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Note: This article was AI-translated from Arabic and is currently under manual review. The author is not responsible for any translation errors. Please refer to the original Arabic text for the most accurate and authoritative information.
Are you throwing away oil when you discard olive pits?
Inside the hard, woody shell of the olive pit hides a small seed that contains oil; and that is where the story begins. You eat the olive, push its pit aside on the table, and the story ends. A small, hard piece that has played its part and no longer has a place on your plate. But what looks like a sealed stone hides a seed inside it, and that seed stores oil. Have we just thrown away a raw material that deserves a second look?
Thus begins the story of “olive pit oil”: an oil few people know, and questions that go beyond its unusual name. Where exactly is it found? How is it extracted? Is it similar to the olive oil we know? And most importantly, what does science say about its value, away from the promises that turn every agricultural by-product into a “treasure” ready for sale?
To answer, we first need to open the pit scientifically and see what lies behind this name.
When we say “olive pit”, we usually mean the hard body we separate from the pulp. But the picture from the inside is more detailed: a woody shell that protects a seed, and a seed that contains an embryo and storage tissues. The oil we are discussing here belongs to the seed inside the shell, which is why its more accurate name is “olive seed oil”.
The woody shell is known botanically as the inner layer of the fruit wall, or endocarp. It is surrounded on the outside by the pulp and skin tissues. Distinguishing between these parts prevents a basic mistake: attributing the composition of the seed inside to the whole stone.
This also deserves attention when reading English-language studies. The terms olive stone and olive pit are usually used for the stone, while olive seed refers to the seed. The word kernel can carry different meanings, so it is important to know what the researchers separated and what they ground before comparing figures. [1, 3, 4]
The seed carries the beginning of a new plant, and that beginning needs provisions. In the early stages of germination, growth depends on stored materials until the seedling develops the ability to produce its own food through photosynthesis. Oil contributes energy and carbon, while proteins and other components play roles in tissue growth.
In this sense, the stone protects a store for the life to come. This fact explains why there is oil inside, but it does not automatically give it therapeutic benefits for humans. Understanding the oil’s function in the seed is one step towards understanding it; evaluating it nutritionally involves other questions and tests.
The names are similar because they come from the same tree, but it is the material fed into the extraction machine that opens the door to telling them apart. There are fruits that are pressed, seeds that are separated, and pomace left over after the oil is extracted. Confusing them can mislead both the reader and the consumer.
| Product | Where it comes from | How it is obtained |
|---|---|---|
| Olive seed oil | Seeds separated from inside the stone | By pressing or extraction, depending on the process |
| Virgin olive oil | Olive fruits, which may be pressed with their pits | By mechanical or physical means under specified conditions |
| Olive pomace oil | Pomace left after the oil is extracted from the fruits | With solvents or other physical treatments, then processed according to category |
To correct a common idea: most of the fruit’s oil is in the pulp, but virgin oil does not have to be extracted from pitted pulp; the fruits may be pressed with their pits. Likewise, “extra virgin” is a category with requirements for purity, quality and sensory characteristics, and it is not granted to an oil simply because it comes from olives or is extracted by pressing. [2]
Oil from separated seeds, on the other hand, needs characterisation, analysis and a regulatory assessment suited to the product and the country where it is marketed. The common name alone does not settle its commercial category.
In a study published by Maestri and colleagues in 2019, fat in the seeds reached about 30.4% of their dry weight, alongside 17.2% protein and 47.6% total dietary fibre. These are results for the seeds studied, not a fixed recipe for every variety or every pit. [1]
The two most important words here are “dry seeds”. Calculating the percentage in a seed separated from its wood differs from calculating it in a whole pit, and calculating it after excluding water differs from calculating it in moist material. Then comes a third step: the oil theoretically present does not necessarily equal the oil a press recovers.
Let us put this in a hypothetical worked example: if 100 kilograms of dry seeds contain 30% oil, their theoretical content is 30 kilograms. If a hypothetical process recovers 80% of it, the output becomes 24 kilograms. This is a way to understand the calculation, not a promise of plant yield.
As for the question “how much oil does a tonne of pits give us?”, the previous calculation alone does not answer it. We first need the weight of the seeds that can be separated from that tonne, then the processing losses and the extraction efficiency. In these details, the whole profit estimate may change.
Oleic acid leads the picture in the results of the 2019 study, followed by linoleic acid, with saturated fatty acids and minor components also present. The following table brings together the main approximate values the study recorded in the oil. [1]
| Component | Approximate value | Basis of measurement |
|---|---|---|
| Oleic acid | 61.83% | Of total fatty acids |
| Linoleic acid | 24.24% | Of total fatty acids |
| Saturated fatty acids | 12.34% | Of total fatty acids |
| Total tocopherols | About 459 mg/kg | Per kilogram of oil |
| Squalene | About 194 mg/kg | Per kilogram of oil |
Phytosterols and triterpenic compounds were also detected. However, the seed’s protein and fibre do not carry over to the oil’s label as nutritional components of it; the composition of the raw material differs from that of the extracted fat fraction. [1]
We should not be misled by how clear the figures look. In a 2012 study of six varieties, Moghaddam and colleagues recorded tocopherols in kernel oils of about 15 to 38.8 mg/kg. This variation calls for checking the variety, sample definition, preparation and analysis before turning a research figure into a claim on a bottle. [3]
The journey starts before the first drop comes out: defining the raw material, separating the target part, and controlling moisture, storage and particle size. Then the extraction technique is chosen. What works for characterising a sample in the laboratory does not automatically become an economic production line or an approved food process.
A 2022 study used mechanical pressing to extract oil from the material it described as olive seeds. This route makes it possible to evaluate production without organic solvents, but the output, recovery efficiency and temperature need to be measured. Even the word “pressed” does not always mean “cold-pressed”; the sample temperature in the study’s trial reached about 60°C. [4]
The 2012 study comparing pulp and kernel oils used hexane to extract the oil. A solvent can help recover and analyse the fat, but food application requires a permitted solvent, safe process management and verification of residues. This is where the difference appears between a research method for extracting a sample and a product fit for consumption. [3]
The 2022 study also tested extraction with supercritical carbon dioxide, which works under controlled pressure and temperature to extract components from the raw material and then separate them. But choosing a technique requires accounting for equipment, energy, throughput and oil quality. A novel-sounding name does not settle the outcome, and which option is better may differ depending on the indicator being measured. [4]
The same applies to assisting technologies: a study on ultrasound-assisted extraction of phenolics does not by itself prove an increase in oil extraction, and a result that concerns pomace does not automatically transfer to the separated seed.
Here lies one of the most important surprises: the seed may contain compounds that do not all transfer to its oil. Some phenolics favour polar media over the fat fraction. The 2019 study recorded far lower phenolics in the oil than in the seeds, with limited oxidative stability in its accelerated test. [1]
The 2022 study also found that the pressed oil was more stable than the oil extracted with supercritical carbon dioxide under its trial conditions. The result applies to those samples, but it reminds us that advanced technology does not guarantee superiority in every attribute. [4]
So the phrase “contains vitamin E” is not enough to determine shelf life. That decision requires tests on the finished oil, its packaging and its storage conditions, while limiting its exposure to heat, light and air. Hours in an accelerated oxidation test do not translate directly into a fixed number of months in storage.
The answer starts with analysis, not with the oil’s name. The crude oil may need processing, and its stages are determined by its composition, its quality and its intended purpose.
In the oils industry in general, processing may include degumming, reducing free fatty acids, bleaching with adsorbents, filtration and deodorisation. Bleaching here is an industrial term and does not mean adding household bleach. Nor does every crude oil have to go through all of these stages.
The practical criterion is the effect of processing on quality, safety and the desirable components, not merely an improvement in colour and odour. Refining is no substitute for qualifying the raw material, and it does not on its own settle the product’s regulatory classification. [7]
The next step may seem obvious: a vegetable oil containing well-known fatty acids, so why not use it in the kitchen? But between knowing the composition and recommending consumption lies a distance that must be covered with testing and assessment.
A food product needs its regulatory status determined in the country of sale, a safety assessment, controlled production, verification of quality, contaminants and solvent residues where solvents are used, and a clear label. Assessment indicators include acidity or acid value in its correct units, peroxide value, and indicators of oxidation, moisture, impurities and stability. The appropriate tests and limits are chosen without automatically copying another oil’s standard. [7]
Frying, for its part, requires data on heat tolerance and the formation of degradation products under the conditions of use. The oleic acid content is not enough to determine its suitability, and the references here do not allow declaring a general smoke point for it or describing it as an ideal frying oil.
The chemical composition gives researchers reasons to study the oil, but it does not give the consumer a therapeutic promise. The references cited are not enough to prove that this oil treats a disease, lowers cholesterol in humans, or is healthier than extra virgin olive oil.
It is important to know what was actually tested. Research in 2022 studied phenolic extracts from the seeds of three varieties and ran laboratory and cell-based tests. These are results on specific extracts, not a clinical trial of consuming seed oil. [5]
Likewise, the presence of a known compound does not prove that the oil treats hair loss or eczema or delays ageing. Any cosmetic use requires evaluating the final formulation, its stability and safety, and evidence that fits the claim. Scientific interest in a product does not require us to get ahead of it with a promise research has not proven.
Before the word “better”, we need another question: better for what purpose? Stability during storage differs from suitability for frying, and sensory characteristics differ from recovery efficiency or economic value.
The references here do not support a general verdict of superiority. Nor is comparing a single fatty acid or vitamin enough to judge two complete products. A useful comparison starts with characterised samples, analyses and a defined use, not with the similarity of two names.
The clearest value of seed oil may lie in making use of an additional resource within the olive industry, while proving the product’s quality and feasibility, without needing to declare it the winner over an oil that consumers know and whose categories they trust.
Even after the seed is separated, the woody shell still raises the question of how to use it. This lignocellulosic material opens routes different from oil extraction, including energy applications and carbon materials.
In an experimental study in 2023, olive pit waste was converted by pyrolysis into a solid carbon material, liquids and gases, and their distribution was affected by operating conditions. Here we must pause at the word “oil” once again: the pyrolysis liquid that may be called “bio-oil” is chemically different from seed oil and is not treated as an edible oil. [6]
A 2024 study also tested activated carbon prepared from olive pits for adsorbing pollutants from water. But ordinary charcoal, biochar and activated carbon are not interchangeable names; each has its own properties, preparation and purpose, and a charred pit does not become a material suitable for water treatment or for soil simply because it has been charred. [8]
As for using pit powder or extraction meal as feed, this requires an assessment specific to the material, the processing, the animal and the ration. Proximate analysis alone does not make a ready-to-use feed.
Oil content is the start of the calculation. After it come the costs of separating, drying, transporting and storing the seeds, the amount of oil recovered, its quality, the processing it needs, and the market that will buy it.
Alternative uses must also be accounted for; pits may already have value in energy or elsewhere and are not necessarily a free raw material. Combining oil with other products may help, but the success of the route requires a mass and energy balance and an economic assessment based on operating data.
Sustainability, in turn, must be measured. Using an agricultural by-product does not automatically prove a lower environmental impact if recovering it consumes a lot of energy, water or materials. Comparing routes reveals where the benefit is actually achieved, and where extracting value consumes resources that exceed its return.
The next time you push an olive pit aside on your plate, you will know that behind its hardness lies a seed carrying oil. A small piece of information that is enough to change how we see what is left of the fruit, and that opens questions worth working on for researchers and manufacturers.
The road from pit to product, however, passes through careful separation, reliable analysis, safety testing and clear economic accounting. The oil may find its place on this road, or a greater value may be proven for another route. Good research gives us the ability to choose.
The drop hidden inside the stone deserves to be looked for; its real value appears when we know how to extract it, what it is good for, and at what cost. Only then does an attractive story turn into useful knowledge and an industry worth starting.
[1] Maestri D et al. Nutritional profile and nutraceutical components of olive (Olea europaea L.) seeds. Journal of Food Science and Technology. 2019;56:4359–4370. DOI: 10.1007/s13197-019-03904-5.
https://doi.org/10.1007/s13197-019-03904-5
[2] International Olive Council. Trade Standard Applying to Olive Oils and Olive Pomace Oils. COI/T.15/NC No. 3/Rev. 22. June 2026. Sections on definitions, purity and quality.
https://www.internationaloliveoil.org/wp-content/uploads/2026/09/TRADE-STANDARD-REV-22_EN.pdf
[3] Moghaddam G et al. Characterization of different olive pulp and kernel oils. Journal of Food Composition and Analysis. 2012;28(1):54–60. DOI: 10.1016/j.jfca.2012.06.008.
https://doi.org/10.1016/j.jfca.2012.06.008
[4] Kongi Mosibo O et al. Oxidizability of Oils Recovered from Olive Seeds by Isothermal Calorimetry. Foods. 2022;11(7):1016. DOI: 10.3390/foods11071016.
https://doi.org/10.3390/foods11071016
[5] Gouvinhas I et al. Seed Phytochemical Profiling of Three Olive Cultivars, Antioxidant Capacity, Enzymatic Inhibition, and Effects on Human Neuroblastoma Cells (SH-SY5Y). Molecules. 2022;27(16):5057. DOI: 10.3390/molecules27165057.
https://doi.org/10.3390/molecules27165057
[6] Ebrahim Atakoohi S et al. Investigating the Effect of Operational Variables on the Yield, Characterization, and Properties of End-of-Life Olive Stone Biomass Pyrolysis Products. Molecules. 2023;28(18):6516. DOI: 10.3390/molecules28186516.
https://doi.org/10.3390/molecules28186516
[7] Codex Alimentarius. Standard for Edible Fats and Oils not Covered by Individual Standards. CXS 19-1981. With reference to the specific standard and the applicable legislation where they apply. The official standards index provides the updated text.
https://www.fao.org/fao-who-codexalimentarius/codex-texts/all-standards/en/
[8] Ozcan DO et al. Enhancing the adsorption capacity of organic and inorganic pollutants onto impregnated olive stone derived activated carbon. Heliyon. 2024;10(12):e32792. DOI: 10.1016/j.heliyon.2024.e32792.
