Compendium of the most significant studies with reference to properties, intake, effects.

Lin LY, Chuang CH, Chen HC, Yang KM. Lime (Citrus aurantifolia (Christm.) Swingle) Essential Oils: Volatile Compounds, Antioxidant Capacity, and Hypolipidemic Effect. Foods. 2019 Sep 7;8(9):398. doi: 10.3390/foods8090398. 

Abstract. Lime peels are mainly obtained from the byproducts of the juice manufacturing industry, which we obtained and used to extract essential oil (2.3%) in order to examine the antioxidant and hypolipidaemic effects. We identified 60 volatile compounds of lime essential oil (LEO) with GC/MS, of which the predominant constituents were limonene, γ-terpinene, and β-pinene. Lime essential oil was measured according to the DPPH assay and ABTS assay, with IC50 values of 2.36 mg/mL and 0.26 mg/mL, respectively. This study also explored the protective effects of LEO against lipid-induced hyperlipidemia in a rat model. Two groups of rats received oral LEO in doses of 0.74 g/100 g and 2.23 g/100 g with their diets. Eight weeks later, we found that the administration of LEO improved the serum total cholesterol, triglyceride, low-density lipoprotein cholesterol, alanine aminotransferase, and aspartate transaminase levels in the hyperlipidemic rats (p < 0.05). Simultaneously, the LEO improved the health of the rats in terms of obesity, atherogenic index, and fatty liver.

Narang N, Jiraungkoorskul W. Anticancer Activity of Key Lime, Citrus aurantifolia. Pharmacogn Rev. 2016 Jul-Dec;10(20):118-122. doi: 10.4103/0973-7847.194043. 

Abstract. Citrus aurantifolia (family: Rutaceae) is mainly used in daily consumption, in many cultural cuisines, and in juice production. It is widely used because of its antibacterial, anticancer, antidiabetic, antifungal, anti-hypertensive, anti-inflammation, anti-lipidemia, and antioxidant properties; moreover, it can protect heart, liver, bone, and prevent urinary diseases. Its secondary metabolites are alkaloids, carotenoids, coumarins, essential oils, flavonoids, phenolic acids, and triterpenoids. The other important constituents are apigenin, hesperetin, kaempferol, limonoids, quercetin, naringenin, nobiletin, and rutin, all of these contribute to its remedial properties. The scientific searching platforms were used for publications from 1990 to present. The abstracts and titles were screened, and the full-text articles were selected. The present review is up-to-date of the phytochemical property of C. aurantifolia to provide a reference for further study.

Lemes RS, Alves CCF, Estevam EBB, Santiago MB, Martins CHG, Santos TCLD, Crotti AEM, Miranda MLD. Chemical composition and antibacterial activity of essential oils from Citrus aurantifolia leaves and fruit peel against oral pathogenic bacteria. An Acad Bras Cienc. 2018 Apr-Jun;90(2):1285-1292. doi: 10.1590/0001-3765201820170847. 

Abstract. Tooth decay is a major public health problem which affects a large number of people in several countries. Even though more than 700 bacterial species have been detected in the oral cavity, Streptococcus and Lactobacillus stand out as the genera that cause tooth decay and other periodontal diseases. In this study, essential oils from Citrus aurantifolia leaves (CL-EO) and fruit peel (CP-EO) were obtained by hydrodistillation by a Clevenger-type apparatus whereas their chemical composition was analyzed by gas chromatography-flame ionization detector (GC-FID) and gas chromatography-mass spectrometry (GC-MS). Limonene (77.5 %), linalool (20.1 %), citronellal (14.5 %) and citronellol (14.2 %) were the main constituents found in the essential oils from C. aurantifolia leaves and fruit peel. Antibacterial activity of essential oils was evaluated in terms of its minimum inhibitory concentration (MIC) values by the broth microdilution method in 96-well microplates. Both CL-EO and CP-EO displayed some activity against all oral pathogens under investigation; MIC values ranged from 20 to 200 µg/mL. CL-EO and CP-EO not only had promising activity against Streptococcus mutans (MIC = 20 µg/mL) and Lactobacillus casei (31.25 µg/mL), but also displayed antibacterial activity against all studied cariogenic bacteria. Efficacy of essential oils against S. mutans and L. casei is noteworthy and should be further investigated.

Şeker Karatoprak G, Yücel Aşık Ç, Çakır A, Köngül Şafak E. In vitro pharmacological screening of antioxidant, cytotoxic and enzyme inhibitory activities of Citrus aurantifolia Linn. Dried fruit extract. Int J Environ Health Res. 2021 Dec;31(8):991-1000. doi: 10.1080/09603123.2020.1714558. 

Abstract. The Lime Basra (Citrus aurantifolia Linn., Rutaceae) plant also known as dried lime, and Limoo Omani, is used both as a spice in meals and as an herbal tea in the treatment of some diseases in the Middle East. It was aimed to determine the biological activity screening of the 70% methanol, ethanol extracts and infusion which were prepared from dried fruits. 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS+) radical scavenging activities, ferric reducing activity, cytotoxicity on A 549, MCF 7 and L929 cell lines and α-amylase inhibitory effects were determined. According to the results, 70% methanol extract was more active in antioxidant activity tests and ethanol extract was more active in cytotoxicity tests. Interestingly both 70% methanol and ethanol extracts were found to have potent hypoglycemic activity. The present findings shed light on the fact that it is important to research and scientifically evaluate plants with traditional medicinal use.

Sarma R, Adhikari K, Mahanta S, Khanikor B. Insecticidal activities of Citrus aurantifolia essential oil against Aedes aegypti (Diptera: Culicidae). Toxicol Rep. 2019 Oct 14;6:1091-1096. doi: 10.1016/j.toxrep.2019.10.009. 

Abstract. Background: In the recent time, global attention for the control of vectors has shifted from chemical insecticides to botanicals. In the present investigation, authors attempted to evaluate the efficacy of peel and leaf essential oil (EO) of Citrus aurantifolia against Aedes aegypti....Conclusion: From this study, it can be concluded that the essential oil extracted from the leaf and peel of Citrus aurantifolia and one of its major constituent compound citral can be included in the mosquito control programme of Aedes aegypti. © 2019 The Authors.

Patil JR, Chidambara Murthy KN, Jayaprakasha GK, Chetti MB, Patil BS. Bioactive compounds from Mexican lime ( Citrus aurantifolia ) juice induce apoptosis in human pancreatic cells. J Agric Food Chem. 2009 Nov 25;57(22):10933-42. doi: 10.1021/jf901718u. 

Abstract. Lime (Citrus aurantifolia Swingle) is one of the major citrus fruits and widely consumed, but there is limited evidence about its health-promoting properties. Hence, an investigation was conducted to understand the chemopreventive effects of lime juice on pancreatic cancer cells and the possible mechanism for induction of apoptosis using Panc-28 cells. Freeze-dried lime juice was extracted with different solvents, such as chloroform, acetone, MeOH, and MeOH/water (8:2). The chloroform extract showed the highest (85.4 and 90%) radical-scavenging activity by 1,1-diphenyl-2-picryl hydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) methods at 624 microg/mL, whereas the MeOH/water extract showed the lowest (<20%) activity. The active components were identified by high-performance liquid chromatography (HPLC) using a C-18 column as rutin, neohesperidin, hesperidin, and hesperitin. Furthermore, the limonoids identified are limonexic acid, isolimonexic acid, and limonin. All of the extracts of lime juice inhibited Panc-28 cancer cell growth. The MeOH extract exhibited the maximum activity, with an IC50 value of 81.20 microg/mL after 72 h. The inhibition of Panc-28 cells was in the range of 73-89%, at 100 microg/mL at 96 h. The involvement of apoptosis in induction of cytotoxicity was confirmed by expression of Bax, Bcl-2, casapase-3, and p53. The results of the present study clearly indicate that antioxidant activity is proportionate to the content of flavonoids and proliferation inhibition ability is proportionate to the content of both flavonoids and limonoids.

Song BW, Lee CY, Park JH, Kim B, Lee S, Lim S, Kim SW, Choi JW, Kang M, Kang JH, Lee SS, Park MJ, Moon H, Hwang KC, Kim IK. Cold-pressed oil from Citrus aurantifolia inhibits the proliferation of vascular smooth muscle cells via regulation of PI3K/MAPK signaling pathways. Exp Ther Med. 2022 Jan;23(1):21. doi: 10.3892/etm.2021.10943.

Abstract. Vascular occlusive disease is a chronic disease with significant morbidity and mortality. Although a variety of therapies and medications have been developed, the likelihood of disease re-emergence is high and this can be life-threatening. Based on a previous screening experiment related to vascular obstructive diseases using 34 types of essential oils, cold-pressed oil (CpO) from Citrus aurantifolia (lime) has been demonstrated to have the best effect for the inhibition of vascular smooth muscle cells (VSMCs) proliferation. The aim of the present study was to evaluate the effect of lime CpO on the pathological changes of VSMCs. To determine this, the effect of lime CpO on VSMC proliferation, a major cause of vascular disease, was investigated. To determine the safe concentration interval for toxicity of CpO during VSMC culture, a dilution of 1x10-5 was determined using Cell Counting Kit-8 assay, which was confirmed to be non-toxic using a lactate dehydrogenase assay. To examine the effect of lime CpO in cellular signaling pathways, changes in phosphorylation of both the PI3K/AKT/mTOR and extracellular signal-regulated MEK/ERK signaling pathways with serum were investigated. Furthermore, lime CpO with FBS also significantly decreased the expression levels of the cell cycle regulators cyclin D1 and proliferating cell nuclear antigen. Additionally, lime CpO with FBS significantly inhibited the sprouting of VSMCs in an ex vivo culture system. These results suggested that lime CpO inhibited the abnormal proliferation of VSMCs and can be developed as a nature-based therapeutic agent for obstructive vascular disease. Copyright: © Song et al.

Lime (Citrus Aurantifolia) is a fruit plant belonging to the Rutaceae family that grows in temperate zones around the world. It is used industrially by the food, cosmetic and pharmaceutical industries. The fruits and leaves yield essential oils with biologically active compounds that are important for human nutrition and proper diet.

Lime, plant and fruit
(Citrus spp. — mainly Citrus × aurantiifolia and Citrus × latifolia, family Rutaceae)

Common name: Lime

Source plant: Citrus aurantiifolia (Christm.) Swingle
(another important commercial species: Citrus latifolia Tanaka, “Tahiti lime”)

Kingdom: Plantae
Clade: Angiosperms
Clade: Eudicots
Order: Sapindales
Family: Rutaceae
Genus: Citrus
Main species: Citrus aurantiifolia (acid lime, key lime)

Cultivation and growing conditions of lime

• Climate:

  • Prefers warm, bright subtropical and tropical climates.

  • More sensitive to cold than lemon; does not tolerate frost and is damaged near 0 °C.

  • In temperate regions it is grown in very sheltered positions or in pots, to be protected in winter.

• Exposure:

  • Requires full sun for good growth, flowering and essential oil content in the peel.

  • Protection from cold, dry winds is important.

• Soil:

  • Prefers well-drained, medium-textured soils with good organic matter.

  • Grows best at slightly acidic to neutral pH; poorly adapted to heavy, compact, waterlogged soils.

• Watering:

  • Needs regular irrigation in spring and summer, keeping the soil moderately moist.

  • Avoid both prolonged drought (flower and young fruit drop) and excess water (root rot risk).

  • In mild climates and open ground, irrigation is greatly reduced or stopped in winter.

• Temperature:

  • Optimal growth roughly between 18 and 30 °C.

  • Temperatures below about 5–7 °C can cause damage, especially to young plants and fruits.

• Fertilization:

  • Requires good nitrogen supply along with phosphorus, potassium and micronutrients (especially iron, zinc and manganese).

  • Regular applications of compost or well-rotted manure and citrus-specific fertilizers are beneficial.

• Crop management:

  • Light pruning to keep the canopy open, remove dead or diseased branches and support fruiting.

  • Weed control in the area around the trunk.

  • In pots: periodic repotting and careful attention to drainage (drainage layer at the bottom).

• Harvest:

  • Fruits are generally harvested while still green or just starting to turn color, depending on market and use.

  • Hand harvesting requires care not to damage the peel, which is rich in essential oils.

• Propagation:

  • Mainly by grafting onto rootstocks of other citrus species (e.g. sour orange, trifoliate orange or hybrids) to improve soil adaptation and stress tolerance.

  • Seed is used mainly in nurseries or for rootstock production, not to maintain varietal traits.

Description

• Plant: small evergreen tree or large shrub with rounded, dense canopy, typically 3–5 m tall (up to ~6–7 m in ideal climates).

• Key/Mexican lime (Citrus × aurantiifolia): more spiny, irregular growth habit, small ovate–elliptic leaves, very aromatic.

• Persian/Tahiti lime (Citrus × latifolia): almost thornless, more vigorous, compact canopy; larger fruits, usually seedless.

• Flowers: white with occasional purple tinge, strongly fragrant, often multiple blooms per year (tends to be “everbearing” in suitable climates).

• Fruit: small round–oval citrus (2–6 cm), thin peel, bright green turning yellow at full maturity; juicy pulp, very acidic and intensely aromatic.

Indicative nutritional values (per 100 g fresh pulp, raw)

• Energy: ~30–40 kcal

• Water: ~88–90 g

• Protein: ~0.7–0.8 g

• Total carbohydrates: ~10–11 g

  • Simple sugars: ~1.5–2.0 g

  • Dietary fibre: ~2.5–3 g

• Total fat: ~0.2 g (traces of SFA/MUFA/PUFA — saturated/mono-/polyunsaturated fatty acids; amounts are nutritionally negligible, but in general it is advisable to limit saturated fats in the overall diet)

• Minerals (typical): Potassium ~100 mg; Iron ~0.5–0.6 mg

• Vitamins: Vitamin C ~25–30 mg; small amounts of folates and carotenoids

(Values vary slightly with variety, origin, and ripeness.)

Key constituents

• Organic acids: predominantly citric acid, responsible for the marked acidity; malic acid and others in trace amounts.

• Vitamin C (ascorbic acid): moderate–good content; sensitive to oxygen, light, and heat.

• Polyphenols: citrus flavonoids (e.g. eriocitrin, hesperidin) and minor phenolics with potential antioxidant activity.

• Essential oils in the peel: mainly monoterpenes (limonene, γ-terpinene, pinene isomers) plus oxygenated compounds (citral, linalool), with small amounts of furanocoumarins in the non-volatile fraction.

• Carbohydrates: simple sugars and pectins (in membranes and albedo).

• Lipids: traces in the peel oil; almost none in the pulp.

Production/cultivation process

• Climate: typically tropical/subtropical, very sensitive to frost; prefers sunny, warm, and wind-sheltered exposures.

• Soil: well-drained soils, slightly acidic to neutral, rich in organic matter; suffers from waterlogging and strongly calcareous soils (risk of chlorosis).

• Propagation: mainly by grafting onto citrus rootstocks (e.g. sour orange, citrange); Key lime can also be grown from seed (relatively true-to-type).

• Agronomy: training and maintenance pruning, balanced NPK fertilisation with micronutrients, regular irrigation during flowering/fruit set and fruit enlargement.

• Harvest: fruits are usually picked green (maximum acidity and aroma); if allowed to ripen fully they turn yellow and become less acidic.

Physical properties of the fruit

• Size: small (Key) ~2–4 cm; medium (Persian/Tahiti) ~4–6 cm.

• Peel: thin, smooth to slightly rough, with many oil glands.

• Pulp: segmented, yellow–green, very juicy.

• Juice pH: typically ~2.0–2.4 (very acidic).

• aw: high water activity, as expected for fresh fruit.

Sensory and technological properties

• Aroma profile: fresh citrus with a distinctive “lime” character, more herbal/green and less pungent than lemon; Key lime is generally more intense and complex.

• Taste: strongly acidic with slight peel/albedo bitterness; very effective at “brightening” flavours.

• Technological role:

  • pH control and mild preservative effect in sauces, beverages, and marinades;

  • contribution to gelation/texture when pectins and sugars are present (e.g. in mixed jams and marmalades);

  • flavour enhancement in combination with sugar, salt, and spices.

Food applications

• Culinary/home use:

  • raw seasoning (fish, seafood, salads, ethnic dishes);

  • marinades (ceviche, white meats, tofu, vegetables);

  • beverages (limeade, lemon–lime drinks, cocktails, cold infusions);

  • desserts (key lime pie, cheesecakes, sorbets, curds, toppings).

• Industry:

  • juices, nectars, flavoured soft drinks;

  • flavouring of baked goods, snacks, candies, chewing gum;

  • production of lime essential oil and compounded flavours;

  • acidity correction in juice and beverage blends.

Nutrition & health

• Low energy density, modest sugars, and a useful amount of vitamin C and fibre (especially if some albedo and membranes are consumed).

• Fat intake from lime is essentially zero; the tiny amounts of fatty acids (saturated and unsaturated) are irrelevant for the lipid profile of the diet.

• The strong acidity can help:

  • improve the palatability of dishes with reduced salt or sugar;

  • stimulate salivation and perceived digestion (physiological perception, not a guaranteed medicinal effect).

• Vitamin C supports immune function, protection against oxidative stress, and collagen synthesis.

• In people with GERD, gastritis, or peptic ulcer, large amounts of highly acidic juices may be irritating.

Serving note

• As fresh fruit, 1 serving ≈ 1–2 limes (about 80–120 g total).

• As juice, ~15–30 ml (1–2 tablespoons) per serving of dressing or diluted beverage.

Allergens and intolerances

• Lime is not among the 14 major EU allergens; however, rare individual citrus allergies exist.

• Juice and peel on skin + sunlight (especially if not washed off) can cause phytophotodermatitis because of furanocoumarins — relevant in bar/kitchen work outdoors.

• In processed foods (drinks, desserts, candies), allergens typically come from recipe ingredients (milk, soy, gluten, etc.) rather than from lime itself.

Quality and specifications (fresh fruit)

• Appearance: smooth, firm peel, bright green colour (or green–yellow for more mature fruits), free from deep bruises, mould, or rots.

• Weight and juiciness: fruits that feel heavy for their size are usually juicier.

• Seeds: numerous in Key lime; few or none in Persian/Tahiti.

• Pesticide residues: must comply with legal limits; especially important if the peel is used in cooking.

Storage and shelf-life

• At room temperature: 1–2 weeks in a cool, dry, well-ventilated place; avoid high-ethylene environments from other ripe fruits.

• In the refrigerator (4–7 °C): 3–4 weeks in the vegetable drawer, preferably in a perforated bag or net.

• Juice: best consumed soon after squeezing; in the fridge 1–2 days in a closed container; more stable if frozen as cubes.

• Zest: can be grated and frozen or dried for later flavouring use.

Safety and regulatory

• Production and post-harvest operations should follow GMP/HACCP with controls for pesticides, mycotoxins (where relevant), and foreign bodies.

• For processed lime products (juices, beverages, flavours), specific rules apply regarding:

  • minimum fruit content and acidifiers;

  • use of natural flavourings;

  • limits for additives (preservatives, colours) and residues.

Labeling

• Fresh fruit: name “lime” (or commercial name, e.g. “Tahiti lime”), origin, size and class where required, lot identification and, if prepacked, storage conditions.

• Lime-based products: clear indication of juice/pulp content, use of natural flavours or nature-identical flavours, and any preservatives (e.g. sulphites) and sweeteners.

Troubleshooting (culinary/industrial)

• Bitter juice → excessive peel/albedo extraction or too vigorous squeezing (oil and compounds from peel and seeds) → press more gently, filter, or blend with other citrus juices.

• Loss of fresh aroma in drinks/desserts → volatilisation and oxidation → add juice or flavour as late as possible in processing, limit heat and air exposure, use closed containers.

• Dull colour in sweet/dairy products → oxidation and pH effects → combine lime with other citrus or natural colours; manage pH and antioxidants.

• Unwanted milk curdling with lime → too much acid → add lime at low levels, at colder temperatures, or use stabilised preparations.

Sustainability and supply chain

• Lime is suitable for by-product valorisation: peel for essential oils, extracts, pectin, and feed.

• Key agricultural issues: water and soil management in orchards, rational use of pesticides, conservation of citrus biodiversity.

• At processing plants: heat recovery in pasteurisation/concentration lines, wastewater treatment with BOD/COD reduction, recyclable/mono-material packaging, and FIFO stock rotation to limit waste.

Main INCI functions (cosmetics)

• Citrus Aurantifolia (Lime) Oil — fragrance, masking, mild skin conditioning; phototoxicity from furanocoumarins must be controlled (usage limits).

• Citrus Aurantifolia (Lime) Juice/Extract — mild astringent, skin conditioning, pH adjuster in cleansers and toners.

• Lime-derived cosmetic ingredients must be cosmetic grade, with controlled fragrance allergens and photo-irritants.

Fragrance. It plays a very important role in the formulation of cosmetic products as it allows perfume to be enhanced, masked or added to the final product, improving its commercial viability.  The consumer always expects to find a pleasant scent in a cosmetic product.

Surfactant - Cleansing agent. Cosmetic products used to cleanse the skin utilise the surface-active action that produces a lowering of the surface tension of the stratum corneum, facilitating the removal of dirt and impurities. 

Skin conditioning agent - Miscellaneous.  This ingredient has the task of modifying the condition of the skin when it is damaged or dry by reducing its flakiness and restoring its elasticity.

Conclusion

Lime is a citrus fruit of high agronomic, culinary, and industrial interest. The plant, a small frost-sensitive evergreen tree, produces small but highly aromatic fruits with juice rich in citric acid and vitamin C, low calories, and moderate sugars. In the kitchen it is a key ally for both sweet and savoury dishes, drinks, and sauces, while industry uses not only the juice but also essential oils and by-products. Careful management of variety, maturity, storage, and processing helps preserve aroma, freshness, and safety along the entire chain.

Mini-glossary

• SFA/MUFA/PUFA — Saturated/monounsaturated/polyunsaturated fatty acids; in lime they are present only in traces and do not affect the lipid profile, but in general it is advisable to limit SFA in the diet.

• aw — Water activity; high in fresh fruits, which makes them perishable.

• GMP/HACCP — Good Manufacturing Practices / Hazard Analysis and Critical Control Points; core systems to ensure hygiene and safety.

• BOD/COD — Biochemical/Chemical Oxygen Demand; measures of organic load in effluents, important for environmental management.

• Phytophotodermatitis — Skin reaction caused by contact with certain plants (e.g. citrus, umbellifers) followed by UV exposure.

CAS     90063-52-8  generic

Studies

Many interesting components have been found in the juice and peel of limes that play different roles in protecting the human body from external agents such as oleic acid, palmitic acid, citral, linalool, limonene and caryophyllene, which, together with vitamin C, act as protective agents against free radicals. Antioxidants (in particular polyphenols and carotenoids) and antimicrobials as well as anti-inflammatory agents (aldehydes, terpenes, sesquiterpenes, alcohols and esters) are also present (1) Even in the treatment of cardiovascular diseases, daily intake has shown great benefits: the cold-pressed oil obtained from Citrus aurantifolia is considered a therapeutic agent that can inhibit the abnormal proliferation of vascular smooth muscle cells (2).

Alongside the components mentioned above, it is interesting to note the presence of rutin, apigenin, hexpertin, quercetin, naringenin and nobiletin, which, although in lesser quantities, collectively act the same protective functions. 

The most relevant studies on this ingredient have been selected with a summary of their contents:

Lime Citrus Aurantifolia studies

References_____________________________________________________________________

(1) Tundis R, Loizzo MR, Bonesi M, Menichini F, Mastellone V, Colica C, Menichini F. Comparative study on the antioxidant capacity and cholinesterase inhibitory activity of Citrus aurantifolia Swingle, C. aurantium L., and C. bergamia Risso and Poit. peel essential oils. J Food Sci. 2012 Jan;77(1):H40-6. doi: 10.1111/j.1750-3841.2011.02511.x.

(2) Song BW, Lee CY, Park JH, Kim B, Lee S, Lim S, Kim SW, Choi JW, Kang M, Kang JH, Lee SS, Park MJ, Moon H, Hwang KC, Kim IK. Cold-pressed oil from Citrus aurantifolia inhibits the proliferation of vascular smooth muscle cells via regulation of PI3K/MAPK signaling pathways. Exp Ther Med. 2022 Jan;23(1):21. doi: 10.3892/etm.2021.10943.

Dosoky NS, Setzer WN. Biological Activities and Safety of Citrus spp. Essential Oils. Int J Mol Sci. 2018 Jul 5;19(7):1966. doi: 10.3390/ijms19071966. 

Abstract. Citrus fruits have been a commercially important crop for thousands of years. In addition, Citrus essential oils are valuable in the perfume, food, and beverage industries, and have also enjoyed use as aromatherapy and medicinal agents. This review summarizes the important biological activities and safety considerations of the essential oils of sweet orange (Citrus sinensis), bitter orange (Citrus aurantium), neroli (Citrus aurantium), orange petitgrain (Citrus aurantium), mandarin (Citrus reticulata), lemon (Citrus limon), lime (Citrus aurantifolia), grapefruit (Citrus × paradisi), bergamot (Citrus bergamia), Yuzu (Citrus junos), and kumquat (Citrus japonica).