Peanut oil extraction production line
The peanut oil in the peanut oil extraction production line is a non-dry vegetable oil (the iodine value is generally between 80 and 107). The specially processed peanut oil has an attractive and rich fragrance and is a kind of edible oil with high market value. Because it contains a higher proportion of unsaturated fatty acids (monounsaturated fatty acids account for 49%, polyunsaturated fatty acids account for 30%), especially the human essential fatty acid-arachidonic acid makes it have a higher nutritional value. In addition, peanut oil also has a lighter color, lower phospholipid content, higher smoke point and has better sensory indicators and cooking performance.
Peanut kernels have high oil content, and there are three main oil-making processes: traditional pre-extracted leaching process, concentrated aromatic peanut oil process, cold-pressed peanut oil and peanut protein powder process. Considering that fragrant peanut oil is the main product in the peanut oil product consumer market, the market demand has great potential. At present, the oil production process mainly uses the fragrant peanut oil process, that is, the use of fried seed peanut kernels and hot air roasting: the total amount of 15%~20% peanuts The petals are sent to the hot air roaster, where the oil is heated to 180℃~200℃. The roasting temperature is the key factor for the aroma of peanut oil with strong aroma. The temperature is too low, the aroma is light; the temperature is too high, the oil is easy to gelatinize.
Cooling and rolling grits of peanut oil extraction production line: To prevent the oil from gelatinizing and spontaneous combustion, heat should be radiated and cooled quickly after roasting. After cooling, it will be rolled into a granular shape with a tooth roller crusher.
1. Steaming and frying of peanut oil extraction production line: vertical steaming and frying pan is used to steam and fry the green body. 1st ~ 2nd layer must be full, play the role of steaming; 3rd ~ 5 [or 6, 7] layer should be shallow, play the role of removing moisture; discharge temperature 108 ℃ ~ 112 ℃, moisture 5 %～7. In order to ensure the rich aroma of peanut oil, the indirect steam pressure of the steaming boiler should not be less than 0.6M.
2. Pressing of peanut oil extraction production line: Taking into account the particularity of the production process of peanut oil, the spindle speed of the oil press is appropriately adjusted, and the thickness of the thick cake is appropriately placed. The pressing temperature is 135℃, the pressing moisture is 1.5% to 2%, and the residual oil of the machine pressed cake is 9% to 10%.
The resulting crude oil is precipitated, filtered with a vertical blade filter, and then sent to the refining workshop. The crushed cake is sent to the leaching workshop for secondary leaching after crushing. The leached crude oil is refined and sold separately as ordinary oil.
3. Process flow of crude oil refining process
Filtration of crude oil – cooling – adding filter aid – secondary cooling – precipitation for 48h – filtration – product oil – filter cake
4. Process description
4.1 One-time cooling: the temperature of the filtered crude oil sent from the machine press workshop is generally between 60℃ and 70℃. In order to save energy, the tap water (cooling water) is first used to cool the heat under low-speed stirring, and the temperature drops to near room temperature.
4.2 Adding filter aid: The purpose of adding filter aid is to improve the final filtration effect, accelerate the formation of filter cake, and reduce the content of phospholipids and peptizer soluble impurities in the finished oil; filter aids and types include activated carbon and solid peanut cake powder; The amount is about 0.1% of the oil weight.
4.3 Secondary cooling: Peanut oil was cooled to 10°C to 15°C with frozen brine under low speed stirring, and then kept warm and settled for 48 hours.
4.4 Filtration: Pump the crude oil after 48 hours of sedimentation into the plate and frame filter press for filtration. The filter oil obtained before the filter cake is formed is relatively turbid, and should be filtered again after the filter cake is formed, and the finished oil obtained after the filter can be packaged.
4.5 Treatment of filter cake: The filter cake obtained in the machine press workshop can be back pressed; the filter cake obtained in the refining workshop can be added to the meal.
5. Analysis of the factors affecting the aroma of peanut oil
The main factors that affect the fragrance of agricultural peanut oil are the following:
5.1 Influence of peanut raw materials
The oil for the production of rich-flavored peanut oil requires full grains without aging. Immature grains, damaged grains, mildewed grains and aged grains cannot be used to produce strong aromatic peanut oil. The immature grains and aged grains produce oils with higher acid value and poor flavor, while the mildewed grains and damaged grains are easily contaminated with aflatoxin. Therefore, in the production process, these oils must be separated for the processing of ordinary secondary oil alone.
5.2 The influence of the ratio of road to road
Raw materials (big road) and hot air baking materials (small road) are generally mastered at 4:1. The proportion of baking ingredients is too small, and the aroma of peanut oil is light; the proportion is too large, the cake is difficult to form during oil extraction, the oil yield is reduced, and the crude oil is turbid, which makes it difficult to handle the subsequent processes.
5.3 Effect of baking temperature
Hot air roasting is a key process for producing rich-flavor peanut oil. The aroma of peanut oil is directly related to the roasting temperature. The temperature is too low, the fragrance is light; the temperature is too high, the oil is easy to burn. Generally control the roasting temperature 180℃～200℃. In order to prevent the oil from gelatinizing and spontaneous combustion, it should be cooled and cooled immediately after baking.
5.4 The impact of steaming
Steaming and roasting the green body is another important step in the production of strong aromatic peanut oil. Luminous peanut oil has a direct relationship with the level of oil yield, flavor and color, phospholipids and pectin-soluble components. To adopt high-moisture steam billet technology, adjust the moisture of the oil material in the steaming wok to 12% to 13%; as long as the equipment withstands pressure, try to increase the pressure of indirect water vapor, generally controlled at 0.6MPa to 1MPa; Enterprises with good conditions are better to use superheated steam. In the process of steaming and frying, it is necessary to make the phospholipids and peptizers fully absorb water, coagulate and combine with proteins. This is the key to ensuring that the product oil passes the 280℃ heating test and improves the transparency of the product oil.
The peanut oil extraction production line clearly stipulates the 280°C heating test of the Luzhou-flavored peanut oil, which requires that the oil color of the 280°C heating test should not be darkened, and no precipitates. The key to solving this technical problem is the use of high-moisture steaming process, reasonable control of freezing temperature, precipitation time and the use of filter aids.
The peanut oil extraction production line also has a cold-pressed peanut processing method and a pre-pressed peanut leaching oil-making method.