Testing method for no-cook premixed powder and its rapid ductility testing instrument

Abstract

The present invention provides a method for testing no-cook premixed powder and a rapid ductility testing instrument thereof. The method comprises the following steps: an insolubility index test, wherein the no-cook premixed powder is dissolved in water and centrifuged in a graduated centrifuge tube, and the volume of the resulting precipitate is recorded; a ductility test, wherein the no-cook premixed powder is mixed with water in a certain proportion to form a sample, and after the starch in the sample is completely gelatinized, the sample is kneaded into a mass and placed in a beaker for later use; a glass rod is used to quantitatively take the mixed sample and adhere it between two opposing thin sheets; the two thin sheets are attached to each other and allowed to stand for a period of time, and the thickness and diameter of the sample after being flattened are recorded; the two thin sheets are separated by a uniform tensile force until the sample is broken, and the peak tensile force and the distance at which the sample is broken are recorded; and a ductility parameter is calculated. The present invention is directed to the testing of no-cook premixed powder, and determines whether the no-cook premixed powder meets the testing standards. The operation is simple and the use is quick.

Description

Technical Field

[0001] The present invention relates to the technical field of pre-prepared food detection, and in particular to a method for detecting no-cooking pre-mixed powder and a rapid ductility detection instrument thereof. Background Art

[0002] No-cook premixes are made with one or more of glutinous rice flour and edible starch as the primary ingredients, with or without auxiliary ingredients, and then crushed, mixed, sieved, and packaged. Auxiliary ingredients include modified starch, emulsifiers, thickeners, and the like. Modified starch is a starch whose natural properties are altered through physical, chemical, or biological methods. Chemically modified starches include acetylated starch, hydroxypropyl starch, and cross-linked starch. Different types of modified starch have different properties and gelatinization requirements. Different auxiliary ingredients and proportions can also affect the gelatinization level of the starch, which in turn affects the performance, ductility, and shelf life of the finished product.

[0003] To ensure the performance and quality of no-cook premixes in practice, promptly troubleshoot problems, and meet the needs of manufacturers and consumers, manufacturers typically conduct application testing on these premixes, particularly for insolubility and ductility. However, there are no clear standards for these existing testing methods. A review of existing national, group, or enterprise standards for premix testing reveals that these standards primarily focus on safety and physical and chemical indicators, but do not examine the performance of the premix itself or the resulting finished product. Food ductility refers to the ability of a food to stretch or extend without breaking when a force is applied. This ductility can impact key factors such as flowability, formability, and taste. Solubility is a key property of premixes, impacting the performance of finished products made with them. Improper processing or production conditions can lead to degradation of starch molecules or insufficient cross-linking, resulting in the formation of insoluble substances. Testing the insolubility coefficient can reflect the effectiveness and consistency of production or processing processes, ensuring that no impurities have been introduced during production or that there are significant issues with the production process. Therefore, the present invention provides additional information in this regard, and it is necessary to conduct insolubility index and ductility tests on premixed powder foods that do not require cooking.

[0004] Currently, laboratory tests for the ductility of food typically use instruments such as texture analyzers, which require complex physical and chemical testing methods and the targeted mixing of various reagents for testing. These tests are cumbersome and complex, requiring specialized technicians to operate, making them unsuitable for testing large numbers of samples and for use by grassroots personnel. Furthermore, these tools are not specifically designed for testing premixed foods, but are more suitable for items with greater ductility, such as building materials. Furthermore, grassroots personnel often use an applied test method, which involves mixing a large ball of dough based on experience, then manually pulling the dough between two iron plates based on feel, until the dough is pulled a certain distance apart without breaking or falling off the plates, and then judging its viscosity. This method fails to control the influence of various variables, and lacks specific parameters for judgment, resulting in missed detection of some defective products. Summary of the Invention

[0005] To address the problems of the prior art, one of the objectives of the present invention is to provide a method for testing no-cook premixed powders. This method tests the insolubility index, water solubility, and ductility of no-cook premixed powder foods. It uses water solubility and centrifugation to reflect product production process issues, and uses tension and stretch length to test ductility. This method can quickly determine the corresponding parameters, allowing for reasonable comparison and judgment of the results. A second objective of the present invention is to provide an instrument for rapid testing the ductility of no-cook premixed powders. This instrument eliminates the need for additional reagents, is quick and easy to operate, minimizes testing time, and produces accurate results, making it suitable for rapid testing by grassroots personnel and on-site.

[0006] The method for detecting the no-cook premix powder of the present invention comprises the following steps:

[0007] S1. Insolubility index test: dissolve the no-cook premix in water and centrifuge in a graduated centrifuge tube, and record the volume of the resulting precipitate.

[0008] S2. Ductility test: Mix the no-cook premixed flour with water in proportion to form a sample. After the starch in the sample is completely gelatinized, knead it into a ball and place it in a beaker for later use.

[0009] S3. Use a glass rod to quantitatively take the mixed sample and stick it between two opposing thin sheets;

[0010] S4, the two thin sheets are attached to each other and left to stand for a period of time, and the thickness d1 and the diameter d2 of the sample after being flattened are recorded;

[0011] S5. Separate the two sheets with a uniform pulling force until the sample is broken, and record the peak pulling force at this time. The distance d3 from the sample when it is broken;

[0012] S6. Calculate the ductility parameters , determine whether it meets the testing standards.

[0013] In one embodiment, in step S6, the ductility parameter The calculation method is:

[0014] ,

[0015] in, The mass of the sample taken for quantitative purpose.

[0016] In one embodiment, in step S2, the method of mixing the no-cooking premix powder with water is as follows: weigh a certain amount of the no-cooking premix powder, add a certain amount of 100°C boiling water, knead into a dough, and then put it into a blender and stir for 3 to 5 minutes or take out the dough and stretch it by hand until it is a smooth dough without dry powder.

[0017] In one embodiment, in step S2, the ratio of the no-cook premix powder to water is 1:1 to 5:6.

[0018] In one embodiment, in step S3, the mass of the sample quantitatively taken is 10 g.

[0019] In one embodiment, in step S4, when the two sheets are attached together, it is necessary to ensure that there is no gap after the sample is flattened, and the static time is at least 5 seconds.

[0020] In one embodiment, in step S5, the separation process of the two sheets adopts horizontal pulling force.

[0021] In one embodiment, in step S1, the specific method of detecting the insolubility index is:

[0022] S11. Add 500 g of water to a 1000 ml beaker, start the digital electric stirrer, and adjust the stirring paddle position to maintain the speed at 250-300 rpm.

[0023] S12, add 70g of the no-cook premix powder to be tested, maintain the speed at 200±25rpm, and stir for 3-4 minutes;

[0024] S13. Take 50 ml of the stirred sample into a 100 ml centrifuge tube using a graduated cylinder, stir it thoroughly before sampling;

[0025] S14, placing the sample in a centrifuge and centrifuging at 4000 rpm for 5 minutes;

[0026] S15. After centrifugation, discard the supernatant and read the numbers.

[0027] The rapid ductility detection instrument for no-cooking premixed powder of the present invention is applied to the above-mentioned detection method for no-cooking premixed powder, and includes a base, fixed plates are vertically arranged on both sides of the base, and a horizontally extending positioning column is provided between the two fixed plates. A movable plate is provided on the positioning column so that the movable plate can move back and forth horizontally along the positioning column; a tensile gauge is fixedly provided on the inner side of one of the fixed plates, and the other end of the tensile gauge is connected to the first thin sheet, and the movable plate is provided with a second thin sheet corresponding to the horizontal position of the first thin sheet, and a horizontal scale is also provided on the base along the direction of the positioning column.

[0028] In one embodiment, the first sheet and the second sheet are both disc-shaped structures made of metal material, and a plurality of circular scales are provided along the centers of the two opposite sides of the first sheet and the second sheet.

[0029] Compared with the prior art, the beneficial effects of the technical solution of the present invention are:

[0030] 1. The method of the present invention is aimed at testing the insolubility index, water solubility and ductility of pre-mixed powder foods that do not require cooking. It reflects product production process problems through water dissolution and centrifugation, and tests its ductility through tension and stretching length. The corresponding parameters can be quickly obtained, so that the results can be judged through reasonable comparison.

[0031] 2. The test uses 100°C boiling water to quickly form dough from pre-mixed flour. Generally, 50g of pre-mixed flour is mixed with 50g-60g of boiling water. Testing has shown that exceeding this ratio can result in a dough that is not sticky and cannot form a ball, or excessive powder, resulting in numerous pores and other factors that affect the test results. A 10g sample is used; this amount ensures that the dough still has a certain visual thickness when flattened, which is convenient for reference and subsequent calculations.

[0032] 3. The instrument of the present invention has a compact structure and high precision. No additional reagents are required when using the instrument for detection. The operation is quick and easy, the detection time is short, and the measurement results are accurate. It is suitable for grassroots personnel and rapid detection on site.

[0033] 4. When using this instrument, place the test dough on the first thin sheet, move the movable plate, and use the second thin sheet on it to press the first thin sheet. After standing for 5 seconds, measure the thickness and circular diameter of the flattened test dough. Then, slowly and evenly pull the movable plate apart. With the help of the positioning column, try to keep the movable plate perpendicular to the base while sliding. When the test dough is broken, read the distance between the movable plate and the first thin sheet and the reading of the tensile gauge according to the scale on the base. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1This is a flow chart of the method for detecting the no-cook premix powder of the present invention;

[0035] Figure 2 It is a structural schematic diagram of the apparatus for rapid detection of ductility of premixed powders without cooking according to the present invention.

[0036] Explanation of the accompanying reference numerals: 1-base, 2-fixed plate, 3-positioning column, 4-movable plate, 5-tensile gauge, 6-first thin sheet, 7-second thin sheet. DETAILED DESCRIPTION

[0037] The accompanying drawings are for illustrative purposes only and are not to be construed as limitations on this patent. To better illustrate this embodiment, some components of the accompanying drawings may be omitted, enlarged, or reduced in size, and do not represent the actual dimensions of the product. For those skilled in the art, it is understandable that some well-known structures and their descriptions may be omitted from the accompanying drawings.

[0038] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "installation" and "connection" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium, which can be considered as internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances. The technical solution of the present invention is further described below with reference to the accompanying drawings and embodiments.

[0039] The inventors have found that, since the premixed powder of the no-cooking type is a special food, it is directly edible, and manufacturers often need to judge the molding effect and its mouthfeel during product application by testing its ductility. However, the complicated steps and expensive cost of physical and chemical testing make it impossible for many manufacturers to do more testing. It is difficult to ensure the quality of all products by only doing necessary sampling tests. With reference to the commonly used application detection method of grassroots personnel, that is, directly clamping a piece of dough with an iron plate and stretching it to both sides with hands, judging its ductility according to experience and feeling, it is more convenient and quick in actual application, but there is no control variable, and there is no clear parameter as a basis for judgment, which sometimes causes large errors. In addition, because modified starch is mostly white powder, there is no difference in appearance, and there is a risk of error in feeding. Manufacturers also need to test whether the premixed powder is mixed with impurities or modified starch with different properties. At present, there are more tests on the physical and chemical properties of premixed powder, and there is no test on the accuracy of the premixed powder ingredient ratio. Therefore, the present invention further improves the method for detecting the insolubility index and ductility of premixed powders to perform rapid detection on no-cook premixed powders without the need for additional reagent preparation, and can derive reasonable insolubility index and ductility parameters, thereby quickly and roughly judging the production process consistency of the no-cook premixed powders, and key factors such as the fluidity, formability, and taste of the finished product.

[0040] like Figure 1 As shown, the method for detecting the no-cook premix powder of the present invention comprises the following steps:

[0041] S1. Insolubility index test: dissolve the no-cook premix in water and centrifuge in a graduated centrifuge tube, recording the volume of the resulting precipitate. Further appearance testing can be performed to observe the state, color, and odor of the no-cook premix after dissolution.

[0042] S2. Extensibility test: Mix the no-cook premixed flour with water in a certain proportion to form a sample. After the starch in the sample is completely gelatinized, knead it into a dough and place it in a beaker for later use. Starch gelatinization is the process in which starch granules, when heated to a certain temperature in the presence of sufficient water, absorb water, swell, rupture, and disintegrate, losing their recognizable granular shape. At high temperatures, starch absorbs water, swells, and breaks apart, forming a uniform paste-like solution or dough.

[0043] S3. Use a glass rod to quantitatively take the mixed sample and stick it between two opposing thin sheets. The test is generally performed on samples at room temperature. The viscosity of the mixed sample may change differently at different temperatures. It is observed that the lower the temperature, the lower the viscosity. Cooling the sample to room temperature helps avoid significant data errors caused by continuous temperature drop during the measurement process.

[0044] S4. The two thin sheets are placed together and left to stand for a period of time, and the thickness d1 and the diameter d2 of the sample after being flattened are recorded;

[0045] S5. Separate the two sheets with a uniform pulling force until the sample is broken and record the peak pulling force at this time. The distance d3 from the sample when it is broken;

[0046] S6. Calculate the ductility parameters , determine whether it meets the testing standards.

[0047] The method of the present invention is aimed at detecting the insolubility index, water solubility and ductility of premixed powder foods that do not require cooking. It reflects the production process problems of the product by water solubility and centrifugation, and tests its ductility by tension and stretching length. The corresponding parameters can be quickly obtained, so that the results can be judged by reasonable comparison. The method is simple to operate, low in cost, safe and environmentally friendly, and quick to use. The method can roughly judge whether there are any errors in the raw materials, whether modified starch with different properties from ordinary edible starch is added, or whether impurities of different colors are mixed in, by measuring the water solubility during the insolubility index test. The appearance test can further judge whether impurities are mixed in during production by combining the texture, smell, impurities and color during the water solubility test. At the same time, if modified starch that prevents sticking is added to the premixed powder, it can be seen from the degree of adhesion to the iron plate that the added pull-off distance will be relatively short and one of the iron plates will be smooth. This is also part of the appearance test. In practical applications, a ductility coefficient above a certain value or above a certain pull-off distance is an acceptable degree of starch aging. The product can first select qualified reference samples according to the standards of physical and chemical testing, and then use this method to obtain reasonable data for the reference samples, especially the calculated ductility parameters. range so that the ductility parameters obtained when testing other products with this method Products within this qualified range are qualified products with good shape and excellent taste.

[0048] In step S1, the insolubility index test requires dissolving the no-cook premix powder in water. At this time, the solubility of the solution, whether there is precipitation, whether the color is uniform, and whether there are impurities can be observed:

[0049] Color: White uniform liquid. If colorant is added to the premixed powder, the color will be evenly distributed without abnormal color. Take 20-30ml of sample solution and place it in a beaker under natural light. Observe with the naked eye to see whether the color is evenly distributed and whether there is black, gray or other abnormal colors.

[0050] Impurities: No impurities visible to normal vision; take 20-30 ml of sample solution and place it in a transparent container, place it under natural light, and observe with the naked eye whether there are abnormal precipitation or suspended matter;

[0051] Odor: No bitter, moldy, or spoiled odor. If the formula contains edible starch such as cooked cake powder, it will have a special odor. If there is non-dairy creamer, it will have a milky flavor. Take 20-30ml of sample solution and place it in a clean glass beaker. Smell it directly or with a fan.

[0052] Based on the observation results, a preliminary and rough assessment can be made as to whether there are any errors in the raw materials, including the addition of modified starch with different properties from ordinary edible starch, or the inclusion of impurities of different colors. Modified starch has properties such as improved frost resistance, elasticity, viscosity, and anti-stickiness, to avoid possible impacts on the following tests, such as ductility. No-cook premixed flours are generally in powder form before processing. Therefore, in step S2, no-cook premixed flours must be mixed with water. The processing method is as follows: weigh a certain amount of no-cook premixed flour, add a certain amount of 100°C boiling water, knead into a dough, and place in a blender for 3-4 minutes. The time can be extended or shortened depending on the amount of sample. The temperature should be maintained at 100°C throughout the process, or the dough can be taken out and stretched by hand until it is smooth and free of dry powder. Take a sample of the premix and add boiling water to it. Mix thoroughly in a blender or stretch and knead the mixture by hand repeatedly. The goal is to ensure the powder and water form a smooth dough free of dry powder to facilitate subsequent flattening and stretching. Maintaining high temperature ensures complete starch gelatinization and reduces the risk of ungelatinized powder and air intrusion that could affect the test results. For large sample sizes, first pour the no-cook premix into a temperature-controlled blender and mix slowly. Then, add boiling water or another high-temperature liquid and stir at high speed until the starch is fully gelatinized. Ensure the temperature does not drop during this process. Remove a portion of the dough for testing. For smaller sample sizes, pour boiling water into the container containing the no-cook premix and stir with a glass rod or silicone spatula until no liquid is visible. Then, knead the dough by hand. This method for smaller sample sizes can result in errors, as it is not possible to maintain a constant temperature during kneading. Using water at different temperatures can lead to varying degrees of starch gelatinization and viscosity in the final product. Incomplete gelatinization can accelerate starch aging, which can cause the finished product to become hard, break, or lose elasticity.

[0053] Specifically, in step S1, the specific method of insolubility index detection is:

[0054] S11. Add 500g of water to a 1000ml beaker. Take water at room temperature of 25°C as an example, and set the pH value to 6.5-7. Start the digital electric stirrer and adjust the stirring blade position to ensure that it is in the water. Keep the speed at 150-200rpm.

[0055] S12. Add 70g of the no-cook premixed powder to be tested, maintain the speed at 200±25rpm, and stir for 3-4 minutes; turn on the stirrer to stir the water first, and then add the powder. This way of adding the powder to the water can prevent the sample from absorbing water and forming a precipitate at the bottom and being unable to be stirred by the stirring paddle. Control the speed to avoid uneven mixing of the sample water and powder due to too low a speed, while too high a speed will cause the powder to stick to the edges and leave large gaps in the middle, or even cause splashing, affecting the results;

[0056] S13. Take out 50ml of the sample from the stirred sample using a graduated cylinder and transfer it to a 100ml centrifuge tube. Stir it evenly before sampling. Because some modified starches have strong water absorption and agglomeration properties, they will absorb water and agglomerate to form insoluble suspended matter.

[0057] S14, placing the sample in a centrifuge and centrifuging at 4000 rpm for 5 minutes;

[0058] S15. After centrifugation, discard the supernatant and read the number again to prevent the supernatant from re-merging with the precipitate.

[0059] In the insolubility index test, a powder-to-water ratio of 1:1 causes clumping and makes the measurement impossible. Meanwhile, a powder-to-water ratio of 1:20 (25g powder to 500g water) results in a more dispersed pellet after centrifugation, leading to large errors in volume measurement. Therefore, a powder-to-water ratio of 1:7 is optimal. Furthermore, a stirrer speed that is too low, such as 50±25rpm, results in low dissolution efficiency. A speed that is too high, such as 375±25rpm, causes powder to splatter against the sides of the cup and remain stuck. Powder clumping, which adheres to the stirring paddle, prevents it from coming into contact with the water, affecting the results. Therefore, a stirring speed of 200±25rpm and stirring for 3-4 minutes is preferred.

[0060] Furthermore, in the insolubility index test, for example, using white oil ice skin premix as an example, too low a centrifuge speed results in incomplete precipitation, making it easy to re-blend with water. Excessive centrifugation time can damage the machine, while too short a centrifugation time can obscure the precipitation and make readings difficult. Therefore, after multiple comparative experiments with controlled variables, it was determined that centrifugation at 4000 rpm for 5 minutes was optimal. Multiple sampling results were consistent, and centrifugation for more than 5 minutes did not affect the results. However, centrifugation for 1 minute or at a speed of only 1000 rpm resulted in different precipitation results for some samples.

[0061] The following are the insolubility index test results of some no-cook premix powders:

[0062] Table 1 shows the ingredients list and insolubility index test results of some no-cook premix powders

[0063]

[0064] It can be seen that some no-cook premix powders are highly insoluble, with a sedimentation volume between 20-50ml. The results can roughly determine the natural edible starch and modified starch in the sample formula. Natural edible starches such as corn starch, potato starch, wheat starch, etc. are insoluble at room temperature or in cold water. Modified starch can clump or combine to form a viscous liquid when it comes into contact with water. The amount of sedimentation in no-cook premix powder is not only related to the type of starch used, but also to the properties of the modified starch used, such as whether it clumps when it comes into contact with water, its water absorption, and its solubility. Taking the Snow Meringue premix powder as an example, after adding water and centrifuging, a homogeneous colloidal liquid is formed, without separation of precipitation and water, indicating that the modified starch added to the premix powder has the characteristics of highly clumping and clumping when it comes into contact with cold water. If the insolubility index of the same sample in different batches is different, too high or too low, it may mean that the production process cannot guarantee consistency or there is a problem with the production of a batch of samples, and timely adjustments are required.

[0065] Preferably, in step S2, the ratio of the no-cook premix to boiling water is 1:1 to 5:6. Using 100°C boiling water for mixing allows the no-cook premix to quickly form into dough and ensures complete gelatinization of the starch. Generally, 50g of no-cook premix is mixed with 50g to 60g of boiling water. The temperature, water-to-powder ratio, and beating time are for reference only. Different types and contents of modified starch require different temperatures and water contents for gelatinization. Testing has shown that, in general, mixing methods exceeding the above ratios will result in a lack of stickiness and inability to form a dough, or excessive powder, resulting in a large number of pores and other factors that affect the test results.

[0066] Furthermore, in step S3, the sample is quantitatively taken with a mass of 10g. This sample amount allows the dough to have a certain visual thickness when flattened, which is convenient for use as a reference value and subsequent calculations. At the same time, the amount is small, and it is easy to control the flattening into a round shape, so as not to waste the test sample and avoid the influence of different amounts on the test. Furthermore, in step S4, when the two slices are fitted together, it is necessary to ensure that there is no gap after the sample is flattened, and the static time is at least 5s. After the sample is flattened, if the powder-water ratio is unreasonable and the water temperature is not appropriate, resulting in incomplete starch gelatinization and ultimately product quality problems, it will usually cause small particles in the finished product and a crack-like surface, which will eventually lead to a decrease in ductility. At this time, it is easy for air to mix in and form pores, etc., which can easily cause uneven force and premature breakage during stretching. Therefore, static observation is also to ensure the accuracy of the detection method as much as possible, and it can also make the sample dough adhere to the slice and not fall off easily. Preferably, in step S5, the separation process of the two slices adopts horizontal tension, stretching horizontally to both sides, and the peak tension obtained is This is the value required to break the dough of the test sample, without further considering the influence of gravity.

[0067] Different types of no-cook premixes have different ingredient lists and production processes. Take white oil snow skin premix, green rice dumpling premix, no-cook stretched mochi premix, and frozen snow skin premix as examples:

[0068] Ingredients for white oil-free snow skin premix: acetylated distarch adipate, hydroxypropyl distarch phosphate, wheat starch, edible starch, non-dairy creamer, trehalose.

[0069] Production process of white oil-free snow skin premix: bake wheat starch at 140-150℃ for 1 hour, sieve the raw materials, weigh the raw materials, put them into the blender for stirring, sieve the finished product and package it.

[0070] Ingredients for Qingtuan premix: hydroxypropyl distarch phosphate, powdered sugar, glutinous rice flour, barley grass powder, guar gum, non-dairy creamer, glucose.

[0071] Production process of Qingtuan premix: bake glutinous rice flour at 140-150℃ for 1 hour, crush white sugar granules, sieve the raw materials, weigh the raw materials, premix hydroxypropyl distarch phosphate and guar gum, put them into a blender and stir, sieve the finished product and package.

[0072] Ingredients for no-cooking stretched mochi premix: hydroxypropyl starch, edible starch, glucose powder, trehalose, rice flour, and skimmed milk powder.

[0073] The production process of the no-cooking drawn mochi premix is as follows: sieving the raw materials, weighing the raw materials, putting them into the blender for stirring, sieving the finished products, and packaging.

[0074] Ingredients for frozen snow skin mooncake premix: hydroxypropyl starch, hydroxypropyl distarch phosphate, powdered sugar, glucose, non-dairy creamer, monoglyceride, calcium stearoyl lactylate.

[0075] Production process of frozen snow skin mooncake premix: crush the white sugar granules, sieve the raw materials, weigh the raw materials, put them into the blender and mix them, sieve the finished product and package it.

[0076] Example 1

[0077] Using premixes for white oil snowy mooncakes, qingtuan (green rice dumpling), no-cook mochi (striped mochi), and wagashi (Japanese confectionery) as examples, the present method demonstrated that the tensile force increased before the sample was pulled apart, reaching a peak before the sample was pulled apart, and then decreased until the sample broke. The maximum diameter of the test sheet was 10 cm; testing was not possible with an area larger than this. All samples were cooled to room temperature during testing.

[0078] First, take 50g of premixed powder and mix it with 50g of 100℃ boiling water, stir it with a blender and maintain a high temperature of 100℃ for 3 to 5 minutes. During this period, the premixed powder can fully absorb water, so that the sample reaches the ideal viscosity and humidity, and at the same time, the sample can begin to form gluten tissue, which is the key to giving the premixed powder sample elasticity and ductility. After kneading it into a dough, place it in a beaker for later use; wait for it to cool to room temperature, use a glass rod to take 5g of the mixed sample, and stick it between two relative thin slices; the two thin slices fit each other to flatten the sample, and it is necessary to ensure that there is no gap after the sample is flattened. Let it stand for 5s, and record the thickness d1 and diameter d2 of the sample after being flattened; use a uniform horizontal pull to separate the two thin slices until the sample is broken, and record the peak tensile force at this time and the distance d3 when the sample is broken; the ductility parameter is calculated:

[0079] .

[0080] Afterwards, wash the used items and use the glass rod to take 10g and 20g of the mixed sample in the beaker again. Repeat the above steps to conduct experiments with different grams and record the corresponding data.

[0081] The test data of the premixed powder for snowy mooncakes without white oil is as follows:

[0082] Table 2 is the data table of the mixing ratio of 50g premixed powder and 50g water for white oil-free snowy mooncake premix.

[0083]

[0084] The test data of Qingtuan premix powder are as follows:

[0085] Table 3 is the data table of the mixing ratio of 50g premixed powder and 50g water.

[0086]

[0087] The test data of the drawn mochi premix is as follows:

[0088] Table 4 is the data table of the mixing ratio of 50g premixed powder and 50g water for the non-cooked drawn mochi premix.

[0089]

[0090] The test data of wagashi premix powder are as follows:

[0091] Table 5 is the data table of the mixed ratio of 50g premixed powder and 50g water.

[0092]

[0093] From the comparison of the above tables, it can be seen that the data of the samples of white oil-free snowy mooncake premix, green rice dumpling premix and drawn mochi premix are more accurate when the weight is 10g or 20g. In order to save the amount and obtain more moderate data, the test sample is quantitatively taken with 10g as the best choice. This method can also quickly obtain the ductility parameters on site. The value is used to compare the extensibility and taste of the tested ready-mixed powder.

[0094] Example 2

[0095] The difference from Example 1 is that in the first step, a sample was prepared by mixing 50g of premixed powder with 60g of 100°C boiling water. The other experimental steps were basically the same, and quantitative test samples of 5g, 10g, and 20g were also selected for subsequent testing. The test data of the white oil-free snowy mooncake premix tested using the method of this example are shown in the following table:

[0096] Table 6 is a data table of the mixing ratio of 50g premixed powder and 60g water for white oil-free snowy mooncake premix.

[0097]

[0098] The test data of Qingtuan premix powder are as follows:

[0099] Table 7 is the data table of the mixing ratio of 50g premixed powder and 60g water.

[0100]

[0101] The test data of the drawn mochi premix is as follows:

[0102] Table 8 is a data table of the mixing ratio of 50g premixed powder and 60g water for the non-cooked drawn mochi premix.

[0103]

[0104] The test data of wagashi premix powder are as follows:

[0105] Table 9 is a data table of the mixed ratio of 50g premixed powder and 60g water.

[0106]

[0107] From the comparison of the above table, we can see that the test sample also needs to be 10g to easily obtain the corresponding ductility parameters, especially for the no-cooking mochi premix. Taking 20g will make the diameter after flattening exceed 10cm, which is not convenient for measuring the ductility parameters. When the test sample is small, it is easy to have a tensile peak. The results are not stable. For example, the qingtuan premix powder shows a large difference when combined with the breaking distance d3. This is likely due to the amount of powder taken just exceeding the critical value of dough viscosity, affecting the dough's adhesion to the sheet and its own fluidity, thus causing experimental error. Therefore, it is best to use a 10g quantitative qingtuan premix powder test sample.

[0108] In summary, Example 2, as a comparative example to Example 1, shows that products similar to the premix for white oil-free snowy mooncakes are more easily measured within the detectable range using the flour-to-water ratio of Example 1. However, products similar to the premix for qingtuan (green rice dumpling) require the flour-to-water ratio of Example 2 to achieve better toughness and avoid the situation where the pull-off distance d3 is missing. Furthermore, experiments with other different flour-to-water ratios show that, for example, a wagashi premix with a ratio of 50g flour to 40g water cannot produce any data and lacks stickiness. Therefore, exceeding the flour-to-water ratios of these two examples can easily result in a dough that lacks stickiness and cannot form into a ball.

[0109] In addition, for the appearance inspection part, if modified starch is added to the premixed powder to prevent sticking, it can be seen from the degree of adhesion to the iron plate. The breaking distance will be relatively short and one of the iron plates will be smooth.

[0110] Example 3

[0111] There are also differences in water solubility testing between frozen and room temperature premixes. The difference lies in the different results obtained after adding water twice when tested using method 2. Refer to the difference between white oil-free snow skin mooncake premix and frozen snow skin mooncake premix above. To extend the shelf life and quality of the finished product, frozen snow skin mooncake premix is a premix designed for frozen storage. Finished products made with frozen snow skin mooncake premix can be stored in the freezer without starch aging due to prolonged freezing. The shelf life can reach 2-3 months, and the product retains a certain degree of ductility after thawing. However, white oil-free snow skin premix will experience starch aging and lose ductility after being frozen for two days.

[0112] Take white oil snow skin mooncake premix and frozen snow skin mooncake premix as examples.

[0113] Sample 1: Knead 50g boiling water and 50g white oil-free snow skin premix until the dough is smooth and uniform;

[0114] Sample 2: Bring 300g water, 30g white oil, and 100g maltose syrup to a boil and mix well. Pour in 300g frozen snow skin premix and mix for 5 minutes until the dough is smooth and uniform.

[0115] The two samples were frozen at -18°C for 24 h and then dried at 30°C to return to the original temperature. The purpose of drying was to speed up the thawing process and facilitate ductility testing.

[0116] Table 10 is the data table of the white oil-free snowy mooncake premix and the frozen snowy mooncake premix after freezing.

[0117]

[0118] The two samples were refrigerated at 4°C for 24 hours and then dried at 30°C to return to temperature. The purpose of drying is to speed up the thawing process and facilitate ductility testing.

[0119] Table 11 is the data table of the white oil-free snowy mooncake premix and the frozen snowy mooncake premix after refrigeration

[0120]

[0121] As can be seen from the comparison in the table above, frozen snow skin premix is more resistant to freezing than white oil-free premix, resulting in a higher ductility coefficient, resulting in greater stretching distance and force. Since refrigeration accelerates starch aging more rapidly than freezing, the same storage time can better reflect the elongation properties of the premix, making it easier to record valid data. Therefore, when testing the ductility of frozen snow skin mooncake premix, the optimal test method is to freeze the sample at -18°C for 24 hours.

[0122] Example 4

[0123] Different from Example 1 and Example 2, the ductility parameter The calculation method is:

[0124] ,

[0125] in, The mass of the sample taken for quantitative purpose.

[0126] To further reasonably calculate the ductility parameters , further reducing the impact of the dough forming volume, stretching length and quality of the test sample, the above formula can be used for better comparison and more accurately judge the fluidity, extensibility and taste of the product. Combining the comparison of different powder-water ratios in Example 1 and Example 2, since some premixed powders easily exceed the maximum diameter of 10cm after flattening when taking 20g of quantitative, therefore, in order to achieve the purpose of rapid detection, the test data when taking 10g of quantitative is used for calculation. The ductility parameter calculated in this embodiment is As shown in the following table:

[0127] Table 12 is a comparison table of new ductility parameters calculated based on the test data of quantitatively taking 10g samples at different powder-water ratios in Example 1 and Example 2

[0128]

[0129] From the comparison of the above tables, it can be seen that the ductility parameters of the fourth embodiment are The calculation method can be used to conduct horizontal comparisons of different products, and thus different products can be tested under a more reasonable powder-water ratio, and a more reasonable powder-water ratio can be provided for the processing of subsequent products.

[0130] like Figure 2 As shown, the food ductility detection instrument of the present invention is applied to the above-mentioned food ductility rapid detection method, comprising a base 1, with fixed plates 2 arranged vertically on both sides of the base 1, a horizontally extending positioning column 3 provided between the two fixed plates 2, and a movable plate 4 sleeved on the positioning column 3, so that the movable plate 4 can move horizontally back and forth along the positioning column 3; a tensiometer 5 is fixed on the inner side of one of the fixed plates 2, the other end of the tensiometer 5 is connected to the first thin sheet 6, and the movable plate 4 is provided with a second thin sheet 7 at the horizontal position corresponding to the first thin sheet 6, and a horizontal scale is also provided on the base 1 along the direction of the positioning column 3. The instrument of the present invention has a compact structure and high precision. No additional reagents are required when using this instrument for detection. The operation is quick and simple, the detection time is short, and the measurement results are accurate. It is suitable for grassroots personnel and rapid detection on site. Before using this instrument, the user needs to place the base 1 on a horizontal surface, clean any residue that may exist on the first thin sheet 6 and the second thin sheet 7, return the tensiometer 5 to zero, and ensure that the movable plate 4 can slide freely on the positioning column 3. In combination with the experimental steps of the above embodiment, when starting the test, the test dough is placed on the first thin sheet 6, and the movable plate 4 is moved to press the first thin sheet 6 with the second thin sheet 7 thereon. After standing for 5 seconds, the thickness and circular diameter of the flattened test dough are measured. If the dough is offset and becomes elliptical, the deviation is not large due to the small amount. It is preferably read at the position with the smallest diameter, and then the movable plate 4 is slowly and evenly pulled open. With the limited cooperation of the positioning column 3, the movable plate 4 is kept as perpendicular to the base 1 as possible and slides. When the test dough is broken, the distance between the movable plate 4 and the first thin sheet 6 and the reading of the dynamometer 5 are read according to the scale on the base 1, thereby completing the above-mentioned method for rapid detection of the extensibility of food.

[0131] Furthermore, both the first sheet 6 and the second sheet 7 are circular structures made of metal material, and a plurality of circular scales are provided along the center of the first sheet 6 and the second sheet 7 on two opposing sides. The test dough is placed as close to the center of the first sheet 6 as possible. Through the above-mentioned operation of flattening the test dough, the dough can be adjusted to a position where the diameter is easy to read. Then, through direct observation during flattening or residual marks on the test dough, the circular scale can be used to quickly obtain the data of the test dough during flattening. Preferably, the tensile gauge 5 is an electronic tensile gauge that can record the maximum peak tensile force reached when the test dough is broken, thereby avoiding errors caused by instantaneous observation. When reset, the first sheet 6 should be located at the 0 scale line of the horizontal scale of the base 1. In this way, even if the first sheet 6 moves forward due to the tension, the distance when the test dough is broken can be obtained by subtracting the reading of the first sheet 6 from the reading of the second sheet 7, thereby reducing errors.

[0132] In the description of this application, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of this application.

[0133] In the figure, the description of the positional relationship is only for illustrative purposes and should not be understood as a limitation on this patent; obviously, the above embodiments of the present invention are only examples for clearly illustrating the present invention, and are not limitations on the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made on the basis of the above description. It is not necessary and impossible to list all the implementation methods here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the claims of the present invention.

Claims

1. A method for detecting premixed powders that do not require cooking, characterized in that: The following steps are involved: S1. Insolubility index test: dissolve the no-cook premix in water and centrifuge in a graduated centrifuge tube, and record the volume of the resulting precipitate. S2. Ductility test: Mix the no-cook premixed flour with water in proportion to form a sample. After the starch in the sample is completely gelatinized, knead it into a ball and place it in a beaker for later use. S3. Use a glass rod to quantitatively take the mixed sample and stick it between two opposing thin sheets; S4, the two thin sheets are attached to each other and left to stand for a period of time, and the thickness d1 and the diameter d2 of the sample after being flattened are recorded; S5. Separate the two sheets with a uniform pulling force until the sample is broken, and record the peak pulling force at this time. The distance d3 from the sample when it is broken; S6. Calculate the ductility parameters , to determine whether the test standard is met, the ductility parameter The calculation method is: ， in, The mass of the sample taken for quantitative purpose.

2. The method for detecting the no-cook premix powder according to claim 1, characterized in that: In step S2, the no-cook premixed powder and water are mixed in the following manner: a certain amount of the no-cook premixed powder is weighed, a certain amount of 100°C boiling water is added, the mixture is kneaded into a dough, and then the dough is put into a blender and stirred for 3 to 5 minutes, or the dough is taken out and stretched by hand until it becomes a smooth dough without dry powder.

3. The method for detecting the no-cook premix powder according to claim 2, characterized in that: In step S2, the ratio of the no-cook premix powder to water is 1:1 to 5:

6.

4. The method for detecting the no-cook premix powder according to claim 1, wherein: In step S3, the mass of the sample quantitatively taken is 10 g.

5. The method for detecting the no-cook premix powder according to claim 1, characterized in that: In step S4, when the two sheets are attached together, it is necessary to ensure that there is no gap after the sample is flattened, and the static time is at least 5 seconds.

6. The method for detecting the no-cook premix powder according to claim 1, characterized in that: In step S5, the two sheets are separated by a horizontal pulling force.

7. The method for detecting the no-cook premix powder according to claim 1, characterized in that: In step S1, the specific method of insolubility index detection is: S11. Add 500 g of water to a 1000 ml beaker, start the digital electric stirrer, and adjust the stirring paddle position to maintain the speed at 150-200 rpm; S12, add 70g of the no-cook premix powder to be tested, maintain the speed at 200±25rpm, and stir for 3-4 minutes; S13. Take 50 ml of the stirred sample into a 100 ml centrifuge tube using a graduated cylinder, stir it thoroughly before sampling; S14, placing the sample in a centrifuge and centrifuging at 4000 rpm for 5 minutes; S15. After centrifugation, discard the supernatant and read the numbers.

8. The method for detecting the no-cook premix powder according to any one of claims 1 to 7, characterized in that: The method adopts a rapid ductility detection instrument for premixed powder without cooking, the instrument comprising a base (1), fixed plates (2) vertically arranged on both sides of the base (1), a horizontally extending positioning column (3) provided between the two fixed plates (2), a movable plate (4) sleeved on the positioning column (3), so that the movable plate (4) can horizontally reciprocate along the positioning column (3); a tensile gauge (5) is fixedly provided on the inner side of one of the fixed plates (2), the other end of the tensile gauge (5) is connected to a first thin sheet (6), a second thin sheet (7) is provided on the movable plate (4) corresponding to the horizontal position of the first thin sheet (6), and a horizontal scale is also provided on the base (1) along the direction of the positioning column (3).

9. The method for detecting no-cook premixed powder according to claim 8, characterized in that: The first thin sheet (6) and the second thin sheet (7) are both circular sheet structures made of metal material, and a plurality of circular scales are provided along the centers of the two opposite sides of the first thin sheet (6) and the second thin sheet (7).

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