Citrus 101: The Different Types and Extracting Methods

Citrus plays a vital role in numerous aspects of food, flavoring, fragrance, and well-being. In this article, we will discuss the various types of citrus oils, their characteristics and history, as well as different methods of extraction.

The Different Citrus Oils

Bergamot Oil

Scent Profile: Citrusy and fruity with a warm, spicy, floral quality

Origin: While bergamot is native to Asia, today it is almost exclusively cultivated in Southern Italy

Cultivation: The peel of the fruit is cold-pressed to extract the oil

History: The name bergamot is thought to be derived from the town of Bergamo in Lombardy, Italy, where the oil was first sold. While the fruit itself is not edible, bergamot oil has been used extensively in the flavor and fragrance industry. It was even a component in the original Eau de Cologne.

Harvest: Italy (Dec-March)

Grapefruit Oil

Scent Profile: refreshing, sharp, and tart citrusy scent

Origin: The pomelo, the ancestor of the grapefruit, is native to Southeast Asia, however, the grapefruit was created in the Caribbean

Cultivation: The oil is contained inside the peel of the fruit and extracted using a cold press

History: It wasn’t until the early 18th century in the Caribbean that oranges were hybridized with the pomelo to create the grapefruit. During that time, grapefruits were not very popular due to their bitter taste. It wasn’t until the fruit was brought to the USA that its popularity began to rise. While it is now enjoyed almost worldwide, the grapefruit is mainly cultivated in the USA, Israel, and Brazil.

Harvest:

Brazil (July-Aug)

Israel (Nov-May)

USA (Nov-June)

Lemon Oil

Scent Profile: Fresh, zesty, and citrusy scent

Origin: The lemon plant is thought to be native to India

Cultivation: Traditionally, the peel of the lemon fruit is cold-pressed to extract the oil

History: Lemons are native to India and were brought to Europe during the Crusades. Due to their high vitamin C content, lemons were highly sought after by sailors in the British Navy to ward off the effects of scurvy and other nutrient deficiencies. Now, lemon oil is produced mostly in Italy and Argentina.

Harvest:

Argentina (Feb-Dec)

Brazil (Feb-Sept)

Italy (Nov-March)

Spain (Nov-March)

USA (Nov-June)

Lime Oil

Scent Profile: Sweet citrus aroma with a light tartness

Origin: Asia

Cultivation: The peels of the fruit are cold-pressed to extract the oil

History: In their ongoing effort to ward off the effects of scurvy, the British Navy supplied their sailors, later referred to as “limeys,” with a daily ration of lime juice. The switch from lemons to limes occurred after the cost to import lemons from Europe became greater than the cost to grow limes in the colonies.

Harvest:

Brazil (Jan-May)

Mexico (April-Aug)

Mandarin Oil

Scent Profile: Sweet, fruity, citrus aroma

Origin: Southeast Asia

Cultivation: The oil is cold-pressed from the peels of the fruit

History: It is thought the name “Mandarin” comes from the Swedes who referred to the fruit as “Mandarin Apelsin” or “Chinese Apple.” In traditional Chinese medicine, the dried peel of the fruit was used to aid with digestion, reduce phlegm, and balance one’s “Chi.”

Harvest:

Brazil (Feb-June)

Italy (Nov-March)

Orange Oil

Scent Profile: Fresh, juicy, light citrus aroma

Origin: Southeast Asia

Cultivation: Orange peels are cold-pressed to extract the oil

History: Oranges are one of the oldest cultivated fruits and became a vital part of trade routes spanning through Africa, the Middle East, and China. In the 16th century, the Portuguese brought oranges to Europe, which led to European explorers bringing orange seeds to the Americas.

Market: Orange oil is a byproduct of the orange juice processing industry.  It is extracted from the leftover peels along with d-limonene. Historically, both orange oil and d-limonene have enjoyed low pricing as the orange peels were considered a waste product.  This low pricing spurred demand for these natural materials in both the flavor & fragrance market and the resins & adhesives market. Over time, demand for orange juice has fallen, leading to fewer oranges being processed every year, resulting in less waste available to be processed for the oil and terpenes.  Combined with a few years of bad harvests, environmental conditions, and the threat of citrus greening, prices for the raw fruit and all subsequent products rose dramatically. 

Harvest:

Brazil (July- Dec)

Italy (Jan-April)

USA (Dec-June)

Extracting Methods

These are the different methods used to extract oil from citrus fruits

Expression (Cold Pressed)

Process: The modern method of extraction, termed “écuelle à piquer,” involves pricking and prodding the fruit to release the oil. The rind of the fruit is placed in a rotating container with spikes to puncture the peel, releasing both oil and juice.  The resulting liquid is then sent through a centrifuge to separate the oil from the juice.

History: Originally, expression was done by hand using a technique called sponge pressing. A sponge would be used to press the soaked rind of a citrus fruit and break the cavities containing the essential oil.  This oil would be collected in the sponge as it was being used. Once full, the sponge is wrung out into a container and the resulting mixture of oil and juice is allowed to separate before the oil is siphoned off.

Pelatrice

Process: The process takes the whole fruit through a large Archimedes screw, where the screw surface is covered with thousands of protrusions that rip and tear micro-slices of the secretory oil sacs off the peel.  The resulting oil-water emulsion is then filtered and centrifuged, leaving behind the pure oil.  Most Italian bergamot and lemon oils are produced using this method.

History: Pelatrice means “peeler” in Italian. This method originated in Italy just prior to WWII and is commonly used in Europe and the Middle East.

Sfumatrice

Process: Citrus peels are sent down rollers after juicing, which bend and fold the peels, releasing the oil-water emulsion.  This emulsion is then filtered similarly to the pelatrice process. This used to be the most popular method for extracting citrus oils and is similar to the traditional way of manual citrus peel oil expression.

History: Sfumatrice means “shading” in Italian and is most commonly used in the Mediterranean.

FMC (JBT Method)

Process: This extractor method revolutionized the juice industry by allowing both the juice and oil to be harvested simultaneously. Whole citrus fruits are positioned between two stainless steel cupped jaws and are individually punctured from below with a “juice tube.” As the stainless-steel jaws compress the fruit, jets of water spray the outside of the citrus fruit to wash off the expressed essential oil.

History: This method is also referred to as the JBT method, as FMC was acquired by JBT Corporation.

Brown Oil Extraction (BOE)

Process: A machine designed to remove the oil from the peel of citrus fruits while leaving the fruit intact, ready for further processing. The oil is then released as the fruit rolls over thousands of tiny needles.

History: Brown International calls this method BOE, Brown Oil Extraction. This method of extraction is the most common in the Western Hemisphere. It achieves greater yields than traditional cold-pressed methods and can process truckloads of raw fruit in a single day.

Thin Film Molecular Evaporation

Process: Thin Film Molecular Evaporation is a distillation process that occurs under vacuum conditions at -10 degrees Celsius.  The lack of heat allows for molecules to be extracted in their natural state. This process produces a distilled oil while retaining a more aromatic odor profile when compared to traditional distillation.  It also allows for the separation of color, furocoumarins, and waxes from the oil.