29 Oct The process and the quality difference between cold and hot olive pressing
The process and the quality difference between cold and hot olive pressing
Olive oil is the oil extracted from the olive fruit. It is extracted with the use of an olive press equipped with special compressors, either by the method of hot or cold processing (Balatsouras, 1997). The nutritional value of olive oil is largely determined by the content of antioxidants, especially vitamin E and polyphenols, both substances that decompose easily at high temperatures, such as 40 degrees Celsius and above
Such temperatures develop during hot pressing and compression in order to separate the oil from the pulp. The cold pressing process protects the quality of the olive oil produced, at the cost, however, of high production costs.
Whether you use olive oil, sunflower oil, coconut oil or any kind of cooking oil, they are all produced in one of two ways. If you are unfamiliar with olive oil, you may not be able to tell the difference when cooking or tasting food, but the two different methods of squeezing olives end up being about two completely different end products. In today’s article we analyze the difference between cold and hot pressure.
Method of preparation
The first difference lies in the way they are made. In cold pressing, the oil is extracted at room temperature, at about 27 degrees Celsius, and the degree of acidity is low, so the product is obtained after precipitation and filtration. This means that no intervention is needed to improve it. Our olive oil is produced exclusively by cold pressing, maintaining its rich taste, aroma and color. In addition, its acidity remains low while its important antioxidants such as vitamin E and polyphenols are not altered (Satriana et al, 2019).
In hot pressing, the oil is extracted at high temperatures and because the degree of acidity increases significantly, the oil loses a fairly large part of its natural quality. Therefore, in this case there is a “refinement” of the olive oil produced, in order to be ready for consumption (Haji‐Moradkhani, 2019).
The oil that is a product of cold pressing, as we mentioned, retains most of its natural physiological and chemical properties and most importantly, its original taste. In contrast, oil extracted by the hot pressing method retains a small amount of its natural composition due to the conditions created by that method. High temperatures not only change the chemical structure of the oil, but many important substances such as vitamin E, sterols and carotenoids are lost in the process. However, there is also a positive side of the hot pressing method, the nice aroma of the oil, especially when extracted from the seeds of plants with a high fat content, such as sesame.
Performance and cooking process
The yield for cold pressed oils averages 35% of the total weight of the olive pulp, while the hot pressed oils yield 37% of the total olive pulp. During the cooking process, the cold pressed oils do not swell or muddy, unlike the hot pressed oil which undergoes these changes (Ling et al., 2016).
In conclusion, based on all the above, we can safely say that the oil that is a product of cold pressing, is the winner. Hot pressed oils are oxidized and have lost healthy compounds, which can lead to health complications, unlike cold oils where all the beneficial compounds are retained. Another important factor that makes the first type of production the winner is that these oils are not interfered with for the sake of their refinement, in contrast to the hot-pressed oils that are refined to improve their taste and acid content.
It should be noted that high production costs are the main reason why cold press is not chosen by the majority of producers, resulting in the production of lower quality olive oil and the dominance of products with reduced nutritional value. Only traditional methods of crushing fruits with stone, or modern methods of cold pressing, produce unheated olive oil, in order to ensure the preservation of the nutrients that are considered the basis for good health.
The Mavroudi family is guided by the production of a high level of olive oil, which is characterized by an intense aroma, golden green color, discreet taste and minimal acidity. Analyzing their composition, one finds a plethora of nutrients in our products, and the importance of this miracle of nature, the olive fruit.
View more about Mavroudis Olive OIl
Haji‐Moradkhani, A., Rezaei, R., & Moghimi, M. (2019). Optimization of pulsed electric field‐assisted oil extraction from cannabis seeds. Journal of Food Process Engineering, 42(4), e13028.
Ling, B., Yang, X., Li, R., & Wang, S. (2016). Physicochemical properties, volatile compounds, and oxidative stability of cold pressed kernel oils from raw and roasted pistachio (Pistacia vera L. Var Kerman). European Journal of Lipid Science and Technology, 118(9), 1368-1379.
Satriana, S., Supardan, M. D., Arpi, N., & Wan Mustapha, W. A. (2019). Development of methods used in the extraction of avocado oil. European Journal of Lipid Science and Technology, 121(1), 1800210.