Olive oil extraction and refining production line, extra virgin olive oil production line
The production process and equipment for olive oil are relatively simple. The traditional method is to first crush the mature and cleaned locust fruit on a stone mill, then pack it in a clean specialized straw bag and place it on an extruder to squeeze out the oil. After filtration, precipitation, and bottling, it can become finished oil. Modern oil production technology uses high-speed centrifuges to quickly separate oil and slag, effectively improving oil yield and oil quality.
1. Modern oil production process.
Fresh fruit collection → transportation and storage → cleaning of branches and leaves → grinding → fusion → centrifugal tilting → centrifugal separation → storage → bottling.
2 Technical features.
Fresh fruit collection. Due to different varieties, the best collection period is from November to February of the following year. When collecting fruits, direct contact between the fruits and the ground should be avoided. Green fruits have low oil content but high polyphenol compounds, while black fruits have high oil content but low antioxidant content. Therefore, in order to ensure the quality and oil yield of the oil, the optimal ratio of green fruits to black fruits is 75:25, and in actual production, the ratio is controlled at around 50:50.
2.1 Transportation and Storage. The collected fresh fruits should be placed in small baskets, stacked, transported to the processing plant, and laid flat in a ventilated storage room to avoid overpressure, overheating, and damage to the fruits, otherwise they are prone to oxidation and fermentation. But in actual transportation, fruit is stored in burlap bags, so the storage time does not exceed 1-2 days.
2.2 Remove branches and leaves. Using belt conveyor and air selection, the branches and leaves are separated from the fruits by a fan. It is required that there are no leaves in the fruit, as leaves contain a high amount of chlorophyll. During the crushing and fusion process, chlorophyll is prone to oxidation due to high temperature, which affects the quality of the oil. Therefore, the power of the fan is relatively high.
2.3 Cleaning. The purpose is to remove dust and a small amount of leaves. Cleaning requires a certain amount of water, which will generate wastewater. To reduce the amount of wastewater, circulating water cleaning is used, with a controlled amount of 2 tons of water to clean 5 tons of fruits.
2.4 Grinding. The use of a hammer crusher for crushing depends on the size of the sieve holes and the pounding speed. The optimal sieve hole diameter is 6mm and the best pounding speed is 2500-3000r/min. The oil has good results in terms of acidity, peroxide UV value, total phenols, and sterols.
2.5 Fusion. The broken fruit pulp is transferred to the fusion pool and mixed uniformly through the movement of the spiral rod, which is beneficial for heat dissipation; On the other hand, it is beneficial for the formation of oil droplets and avoids emulsification. The key is to control the temperature and mixing time. The optimal time is 30 minutes, and the temperature should be below 40 ℃. The cooling method is to use interlayer water flow.
2.6 Centrifugal centrifugation. Currently, three-phase centrifugation is mostly used, with a few using two-phase centrifugation. Three phase centrifugation requires the addition of 40% to 50% water, of which fruit residue accounts for about 45%, with a residual oil rate of 4% to 6% and an oil yield of about 25%. Two phase centrifugation does not require the addition of water, with fruit residue accounting for about 75%, a moisture content of 60% to 65%, and an oil yield of about 25%. The centrifuge speed is 3000r/min.
2.7 Storage. The oil separated by centrifugation should be stored in a large stainless steel storage tank to avoid light and heat, and nitrogen can be added for protection if necessary.
2.8 Bottling. The oil in the storage tank is periodically drained with a small amount of water and oil residue, and then divided into small bottles.
