Peanut kernels are extracted by pressing method, which helps to maintain the inherent flavor and aroma of peanut oil. The pressing method can be divided into ordinary peanut oil preparation process and aromatic peanut oil preparation process. After pressing, the peanut cake can be further extracted with a solvent extraction method to remove most of the remaining fat.
1. Pre-pressing of peanut kernels-oil extraction process by extraction method
a. Process flow: Pre-pressing of peanut kernels-making oil by leaching method
b. Operating points: After being crushed by a double-pair roller crusher, each peanut kernel becomes 6-8 pieces of kernel material, and the powder degree is less than 8% (20 mesh/square inch sieve inspection). Crumbs are rolled into an embryo with a thickness of about 0.5 mm. The raw embryo becomes a cooked embryo after being processed in a frying pan. When it enters the oil press, the water content is 1%-2%, and the temperature is around 130 degrees. If the cake cannot bear the force during pressing and cannot be pressed into a hard cake, a small amount of peanut shells can be mixed into the cooked embryo to form a cake.
The pressed peanut cake can be further subjected to solvent extraction, and 5-6 kg of peanut oil can be extracted per 100 kg of dry cake.
2. The preparation process of fragrant peanut oil
Operational points: The production of fragrant peanut oil by one-time pressing method requires the use of high-quality newly harvested peanuts to peel the kernels, and the removal of impurities must be clean and thorough. The fragrant peanut oil is usually not refined and processed, but directly used as edible oil after removing solid impurities. If the fragrant peanut oil obtained is of poor quality, it should be refined, but the aroma of the refined oil will be greatly reduced at this time
Refining process of peanut oil
For pressed peanut oil obtained from high-quality peanut kernels, the refining process should be minimized to retain the original flavor of peanut oil. The crude peanut oil obtained by solvent leaching of peanut cake should be fully refined. The process of refining the leached peanut crude oil into ordinary peanut oil is the same as that of ordinary soybean oil. The processing of fragrant peanut oil is as described above, only need to settle the filter press oil and cold filter.
Key production and characteristics of refined oil
When peanut oil is at 0-3 degrees, solid fat will solidify and precipitate. To produce peanut salad oil, the solid fat must be removed by winterization, which is the key to the production of peanut salad oil. According to observations, the peanut oil produced from peanut kernels harvested after fully mature has a lighter color. Peanut oil is a good raw material for preparing edible oil and deep-processed products.
The refined peanut oil has a high smoke point (229.4°C) and is suitable for high-temperature frying oil.
What is fragrant peanut oil?
Luzhou fragrant peanut oil is a peanut oil with a strong fragrance made by a unique pressing process. It maintains the original composition and fragrance of peanut oil, does not need to add antioxidants, and has a long shelf life. It is a pure original oil produced by combining modern and traditional techniques.
The cotyledon and germ of peanut contain high protein, reducing sugar, pentose, sucrose, etc. During the heating process of fried embryo, it can produce Maillard reaction, that is, it can generate flavor substances. The flavor components produced by roasting peanut kernels have been identified in 17 categories and 220 species. Among them, the high-concentration compounds are pyridine compounds, which play a major role in improving the aroma of peanut oil.
The production of aromatic peanut oil requires strict selection of raw materials (peanuts). The relevant indicators must be higher than the national standard for first-grade peanut oil and must not contain aflatoxin. Secondly, the production process is also different from ordinary peanut oil. The general peanut oil is allowed to undergo physical and chemical treatments such as hydration, alkali refining, drying, and deodorization during the refining process. In the refining process, Luzhou-flavored peanut oil does not need to undergo the above-mentioned physical and chemical treatments. Instead, it adopts a unique high-temperature short-fried aroma, one-time pressing, low-temperature dephosphorization and aroma retention technology. It does not use any additives. It can separate phospholipid colloids and at the same time. Reduce fragrance loss. This gives the peanut oil a unique rich fragrance.