JPH11137206A - Production of sweet potato powder with reduced discoloration - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a sweet potato flour with reduced discoloration in order to obtain an instant material, a basal food material, a preserved food material or the like without discoloring at the time of cooking. SOLUTION: A dipping step in an agent for charging cut pieces of a suitable size prepared by cutting a raw sweet potato or commercially available cut pieces into an agent previously prepared by using one of an antioxidant, an oxidizing bleaching agent and a reducing bleaching agent at pH 4-8, then eluting and removing or decomposing or removing a milky juice ingredient into the agent and simultaneously bleaching coloring substances is carried out and the resultant cut pieces are then washed with water, dried and powdered.

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 a discoloration-mitigating sweet potato powder.

[0002]

2. Description of the Related Art In general, sweet potatoes are particularly excellent in nutritional components among potatoes. The main component is starch, the fiber content is high, and vitamins and the like are contained in a considerably large amount. Vitamin A is also rich, and darker flesh contains more. In addition, sweet potato powder is expected to be used as a natural fiber-enriched ingredient to promote the defecation function associated with the decline in physiological functions seen in many elderly people, and attention has been paid to the use of processed foods as basic ingredients. ing. Conventional methods for producing this sweet potato powder include a cutting step of cutting raw sweet potato into appropriate sizes, a washing step of washing the cut piece with water, a drying step of drying after draining, a drying step, and crushing the powder after drying. The sweet potato powder was obtained through each step of the pulverizing step to be obtained.

[0003]

However, when the sweet potato powder obtained by the above-mentioned process is cooked and processed, there is a defect that it turns into an extremely dark black color, and it can be adapted as a basic foodstuff to today's rich diet. Was not. For this reason, there has been a demand for the development of raw sweet potato powder that can be used as instant ingredients, basic ingredients, preserved ingredients, etc., which do not discolor during cooking.

[0004] Although the cause of the sweet potato powder turning black during cooking by adding water and heating is not known,
As a result of various experiments and studies, the present inventors have determined that milky juice in sweet potatoes is the main cause, and that the yarapin of this milky juice component has a property of coloring in black and becoming insoluble resin when exposed to air. . The blackening is sugar. It has been presumed that the crosslinking reaction by air oxidation is involved in addition to the aminocarbonyl reaction. Therefore, since the milky components such as yarapin are soluble in water before coming into contact with air, the present inventors have noticed that the milky components can be eluted and removed in an aqueous solution of a drug solution, and at the same time, It was also noted that the coloring agent can be reduced and decolorized by a reducing agent. Further, when the sweet potato is heated under neutral or alkaline conditions, a phenomenon of discoloration to green is sometimes observed, and this is considered to be caused by a trace amount of chlorogenic acid contained in the sweet potato.

[0005]

Means for Solving the Problems The first manufacturing method of the present invention is to produce raw sweet potatoes simultaneously with the cutting step by using one of an antioxidant, an oxidizing bleaching agent and a reducing bleaching agent. It is poured into a preliminarily prepared chemical solution to elute and remove milky juice components from the chemical solution, further decolorizes the causative substance by bleaching action, then rinses with water, and is dried to form a powder.

The second method of the present invention is a method of pulverizing raw sweet potatoes from commercially available cut pieces which have been cut into appropriate sizes and dried. This method comprises one of an oxidizing bleaching agent and a reducing bleaching agent.
The cut pieces were put into and immersed in a pre-made chemical solution of PH4 to PH8 using one, and the resinous (cross-linked) milky juice component of the sweet potato was decomposed and removed by the chemical solution and formed on the surface. A chemical solution immersion step for bleaching the coloring substance is performed, and then, a continuous washing process is performed to wash out the chemical solution from the cut pieces, and then draining and drying are performed. Make.

[0007] Another method of the present invention is the safest method for food hygiene, in which a chemical solution treatment that can be commercialized at a low price is performed, and vitamin C (ascorbic acid and its salts are hereinafter referred to as vitamin C) is used as an antioxidant. C), one of sulfurous acid and sulfite, one of hypochlorite, hypochlorite, hydrogen peroxide and ozone as oxidizing bleaching agent, and reducing bleaching agent. Is preferably one of vitamin C, sulfurous acid, and sulfite. The concentration of the chemical is 0.5% to 5.0% and PH
It is preferable to use an aqueous solution of 4 to PH8.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a view showing the steps of a first manufacturing method, and the description will be made based on this. First, a fresh sweet potato is washed with water, a defective portion is cut out, and then a cutting process is performed in which the cut portion is cut into an appropriately sized cut piece by using an automatic slicer. At this time, a chemical solution of PH4 to PH8 using one of an antioxidant, an oxidizing bleach and a reducing bleach is prepared in advance and put in a water tank. Next, quickly put the cut raw sweet potatoes into the aquarium,
It is immersed in the chemical for a predetermined time, and a chemical immersion step is performed to elute and remove the milky juice component. As the chemical, one of an antioxidant, an oxidizing bleach and a reducing bleach is used, but it is not used in combination. Next, each drug will be described in detail. First, one of vitamin C, sulfurous acid and sulfite is used as an antioxidant. Next, one of hypochlorous acid, hypochlorite, hydrogen peroxide, and ozone is used as an oxidative bleaching agent, and the coloring substance is oxidatively decomposed to be dissolved or converted into a non-coloring substance. In addition, as a reducing bleach, one of vitamin C, sulfurous acid, and sulfite is used.
In this method, a colored substance is reduced and decomposed to be dissolved or converted into a non-colored substance. At this time, the concentration of the drug solution is 0.5% to 5.0%
The aqueous solution of PH4 to PH8 is hydrolyzed and liquefied to make it difficult to form a powder at a pH of 3 or less, and tends to change to yellow at a pH of 8 or more. In addition, when the concentration is 0.5% or less, the effect is drastically reduced, and when the concentration is 5.0% or more, the components are destroyed, and it becomes difficult to obtain an appropriate PH region to react. Further, at this time, it is preferable to use an alkaline control such as caustic soda or a dilute acidic control such as hydrochloric acid or acetic acid as a PH control.

After immersion for a predetermined time, the cut sweet potato is taken out of the water tank, and continuously washed with water to complete the final washing step. Then, a drying step of draining and drying is performed. At this time, it is preferable to dry by shutting off air at a low temperature or at a low temperature. After drying, the powder is crushed by a crusher and a crushing step for obtaining powder is performed. At this time, component data is taken for each rod, and in order to reduce the variation in the quality of each rod, a product adjustment process is performed in order to obtain a uniform quality by blending and homogenizing. Then, a bag packing process is performed, and the product is produced.

FIG. 2 is a diagram showing the steps of the second manufacturing method, and the description will be made based on this. A commercially available cut piece prepared by previously cutting raw sweet potatoes into appropriate sizes and drying is prepared, and a chemical solution of PH4 to PH8 is put in a water tank in advance using one of an oxidizing bleaching agent and a reducing bleaching agent. First, a commercially available cutting piece is put into a water tank and immersed in a chemical solution for a predetermined time. Then, the chemical liquid permeates from the surface of the cut piece into the inside and is immersed, so that the resinous milky component of the sweet potato is gradually decomposed by the chemical liquid, dissolved in the liquid and removed, and the coloring substance generated on the surface Bleach. One of the oxidizing bleaching agent and the reducing bleaching agent described in detail above may be used as the chemical at the time of performing this chemical immersion step, and each chemical may be the same as described above. After the chemical liquid immersion step, the cut piece is taken out of the water tank, and a water washing step of performing continuous water washing to wash out the chemical solution from the cut piece is performed. After draining and then drying, a powder is obtained through a crushing step. In this case as well, component data is obtained for each rod as described above, and a product adjustment step of blending and homogenizing the powder of each rod so as to obtain a constant quality is performed. It will be commercialized.

[0011]

Example 1 As a raw sweet potato, 200 kg of red azuma quality is prepared. Also, 1% concentration of vitamin C is PH6
Make 600 liters of an aqueous solution and place it in a water tank. First, the raw material is manually washed with water, the skin is peeled off, and a dark spot or a rotten spot is artificially cut off visually to remove a defective spot. Then, a cutting step of cutting into thick pieces of 1 to 2 mm by an automatic slicer is performed. In addition, the cutting of the raw sweet potato is not limited to the above shape, and may be, for example, a dice shape or a bar shape. Next, the raw material is cut into the vitamin C solution, and at the same time, is put into a water tank and immersed. At this time, it is immersed at room temperature for 4 hours. In addition, the chemical solution immersion time is preferably 2 to 5 hours. After the chemical liquid immersion step, normal washing is performed for 1 minute with continuous running water to clean the surface residues and the chemical liquid. At the time of draining, the weight of the treated product was 196 kg. This is subjected to a drying process by applying hot air of 50 to 70 ° C. for 3 hours in a hot air blow-up dryer, and then the dried product is coarsely pulverized by a pulverizer. After drying for an hour, 58.5 kg of sweet potato powder was obtained. After that, after a product adjusting step of blending and homogenizing to obtain a predetermined quality, a bag filling step of bagging sweet potato powder is performed to produce a product.

[0012]

Example 2 200 kg of commercially available cut pieces of raw materials are prepared. Also prepare 600 liters of an aqueous solution of PH5 with a concentration of 0.5% of hydrogen peroxide and put it in a water tank and prepare it. First, the cut pieces in the bag are opened, put into a water tank, and immersed. At this time, it is immersed at room temperature for 4 hours. In addition, the chemical solution immersion time is good for 4 to 5 hours. After the chemical liquid immersion step, normal cleaning is performed for 30 minutes with continuous flowing water to clean the surface residues and the chemical liquid. This is subjected to a drying process by applying hot air of 50 to 70 ° C. for 3 hours in a hot-air blow-up dryer, and then coarsely pulverized by a pulverizer in the same manner as described above, and further, after drying the powder for about 1 hour, 180.5 kg of sweet potato powder was obtained. Thereafter, the sweet potato powder is subjected to a bag-packing step after a product adjustment step, and is then commercialized.

Next, using each sweet potato powder obtained by the method of the present invention and the sweet potato powder obtained by the conventional method, adding water and an appropriate seasoning to form a rice cracker having a diameter of about 3 cm and a thickness of about 3 mm. Each 10 foods were prepared. The processed food was put on a steamer for 10 minutes to check the color of the surface and eat it. Sample 1 is a powder obtained by slicing raw sweet potato and immersing it in a chemical solution of PH6 at a concentration of 1% of vitamin C. Sample 2 is a sample obtained by slicing raw sweet potato and adding hypochlorite soda. Sample 3 is a powder obtained by immersing in a chemical solution of PH6 at a concentration of 0.5%, and Sample 3 is a powder obtained by slicing a raw sweet potato and immersing it in a chemical solution of PH6 at a 1% concentration of soda sulfite. Sample 4 is a powder obtained by slicing raw sweet potato and immersing it in a chemical solution of PH6 at a concentration of 0.5% of hydrogen peroxide, and Sample 5 is a sample obtained by slicing a raw sweet potato at a concentration of 0.5% of ozone. It is a powder obtained by immersing in a chemical solution of PH6. For sample A, a commercially available cut piece was prepared using vitamin C.
Is a powder obtained by immersion in a chemical solution of PH6 at a concentration of 1%. Sample B is a commercially available cut piece of soda hypochlorite.
Sample C is a powder obtained by immersion in a chemical solution of PH6 at a concentration of 0.5%.
Sample D is a powder obtained by immersion in a chemical solution of PH6 at a concentration of 0.5% of hydrogen peroxide in a commercially available cut piece.
6. The powder obtained by immersion in the chemical solution of Sample 6.
Is a powder obtained by immersing a commercially available cut piece with a chemical solution of PH6 at a concentration of 0.5% of ozone. The results of checking the coloring of each sample were as shown in the table of FIG.

[0014] Even if the processed food was cooked with the sweet potato powder obtained by the process of the present invention, the processed food did not turn black, but only had to be discolored to give a slight brown color, and could be used as a foodstuff. In addition, it was possible to eat without worrying about changes in odor or taste other than color. Therefore,
The sweet potato powder obtained by the method of the present invention can be used as a basic ingredient, instant ingredient, or preservative ingredient of processed products such as bread, snack food, potage and the like, which meet today's taste. Further, as a natural fiber-enriched food, it can be provided as a food for promoting the defecation function for the elderly.

[0015]

The present invention having the above-described structure has the following effects.

The raw sweet potato is cut into a water tank of a pre-made chemical solution of PH4 to PH8 using one of an antioxidant, an oxidizing bleach and a reducing bleach simultaneously with the cutting step. By performing a chemical immersion step for eluting and removing the milky components of the sweet potatoes, it becomes difficult to discolor during cooking. Therefore, bread and snack foods are prepared using the sweet potato powder obtained by the method of the present invention. , Potage and other processed products that meet today's food preferences can be used as basic ingredients, instant ingredients, or preserved ingredients. Further, as a natural fiber-enriched food material, it can be provided as a functional food material for the elderly.

A commercially available cut piece as described in claim 2 is prepared, and the pH is adjusted using one of an oxidizing bleach and a reducing bleach.
The cut pieces are put into a pre-made water tank of 4-PH8 and immersed in the tank to decompose and remove resinous milky components of sweet potatoes and to bleach colored substances formed on the surface. 2. A immersion step, a continuous washing treatment for washing out the chemical solution from the cut pieces, and after draining and drying, pulverizing to obtain a powder.
And the yield can be significantly improved.

When vitamin C is used as an antioxidant as described in claim 3, it can be used with a high degree of safety in food hygiene. In addition, when sulfurous acid and sulfite are used, a chemical solution raw material can be easily obtained and a chemical solution can be produced at low cost.
It can process stably and contribute to cost reduction.
Further, the use of vitamin C, sulfite and sulfite stabilizes the product.

The use of hypochlorous acid or hypochlorite as an oxidative bleaching agent makes it possible to obtain a chemical solution easily and at a low cost, so that it can be treated stably and costs can be reduced. It can contribute to down. The use of hydrogen peroxide and ozone has a strong bleaching action and a bactericidal action, which contributes to the maintenance of quality in food hygiene and works effectively especially when powdering commercially available cut pieces. Moreover, the concentration of the chemical solution is 0.5% to 5.0% and PH4
When the aqueous solution of pH 8 is used, the substance to be blackened or the colored substance is oxidized and decomposed to be dissolved and converted into a non-colored substance, so that it can be efficiently removed.

When vitamin C is used as the reducing bleach as in claim 5, it can be used with a high degree of safety in food hygiene. In addition, when sulfurous acid or sulfite is used, a chemical solution raw material can be easily obtained and a chemical solution can be prepared at low cost, so that it is possible to stably process and contribute to cost reduction. Further, the reduced bleaching agent reduces and dissolves the coloring substance by reductive decomposition and converts it into a non-coloring substance.

The concentration of the drug solution may be 0.5% to 5.0%.
% And an aqueous solution of PH4 to PH8, which can efficiently remove blackening substances and coloring substances, can be removed in a stable state, and can be powdered without destroying the components of sweet potatoes Becomes

[Brief description of the drawings]

FIG. 1 is an explanatory view showing steps of a first production method of the present invention.

FIG. 2 is an explanatory view showing steps of a second manufacturing method of the present invention.

FIG. 3 is a table showing a comparison between a product produced by the method of the present invention and a product produced by a conventional method.

Claims (6)

[Claims] 1. A sweet potato powder comprising a cutting step of cutting raw sweet potatoes into appropriate sizes, a washing step of washing with water, a drying step of drying after draining, and a crushing step of crushing after drying to obtain a powder. In the manufacturing method, at the same time as the cutting step, one of an antioxidant, an oxidizing bleach, and a reducing bleach is used to put and immerse a pre-made chemical solution of PH4 to PH8 in a water tank. A process for producing sweet potato powder with reduced discoloration, characterized by performing a chemical soaking step for eluting and removing milky juice components of sweet potatoes. 2. A commercially available cut piece prepared by cutting raw sweet potatoes into appropriate sizes and drying, and using one of an oxidizing bleaching agent and a reducing bleaching agent to prepare a pre-prepared chemical solution of PH4 to PH8. In a water tank, the cut pieces are put and immersed, and a chemical solution immersion step for decomposing and removing the resinous milky component of the sweet potato and bleaching the coloring substance generated on the surface is performed. A method for producing a discoloration-mitigating sweet potato powder, comprising continuously washing with water to wash off, draining, drying, and pulverizing to obtain a powder. 3. The method according to claim 1, wherein the antioxidant is one of vitamin C (ascorbic acid and a salt thereof), sulfurous acid, and sulfite. 4. The oxidative bleaching agent is one of hypochlorous acid, hypochlorite, hydrogen peroxide, and ozone.
Or a method for producing a discoloration-mitigating sweet potato powder according to 2. 5. The method according to claim 1, wherein the reducing bleach is one of vitamin C (ascorbic acid and a salt thereof), sulfurous acid, and sulfite. 6. The concentration of the chemical solution is 0.5% to 5.0% and
An aqueous solution of PH4 to PH8.
A method for producing the discoloration-mitigating sweet potato powder described in the above.