.5, clearance = 0.50m
m, product temperature = 70 ° C to produce sweet potato juice.

6) A so-called Kyushu 113 containing anthocyanin at a color value of 10 is immersed in hot water at 80 ° C for 20 minutes.
While the polyphenol oxidase is substantially inactivated, the amylase is activated to obtain a heat-treated product containing 7% by weight of maltose. The heat-treated product is peeled with a peeler, crushed with a micro grader, and then squeezed with a biaxially different direction rotating type extruder for juice. The squeezed juice was subjected to an outlet pressure P = 1.0 kgf / cm ² , a screen pore size S = 0.50.
mm, log (P / S) = 0.30, clearance = 0.
It is carried out under the conditions of 50 mm and the temperature of the product = 70 ° C. to produce sweet potato juice.

[0019]

【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. Press the squeezed juice to the 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. to produce sweet potato juice. The sweet potato juice has a β-carotene content of 2.6 mg%, a sugar content of 12% by weight, an SV content (a centrifugal amount used as an indicator of pulp content) of 19% by volume, and a yield of 61% by weight.
It was a sweet potato juice which was suitable for drinking with a vivid color tone as desired.

Comparative Example 1 The same well-known Healthy Red as in Example 1 was immersed in hot water at 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. In the sweet potato juice, β-carotene was 1.5 mg%, the sugar content was 9.0% by weight, the SV amount was 20% by volume, and the yield was 40% by weight.

Examples 2 and 3 and Comparative Examples 2 and 3 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. Table 1 summarizes the production conditions of each example, including the case of Example 1 and Comparative Example 1, and the results of the sweet potato juice produced in each example.

[0022]

[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 1 were compared at two points by a total of 50 persons of 25 men and 25 women, and the flavor, color tone, throat and the like were comprehensively evaluated. The selection was made as to which one was preferable, and the number of persons who preferred the sweet potato juice in each example was indicated (note that ** in the table indicates that the significance is 1% or less).

Example 4 A so-called Kyushu 120 containing 10.2 mg% of β-carotene was immersed in hot water at 90 ° C. for 10 minutes to activate polyamylase while substantially inactivating polyphenol oxidase. A heat-treated product containing maltose at 5.0% 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. Press the squeezed juice to the outlet pressure P =
1.0 kgf / cm ² , screen hole diameter S = 0.50 mm, lo
g (P / S) = 0.30, clearance = 0.50 mm,
The sweet potato juice was produced under the condition of the product temperature = 70 ° C. The sweet potato juice has 5.5 mg% of beta-carotene, 17% by weight of sugar, 21% by volume of SV, and 52% by weight of the yield. there were.

Comparative Example 4 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. In the sweet potato juice, β-carotene was 2.5 mg%, the sugar content was 9.0% by weight, the SV amount was 21% by volume, and the yield was 40% by weight.

Examples 5 and 6 and Comparative Examples 5 to 8 The procedure was the same as in Example 4, except that the pressing and squeezing conditions were changed as shown in Table 2 to produce sweet potato juice. The production conditions of each example, including the case of Example 4, and the results of the sweet potato juice produced in each example are summarized in Table 2.

[0027]

[Table 2]

In Table 2, maltose, β-carotene, sugar content, SV amount, and yield are the same as those in Table 1. Sensory evaluation: described 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 4 were compared at two points (the ** mark in the table indicates a risk factor of 1% or less). Indicates significant, and * indicates significant at a risk rate of 5% or less).

EXAMPLE 7 A so-called Yamakawa purple containing 8 anthocyanins in a color value of 3.2 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, temperature = 70 ° C. to produce sweet potato juice.
The sweet potato juice has an anthocyanin 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. there were.

Comparative Example 9 The same as in Example 7 was soaked in purple Yamakawa for 20 seconds in hot water at 80 ° C. 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. The sweet potato juice anthocyanin had a color value of 3.0, a sugar content of 9.5% by weight, an SV amount of 22% by volume, and a yield of 38% by weight.

Examples 8 and 9 The procedure was the same as in Example 7, and the heat treatment conditions were changed as shown in Table 3 to produce sweet potato juice. Table 3 summarizes the production conditions of each example, including the cases of Example 7 and Comparative Example 1, and the results of the sweet potato juice produced in each example.

EXAMPLE 10 A so-called chiran purple containing 1.5 anthocyanins in color value was 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, product temperature = 70 ° C., to produce sweet potato juice. Sweet potato juice anthocyanin has a color value of 1.7, a sugar content of 16% by weight, an SV amount of 21% by volume, and a yield of 51.
It was a sweet potato juice suitable for drinking with a vivid color tone as desired, in a vivid color tone as desired.

Comparative Example 10 The same commonly-known chiran purple as in Example 10 was immersed in hot water at 80 ° C. for 20 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. The anthocyanin of the sweet potato juice had a color value of 1.3, a sugar content of 11% by weight, an SV amount of 23% by volume, and a yield of 35% by weight.

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

[0035]

[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 7 to 9, the sweet potato juice of each example was compared with the sweet potato juice of Comparative Example 9 at two points, and for Examples 10 to 12, the sweet potato juice of each example and Comparative Example 10 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.

[0037]

As is apparent from the above description, the present invention described above has a yield of sweet potato juice which has a high pigment content and a high sugar content and a low pulp content from raw materials, and thus is suitable for drinking with a vivid color tone and good pourability. There is an effect that it can be manufactured well.

────────────────────────────────────────────────── ─── Continued from the front page (72) Inventor Akitaka Muraoka 17-figure, Nishi-Toyama, Nishinasuno-cho, Nasu-gun, Tochigi Prefecture Within Kagome Research Institute (56) References JP-A-6-190594 (JP, A) JP-A-54-135286 (JP, A) JP-A-5-328949 (JP, A) JP-A-8-336376 (JP, A) JP-A-9-275949 (JP, A) JP-A-54-119066 (JP, A) JP-A-6-217744 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) A23L 2/00 JICST file (JOIS)

Claims (10)

(57) [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. A method for producing sweet potato juice, comprising squeezing and squeezing under a condition satisfying the following formula 1 by a squeezing type juicer equipped with a screw and a screen surrounding the screw after heat treatment. [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 2. Sweet potatoes having a high pigment content contain β-carotene.
The method for producing sweet potato juice according to claim 1, which is a sweet potato having a high carotene content containing 0 mg% or more. 3. The method for producing sweet potato juice according to claim 1, wherein the sweet potato with a high pigment content is a sweet potato with a high anthocyanin content containing a color value of 0.10 or more of anthocyanin in a portion excluding its perimeter. 4. A maltose content of 3.0 to 8.0% by weight.
4. The method for producing sweet potato juice according to claim 1, wherein the heat treatment is carried out so as to be as follows. 5. The squeezing type juicer is a screw press or a twin-screw rotary extruder for squeezing.
5. The method for producing sweet potato juice according to 3 or 4. 6. The method for producing a sweet potato juice according to claim 1, wherein the sweet potato having a high pigment content is peeled before the pressing and squeezing. 7. The squeezed juice obtained by crushing or cutting the heat-treated sweet potato having a high pigment content.
Or a method for producing a sweet potato juice according to 6. 8. The squeezed juice under a condition satisfying 0.30 ≦ log (P / S) ≦ 1.5.
The method for producing a sweet potato juice according to 5, 6, or 7. 9. The squeezing and squeezing machine according to claim 1, wherein the clearance between the screw and the screen is set to 1.0 mm or less. Manufacturing method of sweet potato juice. 10. The method for producing sweet potato juice according to claim 1, wherein the juice is squeezed at a product temperature of 75 ° C. or lower.