Preparation method of konjak gel with porous and fluffy taste and konjak gel food

Abstract

The invention provides a preparation method of konjak gel with porous and fluffy taste and konjak gel food. The preparation method comprises the following steps: S1, preparing raw materials: weighing konjak flour, edible starch, water, sodium carbonate and soybean protein isolate; s2, raw material treatment: uniformly mixing the konjaku flour and the edible starch for later use, dividing sodium carbonate into two parts, adding one part of the sodium carbonate into water before the soybean protein isolate is added, adding the other part of the sodium carbonate into the water after the soybean protein isolate is added, adding the konjaku flour and the edible starch into the mixture after the sodium carbonate is added, and quickly stirring; s3, injection molding and swelling: injecting the sol solution into a mold to fully swell the sol solution; s4, konjak forming: after the konjak in the mold is cooked and formed, freezing, and unfreezing after freezing is completed; s5, rinsing and cooking: rinsing the unfrozen embryos, adjusting the rinsing pH to 4.2-4.6 by using citric acid, and cooking again in the environment; and S6, product forming: centrifugally dewatering the cooked konjak, and spreading for cooling to obtain a finished product. The method is beneficial to formation of a porous structure in the konjak gel.

Description

Technical Field

[0001] The invention relates to the technical field of konjac gel preparation, in particular to a method for preparing konjac gel with porous and fluffy mouthfeel and konjac gel food. Background Art

[0002] Konjac, also known as konjac, konjac, and konjac, belongs to the genus Amorphophallus of the Araceae family. It is a perennial root tuber herb, and its main component is konjac glucomannan. In an alkaline environment, konjac can be processed into heat-irreversible konjac gel food. Most of these products have a crisp and tender taste, are hard, and have a dense product structure, which makes it difficult to taste when cooking. Konjac foods with holes such as snow konjac have a strong taste and are difficult to chew, and are not suitable for people with bad teeth. This patent is intended to create a porous, soft and fluffy konjac gel food, which not only solves the problem of taste, but also has a soft and loose taste, suitable for all kinds of people.

[0003] Patent document CN201310071825.8 discloses that konjac glucomannan rehydration and deacetylation chemical reaction are carried out simultaneously, under "appropriate" deacetylation reaction intensity, the degree of rehydration of glucomannan is constrained by the coagulation speed of deacetylation reaction and forms a deacetylated modified glucomannan gel with moderate rehydration and moderate strength. In this process, konjac powder particles are independently reacted to form a unit skeleton structure of the organization, and each unit structure edge adhesion forms a skeleton of the honeycomb tissue structure, and the gap between them is filled with gas produced by deacetylation reaction to form air drums, and these air drum physical cavities are solidified along with continuous deacetylation coagulation reaction, and the heating critical to the gelatinization temperature of konjac starch is finally solidified to form the basic structure of honeycomb organization. The "honeycomb" and "porous" konjac made by this patent is to utilize deacetylation reaction to form a porous structure, which is greatly affected by reaction temperature and time, and the internal reaction degree is difficult to observe with the naked eye, and once the reaction is not thorough, the quality of konjac "porous" is difficult to guarantee. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides a method for preparing a porous and fluffy konjac gel and a konjac gel food, which is conducive to forming a porous konjac gel.

[0005] According to an embodiment of the present invention, a method for preparing a konjac gel having a porous and fluffy mouthfeel comprises the following steps:

[0006] S1, raw material preparation, weighing a certain amount of konjac flour, edible starch, water, sodium carbonate, and soy protein isolate;

[0007] S2, raw material processing, konjac flour and edible starch are mixed for standby use, sodium carbonate is divided into two parts, one part of sodium carbonate is added to water before soy protein isolate is added, and after soy protein isolate is added, another part of sodium carbonate is added to water, and after sodium carbonate is added, konjac flour and edible starch are added to the mixture, and stirred rapidly;

[0008] S3, injection molding swelling, injecting the sol liquid into the mold to make it fully swell;

[0009] S4, konjac shaping, after the konjac is steamed and shaped in the mold, it is frozen before the embryo is completely cooled, and after the freezing is completed, it is sprinkled with an appropriate amount of water to thaw;

[0010] S5, rinsing and steaming, rinsing the thawed embryos, adjusting the rinsing pH to 4.2-4.6 with citric acid, and steaming again under this environment;

[0011] S6, product forming, the cooked konjac is centrifuged and dehydrated, and cooled to obtain a finished product.

[0012] Preferably, in S1, the mass of edible starch is 25%-35% of the mass of konjac flour, the mass of water is 25-35 times the mass of konjac flour, the mass of sodium carbonate is 10%-20% of the mass of konjac flour, and the mass of soy protein isolate is 3%-4% of the mass of konjac flour.

[0013] Further preferably, in step S1, the water is distilled water.

[0014] Further preferably, the sodium carbonate is divided into two equal parts, one of which is added to the water at once, and then the soy protein isolate is added while stirring. After the addition is completed, the other part of the sodium carbonate is gradually added to the water while stirring.

[0015] Further preferably, in the steps S2 and S3, the sol solution is immediately injected into the mold after the stirring is completed and allowed to stand for 1-2 hours.

[0016] Further preferably, in step S4, the cooking time is 30-40 minutes.

[0017] Further preferably, in step S4, the freezing temperature is -20°C to -30°C, and the freezing time is 8-10 hours.

[0018] Further preferably, in step S5, the rinsing time is 20-40 min, the cooking temperature is 90-100° C., and the cooking time is 20-40 min.

[0019] Still further preferably, in S6, the centrifugal frequency is 40 Hz and the centrifugal time is 1-2 min.

[0020] According to an embodiment of the present invention, a konjac gel food is also provided, which is prepared by the above preparation method.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] Soy protein isolate is the non-protein component contained in peeled and defatted soybeans. It contains both hydrophobic and hydrophilic groups, which enable them to reduce interfacial tension at the oil-water interface, thereby exhibiting foaming properties. During the production process, soy protein is adsorbed to the water-air interface to form an interfacial film, reduce interfacial tension, and then form foam. In addition, part of the peptide chains of soy protein unfold on the interface, and through the interaction of intramolecular and intermolecular peptide chains, a two-dimensional protective network is formed, which strengthens the interfacial film and promotes the formation and stability of foam;

[0023] The foaming property of soy protein isolate makes the konjac gel structure soft, and then the gas generated by sodium carbonate when heated destroys the dense structure of the konjac gel, thereby creating internal holes and making it fluffy. DETAILED DESCRIPTION

[0024] The technical solution of the present invention is further described below in conjunction with embodiments.

[0025] Embodiment 1:

[0026] S1, raw material preparation, weighing 10kg konjac flour, 2.5kg edible starch, 250kg distilled water, 1kg sodium carbonate, 0.3kg soy protein isolate;

[0027] S2, raw material processing, konjac flour and edible starch are mixed for standby use, sodium carbonate is divided into two parts, respectively 0.4kg and 0.6kg, one part of 0.4kg sodium carbonate is added to water before soy protein isolate is added, after stirring, soy protein isolate is added, after stirring, another part of 0.6kg sodium carbonate is added to water, after sodium carbonate is added, stir for 1min, then konjac flour and edible starch are added to the mixture, and quickly stirred for 10s;

[0028] S3, injection molding swelling, after the stirring is completed, the sol liquid is immediately injected into the mold and left to stand for 1 hour to allow it to fully swell;

[0029] S4, the konjac is formed and sent into a steaming cabinet together with the mold, and steamed for 35 minutes. After the konjac in the mold is steamed and formed, it is frozen before the embryo is completely cooled, and frozen at -20°C for 9 hours. After the freezing is completed, sprinkle with appropriate amount of water to thaw;

[0030] S5, rinsing and boiling, placing the thawed embryos into a rinsing tank for rinsing, adding citric acid, adjusting the rinsing pH to 4.2 with citric acid, and boiling again under this pH environment at 90° C. for 30 minutes;

[0031] S6, product forming, the cooked konjac is centrifuged for dehydration, the centrifugal frequency is set to 40 Hz, the centrifugal time is 1.5 min, and after the centrifugation is completed, the konjac gel product A is obtained after cooling.

[0032] Embodiment 2:

[0033] S1, raw material preparation, weighing 10kg konjac flour, 2.5kg edible starch, 250kg distilled water, 1kg sodium carbonate, 0.3kg soy protein isolate;

[0034] S2, raw material processing, konjac flour and edible starch are mixed for standby use, sodium carbonate is divided into two parts, 0.5kg and 0.5kg respectively, one part of 0.5kg sodium carbonate is added to water before soy protein isolate is added, soy protein isolate is added while stirring, after adding completely, another part of 0.5kg sodium carbonate is added to water while stirring, after sodium carbonate is added completely, stir for 1min, then add konjac flour and edible starch to the mixture, and stir rapidly for 15s;

[0035] S3, injection molding swelling, after the stirring is completed, the sol liquid is immediately injected into the mold and left to stand for 1.5 hours to allow it to fully swell;

[0036] S4, the konjac is formed and sent into a steaming cabinet together with the mold, and steamed for 35 minutes. After the konjac in the mold is steamed and formed, it is frozen before the embryo is completely cooled, and frozen at -25°C for 9 hours. After the freezing is completed, sprinkle with appropriate amount of water to thaw;

[0037] S5, rinsing and boiling, placing the thawed embryos into a rinsing tank for rinsing, adding citric acid, adjusting the rinsing pH to 4.2 with citric acid, and boiling again under this pH environment at 90° C. for 30 minutes;

[0038] S6, product forming, the cooked konjac is centrifuged for dehydration, the centrifugal frequency is set to 40 Hz, the centrifugal time is 1.5 min, and after the centrifugation is completed, the konjac gel product B is obtained after cooling.

[0039] Embodiment three:

[0040] S1, raw material preparation, weighing 10kg konjac flour, 3.0kg edible starch, 300kg distilled water, 1.5kg sodium carbonate, 0.35kg soy protein isolate;

[0041] S2, raw material processing, konjac flour and edible starch are mixed for standby use, sodium carbonate is divided into two parts, 0.75kg and 0.75kg respectively, one part of 0.75kg sodium carbonate is added to water before soy protein isolate is added, soy protein isolate is added while stirring, after adding completely, another part of 0.75kg sodium carbonate is added to water while stirring, after sodium carbonate is added completely, stir for 1min, then add konjac flour and edible starch to the mixture, and stir rapidly for 15s;

[0042] S3, injection molding swelling, after the stirring is completed, the sol liquid is immediately injected into the mold and left to stand for 1.5 hours to allow it to fully swell;

[0043] S4, the konjac is formed and sent into a steaming cabinet together with the mold, and steamed for 35 minutes. After the konjac in the mold is steamed and formed, it is frozen before the embryo is completely cooled, and frozen at -25°C for 9 hours. After the freezing is completed, sprinkle with appropriate amount of water to thaw;

[0044] S5, rinsing and cooking, placing the thawed embryos into a rinsing tank for rinsing, adding citric acid, adjusting the rinsing pH to 4.4 with citric acid, and cooking again under this pH environment at 90° C. for 30 minutes;

[0045] S6, product forming, the cooked konjac is dehydrated by centrifugation, the centrifugal frequency is set to 40 Hz, the centrifugal time is 1.5 min, and after the centrifugation is completed, the konjac gel product C is obtained after cooling.

[0046] Embodiment 4:

[0047] S1, raw material preparation, weighing 10kg konjac flour, 3.5kg edible starch, 350kg distilled water, 2kg sodium carbonate, 0.4kg soy protein isolate;

[0048] S2, raw material processing, konjac flour and edible starch are mixed for standby use, sodium carbonate is divided into two parts, 1kg and 1kg respectively, one part of 1kg sodium carbonate is added to water before soy protein isolate is added, soy protein isolate is added while stirring, after adding completely, another part of 1kg sodium carbonate is added to water while stirring, after sodium carbonate is added completely, stir for 1min, then add konjac flour and edible starch to the mixture, and stir rapidly for 15s;

[0049] S3, injection molding swelling, after the stirring is completed, the sol liquid is immediately injected into the mold and left to stand for 1.5 hours to allow it to fully swell;

[0050] S4, the konjac is formed and sent into a steaming cabinet together with the mold, and steamed for 35 minutes. After the konjac in the mold is steamed and formed, it is frozen before the embryo is completely cooled, and frozen at -25°C for 9 hours. After the freezing is completed, sprinkle with appropriate amount of water to thaw;

[0051] S5, rinsing and boiling, placing the thawed embryos into a rinsing tank for rinsing, adding citric acid, adjusting the rinsing pH to 4.6 with citric acid, and boiling again under this pH environment at 90° C. for 30 minutes;

[0052] S6, product forming, the cooked konjac is centrifuged for dehydration, the centrifugal frequency is set to 40 Hz, the centrifugal time is 1.5 min, and after the centrifugation is completed, the konjac gel product D is obtained after cooling.

[0053] Embodiment five:

[0054] S1, raw material preparation, weighing 10kg konjac flour, 2.5kg edible starch, 250kg distilled water, 1kg sodium carbonate, 0.3kg soy protein isolate;

[0055] S2, raw material processing, konjac flour and edible starch are mixed for standby use, 1kg sodium carbonate and 0.3kg soy protein isolate are added, and after stirring evenly, konjac flour and edible starch are added to the mixture, and quickly stirred for 10s;

[0056] S3, injection molding swelling, after the stirring is completed, the sol liquid is immediately injected into the mold and left to stand for 1 hour to allow it to fully swell;

[0057] S4, the konjac is formed and sent into a steaming cabinet together with the mold, and steamed for 35 minutes. After the konjac in the mold is steamed and formed, it is frozen before the embryo is completely cooled, and frozen at -20°C for 9 hours. After the freezing is completed, sprinkle with appropriate amount of water to thaw;

[0058] S5, rinsing and boiling, placing the thawed embryos into a rinsing tank for rinsing, adding citric acid, adjusting the rinsing pH to 4.2 with citric acid, and boiling again under this pH environment at 90° C. for 30 minutes;

[0059] S6, product forming, the cooked konjac is centrifuged for dehydration, the centrifugal frequency is set to 40 Hz, the centrifugal time is 1.5 min, and after the centrifugation is completed, the konjac gel product E is obtained after cooling.

[0060] Embodiment six:

[0061] S1, raw material preparation, weigh 10kg konjac flour, 2.5kg edible starch, 250kg distilled water, 0.6kg calcium hydroxide;

[0062] S2, raw material processing, konjac flour and edible starch are mixed, added to water, stirred evenly, and then unprecipitated calcium hydroxide solution is added and stirred for 15min-20min;

[0063] S3, injection molding swelling, stirring until there is no fluidity, the material is viscous, and then injected into the mold and allowed to stand for 1 hour to allow it to swell fully;

[0064] S4, the konjac is formed and sent into a steaming cabinet together with the mold, and steamed for 35 minutes. After the konjac in the mold is steamed and formed, it is frozen before the embryo is completely cooled, and frozen at -20°C for 9 hours. After the freezing is completed, sprinkle with appropriate amount of water to thaw;

[0065] S5, rinsing and boiling, placing the thawed embryos into a rinsing tank for rinsing, adding citric acid, adjusting the rinsing pH to 4.2 with citric acid, and boiling again under this pH environment at 90° C. for 30 minutes;

[0066] S6, product forming, the cooked konjac is centrifuged for dehydration, the centrifugal frequency is set to 40 Hz, the centrifugal time is 1.5 min, and after the centrifugation is completed, the konjac gel product F is obtained after cooling.

[0067] Weigh each 10g of the konjac gel products A, B, C, D, and E after the dehydration of embodiment 1-5, and 10g of the conventional konjac gel F product after the dehydration. Measure the quality of each product after saturation with water. (Experimental comparison data table one):

[0068] Table 1

[0069]

[0070] According to above-mentioned measurement result, by conventional product F and embodiment five E, can find out, the adding of soy protein isolate and sodium carbonate, the konjac gel product of preparation has more hole, soy protein isolate is a kind of hydrophilic protein, has larger surface activity, after rehydration forms colloidal sol, water molecules and protein micelle form the adsorption layer of dividing place, under the rapid stirring of machinery, sneak into a large amount of air, this adsorption layer wraps up the air sneaked into; Simultaneously because protein colloid solution when splitting into droplet very soon, can make every effort to reduce the surface of dividing place and become the form of spheroid, thereby formed bubble group, promptly lose the liquid state of original protein colloid, become white protein foam adsorption layer with mechanical stability.At this moment, konjac flour and starch slowly rush into the protein foam adsorption layer, due to the continuation effect of mechanical stirring, make konjac glucomannan and other fillers be evenly distributed around the protein foam layer, and konjac glucomannan absorbs water and expands, makes original thin and soft protein foam tissue become gradually solid. Then after heating, the gas in the foam expands due to the heat, the protein denatures when exposed to heat, the konjac glucomannan molecules deacetylate to form hydrogen bonds, polymerize with each other, and after cooling, condense into a thermally irreversible gel, which enhances their mechanical stability and makes the finished food form a loose, tough and elastic texture.

[0071] It can be seen from Example 1A, Example 2B and Example 5E that the method of adding sodium carbonate twice can be beneficial to the formation of a porous structure. When sodium carbonate is added for the first time but not stirred, the pH of the mixture has not changed significantly. Soy protein isolate is added immediately while stirring. During the stirring process, the pH of the overall mixture changes slowly and the speed of change is more stable. After the first portion of sodium carbonate is evenly mixed with the soy protein isolate, the second portion of sodium carbonate is added, so that the generated bubbles are more stable, and when the konjac gel is formed, the number of holes is greater.

[0072] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A method for preparing a konjac gel having a porous and fluffy mouthfeel, characterized in that: The following steps are involved: S1, raw material preparation, weighing a certain amount of konjac flour, edible starch, water, sodium carbonate, and soy protein isolate; S2, raw material processing, konjac flour and edible starch are mixed for standby use, sodium carbonate is divided into two parts, one part of sodium carbonate is added to water before soy protein isolate is added, and after soy protein isolate is added, another part of sodium carbonate is added to water, and after sodium carbonate is added, konjac flour and edible starch are added to the mixture, and stirred rapidly; S3, injection molding swelling, injecting the sol liquid into the mold to make it fully swell; S4, konjac shaping, after the konjac is steamed and shaped in the mold, it is frozen before the embryo is completely cooled, and after the freezing is completed, it is sprinkled with an appropriate amount of water to thaw; S5, rinsing and steaming, rinsing the thawed embryos, adjusting the rinsing pH to 4.2-4.6 with citric acid, and steaming again under this environment; S6, product forming, the cooked konjac is centrifuged and dehydrated, and cooled to obtain a finished product.

2. A method for preparing a konjac gel with a porous and fluffy mouthfeel according to claim 1, characterized in that, In S1, the mass of edible starch is 25%-35% of the mass of konjac flour, the mass of water is 25-35 times the mass of konjac flour, the mass of sodium carbonate is 10%-20% of the mass of konjac flour, and the mass of soy protein isolate is 3%-4% of the mass of konjac flour.

3. A method for preparing a konjac gel with a porous and fluffy mouthfeel according to claim 2, characterized in that, In the step S1, the water is distilled water.

4. A method for preparing a konjac gel with a porous and fluffy mouthfeel according to claim 1, characterized in that: Divide the sodium carbonate into two equal parts, add one part of the sodium carbonate into the water at once, then add the soy protein isolate while stirring. After stirring evenly, gradually add the other part of the sodium carbonate into the water while stirring.

5. A method for preparing a konjac gel with a porous and fluffy mouthfeel according to claim 1, characterized in that: In the steps S2 and S3, the sol solution is immediately injected into the mold after the stirring is completed and allowed to stand for 1-2 hours.

6. A method for preparing a konjac gel with a porous and fluffy mouthfeel according to claim 1, characterized in that: In step S4, the cooking time is 30-40 minutes.

7. A method for preparing a konjac gel with a porous and fluffy mouthfeel according to claim 1, characterized in that: In step S4, the freezing temperature is -20°C to -30°C, and the freezing time is 8-10 hours.

8. A method for preparing a konjac gel with a porous and fluffy mouthfeel according to claim 1, characterized in that: In step S5, the rinsing time is 20-40 minutes, the cooking temperature is 90-100° C., and the cooking time is 20-40 minutes.

9. A method for preparing a konjac gel with a porous and fluffy mouthfeel according to claim 1, characterized in that: In S6, the centrifugal frequency is 40 Hz and the centrifugal time is 1-2 min.

10. A konjac gel food obtained by the preparation method according to any one of claims 1 to 9.

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