Preparation method of ice cream sweet potato regenerated rice

Abstract

This invention discloses a method for preparing regenerated sweet potato rice for ice cream production, comprising washing, grinding, enzymatic hydrolysis, conditioning, and granulation steps. The enzymatic hydrolysis step involves rapidly adding washed fresh sweet potatoes, rice, soybeans, wheat, corn, and oats in a mass ratio of 100:(100-130):(35-46):(25-35):(15-25):(10-25) to a grinder for grinding, obtaining a composite slurry. The mixed slurry accounts for approximately 35-50% of the total mass. A composite enzymatic hydrolysate is added at 0.7-1.5% of the total mass for enzymatic hydrolysis, and the mixture is stirred at 45°C for 5 hours. The composite protease includes amylase, neutral protease, and alkaline protease. The stirring speed is controlled at 300 rpm. The enzymatic hydrolysate is then heated to 85°C and maintained for 20 minutes to obtain an enzyme-inactivated mixed slurry. The preparation technique involves cooling the slurry to 50-65°C, adding the slurry, dietary fiber powder, brown rice flour, and trace elements, mixing them in a ratio of 100:(30-40):(10-30):(1-10), and controlling the temperature at 37-45°C. The regenerated rice prepared according to this invention combines the texture, flavor, and chewiness of ice cream sweet potato. The nutrients and proteins in the rice are more easily absorbed by the human body through enzymatic hydrolysis, increasing the nutritional value of the regenerated rice.

Description

Technical Field

[0001] This invention pertains to food processing technology, specifically relating to a method for preparing recycled rice from sweet potato ice cream. It utilizes enzymatic hydrolysis technology combined with recycled rice manufacturing processes to produce recycled rice that combines the texture, flavor, and chewiness of sweet potato ice cream, while its nutrients and proteins are more easily absorbed by the human body through enzymatic hydrolysis. Background Technology

[0002] Regenerated rice, also known as artificial rice or fortified rice, is a granular food made primarily from the fine powder of one or more grains (such as rice, wheat, and corn), reshaped through processes like extrusion and granulation to resemble the appearance of natural rice. Regenerated rice not only effectively utilizes grain resources such as broken rice, but also allows for the scientific formulation of various grains and fortifying agents to meet nutritional needs, resulting in a new type of staple food with more balanced nutrition and comprehensive functions.

[0003] Ice cream sweet potatoes are a new and unique variety of sweet potato, popular among consumers for their smooth, sweet, and soft texture after cooking, reminiscent of ice cream. They are rich in dietary fiber, vitamins, minerals, and various antioxidants, making them highly nutritious. However, ice cream sweet potatoes are primarily eaten fresh, do not store well for long periods, and lack the convenience of being a staple food.

[0004] Currently, applying sweet potato ice cream to the preparation of recycled rice presents the following technical challenges: first, how to retain its unique flavor and texture to the greatest extent possible; and second, how to improve the bioavailability of macromolecular nutrients such as protein, making them easier for the human body to digest and absorb. Traditional recycled rice preparation processes often focus on shaping the form and simple nutritional fortification, with less attention paid to preserving the flavor of the raw materials themselves and in-depth processing of their nutrients.

[0005] Enzymatic hydrolysis utilizes the mild and efficient nature of enzymatic reactions to rapidly break down proteins into peptides that are easily absorbed by the human body under specific environmental conditions. Currently, the most commonly used enzymes include pepsin, trypsin, acidic proteases, alkaline proteases, neutral proteases, and papain. By breaking down proteins into polypeptides that are more easily absorbed by the body, the body can better absorb nutrients. Summary of the Invention

[0006] The purpose of this invention

[0007] This invention aims to solve the aforementioned problems in the prior art and provides a method for preparing regenerated rice from ice cream sweet potatoes. This method, through specific enzymatic hydrolysis, preserves the unique flavor and texture of ice cream sweet potatoes while enzymatically breaking down the protein components into small peptides and amino acids, thereby producing a regenerated rice with both excellent flavor and high nutrient absorption.

[0008] A method for preparing recycled sweet potato rice for ice cream, characterized by comprising the following steps: washing, grinding, enzymatic hydrolysis, conditioning and granulation.

[0009] Washing and pretreatment: Select fresh sweet potatoes, wash them thoroughly, remove inedible parts, and cut them into small pieces. Meanwhile, prepare grains such as rice, soybeans, wheat, corn, and oats.

[0010] Grinding and enzymatic hydrolysis: Prepare the raw materials according to the following mass proportions: 100 parts sweet potato chips for ice cream, 100-130 parts rice, 35-46 parts soybeans, 25-35 parts wheat, 15-25 parts corn, and 10-25 parts oats. Quickly add all raw materials to a grinder for grinding to obtain a composite slurry. Control the total solids content of the mixed slurry to be 35-50% of the total mass.

[0011] Add 0.7-1.5% (by mass) of a complex enzymatic hydrolysate to the obtained complex slurry. The complex enzymes include amylase, neutral protease, and alkaline protease.

[0012] Enzymatic hydrolysis is carried out at a temperature of 33-45℃ and a speed of 200-300 rpm for 3-5 hours.

[0013] After enzymatic hydrolysis, the hydrolysate is heated to 85°C and maintained for 10-20 minutes to inactivate the enzyme, resulting in an inactivated hydrolysate mixture.

[0014] Preparation: Cool the enzymatically hydrolyzed slurry after enzyme inactivation to 50-65℃. Then, mix and prepare the following proportions by weight: 100 parts enzymatically hydrolyzed slurry, 30-40 parts dietary fiber powder, 10-30 parts brown rice flour, and 1-10 parts trace elements. During mixing, control the temperature at 37-45℃ and stir thoroughly to obtain the prepared material.

[0015] Granulation and drying: The prepared materials are granulated to obtain rice-grain-shaped semi-finished products, and then dried to ensure that the moisture content of the final product meets the storage standards, thus obtaining ice cream sweet potato regenerated rice.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] Excellent flavor and texture: This invention uses ice cream sweet potato as the core ingredient. Through scientific grain ratio and gentle processing technology, it successfully preserves the unique flavor and smooth texture of ice cream sweet potato in the recycled rice product. At the same time, the addition of ingredients such as brown rice flour enriches the chewiness of the product.

[0018] Significantly improved nutrient absorption: Through the synergistic enzymatic hydrolysis of the slurry by a complex enzyme system (amylase, neutral protease, and alkaline protease), not only is some of the starch converted into more easily absorbed sugars, but more importantly, the large protein molecules in soybeans and grains are efficiently broken down into smaller peptides and amino acids. These active peptides and amino acids are more easily absorbed directly by the human intestines, greatly improving the product's nutritional value, making it especially suitable for people with weak digestive systems.

[0019] Nutritionally comprehensive and balanced: The product's ingredients include tubers, various grains, and legumes, achieving protein complementarity. Furthermore, the addition of dietary fiber, brown rice flour, and trace elements further enhances the product's nutritional structure, making it a nutritionally complete staple food choice.

[0020] Controllable process and stable quality: This invention precisely controls key process parameters such as enzymatic hydrolysis, modulation, extrusion, and drying, ensuring the stability between product batches and the excellent quality of the final product.

[0021] Instruction manual illustrations

[0022] Figure 1 Ice cream, sweet potato, and recycled rice sample image Detailed Implementation

[0023] The present invention will be further described in detail below with reference to specific embodiments. These are all illustrative and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art described in this application.

[0024] It should be noted that the terminology used herein is for the purpose of describing particular implementations only and is not intended to limit the exemplary implementations of the methods according to this application. As used herein, the singular form includes the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms “comprising” and / or “including” are used in this description, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0025] The technical solutions of the invention have been clearly and completely described. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] Example 1:

[0027] Weigh out 100kg of fresh sweet potatoes, 100kg of rice, 35kg of soybeans, 25kg of wheat, 15kg of corn, and 10kg of oats. Wash all ingredients thoroughly and cut the sweet potatoes into small pieces.

[0028] Quickly add all chopped raw materials to a pulper, add water, and pulp, controlling the total solids content of the mixed pulp to approximately 40%. Add 0.7% by weight of a compound enzyme (amylase:neutral protease:alkaline protease mass ratio = 2:1:1) to the pulp, and hydrolyze at 33°C with stirring at 200 rpm for 5 hours. After hydrolysis, rapidly raise the temperature to 85°C and maintain this temperature for 20 minutes to inactivate the enzyme.

[0029] Cool the enzymatically hydrolyzed slurry after enzyme inactivation to 50℃. Take 100kg of the cooled slurry, add 30kg of dietary fiber powder, 10kg of brown rice flour and 1kg of trace elements, and stir evenly at 37℃.

[0030] The prepared material is fed into a twin-screw extruder. The extruder's compression section temperature is set to 80°C, the feeding and metering sections to 55°C, and the screw speed to 150 rpm. After extrusion, the material is shaped by a die and cut into rice grains by a cutter. The resulting rice grains are first dried at 30°C for 45 minutes, then dried at 50°C for 25 minutes, resulting in a final product with a moisture content of 15%. This yields the recycled sweet potato rice for ice cream in this embodiment.

[0031] Example 2:

[0032] Weigh out 100kg of fresh ice cream sweet potatoes, 115kg of rice, 40kg of soybeans, 30kg of wheat, 20kg of corn, and 17kg of oats. Wash all ingredients thoroughly and cut the ice cream sweet potatoes into small pieces.

[0033] Add all chopped raw materials quickly to a pulper, add water, and pulp until the total solids content of the mixed pulp is approximately 45%. Add 1.1% by weight of a compound enzyme (amylase:neutral protease:alkaline protease mass ratio = 1:1:1) to the pulp and hydrolyze at 250 rpm for 4 hours at 40°C. After hydrolysis, rapidly raise the temperature to 85°C and maintain this temperature for 15 minutes to inactivate the enzyme.

[0034] Cool the enzyme-inactivated hydrolysate to 57℃. Take 100kg of the cooled hydrolysate, add 35kg of dietary fiber powder, 20kg of brown rice flour and 5kg of trace elements, and stir evenly at 40℃.

[0035] The prepared material is fed into a twin-screw extruder. The extruder's compression section temperature is set to 85°C, the feeding and metering sections to 57°C, and the screw speed to 200 rpm. After extrusion, the material is shaped by a die and cut into rice grains by a cutter. The resulting rice grains are first dried at 40°C for 42 minutes, then dried at 52°C for 22 minutes, resulting in a final product with a moisture content of 12%. This yields the recycled sweet potato rice for ice cream in this embodiment.

[0036] Example 3:

[0037] Weigh out 100kg of fresh ice cream sweet potatoes, 130kg of rice, 46kg of soybeans, 35kg of wheat, 25kg of corn, and 25kg of oats. Wash all ingredients thoroughly and cut the ice cream sweet potatoes into small pieces.

[0038] Quickly add all the chopped raw materials to a grinder, add water, and grind to control the total solids content of the mixed slurry to approximately 50%. Add 1.5% by weight of a compound enzyme (amylase:neutral protease:alkaline protease mass ratio = 1:2:2) to the slurry, and hydrolyze at 300 rpm for 3 hours at 45°C. After hydrolysis, rapidly raise the temperature to 85°C and maintain this temperature for 10 minutes to inactivate the enzyme.

[0039] Cool the enzyme-inactivated hydrolysate to 65℃. Take 100kg of the cooled hydrolysate, add 40kg of dietary fiber powder, 30kg of brown rice flour and 10kg of trace elements, and stir evenly at 45℃.

[0040] The prepared material is fed into a twin-screw extruder. The extruder's compression section temperature is set to 90°C, the feeding and metering sections to 60°C, and the screw speed to 250 rpm. After extrusion, the material is shaped by a die and cut into rice grains by a cutter. The resulting rice grains are first dried at 45°C for 40 minutes, then dried at 55°C for 20 minutes, resulting in a final product with a moisture content of 10%. This yields the recycled sweet potato rice for ice cream in this embodiment.

[0041] Efficacy evaluation experiment

[0042] 1. Evaluation of satiety-related indicators

[0043] In vitro digestion simulation was performed using the Englyst method. 2.0 g samples of regenerated rice and conventional rice (control group) from each example were accurately weighed and added to simulated gastric juice (containing pepsin). Digestion was carried out at 37°C with shaking for 30 min. The pH was then adjusted to 6.8, and simulated intestinal juice (containing pancreatic enzymes and amylase) was added for further digestion. Samples were taken at 0, 20, 60, 120, and 180 min after the start of digestion to determine the released glucose content and calculate the starch hydrolysis rate. The content of resistant starch in the samples was also determined simultaneously.

[0044] Sixty male SD rats of similar weight (200±10 g) were randomly divided into 6 groups (control group and groups of Examples 1-3, 10 rats in each group). The control group was fed conventional rice, while the experimental groups were fed the ice cream sweet potato regenerated rice prepared in Examples 1-3 of this invention, respectively. All rats were housed individually with free access to food and water. After acclimatization for 3 days, the formal experiment began. Daily food intake was recorded during the experiment, and rats were weighed weekly for 4 consecutive weeks. At the end of the experiment, the food efficiency ratio (FER, i.e., weight gain / total food intake) was calculated. The lower the FER value, the less weight gain per unit of food and the stronger the feeling of satiety.

[0045] The test results are as follows:

[0046] Sample group Resistant starch content (%) Starch hydrolysis rate (%) after 180 min Food efficiency ratio (FER) control group 1.82 ± 0.21 95.26 ± 2.18 0.532 ± 0.009 Example 1 12.38 ± 0.72 68.45 ± 2.86 0.482 ± 0.007 Example 2 13.15 ± 0.68 65.92 ± 2.54 0.475 ± 0.006 Example 3 12.92 ± 0.81 67.13 ± 3.02 0.478 ± 0.008

[0047] The regenerated sweet potato rice for ice cream prepared in Examples 1-3 of this invention all have a resistant starch content of over 12%, significantly higher than the control group. Resistant starch is a type of starch that is not digested and absorbed by the small intestine and has physiological functions similar to dietary fiber, such as delaying gastric emptying and increasing satiety. In in vitro digestion simulations, the starch hydrolysis rate of the example group was significantly lower than that of the control group, with a hydrolysis rate of 63-68% at 180 min, while the control group reached as high as 95.26%. This indicates that the product of this invention has a slower digestion characteristic, which helps maintain stable postprandial blood glucose levels.

[0048] Animal experiments showed that the food efficiency ratio (FER) of all the example groups was lower than that of the control group, with Example 2 having the lowest FER value (0.475), a decrease of 10.7% compared to the control group (0.532). This study indicates that foods high in resistant starch can reduce the food efficiency ratio and decrease weight gain. This is consistent with the resistant starch determination results of this invention.

[0049] 2. Determination of small molecule peptide content

[0050] High-performance liquid chromatography (HPLC) was used to determine the content of small molecule peptides in the samples. Sample pretreatment: The regenerated rice samples prepared in each example were pulverized and passed through a 60-mesh sieve. 1.0 g of the sample was accurately weighed, added to 10 mL of phosphate buffer (pH 7.0), and extracted by sonication for 30 min. The sample was then centrifuged at 10,000 r / min for 15 min at 4℃. The supernatant was filtered through a 0.45 μm filter membrane before analysis. A molecular weight calibration curve was established using standard peptides of known molecular weights (bovine serum albumin, cytochrome C, aprotinin, and vitamin B12) to calculate the content of small molecule peptides with a molecular weight below 5 kDa in the samples. The test results are as follows:

[0051] Sample group Small molecule peptide content (%, as a percentage of total protein) Increased rate compared to ordinary rice Control group (regular rice) 8.43 ± 0.67 — Example 1 61.84 ± 2.15 +633.6% Example 2 68.92 ± 1.87 +717.6% Example 3 63.45 ± 2.32 +652.7%

[0052] The small molecule peptide content of ordinary rice is only 8.43%, because the protein in rice mainly exists in the form of gluten, and large molecule proteins dominate when not enzymatically hydrolyzed. However, the ice cream sweet potato regenerated rice prepared in Examples 1-3 of this invention has a small molecule peptide content of over 60%, which is 7-8 times that of ordinary rice. This result fully demonstrates that the synergistic enzymatic hydrolysis process using composite enzymes (amylase, neutral protease, and alkaline protease) employed in this invention can effectively degrade large molecule proteins in the raw materials into small molecule peptides.

[0053] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. All equivalent changes or modifications made based on the technical essence of the present invention should be covered within the scope of the claims of the present invention.

Claims

1. A method for preparing recycled sweet potato rice for ice cream, characterized in that: Through enzymatic hydrolysis, peptides that combine the texture of sweet potato ice cream with easier absorption by the human body are obtained.

2. The method for preparing ice cream-flavored sweet potato recycled rice according to claim 1, characterized in that, The main ingredients include ice cream sweet potato, rice, soybeans, wheat, corn, and oats, with a weight ratio of 100:(100-130):(35-46):(25-35):(15-25):(10-25).

3. The method for preparing ice cream-flavored sweet potato recycled rice according to claim 1, characterized in that: Add a complex enzyme, including amylase, neutral protease and alkaline protease, to the pulping process at a ratio of 0.7-1.5%. Stir at 33-45℃ for 3-5 hours at a stirring speed of 200-300 rpm. Heat the enzymatically hydrolyzed slurry to 85℃ and maintain the temperature for 10-20 minutes.

4. The method for preparing ice cream-flavored sweet potato recycled rice according to claim 3, characterized in that, It also includes the preparation step: cooling the mixed slurry to 50-65℃, mixing the mixed slurry, dietary fiber powder, brown rice powder, and trace elements in a ratio of 100:(30-40):(10-30):(1-10), and controlling the temperature at 37-45℃.

5. The method for preparing ice cream-flavored sweet potato recycled rice according to claim 4, characterized in that, In the preparation step, the slurry, dietary fiber powder, brown rice flour, glutinous rice flour, and trace elements are mixed in a ratio of 100:(35-40):(20-30):(7-10).

6. The method for preparing ice cream-flavored sweet potato recycled rice according to claim 5, characterized in that, Also includes: Extrusion granulation, surface hardening treatment, and drying produce regenerated rice that combines the texture, flavor, and chewiness of ice cream sweet potatoes, while its nutrients and proteins are more easily absorbed by the human body through enzymatic hydrolysis.

7. The method for preparing ice cream-flavored sweet potato recycled rice according to claim 6, characterized in that, The granulation process is as follows: the prepared material is added to a twin-screw extruder. The temperature of the extruder compression section is 80-90℃, the temperature of the feeding section and metering section is 55-60℃, and the screw speed is 150-250 rpm. After the material is extruded and melted, it is shaped by a die and cut into rice grain shape by a cutter.

8. The method for preparing ice cream-flavored sweet potato recycled rice according to claim 6, characterized in that, The drying process is as follows: the rice-grain shaped material after surface hardening treatment is dried in two stages with a moisture content of 10-15%; the air temperature in the first stage is 30-45℃ and the drying time is 40-45 minutes; the air temperature in the second stage is 50-55℃ and the drying time is 20-25 minutes.

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