BACKGROUND
The concept of olive oil yield is understood as its total oil content, expressed in weight percentage units. It is well known that in any industrial process, the optimization yield never reaches 100%, and an oil extraction process in an olive mill is no exception. In this regard, we must also mention the concept of industrial yield, understood as the amount of oil extracted per kilogram of olive.
Industrial yield is easy to determine by taking a winery survey at any time during the campaign:
This variable is only accurate at the end of the process, but there are formulas that allow for very approximate and valid estimates to be made, allowing for price negotiation in advance as the olive is delivered by a producer, applying a correction index to the total oil yield.
Theoretical Industrial Yield = Total Fat Yield – Correction Index
LIPOGENESIS OF THE OLIVE
Lipogenesis refers to a biological process by which fat is synthesized and stored within cells. In the case of olives, this occurs during their development and ripening on the tree. These fat cells are also known as adipocytes. They are responsible for storing lipids within the fruit, something that directly influences its oil content. This process takes place over several months, and throughout this time, the olive changes both its composition and color. Although the dates are not exact, as it depends on both the weather and the geographical area, this lipogenesis usually begins in June. This is when lipids begin to form within the pulp, and the fruit changes color to a deeper green. It is in summer that this lipogenesis accelerates, producing more oil, until September, when veraison begins.
Lipogenesis is understood as the biological process by which fat is generated and stored within cells, these fat cells being known as adipocytes, with lipid storage that directly influences the oil content in the fruit pulp.
In reference to this process, we will mention that when the olive changes its hue from green to yellowish hues, its ripening phase begins. Although fat is still produced at this point, the rate slows significantly. Depending on the climate and environmental conditions of the area, the end of November is approximately the end of olives' ripening process. It is recommended that olive oil production be harvested early, just when the veraison begins and the green hues are still present, since these olives have not undergone oxidative reactions, thus preserving their highest levels of polyphenols. The disadvantage is that these fruits will have less pulp and lower yields.
Authors suggest that in order to find a balance between quality and productivity, it is necessary to look for the optimal harvesting time and rely on bioactive compounds for this purpose.
VARIABLES INFLUENCING FAT PERFORMANCE
Weather conditions
To optimize olive cultivation in terms of oil yield, areas with high temperatures and high radiation are recommended, rather than cold or shady areas. Furthermore, specific weather conditions can influence this, such as the date of flowering, delayed by spring rains, or decreases in photosynthetic activity resulting from winters with milder average temperatures or temperatures that exceed normal temperatures.
Loading the olive tree
Olive groves are alternate-bearing crops, meaning they alternate between high and low yields every two years, so if they have a significant crop load, the nutritional resources must be distributed among all the fruit that has set.
Variety of olive tree
The variety of olive trees in a plantation influences the olive yield. Thus, there are some varieties that have a very high yield, even exceeding 20% of the oil per olive. Some examples are picual variety (variety of olive trees of Vallejo Oils), cornicabra, weevil or arbequina.
Olive tree care
Olive tree care directly influences olive yield. For example, olive tree pruning is done to promote good light for the branches and thus increase yield; if an olive tree is subjected to water stress, it reduces water consumption and, therefore, produces olives with lower yields; and pests and diseases weaken the olive tree, reducing its harvest and olive yield.
CARE AND APPLICATIONS FOR INCREASING OLEIC ACID IN OLIVES
Oleic acid is the most representative naturally occurring fatty acid in olive oil and is directly correlated with fat yield. In this regard, numerous studies corroborate that the use of oleic acid boron and calcium by foliar application can increase the oleic acid content in the applied olives, Also supported by applications followed by autumn applications with bioactive biostimulants. During the filling process, the use of algae-based biostimulants improves the plant's nutritional status, serving as a source of essential nutrients such as nitrogen, calcium, and potassium, which are directly involved in olive ripening and the final oil yield. Furthermore, these types of formulations provide essential amino acids, which are part of the enzymes involved in lipogenesis (oil formation).. See parallel information Fruiting, production and ripening of the olive, where the vital importance of managing water stress is also specified through highly antioxidant active ingredients for the elimination of reactive oxygen species (ROS), promoting the generation of photoassimilates and vascular flow in the olive tree and increasing resistance to this type of stress.
CULTIFORT RECOMMENDATIONS
Algae emulsion that promotes cell division, with easily assimilated active ingredients such as phytohormones and growth regulators (cytokinins, auxins, gibberellins, betaines, abscisic acid and brassinosteroids), matrix and reserve polysaccharides (alginates, carrageenans, agar, ulvans, mucopolysaccharides and their oligosaccharides, fucoidan, laminaran, starch and fluroid), oligosaccharides, biotoxins and antioxidant compounds (polyphenols, bromophenols, flavonoids, fluoroglucinol polymers, gallic esters, coumarins, flavonones, fluorotannins, oligomeric protoanthocyanidins, polyhalogenated diterpenes and monoterpenes, halogenated ketones and isoprenoid compounds) , chlorophylls and carotenes, xanthophylls, minerals (iron, calcium, magnesium, phosphorus, iodine, nitrogen, potassium, barium, boron, cobalt, copper, magnesium, manganese, molybdenum, nickel and zinc), organic matter, mannitol, vitamins, amino acids and proteins, alginic, fulvic and other organic acids (palmitic, butyric, oleic, linoleic), enzymes, sterol and fucosterol.
This rich composition of algae is responsible for the beneficial effects its application has on the fat content of olive pulp.