First, the identification method of tea oil:
The quality of oil itself contains two meanings:
One is the difference in the internal composition of the oil itself. For example, the higher the unsaturated fatty acid ester content, the better. Unsaturated acid content According to our tracking of oil in various places, it is concluded that the higher the altitude, the higher the relative unsaturated acid content, which is related to the plant growth cycle. For example, pure natural camellia oil (high unsaturated acid) in Meizhou, Guangdong. But it should be noted that the difference is about 2-3%. In fact, for tea oil with more than 9 1% unsaturated acid, the influence and difference are almost negligible.
There is also the difference between quality indicators, which is the quality indicators in the national standards formulated by the state.
Now, according to several main indicators of national testing, make an explanation:
The lower the acid value, the better. High-quality enterprises are controlled within 0. 15, and general enterprises are controlled within 1.0 (it is discharged to grade IV oil abroad). If the oil you buy is rubbed by hand or heated in a pot, it means that the oil quality is poor, and the oil with good quality can't be sour even if it is heated to more than 200 degrees.
Peroxide value: the lower the better, the lower the index means the lower the degree of oxidation.
Color: The national requirements for color are not high, and in the misunderstanding of consumption, everyone thinks that dark color is more authentic, but it is not. Only good raw oil can be processed into colorless cosmetic oil, medical oil and high-grade cool edible tea oil. Generally speaking, dark color is probably processed from crude oil extracted (leached) from cake.
Solvent residue: the solvent is the residue after oil extraction of tea cakes. Undoubtedly, high content of solvent (n-hexane) is harmful to health, so the national regulations are very strict. The requirements of Japan and South Korea are within 1PPM (that is, within 10 ppm). If the oil you buy has a pungent smell after cooking, it is likely that this indicator will exceed the standard. Even if it is marked by extrusion, it may be a forged process. Moreover, this oil is often dark in color, which is a major feature.
Smoke point: The higher the smoke point, the higher the oil quality. Smoke point is the temperature at which the oil smokes during heating, which can be judged when the oil is in the pot, especially when the heating temperature is high.
Precipitated substances: the state has formulated freezing experiments in the standard to control the content of sediments. Most of the precipitated substances are saturated acid oil, impurities, oxidized oil, water and soap (equivalent to household soap). Obviously, these substances are not good for health. When the temperature is low in winter, the more sediment, the worse the oil product, and the less or no sediment, the better the oil product quality. In summer or high temperature season, the clearer and more transparent the oil with good brightness, the better the quality. In factory processing, the cost of oil will increase by about 10% if freezing is used to reach 0 degree without precipitation and removal of precipitated substances.
Second, the classification of pure natural tea oil:
Various grades of camellia oil can be obtained from camellia oil fruits. According to the new standard formulated in May 2003 and implemented on 10/2003, all the outer packages of camellia oil must be clearly marked with their grades.
(1) Extra virgin camellia oil (the best camellia oil, national standard grade I)
The juice obtained from the first pressed camellia fruit is fruity and fruity, and the acidity of the oil is lower than 1%.
(2) Pure camellia oil (pure camellia oil, national standard grade II)
It is made by removing impurities, deacidifying, dehydrating, decoloring, deodorizing and freezing and degreasing from mechanically pressed camellia oil.
(3) Apple pomace camellia oil (super camellia oil, pharmaceutical injection grade)
It is made by squeezing camellia fruits collected from the deep mountains of virgin forests. According to the technical standards of pharmaceutical production, the purest oil (colorless, odorless, smokeless, close to zero acid value and zero peroxide value) is obtained through physical purification. Oil for medical injection and oil for cosmetics.