Physical oil pressing quality control method

Abstract

The invention discloses a physical oil pressing quality control method, which comprises the following steps of: pumping high-temperature crude oil obtained by purely physical oil pressing at constant pressure in time, conveying the high-temperature crude oil to a cooling device for instant cooling, freezing normal-temperature oil liquid obtained by cooling to perform physical dehydration and dephosphorizing treatment, pumping the frozen oil liquid at constant pressure, filtering, and storing the filtered oil liquid in a storage tank; and oil liquid obtained by filtering is subjected to constant-pressure oil pumping and then is subjected to physical degradation. The invention solves the problems that the quality of the product produced by the existing peanut oil production process is difficult to reach the first-grade quality of the national peanut oil standard, and the product possibly contains harmful substances such as glycidyl ester, aflatoxin and the like.

Description

Technical Field

[0001] The invention relates to the technical field of oil pressing, in particular to a physical oil pressing quality control method. Background Art

[0002] As a kind of oil with unique aroma, peanut oil has a wide range of consumer groups and market demand in my country, especially in southern provinces. However, the current production of peanut oil shows significant differences.

[0003] On the one hand, individual small workshops are an important part of peanut oil production, and there are about 50,000 such workshops across the country. These small workshops mainly rely on physical pressing for production, but are limited by extremely traditional production processes and simple equipment conditions. The production process is simple and has few control steps. It basically consists of three steps: frying, pressing, and filtering. Quality control is highly dependent on manual experience. Therefore, the peanut oil products produced often fail to meet the national secondary standards, and there are problems such as impurities, acid value, heating test failures, and excessive aflatoxin, which seriously affect the safety and market competitiveness of the products.

[0004] On the other hand, large-scale production enterprises use more complex refining processes to produce peanut oil. These enterprises have a large demand for raw materials, complex sources of raw materials, and relatively difficult quality control. In order to ensure the quality and cost of the finished oil, physical pressing is usually combined with chemical solvent extraction, and then a series of refining treatments such as deacidification, decolorization, water washing, high-temperature dehydration, deodorization, and chemical dephospholipidation are carried out. Although this method can produce peanut oil of qualified quality, excessive refining treatment leads to a significant loss of the original color, aroma, taste and nutrients of peanut oil, while increasing production costs. In addition, carcinogens such as glycidyl esters and chloropropanol esters are easily produced during the refining process, which brings safety risks to consumers using edible oil.

[0005] In the production process of edible oil, traditional large factories tend to use chemical processes to deal with problems such as aroma, impurities, dephospholipids and aflatoxin. Although these processes can effectively remove harmful substances, they may also introduce new risks. For example, when treating aflatoxin, the acid-base method can reduce its content, but the subsequent high-temperature deodorization step may produce carcinogens such as glycidyl esters and chloropropanol esters. These substances have potential carcinogenic risks in the human body, and long-term intake may have adverse effects on health.

[0006] In summary, the current peanut oil production faces multiple challenges, such as the simple technology of traditional small workshops, difficult quality control, high production costs of large enterprises, product nutritional loss and potential health risks. Therefore, exploring a more efficient, safe and environmentally friendly peanut oil production process is of great significance to improving product quality and protecting consumer health. Summary of the invention

[0007] The purpose of the present invention is to provide a physical oil pressing quality control method, which can solve the problem that the product quality obtained by the existing peanut oil production process is difficult to reach the first-level quality of the national peanut oil standard and may contain harmful substances such as glycidyl esters and aflatoxin.

[0008] In order to solve the above problems, the technical solution adopted by the present invention is: this physical oil pressing quality control method is to timely transport the high-temperature crude oil obtained by pure physical oil pressing to a cooling device for immediate cooling through constant pressure oil pumping, and the room temperature oil obtained by cooling is physically dehydrated and dephospholipided by freezing, the frozen oil is filtered after constant pressure oil pumping, and the filtered oil is physically degraded after constant pressure oil pumping.

[0009] In the technical solution of the above-mentioned physical oil pressing quality control method, a more specific technical solution can also be: after the oil completes the first filtration, take an oil sample for online heating detection. When the oil sample changes color when heated to 280°C, the oil needs to be filtered for the second time. When no color change occurs, subsequent physical degradation is directly carried out.

[0010] Furthermore, the online heating detection is a timed detection.

[0011] Furthermore, the filtration is performed using a plate filter, and when a second filtration is required, the filtration pressure is adjusted to reduce the pressure.

[0012] Furthermore, when the temperature of the oil after freezing reaches below 10° C., freezing is stopped and stirring is started, and the stirring time is controlled within 4 hours.

[0013] Furthermore, a colorimeter is used to monitor whether the heated oil sample changes color. The colorimeter sends a color change signal to the controller, which is then transmitted to the remote monitoring terminal via the cloud server.

[0014] Furthermore, various types of production information after the operation of aflatoxin degradation machines and oil pressing equipment installed in various small oil mills will be sent to the cloud server through the communication module. The cloud server will send the received production information to the remote monitoring terminal to realize real-time data collection, monitoring and processing.

[0015] Furthermore, the high-temperature crude oil is obtained by steam isolation steaming, two-step frying, removal of benzopyrene, and physical pressing.

[0016] Furthermore, the steam isolation steaming and the two frying stages are both timed controlled.

[0017] Furthermore, the wok temperature for the first stir-fry is higher than the wok temperature for the second stir-fry.

[0018] Due to the adoption of the above technical solution, the present invention has the following beneficial effects compared with the prior art: 1. The quality control of the present invention completely relies on pure physical technology. From oil pressing to cooling, dehydration and dephospholipidation, filtration and physical degradation, there is no chemical process in the whole production process, which avoids the introduction of harmful chemicals such as glycidyl esters and aflatoxin in traditional production, ensures the natural purity of peanut oil, effectively improves the quality of the product, and makes it easier to reach or even exceed the first-class quality of national peanut oil standards; by introducing constant pressure oil extraction, instant cooling, freezing treatment, high-efficiency filtration and physical degradation processes, the stability and consistency of product quality are ensured; the production process is simplified and the production efficiency is significantly improved.

[0019] 2. By online heating and testing the oil sample, impurities or unstable components that may exist in the oil can be discovered in time. The second filtration can effectively remove these undesirable components, thereby improving the purity and stability of the oil and ensuring that the quality of each batch of oil meets uniform standards.

[0020] 3. Regular testing can promptly detect potential problems in the oil. By taking timely measures, it can effectively prevent the occurrence of product quality problems and ensure that the oil quality meets the standards.

[0021] 4. Reducing the pressure during the second filtration can prevent excessive pressure from causing the oil to flow too fast, causing some impurities to be washed away before they fully contact the filter medium, thereby reducing the filtration efficiency. Reducing the pressure helps the oil stay in the filter medium for a longer time, improves the filtration effect, ensures the purity of the oil, and prevents the filter paper from breaking due to excessive pressure.

[0022] 5. When the oil temperature drops below 8°C, most of the water is in a flocculent state, creating favorable conditions for the subsequent stirring and dehydration process; phospholipids and colloids are impurities in the oil, and they may be more easily separated from the oil under slow stirring at low temperature. Through freezing treatment, these impurities may form larger particles or agglomerates, which are easier to be removed by subsequent filtration steps; the control of freezing time and temperature helps to optimize the effects of dephospholipidization and decolloidation, ensuring the best separation effect in the shortest possible time, and also helps to reduce oxidation reactions and enzymatic reactions in the oil, thereby maintaining the quality of the oil.

[0023] 6. The colorimeter can monitor the color changes of oil samples during the heating process in real time. Once the color change is detected, the signal is immediately sent to the controller. The controller transmits the color change signal to the remote monitoring terminal through the cloud server, so that managers can obtain oil status information without going to the site. Through early warning and preventive control, it can effectively avoid the loss and waste of oil due to quality problems, such as rework and returns, reducing production costs and economic losses.

[0024] 7. The remote monitoring terminal can view the production status of each small oil mill in real time, including the aflatoxin degradation effect and the operating status of the oil pressing equipment, which improves the efficiency and convenience of supervision; through the cloud server, centralized management of multiple small oil mills can be achieved, which is convenient for unified scheduling and resource optimization; through comprehensive monitoring and analysis of production information, problems in the production process can be discovered and corrected in time, and the level of product quality control can be improved.

[0025] 8. Steam isolation steaming can isolate steam from oil during the steaming process, ensuring that heat is efficiently transferred to the inside of the oil without directly wetting the surface of the oil, which can not only soften the oil tissue, but also avoid the influence of excess water on subsequent processing; since there is no water residue on the surface of the oil, the direct contact between oil and water is reduced, which helps to maintain the color, aroma and stability of the oil and prevent the oil quality from deteriorating due to water; the internal cell structure of the oil steamed with isolated steam is properly softened, which is conducive to more efficient extraction of oil and oil in the subsequent pressing process and improve the oil yield; two-step frying can reduce the gelatinization of oil frying, help reduce the generation of harmful substances such as benzopyrene, and improve the safety of oil; at the same time, the oil can be fried more evenly, making it easier to release the oil in the subsequent pressing process; removing benzopyrene makes the oil purer and safer, and improves the overall quality of the oil; physical pressing can retain the nutrients in the oil to the maximum extent, and the resulting oil has a low impurity content, is clear and transparent, has good stability, and is not easy to oxidize and deteriorate.

[0026] 9. Timing control of the steam isolation steaming stage can ensure the consistency of the time of each steaming process, thus avoiding differences caused by human factors and ensuring stable and reliable oil processing effects; both frying steps adopt timing and temperature control to ensure the accuracy of the time of each frying process, ensure that the frying time is moderate, avoid excessive frying that causes the oil to burn or oil loss, thereby fully stimulating and fixing the aroma and color components in the oil, and improving the overall flavor and appearance of the oil.

[0027] 10. In the frying stage, a higher temperature is used in the first frying, which can quickly increase the temperature of the oil, help the rapid change of the internal structure of the oil, and create more favorable conditions for the subsequent pressing process; the second frying temperature is lowered to avoid the burning and oil loss caused by long-term high-temperature frying of the oil, make the frying temperature more uniform, and at the same time maintain the good flavor and color of the oil. DETAILED DESCRIPTION

[0028] The present invention will be further described below in conjunction with embodiments: This physical oil pressing quality control method uses pure physical means throughout the process from raw material pretreatment to finished oil preparation, and ensures product quality by precisely controlling each process link. The specific implementation process is as follows: First, the raw materials are wet steamed, and the green dough is made to reach the optimal initial moisture by adding water or directly spraying steam. The wetted dough is then steamed. The chemical composition and physical state of the dough will change during the steaming process, mainly manifested in the fat particles absorbing water and fully expanding, which provides the necessary conditions for the subsequent Maillard reaction to increase the oil extraction rate and improve the quality of oil and oil cakes. The steamer system controls the steaming process at a fixed time, and the process does not need to rely on temperature sensing. After quantitative feeding to the steamer system, the steam on and off time, feeding time and discharging time are all controlled by programmable preset programs without manual intervention.

[0029] Subsequently, the steamed oil with a dry surface is fried twice. The first frying uses a higher pot bottom temperature of more than 300°C to quickly heat the raw materials and preliminarily remove moisture; the second frying uses another wok to reduce the frying temperature to about 280°C to ensure that the temperature inside and outside the wok is uniform, so that the oil in all parts of the wok can be fried thoroughly; the temperature is strictly controlled in both frying, and the time is accurately controlled by a timer to ensure the consistency of each batch of raw material processing and the full release of the oil flavor substances. At the same time, avoid scorching, and the loss of nutrients such as amino acids and possible harmful substances caused by frying at too high a temperature and for too long a time. In the continuous production process, the independence of each pot of fried materials is strictly controlled to avoid mixing, so as to ensure the aroma and oil yield of the oil.

[0030] The steaming and frying conditions of this method are set, and the moisture, temperature and structural properties of the cooked dough after steaming and frying are more suitable for the requirements of oil pressing; the oil cells are completely destroyed; the protein is denatured, the oil is aggregated; the oil viscosity and surface tension are reduced; the elasticity and plasticity of the dough are adjusted; the enzymes contained are passivated, which is conducive to the smooth progress of the oil production process. This can not only improve the oil extraction rate and product quality, but also reduce the load of the oil press, reduce the wear of the oil press and reduce the power consumption.

[0031] After frying, the raw materials need to be stripped of their outer skins in a peeling machine to remove the possible excessive levels of benzodiazepines caused by the burning of the skin during peanut frying, as well as the burnt smell and pigment dissolution problems caused by the subsequent pressing of the peanuts.

[0032] The oil from which benzopyrene has been removed enters the physical pressing stage. The oil press needs to properly adjust the tail teeth after each pressing to ensure that the oil cake is completely discharged, to avoid carbonization of the cake residue in the tail teeth and to ensure that the residual oil rate of the oil cake is below 5%.

[0033] The high-temperature crude oil obtained by pure physical pressing is promptly transported to the cooling device through a constant pressure oil pump. The cooling device uses an oil pipe and cooling water heat exchange method to quickly cool the high-temperature crude oil to room temperature to reduce the loss of aroma.

[0034] The cooled oil enters the refrigeration system. After being frozen to below 8°C, the freezing is stopped and the oil is input into the mixing tank for stirring. The stirring time is controlled within 4 hours to effectively remove phospholipids, colloids and water.

[0035] After the oil is frozen, it is first filtered by a plate filter after the second constant pressure pumping. During the first filtering process, online heating detection is performed. In this embodiment, 100 ml of oil sample is taken at a fixed time interval of 20 minutes and heated to 280°C, and the color change of the oil is monitored by a colorimeter. Once the oil changes color, the colorimeter monitors and sends a signal to the controller, and the controller automatically adjusts the filter pressure, reduces the filtering speed, and performs the second filtering. If the oil does not change color, the subsequent physical degradation treatment of aflatoxin is directly carried out.

[0036] The filtered oil is subjected to physical degradation after the third constant pressure pumping. After the degraded oil is tested and qualified, the finished oil is finally obtained as the first-class quality product that meets the national peanut oil labeling.

[0037] In addition, this method also introduces a remote monitoring and control system. Communication modules are set up in each small oil mill to send real-time information of production equipment such as aflatoxin degradation machines and oil presses to the cloud server, and then the real-time data collection, monitoring and processing are realized through the remote monitoring terminal. At the same time, remote monitoring and adjustment are realized through remote detection terminals such as mobile phone APP to ensure production quality and efficiency.

[0038] This physical oil pressing quality control method effectively improves the quality and stability of oil products and improves production efficiency and safety by precisely controlling each process link and combining remote monitoring with an automatic control system.

Claims

1. A physical oil pressing quality control method, characterized in that: The high-temperature crude oil obtained by pure physical oil pressing is promptly transported to the cooling device for immediate cooling through constant pressure oil extraction. The room-temperature oil obtained by cooling is physically dehydrated and dephospholipided by freezing. The frozen oil is filtered after constant pressure oil extraction. The filtered oil is physically degraded after constant pressure oil extraction.

2. The physical oil pressing quality control method according to claim 1, characterized in that: After the oil has completed the first filtration, take an oil sample for online heating testing. When the oil sample changes color when heated to 280°C, the oil needs to be filtered for the second time. If no color change occurs, the subsequent physical degradation is carried out directly.

3. The physical oil pressing quality control method according to claim 2, characterized in that: Online heating detection is a timed detection.

4. The physical oil pressing quality control method according to claim 2, characterized in that: The filtration adopts plate filter. When the second filtration is needed, the filtration pressure is adjusted to reduce the pressure.

5. The physical oil pressing quality control method according to claim 1, characterized in that: After the temperature of the frozen oil reaches below 10°C, stop freezing and start stirring. The stirring time should be controlled within 4 hours.

6. The physical oil pressing quality control method according to any one of claims 2 to 5, characterized in that: A colorimeter is used to monitor whether the heated oil sample changes color. The colorimeter sends a color change signal to the controller and transmits it to the remote monitoring terminal through the cloud server.

7. The physical oil pressing quality control method according to claim 6, characterized in that: All kinds of production information after the operation of aflatoxin degradation machines and oil pressing equipment installed in various small oil mills will be sent to the cloud server through the communication module. The cloud server will send the received production information to the remote monitoring terminal to realize real-time data collection, monitoring and processing.

8. The physical oil pressing quality control method according to claim 1, characterized in that: The high-temperature crude oil is obtained through steam isolation steaming, two-step frying, removal of benzopyrene, and physical pressing.

9. The physical oil pressing quality control method according to claim 8, characterized in that: The steam isolation steaming and two frying stages are both controlled by timing and temperature.

10. The physical oil pressing quality control method according to claim 9, characterized in that: The wok temperature for the first stir-fry is higher than the wok temperature for the second stir-fry.