Production process for squeezing peanut oil and peanut protein at proper temperature through infrared rays

Abstract

The invention discloses a production process for squeezing peanut oil and peanut protein through infrared rays at a proper temperature, the oil squeezing process is high in oil yield, the product is nutritional and safe, the flavor is lasting and aromatic, the best fragrance release effect is achieved, the original taste and flavor of peanut oil are reserved, the fragrance is aromatic and lasting, the acid value is low, and the content of VE and polyphenol is high; the obtained peanut protein is low in denaturation, the solubility of the peanut protein powder is remarkably improved, the protein powder extraction rate is remarkably improved, the method is suitable for developing high-added-value products such as the peanut protein powder, peanut milk and protein isolate, and dual protection processing of peanut grease and protein is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of peanut oil preparation methods, and in particular relates to an infrared suitable temperature pressing peanut oil and peanut protein production process. Background Art

[0002] As an important oil crop, the efficient extraction and comprehensive utilization of peanut oil and protein resources are the core research directions in the field of grain and oil processing. Traditional peanut oil production processes mainly include high-temperature pressing, solvent extraction and cold pressing. Although the high-temperature pressing method has a high oil yield, its seed frying temperature exceeds 180°C and the pressing temperature exceeds 130°C. Excessive processing temperature can easily lead to oil oxidation and thermal degradation of nutritional active substances (such as vitamin E and phytosterols), significantly reducing the nutritional value of oil products, and accompanied by benzopyrene and other risk factors. At the same time, peanut protein loses its functionality due to severe thermal denaturation, which seriously damages the oil protein, making it impossible to reuse it as food and can only be used as low-value-added feed. Although the solvent extraction method can increase the oil yield, there is a risk of solvent residue, and the subsequent desolventizing process requires high-temperature treatment, which further aggravates protein denaturation and makes it difficult to achieve the coordinated high-quality development of oil and protein. Although the cold pressing method can retain more nutrients, the oil yield is significantly reduced, and the protein extraction from high-residual oil cake is difficult, and its industrial application is limited.

[0003] In view of the common problems in existing peanut processing technology, the oil extraction process temperature is difficult to be compatible with the protein thermal denaturation threshold, and it is impossible to take into account both high oil rate and high protein quality. The traditional heating method has low thermal efficiency and uneven temperature field distribution, which can easily cause local overheating or insufficient heating. The protein extraction process in the pressed cake is complicated and the functionality is not sufficiently retained, which makes it difficult to meet the needs of food-grade applications. It is urgent to develop a peanut oil preparation process that can achieve simultaneous high-quality and green production of peanut oil and protein. Summary of the invention

[0004] The purpose of the present invention is to overcome the deficiencies of the above-mentioned prior art and provide a production process of infrared suitable temperature pressing peanut oil and peanut protein. Aiming at the practical problems of excessively high pressing temperature of traditional fragrant oil, decreased oil quality, and low utilization rate of comprehensive products, based on the physical properties of the oil itself and the correlation between oil permeability and pressure, temperature and time of the pellets during the pressing process, the influence of heat treatment in different physical fields on the oil body, oil and protein structure during the oil processing process is further explored, and a new production process of infrared suitable temperature pressing peanut oil and peanut protein is developed. Compared with the traditional peanut pressing process, this process has a high oil yield while maintaining the original flavor and fragrance of the oil, with a strong and lasting fragrance, low acid value, high VE content, high oxidative stability, and rich unsaturated fatty acids, sterols, wheat germ phenol, phospholipids, and choline. In addition, the obtained peanut protein has low denaturation, and the protein powder obtained after ultrafine grinding has a light color, good flavor, and a high nitrogen solubility index, realizing the dual protection processing of peanut oil and protein.

[0005] Specifically, the present invention is achieved through the following technologies: A production process of infrared temperature-appropriate pressing peanut oil and peanut protein, the specific steps comprising: Step 1 Cleaning and color sorting: The peanut raw materials enter the self-balancing vibrating screen to separate the large stones, shelled peanuts and broken peanuts in the raw materials, and the metal objects in the peanuts are removed by the magnetic separator. Then, the peanuts are transported to the grading and screening machine through the elevator to screen the peanuts with full grains. The color sorter removes the moldy and sprouted peanuts in the raw peanuts; Step 2: Peeling the peanuts: The cleaned and impurity-free peanut kernels are transported to the oven for roasting, and the roasted peanut raw materials are cooled and then air peeled; Step 3: Ozone sterilization: The peeled peanut kernels are transported to an ozone generator for treatment to remove Aspergillus flavus in the raw materials; Step 4: Conditioning of seed material: convey the peanut kernels to a steamer for steam softening, so that the moisture content of the peanut kernels reaches 10% to 15%. After softening, quickly put them into a vacuum freezer for freezing and conditioning at -20 to 0°C; Step 5: Infrared roasting of seeds: The quenched and tempered peanut kernels are transported to a drum-type infrared device for infrared treatment; Step 6: Pressing at appropriate temperature: conveying the infrared heated peanut kernels to a single screw oil press, controlling the inlet temperature to 50-95°C and the rotation speed of the single screw oil press to 20-40r / min, to obtain virgin peanut crude oil and protein cake; Step 7: Cooling and filtering: coarsely filtering the crude peanut oil through a plate-and-frame filter to obtain coarsely filtered peanut oil; rapidly cooling the coarsely filtered peanut oil through an exchanger, adding deionized water to the obtained peanut oil, stirring, standing, and then physically filtering at low temperature to remove impurities to obtain pure peanut oil; Step 8: Crushing and sterilization: The protein cake obtained by squeezing is ultra-finely crushed and microwave sterilized to obtain high-quality protein powder.

[0006] Preferably, in step 2 of removing the red coating, the baking temperature is controlled at 85-105° C., and the baking time is 40-50 minutes.

[0007] Preferably, in step 3, the ozone concentration in the ozone sterilization is 80 mg / L, the temperature is controlled at 30-35° C., the stirring speed is 80-100 r / min, and the treatment time is 20-40 min.

[0008] Preferably, the vacuum of the vacuum freezer in step 4 is controlled to be 10-20 Pa, and the freezing and tempering time is 20-50 min.

[0009] Preferably, in step 5, the temperature of the infrared roasted seeds is 110-150°C, the processing time is 20-30min, the infrared physical field parameters are set to a short-wave infrared wavelength range of 0.78-1.4μm, a medium-wave infrared wavelength range of 1.4-4μm, wherein the short-wave: medium-wave infrared power ratio is 1:1-2, the feed amount is 10-25% of the effective volume of the drum, the infrared processing distance is 15-22cm, and the material thickness is 3-7cm.

[0010] Preferably, in the cooling filtration of step 7, the coarsely filtered peanut oil is rapidly cooled to 15-20° C., the amount of deionized water added is 0.5-1% of the weight of the peanut oil, the stirring speed is 50-60 r / min, and the stirring time is 10-30 min.

[0011] Preferably, in step 8, the peanut protein powder is crushed and sterilized into ultrafine powder to 100-200 mesh, and microwave sterilized for 2-3 minutes, the microwave sterilization temperature is 45-55° C., and the microwave frequency is 2300-2600 MHz.

[0012] Beneficial effects of the present invention: The oil pressing process of the invention has a high oil yield, and the product is nutritious and safe, and has a long-lasting and strong flavor, achieves the best flavor release effect, retains the original flavor and fragrance of the peanut oil, has a strong and long-lasting flavor, is low in acid value, and has high VE and polyphenol contents. The obtained peanut protein has low denaturation, and the solubility of the peanut protein powder is significantly improved, and the protein powder extraction rate is significantly improved. The invention is suitable for developing high value-added products such as peanut protein powder, peanut milk, and isolated protein, and realizes the dual protection processing of peanut oil and protein. DETAILED DESCRIPTION

[0013] The present invention is further described below by way of examples. The test methods used in the following examples are conventional methods unless otherwise specified; the materials and reagents used are reagents and materials that can be obtained from commercial sources unless otherwise specified.

[0014] Example 1 1) Take 10kg of peanuts and put them into the self-balancing vibrating screen to separate the large stones, shelled peanuts and broken peanuts. Use the magnetic separator to remove the metal in the peanuts. Then use the elevator to transport them to the grading and screening machine to screen the peanuts with full grains. Use the color sorter to remove the moldy and sprouted peanuts. 2) The cleaned and impurity-free peanut kernels are transported to an oven and baked at 95°C for 45 minutes. The roasted peanut raw materials are cooled and then air-peeled; 3) The peeled peanut kernels were transported to the ozone generator for treatment, and the ozone concentration was set to 80 mg / L, the temperature was 32°C, the stirring speed was 90 r / min, and the treatment time was 30 min to remove the Aspergillus flavus in the raw materials; 4) The peanut kernels are transported to the steamer equipment for steam softening treatment, so that the moisture content of the peanut kernels reaches 12%. After softening, they are quickly added to the vacuum freezer, set the vacuum pressure to 15Pa, the temperature to -10℃, and freeze and temper for 30 minutes; 5) The quenched and tempered peanut kernels are transported to the drum-type infrared equipment and infrared treated at a temperature of 135°C for 25 minutes; 6) The infrared heated peanut kernels are transported to a single screw oil press, the inlet temperature is controlled at 80°C, and the speed of the single screw oil press is controlled at 30r / min to obtain virgin peanut crude oil and protein cake; 7) The crude peanut oil is coarsely filtered through a plate-and-frame filter to obtain coarsely filtered peanut oil, and the coarsely filtered peanut oil is rapidly cooled to 15°C through an exchanger. Deionized water is added to the obtained peanut oil, stirred, allowed to stand, and then physically filtered at low temperature to remove impurities, thereby obtaining crystal clear pure peanut oil; 8) The protein cake obtained by squeezing is ultra-finely ground into 100-200 mesh peanut protein powder, and the microwave sterilization temperature is set to 50°C, the wave frequency is 2500MHz, and the microwave sterilization is performed for 3 minutes to obtain protein powder.

[0015] Example 2 1) Take 10kg of peanuts and put them into the self-balancing vibrating screen to separate the large stones, shelled peanuts and broken peanuts. Use the magnetic separator to remove the metal in the peanuts. Then use the elevator to transport them to the grading and screening machine to screen the peanuts with full grains. Use the color sorter to remove the moldy and sprouted peanuts. 2) The cleaned and impurity-free peanut kernels are transported to an oven and baked at 100°C for 40 minutes. The roasted peanut raw materials are cooled and then air-peeled; 3) The peeled peanut kernels were transported to the ozone generator for treatment, and the ozone concentration was set to 80 mg / L, the temperature was 30°C, the stirring speed was 90 r / min, and the treatment time was 30 min to remove the Aspergillus flavus in the raw materials; 4) The peanut kernels are transported to the steamer equipment for steam softening treatment, so that the moisture content of the peanut kernels reaches 10%. After softening, they are quickly added to the vacuum freezer, set the vacuum pressure to 10Pa, the temperature to -5℃, and freeze and temper for 40 minutes; 5) The quenched and tempered peanut kernels are transported to the drum-type infrared equipment and infrared treated at a temperature of 135°C for 25 minutes; 6) The infrared heated peanut kernels are transported to a single screw oil press, the inlet temperature is controlled at 90°C, and the speed of the single screw oil press is controlled at 30r / min to obtain crude peanut oil and protein cake; 7) The crude peanut oil is coarsely filtered through a plate-and-frame filter to obtain coarsely filtered peanut oil, and the coarsely filtered peanut oil is rapidly cooled to 20°C through an exchanger. Deionized water is added to the obtained peanut oil, stirred, allowed to stand, and then physically filtered at low temperature to remove impurities, thereby obtaining crystal clear pure peanut oil; 8) The protein cake obtained by squeezing is ultra-finely ground into 100-200 mesh peanut protein powder, and the microwave sterilization temperature is set to 50°C, the wave frequency is 2500MHz, and the microwave sterilization is performed for 3 minutes to obtain protein powder.

[0016] Comparative Example 1 1) Take 10kg of peanuts and put them into the self-balancing vibrating screen to separate the large stones, shelled peanuts and broken peanuts. Use the magnetic separator to remove the metal in the peanuts. Then use the elevator to transport them to the grading and screening machine to screen the peanuts with full grains. Use the color sorter to remove the moldy and sprouted peanuts. 2) The cleaned and impurity-free peanut kernels are transported to an oven and baked at 95°C for 45 minutes. The roasted peanut raw materials are cooled and then air-peeled; 3) The peeled peanut kernels were transported to the ozone generator for treatment, and the ozone concentration was set to 80 mg / L, the temperature was 32°C, the stirring speed was 90 r / min, and the treatment time was 30 min to remove the Aspergillus flavus in the raw materials; 4) Place the peanut kernels in an electromagnetic seed roasting machine, control the roasting temperature to 160°C, and roast the kernels for 30 minutes; 5) After frying the seeds, they are transported to a single screw oil press, the inlet temperature is controlled at 80°C, and the speed of the single screw oil press is controlled at 30r / min to obtain virgin peanut crude oil and protein cake; 6) The crude peanut oil is coarsely filtered through a plate-and-frame filter to obtain coarsely filtered peanut oil, and the coarsely filtered peanut oil is rapidly cooled to 15°C through an exchanger. Deionized water is added to the obtained peanut oil, stirred, allowed to stand, and then physically filtered at low temperature to remove impurities to obtain pure peanut oil; 7) The protein cake obtained by squeezing is ultra-finely ground into 100-200 mesh peanut protein powder, and the microwave sterilization temperature is set to 50°C, the wave frequency is 2500MHz, and the microwave sterilization is performed for 3 minutes to obtain protein powder.

[0017] Comparative Example 2 1) Take 10kg of peanuts and put them into the self-balancing vibrating screen to separate the large stones, shelled peanuts and broken peanuts. Use the magnetic separator to remove the metal in the peanuts. Then use the elevator to transport them to the grading and screening machine to screen the peanuts with full grains. Use the color sorter to remove the moldy and sprouted peanuts. 2) The cleaned and impurity-free peanut kernels are transported to an oven and baked at 95°C for 45 minutes. The roasted peanut raw materials are cooled and then air-peeled; 3) The peeled peanut kernels were transported to the ozone generator for treatment, and the ozone concentration was set to 80 mg / L, the temperature was 32°C, the stirring speed was 90 r / min, and the treatment time was 30 min to remove the Aspergillus flavus in the raw materials; 4) The peanut kernels were transported to the drum-type infrared equipment and infrared treated at a temperature of 135°C for 25 minutes; 5) The infrared heated peanut kernels are transported to a single screw oil press, the inlet temperature is controlled at 80°C, and the speed of the single screw oil press is controlled at 30r / min to obtain virgin peanut crude oil and protein cake; 6) The crude peanut oil is coarsely filtered through a plate-and-frame filter to obtain coarsely filtered peanut oil, and the coarsely filtered peanut oil is rapidly cooled to 15°C through an exchanger. Deionized water is added to the obtained peanut oil, stirred, allowed to stand, and then physically filtered at low temperature to remove impurities to obtain pure peanut oil; 7) The protein cake obtained by squeezing is ultra-finely ground into 100-200 mesh peanut protein powder, and the microwave sterilization temperature is set to 50°C, the wave frequency is 2500MHz, and the microwave sterilization is performed for 3 minutes to obtain protein powder.

[0018] Comparative Example 3 1) Take 10kg of peanuts and put them into the self-balancing vibrating screen to separate the large stones, shelled peanuts and broken peanuts. Use the magnetic separator to remove the metal in the peanuts. Then use the elevator to transport them to the grading and screening machine to screen the peanuts with full grains. Use the color sorter to remove the moldy and sprouted peanuts. 2) The cleaned and impurity-free peanut kernels are transported to an oven and baked at 95°C for 45 minutes. The roasted peanut raw materials are cooled and then air-peeled; 3) The peeled peanut kernels were transported to the ozone generator for treatment, and the ozone concentration was set to 80 mg / L, the temperature was 32°C, the stirring speed was 90 r / min, and the treatment time was 30 min to remove the Aspergillus flavus in the raw materials; 4) The peanut kernels are transported to the steamer equipment for steam softening treatment, so that the moisture content of the peanut kernels reaches 12%; 5) The softened peanut kernels are transported to the drum-type infrared equipment and infrared treated at a temperature of 135°C for 25 minutes; 6) The infrared-treated peanut kernels were transported to a single-screw oil press, the inlet temperature was controlled at 80°C, and the speed of the single-screw oil press was controlled at 30 r / min to obtain crude peanut oil and protein cake; 7) The crude peanut oil is coarsely filtered through a plate-and-frame filter to obtain coarsely filtered peanut oil, and the coarsely filtered peanut oil is rapidly cooled to 15°C through an exchanger. Deionized water is added to the obtained peanut oil, stirred, allowed to stand, and then physically filtered at low temperature to remove impurities to obtain pure peanut oil; 8) The protein cake obtained by squeezing is ultra-finely ground into 100-200 mesh peanut protein powder, and the microwave sterilization temperature is set to 50°C, the wave frequency is 2500MHz, and the microwave sterilization is performed for 3 minutes to obtain protein powder.

[0019] Comparative Example 4 1) Take 10kg of peanuts and put them into the self-balancing vibrating screen to separate the large stones, shelled peanuts and broken peanuts. Use the magnetic separator to remove the metal in the peanuts. Then use the elevator to transport them to the grading and screening machine to screen the peanuts with full grains. Use the color sorter to remove the moldy and sprouted peanuts. 2) The cleaned and impurity-free peanut kernels are precisely heated by microwave using an intelligent temperature control device to control the material temperature to 130°C, and the microwave heating time is 6 minutes; 3) The microwaved peanut kernels were transported to a drum-type infrared device and treated at 130°C for 22.5 minutes; 4) The peanut kernels after infrared treatment are rapidly cooled to 75°C by air cooling at a cooling rate of 12.5°C / min. The red skin of the peanut kernels is removed by a peeling machine, and the peanut kernels that are not completely peeled are removed by a color sorter. The peanut kernels without red skin are transported to a steamer for steam softening treatment to reduce the moisture content of the peanut kernels to 8%; 5) The softened and tempered peanut kernels are conveyed to a twin-screw oil press, the inlet temperature is controlled at 75°C, and the speed of the twin-screw oil press is controlled at 22r / min to obtain peanut oil and peanut meal; 6) The peanut oil obtained by squeezing is centrifuged and filtered at a centrifugal speed of 5000r / min, and then transported to a heat exchanger for instant cooling at a cooling rate of 5℃ / min, cooled to 25℃, 0.75% water is added, stirred for 45min, allowed to settle for 9h, and then physically filtered at low temperature to remove impurities to obtain pure peanut oil; 7) The protein cake obtained by squeezing is ultra-finely ground into 100-200 mesh peanut protein powder, and the microwave sterilization temperature is set to 50°C, the wave frequency is 2500MHz, and the microwave sterilization is performed for 3 minutes to obtain protein powder.

[0020] Comparative Example 5 1) Take 10kg of peanuts and put them into the self-balancing vibrating screen to separate the large stones, shelled peanuts and broken peanuts. Use the magnetic separator to remove the metal in the peanuts. Then use the elevator to transport them to the grading and screening machine to screen the peanuts with full grains. Use the color sorter to remove the moldy and sprouted peanuts. 2) The cleaned and impurity-free peanut kernels are transported to an oven and baked at 95°C for 45 minutes. The roasted peanut raw materials are cooled and then air-peeled; 3) The peeled peanut kernels were transported to the ozone generator for treatment, and the ozone concentration was set to 80 mg / L, the temperature was 32°C, the stirring speed was 90 r / min, and the treatment time was 30 min to remove the Aspergillus flavus in the raw materials; 4) The peanut kernels are transported to the steamer equipment for steam softening treatment, so that the moisture content of the peanut kernels reaches 8%. After softening, they are quickly added to the vacuum freezer, set the vacuum pressure to 15Pa, the temperature to -10℃, and freeze and temper for 30 minutes; 5) The quenched and tempered peanut kernels are transported to the drum-type infrared equipment and infrared treated at a temperature of 135°C for 25 minutes; 6) The infrared heated peanut kernels are transported to a single screw oil press, the inlet temperature is controlled at 80°C, and the speed of the single screw oil press is controlled at 30r / min to obtain virgin peanut crude oil and protein cake; 7) The crude peanut oil is coarsely filtered through a plate-and-frame filter to obtain coarsely filtered peanut oil, and the coarsely filtered peanut oil is rapidly cooled to 15°C through an exchanger. Deionized water is added to the obtained peanut oil, stirred, allowed to stand, and then physically filtered at low temperature to remove impurities, thereby obtaining crystal clear pure peanut oil; 8) The protein cake obtained by squeezing is ultra-finely ground into 100-200 mesh peanut protein powder, and the microwave sterilization temperature is set to 50°C, the wave frequency is 2500MHz, and the microwave sterilization is performed for 3 minutes to obtain protein powder.

[0021] Performance testing Peanut oil was prepared according to the methods in the examples and comparative examples, and the properties of the obtained peanut oil were tested according to the following methods. The results are shown in Tables 1 and 2.

[0022] 1. Peanut oil yield: The freshly squeezed peanut oil was placed in a constant temperature storage room at 2°C for 48 hours and then filtered. The mass of the residue after filtration was recorded. The peanut kernel cake produced by oil extraction was collected and weighed. The ratio of the mass of peanut oil obtained in each batch to the mass of peanut kernel was the oil yield, as follows: Y = (m 1 -m 2 -m 3 ) / m 1 ×100%, where m 1 is the mass of peanut kernel, m 2 is the mass of peanut protein powder, m 3 is the mass of the residue after filtration.

[0023] 2. Fragrance evaluation: 10 volunteers with a keen sense of smell were randomly selected to take 10 ml of oil sample and smell the odor while stirring. The oil samples were evaluated for their overall flavor. If they had the inherent aroma of peanut oil and no peculiar smell, they scored 8-10 points; if they had a lighter smell and no peculiar smell, they scored 5-7 points; if they had a light smell and a slight peculiar smell, they scored 1-4 points. The evaluation result was the average of the scores of the 10 volunteers.

[0024] 3. Vitamin E detection: HPLC method (C18 chromatographic column, mobile phase methanol: water = 95:5, detection wavelength 294nm).

[0025] 4. Color: According to GB / T 22460-2008 Determination of color of Lovibond of animal and vegetable oils and fats.

[0026] 5. Polyphenol content: in accordance with LS / T 6119-2017 “Grain and Oil Inspection-Determination of Polyphenols in Vegetable Oils-Spectrophotometric Method”.

[0027] 6. Acid value and peroxide value: According to GB / T5009.229 "National Food Safety Standard Determination of Acid Value in Food" The acid value of the peanut oil was measured, and the peroxide value of the peanut oil was measured according to GB / T5009.227 "Determination of Peroxide Value in Foods - National Food Safety Standard"; then the peanut oil was put into a ground-mouth brown glass bottle and covered with a bottle stopper; 2 bottles of the peanut oil of each embodiment or comparative example were put into a constant temperature oven at 70° C. and stored for 15 days, and then the acid value and peroxide value were measured.

[0028] Table 1 Basic indicators of peanut oil Table 2 Peanut oil acid value and peroxide value test results The protein powder was prepared according to the methods in the examples and comparative examples, and the properties of the obtained protein powder were tested according to the following method. The results are shown in Table 3.

[0029] 1. Fat content: refer to GB 5009.6.2016 to determine the fat content in protein powder.

[0030] 2. NSI determination: Determine according to Kjeldahl method (GB 5009.5).

[0031] 3. Determination of protein content and solubility: 1) Sample pretreatment: Take the peanut protein powder sample and pass it through a 60-mesh sieve (particle size ≤ 0.25mm) to ensure uniformity; if the oil content of the sample is greater than 5%, it is necessary to use petroleum ether (boiling range 30-60℃) to Soxhlet extraction and defatting for 6 hours, and then dry it at 60℃ for use; 2) Dissolution and centrifugation: Accurately weigh 1.5g of sample in a 250mL beaker, add 75mL of 0.03% KOH solution (pH≈12.5), place it in a 25℃ constant temperature magnetic stirrer and stir for 20 minutes, transfer the solution to a centrifuge tube, centrifuge it at 3000r / min for 10 minutes, and take the supernatant and filter it through a 0.45μm filter membrane; 3) Determination of protein content: Determine the total protein content of the original sample with reference to the Kjeldahl nitrogen method GB 5009.5-2016 "National Food Safety Standard Determination of Protein in Food"; take the supernatant after centrifugation and determine the soluble protein content in the same way; 4) The solubility calculation formula is as follows: Table 3 Protein powder performance test results The above results show that the peanut oil prepared by the process of the present invention has good color and aroma, high oil yield, and the VE content and polyphenol content are significantly increased compared with the traditional process such as comparative example 1; the solubility of its peanut protein powder is significantly improved, and the protein powder extraction rate is increased, which is more suitable for the development of high value-added products such as peanut protein powder, peanut milk, and isolated protein.

[0032] It is explained here that the embodiments of the present invention are only used to illustrate the present invention, rather than to limit the present invention. Therefore, simple improvements to the present invention based on the method of the present invention are all within the scope of protection required by the present invention.

Claims

1. A process for producing peanut oil and peanut protein by infrared temperature pressing, characterized in that: The specific steps include: Step 1 Cleaning and color sorting: The peanut raw materials enter the self-balancing vibrating screen to separate the large stones, shelled peanuts and broken peanuts in the raw materials, and the metal objects in the peanuts are removed by the magnetic separator. Then, the peanuts are transported to the grading and screening machine through the elevator to screen the peanuts with full grains. The color sorter removes the moldy and sprouted peanuts in the raw peanuts; Step 2: Peeling the peanuts: The cleaned and impurity-free peanut kernels are transported to the oven for roasting, and the roasted peanut raw materials are cooled and then air peeled; Step 3: Ozone sterilization: The peeled peanut kernels are transported to an ozone generator for treatment to remove Aspergillus flavus in the raw materials; Step 4: Conditioning of seed material: convey the peanut kernels to a steamer for steam softening, so that the moisture content of the peanut kernels reaches 10% to 15%. After softening, quickly put them into a vacuum freezer for freezing and conditioning at -20 to 0°C; Step 5: Infrared roasting of seeds: The quenched and tempered peanut kernels are transported to a drum-type infrared device for infrared treatment; Step 6: Pressing at appropriate temperature: conveying the infrared heated peanut kernels to a single screw oil press, controlling the inlet temperature to 50-95°C and the rotation speed of the single screw oil press to 20-40r / min, to obtain virgin peanut crude oil and protein cake; Step 7: Cooling and filtering: coarsely filtering the crude peanut oil through a plate-and-frame filter to obtain coarsely filtered peanut oil; rapidly cooling the coarsely filtered peanut oil through an exchanger, adding deionized water to the obtained peanut oil, stirring, standing, and then physically filtering at low temperature to remove impurities to obtain pure peanut oil; Step 8: Crushing and sterilization: The protein cake obtained by squeezing is ultra-finely crushed and microwave sterilized to obtain high-quality protein powder.

2. The production process according to claim 1, characterized in that: In the step 2 of removing the red coating, the baking temperature is controlled at 85-105° C. and the baking time is 40-50 minutes.

3. The production process according to claim 1, characterized in that: In the step 3, the ozone concentration in the ozone sterilization is 80 mg / L, the temperature is controlled at 30-35° C., the stirring speed is 80-100 r / min, and the treatment time is 20-40 min.

4. The production process according to claim 1, characterized in that: In step 4, the vacuum freezer controls the vacuum to 10-20 Pa, and the freezing and tempering time is 20-50 min.

5. The production process according to claim 1, characterized in that: In the step 5, the temperature of the infrared roasted seeds is 110-150°C, the processing time is 20-30min, the infrared physical field parameters are set to a short-wave infrared wavelength range of 0.78-1.4μm, a medium-wave infrared wavelength range of 1.4-4μm, wherein the short-wave: medium-wave infrared power ratio is 1:(1-2), the feed amount is 10-25% of the effective volume of the drum, the infrared processing distance is 15-22cm, and the material thickness is 3-7cm.

6. The production process according to claim 1, characterized in that: In the cooling filtration of step 7, the coarsely filtered peanut oil is quickly cooled to 15-20° C., the amount of deionized water added is 0.5-1% of the weight of the peanut oil, the stirring speed is 50-60 r / min, and the stirring time is 10-30 min.

7. The production process according to claim 1, characterized in that: In step 8, the peanut protein powder is crushed and sterilized into ultrafine powder to 100-200 mesh, and microwave sterilized for 2-3 minutes. The microwave sterilization temperature is 45-55° C. and the microwave frequency is 2300-2600 MHz.

8. Application of the high-quality protein powder prepared by the production process according to any one of claims 1 to 7 in the preparation of food and medicine.

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