A rapid evaluation method for the hardness and brittleness of room temperature baking fats

Abstract

The present invention relates to the technical field of oil and fat food testing, and in particular to a rapid evaluation method for the hardness and brittleness of room-temperature baking fats. The rapid evaluation method comprises the following steps: taking the oil phase of the room-temperature baking fat and melting it into a liquid state under heating conditions; dropping the melted oil phase between a glass slide and a cover glass to prepare a test sample; heating the test sample and then cooling it to crystallize the oil phase; placing the test sample on a hot stage of a polarizing microscope, adjusting the hot stage temperature so that the hot stage with the test sample is heated from an initial temperature to 35°C to 40°C after several heating cycles according to a preset temperature gradient; and taking crystallization photographs of the test sample at each temperature during the heating process; wherein the initial temperature is lower than the melting point of the oil phase; reading the grayscale value of the crystallization photographs using software, and determining the hardness and brittleness of the room-temperature baking fat based on the changing trend of the grayscale value of the crystallization photographs during the heating process.

Description

Technical Field

[0001] The present invention relates to the technical field of oil and fat food detection, in particular to a rapid evaluation method for the hardness and brittleness of room temperature baking oils. Background Art

[0002] Baking fats and oils are a crucial ingredient in the baking industry, and their properties significantly impact the quality of baked goods. However, ambient-temperature baking fats and oils are susceptible to irreversible post-hardening and brittleness when exposed to high temperatures during storage and transportation, resulting in the loss of their excellent performance and unusability. Consequently, baking fat developers in this field are conducting research on formulations and production processes to mitigate this post-hardening and brittleness issue.

[0003] In the related art, the method commonly used to evaluate the hardness and brittleness of baking fats is: first, the baked fat product is produced according to the formula of the baked fat product and its processing technology, and then the hardness and brittleness of the baked fat product is evaluated through macroscopic observation and puncture method during the storage of the baked fat product. However, the above method has problems such as a long testing cycle, time-consuming and labor-intensive, and high material consumption. Summary of the Invention

[0004] The present application discloses a rapid evaluation method for the hardness and brittleness of room-temperature baking fats, so as to solve the problems of the existing evaluation methods for the hardness and brittleness of baking fats, such as being time-consuming, labor-intensive, and wasteful of materials.

[0005] The present invention provides a method for quickly evaluating the hardness and brittleness of room-temperature baking fats, comprising the following steps:

[0006] Melting: taking the prepared oil phase of the room temperature baking fat and melting it into a liquid state under heating conditions;

[0007] Sample preparation: drop the melted oil phase between a glass slide and a cover glass to prepare a sample to be tested;

[0008] Crystallization: heating the sample to be tested and then cooling it to allow the oil phase to cool and crystallize;

[0009] Heating and photographing: placing the sample to be tested on a hot stage of a polarizing microscope, adjusting the temperature of the hot stage so that the hot stage with the sample to be tested is heated from an initial temperature to 35°C to 40°C after several heating cycles according to a preset temperature gradient, and photographing the crystallization of the sample to be tested at each temperature during the heating process of the hot stage; wherein the initial temperature is lower than the melting point of the oil phase;

[0010] Determining the hardness and brittleness: reading the grayscale value of the crystallization photograph, and determining the hardness and brittleness of the room-temperature baking fat based on the changing trend of the grayscale value of the crystallization photograph during the heating process of the hot plate.

[0011] Furthermore, in the melting step, the oil phase is melted into a liquid state under heating conditions greater than or equal to 55°C.

[0012] Furthermore, the sample preparation step is: preheating the glass slide and the cover glass at 55°C to 70°C respectively, then dropping the melted oil phase onto the glass slide and covering it with the cover glass, so that the oil phase spreads between the glass slide and the cover glass to prepare the sample to be tested.

[0013] Furthermore, the crystallization step is: heating the sample to be tested at 55°C to 70°C for 0.5h to 2h, and then cooling it at -15°C to -20°C for 1h to 2h, so that the oil phase cools and crystallizes.

[0014] Furthermore, after the crystallization step and before the heating and photographing step, a temperature recovery step is performed. The temperature recovery step is as follows: adjusting the temperature of the hot stage of the polarizing microscope to the initial temperature, placing the sample to be tested on the hot stage at the initial temperature and recovering the temperature for 5 minutes to 15 minutes.

[0015] Furthermore, in the step of heating and taking photos, the preset temperature gradient is: 5°C to 10°C as one temperature gradient, and the heating rate is 0.5°C / min to 1°C / min;

[0016] During the heating process of the hot stage, the temperature is maintained for a period of time after each heating and then the temperature is continued to be raised, wherein the temperature is maintained for 3 minutes to 5 minutes after each heating, and the crystallization photograph is taken during the temperature time;

[0017] After heating to 35° C. to 40° C., maintaining the temperature at 35° C. to 40° C. for 30 min to 60 min, and taking pictures of the crystallization every 3 min to 5 min;

[0018] The initial temperature is 15° C. to 20° C. lower than the melting point of the oil phase.

[0019] Furthermore, the melting point of the oil phase is greater than or equal to 40°C.

[0020] Furthermore, the melting point of the oil phase is above 40°C, and the step of heating and photographing is as follows: setting the initial temperature of the hot stage to 20°C to 26°C, the preset temperature gradient to 5°C, and the heating rate to 1°C / min, heating the hot stage with the sample to be tested from 20°C to 26°C to 25°C to 31°C, and maintaining it for 5 minutes, then continuing to heat it to 30°C to 36°C, and maintaining it for 5 minutes, then continuing to heat it to 35°C to 41°C, and maintaining it for 5 minutes, and finally heating it to 40°C and maintaining it for 30 minutes to 60 minutes;

[0021] During the heating process of the hot stage, the crystallization photos were taken every 5 minutes.

[0022] Furthermore, in the step of determining the hardness and brittleness, when the grayscale value of the crystallization photograph first decreases and then increases with increasing temperature, the room temperature baking fat is hard and brittle.

[0023] Furthermore, the oil phase of the room temperature baking oil is one or a mixture of hydrogenated oil, esterified oil, and vegetable oil.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] The embodiment of the present application provides a rapid evaluation method for the hardness and brittleness of room-temperature baking fats and oils, which has the advantages of simple operation, short test cycle, and low raw material consumption. The embodiment of the present application uses the oil phase of room-temperature baking fats and oils as the test sample, melts it, and then cools it to crystallize. The crystallized test sample is then placed on the hot stage of a polarizing microscope and heated according to a preset temperature gradient. Crystallization photographs are taken of the changes in the crystallization state of the test sample during the heating process, and an effective correspondence is established between the change trend of the grayscale value of the crystallization photographs and the hardness and brittleness characteristics of the room-temperature baking fats and oils, thereby achieving a rapid evaluation of the hardness and brittleness of room-temperature baking fats and oils.

[0026] On the one hand, since it is not necessary to make a finished product of normal temperature baking fat, it is only necessary to test the oil phase of the normal temperature baking fat to obtain the hardness and brittleness results of the finished product, so there is no need to spend time to make the finished product of normal temperature baking fat, and it also saves the consumption of raw materials such as the water phase of the normal temperature baking fat. On the other hand, the embodiment of the present application only needs to track the changes in the crystallization state of the oil phase at different temperatures through a polarizing microscope, and quantitatively confirm it through the grayscale value of the specific crystallization photo, so as to accurately judge the hardness and brittleness of the finished product of normal temperature baking fat. The sample preparation time, heating time and photo shooting time required for this process are much shorter than the test cycle of the hardness test of the finished product of normal temperature baking fat on the first day, the second day or even more days in the related art. It can be seen that the rapid evaluation method provided by the embodiment of the present application can not only effectively shorten the cycle for the hardness and brittleness evaluation of normal temperature baking fat, but also has a simple operation method and consumes less raw materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0028] Figure 1 This is a grayscale value variation curve of the normal temperature baking oil at different temperatures in Example 1;

[0029] Figure 2 This is a grayscale value variation curve of the normal temperature baking oil at different temperatures in Example 2;

[0030] Figure 3 This is a grayscale value variation curve of the normal temperature baking oil at different temperatures in Example 3;

[0031] Figure 4 This is a grayscale value variation curve of the normal temperature baking oil at different temperatures according to Example 4;

[0032] Figure 5 This is a product photo of the room temperature baking fat of comparative example 1;

[0033] Figure 6 This is a product photo of the room temperature baking grease of comparative example 2;

[0034] Figure 7 This is a product photo of the room temperature baking grease of comparative example 3;

[0035] Figure 8 This is a product photo of the room temperature baking grease of comparative example 4. DETAILED DESCRIPTION

[0036] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0037] The technical solution of the present application will be further described below with reference to specific embodiments and drawings.

[0038] Room-temperature baking fat refers to a type of baking fat that is stored and transported at room temperature, and is also the most common type of baking fat in this field. Different types of baking fats from room-temperature baking fats include baking fats that need to be stored and transported under refrigerated or frozen conditions. Room-temperature baking fats tend to harden as the storage time increases, resulting in irreversible hardness and brittleness in room-temperature baking fats, also known as post-hardness and brittleness. This phenomenon is particularly evident when encountering a high-temperature environment (for example, in the process of transporting room-temperature baking fats in summer, the ambient temperature can easily exceed 40°C). The irreversible hardness and brittleness phenomenon will further affect the plasticity, whipping properties and other operational properties of room-temperature baking fats, and may even make them unusable. In addition, when evaluating the hardness and brittleness from a sensory perspective, for room-temperature baking fats that exhibit the hardness and brittleness phenomenon, it can be seen that they have a rock-like fat structure, with some structures becoming hard and some structures becoming soft, and losing operational properties such as whipping properties.

[0039] Therefore, those skilled in the art have studied the formula, processing technology, aging technology, storage method, etc. of room temperature baking fats to alleviate their hardness and brittleness phenomenon, which requires testing and evaluating the hardness and brittleness properties of room temperature baking fats. In the related art, when evaluating the hardness and brittleness of room temperature baking fats, it is first necessary to first produce the finished product of room temperature baking fats according to the formula and processing technology, and then simulate the storage conditions (some storage conditions are one to two weeks, and some storage is one to three months) to measure the hardness of the room temperature baking fats by the puncture method, and then combine the macroscopic phenomenon observation to determine whether the room temperature baking fats will show hardness and brittleness during storage. For example, the finished baking fat is first produced and placed at 4°C for 7 days, and the hardness of the finished baking fat is measured by the puncture method every day. The above-mentioned hardness and brittleness evaluation method takes at least a few days and at most several months to confirm the hardness and brittleness, and there is a problem of a long test cycle; in addition, since the hardness and brittleness can only be effectively evaluated after the finished product of room temperature baking fat is produced, it is time-consuming, labor-intensive, and consumes raw materials.

[0040] However, those skilled in the art are aware that refining the formulation or process conditions of ambient-temperature baking fats involves numerous attempts at different formulations or processes. Each improved ambient-temperature baking fat requires evaluation of its hardness and brittleness, and this long hardness and brittleness evaluation cycle can hinder the development of new formulations or processes. Furthermore, since evaluation of hardness and brittleness requires simulating transportation and storage conditions, this requires the use of a large number of finished ambient-temperature baking fats, consuming significant amounts of raw materials.

[0041] It can be seen from this that it is necessary to improve the hardness and brittleness evaluation method of room temperature baking fats in related technologies, shorten the evaluation cycle, reduce raw material consumption, evaluate hardness and brittleness more quickly and accurately, improve R&D and production efficiency, and reduce raw material costs.

[0042] The present invention provides a method for quickly evaluating the hardness and brittleness of room-temperature baking fats, comprising the following steps:

[0043] Melting: Take the oil phase of the prepared room temperature baking fat and melt it into liquid under heating conditions;

[0044] Sample preparation: Drop the melted oil phase between the slide and the cover glass to prepare the sample to be tested;

[0045] Crystallization: Heat the sample to be tested and then cool it to allow the oil phase to cool and crystallize;

[0046] Heating and photographing: Place the cooled sample on the hot stage of a polarizing microscope, and adjust the temperature of the hot stage so that the hot stage with the sample is heated from the initial temperature to 35°C to 40°C after several heating cycles according to a preset temperature gradient. During the heating process, photograph the crystallization of the sample at each temperature. The initial temperature is lower than the melting point of the oil phase.

[0047] Determine the hardness and brittleness: Read the grayscale value of the crystallization photo, and determine the hardness and brittleness of the room temperature baking fat based on the changing trend of the grayscale value of the crystallization photo during the heating process of the hot plate.

[0048] The embodiment of the present application provides a rapid evaluation method for the hardness and brittleness of room-temperature baking fats and oils, which has the advantages of simple operation, short test cycle, and low raw material consumption. The embodiment of the present application uses the oil phase of room-temperature baking fats and oils as the test sample, melts it, and then cools it to crystallize. The crystallized test sample is then placed on the hot stage of a polarizing microscope and heated according to a preset temperature gradient. Crystallization photographs are taken of the changes in the crystallization state of the test sample during the heating process, and an effective correspondence is established between the change trend of the grayscale value of the crystallization photographs and the hardness and brittleness characteristics of the room-temperature baking fats and oils, thereby achieving a rapid evaluation of the hardness and brittleness of room-temperature baking fats and oils.

[0049] On the one hand, since there is no need to produce a finished product of room-temperature baking fat, only the oil phase of the room-temperature baking fat needs to be tested to obtain the hardness and brittleness results of the finished product. Therefore, there is no need to spend time to produce the finished product of room-temperature baking fat, and the consumption of raw materials such as the water phase of the room-temperature baking fat is also saved. On the other hand, the embodiments of the present application only need to track the changes in the crystallization state of the oil phase at different temperatures through polarizing microscopy and quantitatively confirm the grayscale values of specific crystallization photos to accurately determine the hardness and brittleness of the finished room-temperature baking fat. The time required for sample preparation, heating time, and photo shooting is much shorter than the test cycle of the related art of performing hardness tests on the finished room-temperature baking fat on the first day, second day, or even several months.

[0050] As can be seen, the rapid evaluation method provided in the examples of this application can effectively shorten the evaluation cycle for the hardness and brittleness of ambient-temperature baking fats and oils. It can quickly and accurately assess whether ambient-temperature baking fats and oils will become hard and brittle after a period of storage, eliminating the need to first prepare the finished ambient-temperature baking fat, store it, and test it for each measurement. This evaluation method is particularly suitable for situations where the feasibility of a R&D formula design or process method needs to be quickly screened during the R&D process, effectively improving R&D efficiency and reducing costs.

[0051] It should be noted that in the technical field, the conventional function of a polarizing microscope is to observe crystallization. However, the embodiment of the present application uses a polarizing microscope with a photographic function in the prior art and repurposes it for application, which is one of the important inventive points of the present application. The embodiment of the present application does not only use a polarizing microscope to observe the crystallization state of the oil phase, but uses a polarizing microscope to take pictures of the crystallization state of the oil phase at different temperatures, and extracts the grayscale value of the crystallization photo through software. The grayscale value change trend at different temperatures is used to reflect the change in the crystallization state of the associated oil phase, and then the change in the crystallization state is used to reflect the hardness and brittleness of the associated room temperature type baking fat finished product. In other words, the embodiment of the present application effectively associates the relationship between the grayscale value of the crystallization photo of the oil phase of room temperature type baking fat at different temperatures and the hardness and brittleness of the finished product of the room temperature type baking fat, thereby achieving rapid evaluation and confirmation of the finished product of the room temperature type baking fat. The rapid evaluation method of the present application is also compared with the hardness and brittleness evaluation method commonly used in the related art to confirm the reliability of the results of the rapid evaluation method of the embodiment of the present application.

[0052] The grayscale value of the crystallization photograph can be read using software used in the prior art, such as IMAGE J. The grayscale value reflects the brightness of the black-and-white photograph. A larger grayscale value represents a brighter photograph, reflecting a greater amount of crystals in the photograph and a more regular arrangement of the unit cells.

[0053] Among them, the embodiments of the present application emphasize that the baking oil is a normal temperature type baking oil, which is intended to illustrate that this type of oil is stored and transported under normal temperature conditions, so it is easy to become hard and brittle when encountering a high temperature environment, and thus it is necessary to quickly evaluate the hardness and brittleness of this type of baking oil. It should be noted that the normal temperature conditions in this application refer to the natural environment temperature under non-heating conditions. For example, in the summer in southern my country, the temperature is often above 35°C, and after entering the dog days of summer, the temperature is even higher than 40°C. When storing and transporting normal temperature type baking oil under such high temperature conditions, it is more likely to become hard and brittle. Therefore, the normal temperature conditions in this application focus on the outdoor temperature conditions in summer (for example, high temperatures above 35°C), and then focus on whether the normal temperature type baking oil will become hard and brittle under such high outdoor temperature conditions in summer.

[0054] Among them, room-temperature baking fats and oils generally include both an oil phase and an aqueous phase. The finished product of room-temperature baking fats and oils refers to a finished product prepared by a specific process method using the oil phase and aqueous phase. It is a product that can be directly used as a finished baking fat and oil to make baked goods such as bread or cakes. The rapid evaluation method of the embodiment of the present application does not require the production of the finished room-temperature baking fat and oil. It only requires the oil phase of the room-temperature baking fat and oil to be tested to be prepared. By measuring the prepared oil phase, the hardness and brittleness of the finished room-temperature baking fat and oil can be quickly and accurately evaluated. Therefore, it can save a lot of material consumption and shorten the preparation time of the test sample.

[0055] It should be noted that in actual production activities of enterprises, it is necessary not only to test the hardness and brittleness of room-temperature baking fats in the laboratory pilot stage, but also to test and verify the hardness and brittleness of room-temperature baking fats in the pilot and mass production test stages. The amount of sample testing required at this time is very large, so the rapid evaluation method of the embodiment of the present application can save materials and time during the stage of large sample testing, which is of great significance to actual production.

[0056] Furthermore, in the embodiments of the present application, during the melting step, the oil phase is melted into a liquid state under heating conditions of 55°C or greater. The melting points of the various feedstock oils in the oil phase of room-temperature baking fats and oils are generally below 55°C. Therefore, heating conditions of 55°C or greater ensure that the feedstock oils in the oil phase of room-temperature baking fats and oils are completely melted without forming a crystalline structure. The heating condition of 55°C or greater includes any value within this numerical range, for example, heating conditions of 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, or 90°C.

[0057] Furthermore, in an embodiment of the present application, the sample preparation step is: preheating the glass slide and the cover glass at 55°C to 70°C respectively, then dropping the melted oil phase on the glass slide, and covering it with a cover glass, so that the oil phase spreads between the glass slide and the cover glass, and preparing the sample to be tested. Preheating the glass slide and the cover glass at high temperature first, and then dropping the heated and melted oil phase between the preheated glass slide and the cover glass can further reduce the temperature difference between the oil phase and the glass slide and the cover glass in the process of preparing the sample to be tested, thereby avoiding the influence of crystallization on the subsequent test results in the process of preparing the sample to be tested. Among them, preheating at 55°C to 70°C includes any point value within the preheating temperature range, for example, the preheating temperature is 55°C, 60°C, 65°C or 70°C.

[0058] Furthermore, in an embodiment of the present application, the crystallization step is as follows: heating the sample to be tested at 55°C to 70°C for 0.5h to 2h, and then cooling it at -15°C to -20°C for 1h to 2h, so that the oil phase is cooled and crystallized. The sample to be tested is first heated at 55°C to 70°C for 0.5h to 2h, and then cooled at -15°C to -20°C for 1h to 2h. By controlling the above-mentioned crystallization operating conditions, the size and shape of the crystals of the oil phase are more in line with the test requirements, and are closer to the crystallization effect when a processing machine is used to make a normal temperature type baking oil product. When the cooling rate is slower than the cooling rate of 1h to 2h at -15°C to -20°C, the crystallization rate will slow down, resulting in larger crystal particles, which will have a certain impact on the subsequent hardness and brittleness evaluation.

[0059] In which, in the crystallization step, the heating conditions of the sample to be tested are 55°C to 70°C, including any value within the temperature range, for example, the heating conditions of the sample to be tested are 55°C, 60°C, 65°C or 70°C; the heating time of the sample to be tested is 0.5h to 2h, including any value within the heating time range, for example, the heating time of the sample to be tested is 0.5h, 1h, 1.5h or 2h; the cooling conditions are -15°C to -20°C, including any value within the temperature range, for example, the cooling conditions are -15°C, -16°C, -17°C, -18°C, -19°C or -20°C; the cooling time is 1h to 2h, including any value within the cooling time, for example, the cooling time is 1h, 1.5h, 1.8h or 2h.

[0060] Furthermore, in an embodiment of the present application, after the crystallization step and before the step of heating and taking pictures, a temperature recovery step is also performed, and the temperature recovery step is as follows: adjusting the temperature of the hot stage of the polarizing microscope to the initial temperature, placing the sample to be tested on the hot stage at the initial temperature and recovering it for 5 minutes to 15 minutes. First, the temperature of the hot stage of the polarizing microscope is adjusted to the initial temperature, and the sample to be tested is first recovered at the initial temperature for a period of time, which is beneficial to ensure that the subsequent heating and heating of the sample to be tested is at a relatively slow rate, and further helps to better simulate the ambient temperature of the room temperature baking oil under storage conditions, so that the hardness and brittleness evaluation after heating and taking pictures is more accurate. Among them, placing the sample to be tested on the hot stage at the initial temperature and recovering it for 5 minutes to 15 minutes includes any point value within the temperature recovery temperature range, for example, placing the sample to be tested on the hot stage at the initial temperature and recovering it for 5 minutes, 8 minutes, 10 minutes, 12 minutes or 15 minutes.

[0061] Furthermore, in the embodiment of the present application, in the step of heating and taking pictures, the preset temperature gradient is: 5°C to 10°C as one temperature gradient, and the heating rate is 0.5°C / min to 1°C / min;

[0062] During the heating process of the hot plate, maintain the temperature for a period of time after each heating before continuing to heat up. The temperature maintenance time after each heating is 3 minutes to 5 minutes, and take crystallization photos during the temperature time;

[0063] After heating to 35℃~40℃, maintain it at 35℃~40℃ for 30min~60min, and take crystallization photos every 3min~5min;

[0064] The initial temperature is 15°C to 20°C lower than the melting point of the oil phase.

[0065] In the embodiment of the present application, the temperature is raised with a temperature gradient of 5°C to 10°C, and the heating rate is controlled to be 0.5°C / min to 1°C / min, and the temperature is raised from a temperature about 15°C to 20°C lower than the melting point of the oil phase as the initial temperature. Such heating conditions can better simulate the ambient temperature changes of room-temperature baking fats under storage conditions, so that the subsequent tracking and analysis of the changes in the crystallization state of the test samples at different temperatures are closer to the crystallization changes of the finished room-temperature baking fats under actual storage conditions, thereby making the evaluation of hardness and brittleness more accurate and reasonable. In addition, in the embodiment of the present application, after each temperature gradient is increased, the temperature is maintained for a certain period of time, and crystallization photos are taken during this temperature and time to ensure that the crystallization state changes of the test samples caused by temperature changes are recorded under each different temperature condition; in particular, after the temperature is raised to 35°C to 40°C, crystallization photos are still taken every 3 minutes to 5 minutes. Based on the change trend of the grayscale value extracted from the crystallization photos, it is more accurate to evaluate whether the room-temperature baking fat will become hard and brittle after being stored at a constant temperature for a period of time.

[0066] Among them, 5℃~10℃ is a temperature gradient including any point value within this numerical range, for example, the temperature gradient is 5℃, 6℃, 7℃, 8℃, 9℃ or 10℃; the heating rate is 0.5℃ / min~1℃ / min including any point value within this heating rate range, for example, the heating rate is 0.5℃ / min, 0.6℃ / min, 0.7℃ / min, 0.8℃ / min, 0.9℃ / min or 1℃ / min.

[0067] Furthermore, in an embodiment of the present application, the melting point temperature of the oil phase is greater than or equal to 40°C, and the melting point temperature includes any point value within the temperature range, for example, the melting point temperature of the oil phase is 40°C, 42°C, 44°C, 46°C or 50°C.

[0068] Furthermore, in the embodiment of the present application, the oil phase is 40°C to 46°C, and the step of heating and photographing is as follows: setting the initial temperature of the hot stage to 20°C to 26°C, the preset temperature gradient to 5°C, and the heating rate to 1°C / min, heating the hot stage with the sample to be tested from 20°C to 26°C to 25°C to 31°C and maintaining it for 5 minutes, then continuing to heat it to 30°C to 36°C and maintaining it for 5 minutes, then continuing to heat it to 35°C to 41°C and maintaining it for 5 minutes, until it reaches 40°C and maintains it for 30 minutes to 60 minutes;

[0069] During the heating process of the hot stage, crystallization photos were taken every 5 minutes.

[0070] When the oil phase of the room temperature baking fat in the embodiment of the present application is 40°C to 46°C, a heating condition of an initial temperature of 20°C to 26°C, a preset temperature gradient of 5°C, and a heating rate of 1°C / min is adopted. The heating process of this heating condition is relatively gentle, which is closer to the ambient temperature change conditions of the room temperature baking fat during actual storage. The crystallization changes of the sample to be tested with temperature increase are also closer to the changes in actual storage, which is conducive to the accuracy of the subsequent evaluation results of hardness and brittleness.

[0071] Furthermore, in an embodiment of the present application, in the step of determining hardness and brittleness, when the grayscale value of the crystallization photograph first decreases and then increases with increasing temperature, the room temperature baking fat has hardness and brittleness.

[0072] The reason why room-temperature baking fats and oils become hard and brittle when stored in high-temperature environments is mainly due to the polymorphic transformation of the room-temperature baking fats and oils. After rapid cooling, room-temperature baking fats and oils crystallize into α or β' crystal forms. Their disordered crystal structures can make room-temperature baking fats and oils exhibit better operating performance. However, over time, especially in high-temperature environments, the α or β' crystal forms may rearrange themselves after absorbing heat and gradually transform into neat and orderly β crystal forms. It is this crystal structure transformation that causes the hardness and brittleness of room-temperature baking fats and oils on a macro scale. In addition, in high-temperature environments, the low-melting-point triglycerides will melt, causing the liquid oil phase to migrate. This prevents the solid fat and liquid oil phase in the room-temperature baking fat from fusing well, ultimately causing the room-temperature baking fats and oils to exhibit hardness and brittleness on a macro scale.

[0073] The oil phase is the main factor affecting the hardness and brittleness of room-temperature baking fats. It will also experience crystal melting or crystal transformation during storage as the external ambient temperature changes. Therefore, this application dynamically monitors the changes in the crystal structure of the oil phase under different temperature conditions to evaluate whether room-temperature baking fats will have hardness and brittleness problems.

[0074] In the rapid evaluation method of the embodiment of the present application, during the heating process of the oil phase test sample, the low-melting-point triglyceride will melt, and the brightness of the crystallization photograph taken through the polarizing microscope will decrease, which will lead to a decrease in the grayscale value extracted from the crystallization photograph, and vice versa.

[0075] Based on this, when a room-temperature baking fat is stored at a constant temperature for a long time under high-temperature conditions (the present embodiment, after heating to the melting point of the oil phase, is maintained for 30 to 60 minutes, and crystallization photographs are taken every 3 to 5 minutes during this period, simulating the above-mentioned high-temperature constant-temperature storage conditions), if the room-temperature baking fat undergoes molecular rearrangement after absorbing heat, causing the fat's crystal structure to transform into a more regular and orderly β-type structure, this process indicates that the room-temperature baking fat produced using the corresponding oil phase will become hard and brittle during high-temperature constant-temperature storage. At the same time, because the fat's crystal structure has transformed into a regular and orderly β-type structure, the brightness of the crystallization photographs will increase, and the grayscale value extracted from the crystallization photographs will not continue to decrease, but will instead increase. In other words, when the oil phase is heated from the initial temperature to the melting point of the oil phase and then maintained at this high-temperature condition for a period of time, if the grayscale value of the corresponding crystallization photograph shows a trend of first decreasing and then increasing, this trend can be used to determine that the room-temperature baking fat corresponding to the oil phase will have a hard and brittle problem.

[0076] Conversely, if the crystal structure of a room-temperature baking fat remains disordered and irregular after absorbing heat during prolonged storage at high temperatures, this indicates that the room-temperature baking fat produced using the corresponding oil phase will not become hard and brittle during high-temperature storage. Precisely because the crystal structure remains disordered and irregular under high-temperature, constant-temperature conditions, the brightness of the crystallization photographs captured will not change significantly, nor will the grayscale values extracted from the crystallization photographs change significantly. In other words, if the grayscale values in the corresponding crystallization photographs decrease after the oil phase is heated from its initial temperature to its melting point and then maintained at this high temperature for a period of time, then this trend indicates that the room-temperature baking fat corresponding to the oil phase will not become hard and brittle.

[0077] Furthermore, the oil phase of the ambient temperature baking fat is one or a mixture of hydrogenated oil, esterified oil, palm oil, liquid vegetable oil, or lauric oil. The rapid evaluation method of the embodiments of the present application is applicable to various ambient temperature baking fats and oils whose oil phase is at least one of hydrogenated oil, esterified oil, palm oil, liquid vegetable oil, or lauric oil.

[0078] In order to provide a more detailed description of the technical solution and technical effects of this application, this application will be described below through more specific embodiments.

[0079] Example 1

[0080] This embodiment provides a rapid evaluation method for the hardness and brittleness of room temperature baking fats, comprising the following steps:

[0081] Melting: Prepare the oil phase according to the formula of the room temperature baking fat to be tested, and completely melt it into liquid in a 70℃ water bath;

[0082] Sample preparation: Place a glass slide and a cover slip on a heating platform at 70°C to preheat them. Then, use a pipette to drop 5 μL of the melted oil phase onto the glass slide and quickly cover it with a cover slip, allowing the oil phase to spread between the slide and the cover slip to prepare the sample to be tested.

[0083] Crystallization: Place the sample to be tested on a heating table at 70°C for 1 hour, then quickly transfer it to a refrigerator at -20°C and cool it for 1 hour to allow the oil phase to cool and crystallize;

[0084] Reheating: Adjust the temperature of the hot stage of the polarizing microscope to the initial temperature, and place the sample to be tested on the hot stage at the initial temperature for 10 minutes; the initial temperature is 20°C, and the melting point of the oil phase is 40°C;

[0085] Heating and photographing: Place the sample to be tested after returning to temperature on the hot stage of a polarizing microscope, adjust the temperature of the hot stage, set the initial temperature of the hot stage to 20°C, the preset temperature gradient to 5°C, and the heating rate to 1°C / min, and heat the hot stage with the sample to be tested from 20°C to 25°C and hold it for 5 minutes, then continue to heat it to 30°C and hold it for 5 minutes, then continue to heat it to 35°C and hold it for 5 minutes, then continue to heat it to 40°C and hold it for 40 minutes; starting from heating to 25°C, take a crystallization photo every 5 minutes;

[0086] Determine the hardness and brittleness: Use IMAGE J software to read the grayscale value of the crystallization photos at each temperature. The results are shown in Table 1 and Figure 1 As shown, Figure 1 The gray value variation curves at different temperatures in this embodiment are shown. Figure 1 It can be seen that as the temperature increases, the grayscale value of the crystallization photograph of the oil phase gradually decreases and does not change significantly after decreasing to a certain level, indicating that the room temperature baking oil of this embodiment will not become hard and brittle.

[0087] The formula of the room-temperature baking fat of this embodiment includes (by weight): 30-60 parts of extremely hydrogenated palm stearin, 10-30 parts of palm olein, 5-20 parts of soybean oil, 5-10 parts of coconut oil, 0.5-1.0 parts of mono- and diglycerides of fatty acids, 0.5-1.0 parts of phospholipids, 16 parts of water, and 0.002-0.004 parts of beta-carotene. The oil phase of the room-temperature baking fat (by weight) includes: 30-60 parts of extremely hydrogenated palm stearin, 10-30 parts of palm olein, 5-20 parts of soybean oil, and 5-10 parts of coconut oil, and the melting point of the oil phase is 40°C.

[0088] Temperature (℃) Time (min) Grayscale value 25 0 42.353 30 5 36.269 30 10 33.765 35 15 30.081 35 20 26.227 40 25 25.449 40 30 23.939 40 35 23.887 40 40 23.916 40 45 23.892 40 50 23.885 40 55 23.903

[0089] Table 1 Gray values of normal temperature baking oils at different temperatures in Example 1

[0090] Example 2

[0091] This embodiment differs from the first embodiment only in that this embodiment provides another formulation for a room-temperature baking fat. The room-temperature baking fat comprises, by weight, 30-60 parts palm stearin, 10-30 parts palm olein, 5-20 parts soybean oil, 5-10 parts coconut oil, 0.5-1.0 parts mono- and diglycerides, 0.5-1.0 parts phospholipids, 16 parts water, and 0.002-0.004 parts beta-carotene. The oil phase of the room-temperature baking fat comprises, by weight, 30-60 parts palm stearin, 10-30 parts palm olein, 5-20 parts soybean oil, and 5-10 parts coconut oil, with a melting point of 42°C.

[0092] In the rapid evaluation method for the hardness and brittleness of room temperature baking fats provided in this embodiment, the grayscale values of the crystallization photos at various temperatures were read by IMAGEJ software, and the results are shown in Tables 2 and 3. Figure 2 As shown, Figure 2 The gray value variation curves at different temperatures in this embodiment are shown. Figure 2 It can be seen that as the temperature increases, the grayscale value of the crystallization photograph of the oil phase shows a trend of first decreasing and then increasing, indicating that the room temperature baking oil of this embodiment will become hard and brittle when stored at a high temperature and constant temperature.

[0093] Temperature (℃) Time (min) Grayscale value 25 0 45.506 30 5 39.087 30 10 38.739 35 15 35.513 35 20 36.672 40 25 38.853 40 30 40.636 40 35 41.962 40 40 42.501 40 45 43.652 40 50 44.375 40 55 44.872

[0094] Table 2 Grayscale values of normal temperature baking oils and fats in Example 2 at different temperatures

[0095] Example 3

[0096] This embodiment differs from the first embodiment only in that this embodiment provides another formulation for a room-temperature baking fat. The room-temperature baking fat comprises, by weight, 30-60 parts of palm oil stearin esterified oil (obtained by transesterification of 100% palm oil stearin), 10-30 parts of palm olein oil, 5-20 parts of soybean oil, 5-10 parts of coconut oil, 0.5-1.0 parts of mono- and diglycerol fatty acid esters, 0.5-1.0 parts of phospholipids, 16 parts of water, and 0.002-0.004 parts of β-carotene. The oil phase of the room-temperature baking fat comprises, by weight, 30-60 parts of palm oil stearin esterified oil (obtained by transesterification of 100% palm oil stearin), 10-30 parts of palm olein oil, 5-20 parts of soybean oil, and 5-10 parts of coconut oil. The melting point of the oil phase is 44°C.

[0097] In the rapid evaluation method for the hardness and brittleness of room temperature baking fats provided in this embodiment, the initial temperature of the hot plate was set to 25°C during the heating and photographing step, and the remaining steps were the same as in Example 1. The grayscale values of the crystallization photos at each temperature were read using IMAGE J software, and the results are shown in Tables 3 and 4. Figure 3 As shown, Figure 3 The gray value variation curves at different temperatures in this embodiment are shown. Figure 3 It can be seen that as the temperature increases, the grayscale value of the crystallization photograph of the oil phase shows a trend of first decreasing and then increasing, indicating that the room temperature baking oil of this embodiment will become hard and brittle when stored at a high temperature and constant temperature.

[0098] Temperature (℃) Time (min) Grayscale value 25 0 44.355 30 5 37.768 30 10 34.793 35 15 28.887 35 20 20.128 40 25 27.142 40 30 30.328 40 35 32.004 40 40 37.498 40 45 40.652 40 50 41.375 40 55 41.872

[0099] Table 3 Gray values of room temperature baking oils at different temperatures in Example 3

[0100] Example 4

[0101] The only difference between this embodiment and the third embodiment is that this embodiment provides another formula for a room temperature baking fat. The room temperature baking fat comprises, by weight, 30-60 parts of palm oil stearin and coconut oil stearin esterified oil (obtained by transesterification of 70 wt % to 90 wt % of palm oil stearin with 30 wt % to 10 wt % of coconut oil stearin), 10-30 parts of palm olein, 5-20 parts of soybean oil, 5-10 parts of coconut oil, 0.5-1.0 parts of mono- and diglycerol fatty acid esters, 0.5-1.0 parts of phospholipids, 16 parts of water, and 0.002-0.004 parts of β-carotene. The oil phase of the room temperature baking fat (in parts by mass) is: 30-60 parts of palm oil stearin and coconut oil stearin esterified oil (obtained by ester exchange reaction of 70wt% to 90wt% of palm oil stearin and 30wt% to 10wt% of coconut oil stearin), 10-30 parts of palm olein, 5-20 parts of soybean oil, and 5-10 parts of coconut oil. The melting point of the oil phase is 46°C.

[0102] In the rapid evaluation method for the hardness and brittleness of room temperature baking fats provided in this embodiment, the grayscale values of the crystallization photos at various temperatures were read by IMAGEJ software, and the results are shown in Tables 4 and 5. Figure 4 As shown, Figure 4 What is shown is the gray value variation curve diagram under different temperatures of this embodiment. Figure 4 It can be seen that as the temperature increases, the grayscale value of the crystallization photograph of the oil phase shows a trend of first decreasing and then increasing, indicating that the room temperature baking oil of this embodiment will become hard and brittle when stored at a high temperature and constant temperature.

[0103] Temperature (℃) Time (min) Grayscale value 25 0 34.604 30 5 24.858 30 10 23.064 35 15 21.212 35 20 20.718 40 25 19.555 40 30 19.226 40 35 19.183 40 40 19.202 40 45 19.215 40 50 19.194 40 55 19.189

[0104] Table 4 Gray values of normal temperature baking oils and fats in Example 4 at different temperatures

[0105] Comparative Example 1

[0106] This comparative example provides a method for evaluating the hardness and brittleness of room-temperature baking fats, comprising the following steps: preparing a finished product of room-temperature baking fats according to a conventional production process in the prior art, placing the finished product at a constant temperature of 40°C for four weeks, taking samples weekly and testing the hardness of the finished product of room-temperature baking fats by a puncture method. The results are shown in Tables 5 and Figure 5 As shown, Figure 5 The product photo of the room temperature baking fat of this comparative example is shown in FIG. The formula of the room temperature baking fat in this comparative example adopts the formula of the room temperature baking fat of Example 1.

[0107]

[0108] Table 5: Hardness values of comparative example 1 normal temperature baking fat

[0109] Comparative Example 2

[0110] The only difference between this comparative example and comparative example 1 is that the formula of the room temperature baking fat in this comparative example adopts the formula of the room temperature baking fat in Example 2. Figure 6 As shown, Figure 6 This is a product photo of the room temperature baking fat for this comparative example.

[0111]

[0112] Table 6: Hardness values of room temperature baking fats in comparative example 2

[0113] Comparative Example 3

[0114] The only difference between this comparative example and comparative example 1 is that the formula of the room temperature baking fat in this comparative example adopts the formula of the room temperature baking fat in Example 3. Figure 7 As shown, Figure 7 This is a product photo of the room temperature baking fat for this comparative example.

[0115]

[0116] Table 7: Hardness values of room temperature baking fats in comparative example 3

[0117] Comparative Example 4

[0118] The only difference between this comparative example and comparative example 1 is that the formula of the normal temperature baking fat in this comparative example adopts the formula of the normal temperature baking fat in Example 4. Figure 8 As shown, Figure 8 This is a product photo of the room temperature baking fat for this comparative example.

[0119]

[0120]

[0121] Table 8: Hardness values of room temperature baking fats in comparative example 4

[0122] By comparing the experimental results of Comparative Example 1 with Example 1, Comparative Example 2 with Example 2, Comparative Example 3 with Example 3, and Comparative Example 4 with Example 4, it can be seen that the rapid evaluation method of the embodiment of the present application and the puncture method have consistent evaluation conclusions on the hardness and brittleness of the same type of room-temperature baking fat, indicating that the rapid evaluation method of the embodiment of the present application can indeed determine whether the room-temperature baking fat will have a hard and brittle phenomenon in a shorter time, and has multiple advantages such as a short testing cycle and low raw material consumption.

[0123] The above is a detailed introduction to a rapid evaluation method for the hardness and brittleness of room-temperature baking fats disclosed in an embodiment of the present invention. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only intended to help understand the technical solution and core ideas of the present invention. At the same time, for a person skilled in the art, according to the ideas of the present invention, there may be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A rapid evaluation method for the hardness and brittleness of room temperature baking fats, characterized in that: The following steps are involved: Melting: taking the prepared oil phase of the room temperature baking fat and melting it into a liquid state under heating conditions; Sample preparation: drop the melted oil phase between a glass slide and a cover glass to prepare a sample to be tested; Crystallization: heating the sample to be tested and then cooling it to allow the oil phase to cool and crystallize; Heating and photographing: placing the sample to be tested on a hot stage of a polarizing microscope, adjusting the temperature of the hot stage so that the hot stage with the sample to be tested is heated from an initial temperature to 35°C to 40°C after several heating cycles according to a preset temperature gradient, and photographing the crystallization of the sample to be tested at each temperature during the heating process of the hot stage; wherein the initial temperature is lower than the melting point of the oil phase; Determining the hardness and brittleness: reading the grayscale value of the crystallization photograph, and determining the hardness and brittleness of the room-temperature baking fat based on the changing trend of the grayscale value of the crystallization photograph during the heating process of the hot plate.

2. The rapid evaluation method according to claim 1, characterized in that In the melting step, the oil phase is melted into a liquid state under heating conditions of 55° C. or higher.

3. The rapid evaluation method according to claim 1, characterized in that The sample preparation steps are: preheating the glass slide and the cover glass at 55°C to 70°C respectively, then dropping the melted oil phase onto the glass slide and covering it with the cover glass, so that the oil phase spreads between the glass slide and the cover glass, thereby preparing the sample to be tested.

4. The rapid evaluation method according to claim 1, characterized in that The crystallization step is: heating the sample to be tested at 55° C. to 70° C. for 0.5 h to 2 h, and then cooling it at -15° C. to -20° C. for 1 h to 2 h, so that the oil phase is cooled and crystallized.

5. The rapid evaluation method according to claim 1, characterized in that After the crystallization step and before the heating and photographing step, a temperature recovery step is further performed. The temperature recovery step is: adjusting the temperature of the hot stage of the polarizing microscope to the initial temperature, placing the sample to be tested on the hot stage at the initial temperature and recovering the temperature for 5 min to 15 min.

6. The rapid evaluation method according to claim 1, characterized in that: In the step of heating and taking pictures, the preset temperature gradient is: 5°C to 10°C as one temperature gradient, and the heating rate is 0.5°C / min to 1°C / min; During the heating process of the hot stage, the temperature is maintained for a period of time after each heating, and then the temperature is continued to be increased, wherein the temperature is maintained for 3 minutes to 5 minutes after each heating, and the crystallization photograph is taken during the temperature time; After heating to 35°C to 40°C, maintain the temperature at 35°C to 40°C for 30 min to 60 min, and take pictures of the crystallization every 3 min to 5 min; The initial temperature is 15° C. to 20° C. lower than the melting point of the oil phase.

7. The rapid evaluation method according to any one of claims 1 to 6, characterized in that: The melting point of the oil phase is greater than or equal to 40°C.

8. The rapid evaluation method according to any one of claims 1 to 6, characterized in that: The melting point of the oil phase is above 40°C, and the step of heating and photographing is as follows: setting the initial temperature of the hot stage to 20°C, the preset temperature gradient to 5°C, and the heating rate to 1°C / min, heating the hot stage with the sample to be tested from 20°C to 25°C and maintaining it for 5 minutes, then heating it to 30°C and maintaining it for 5 minutes, then heating it to 35°C and maintaining it for 5 minutes, and then heating it to 40°C and maintaining it for 40 minutes; During the heating process of the hot stage, the crystallization photos were taken every 5 minutes.

9. The rapid evaluation method according to any one of claims 1 to 6, characterized in that: In the step of determining the hardness and brittleness, when the grayscale value of the crystallization photograph first decreases and then increases with increasing temperature, the room temperature baking fat is hard and brittle.

10. The rapid evaluation method according to any one of claims 1 to 6, characterized in that: The oil phase suitable for the room temperature baking oil is: hydrogenated oil, esterified oil, vegetable oil or a mixture of several thereof.

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