Bitter orange (Citrus Aurantium Amara) is a fruit that is harvested from the tree which belongs to the Rutaceae family and is cultivated in temperate zones almost all over the world. Extracts and essential oils widely used by the food, cosmetic and pharmaceutical industries are obtained from the peel, leaves, juice, flowers and seeds. It is a source of limonene, carotenoids, polyphenols, dietary fibre, soluble sugars, ascorbic acid, and pectin that exhibit antioxidant properties. Terpenes, flavonoids, carotenes and coumarins are known for their antimicrobial properties.

Citrus Aurantium Amara is known and appreciated for its bitter taste and is often used in traditional medicine and as a flavoring agent.

Chemical Composition

The essential oil extracted from the peel of Citrus Aurantium Amara is rich in limonene, a compound known for its aromatic properties. This oil is a by-product of the fruit processing industry and is valued for its potential health benefits.

Phytochemical analysis also revealed: linalool, rutin, synephrine, vitamin C.

Citrus Aurantium Amara essential oil has shown antioxidant activity, which may help counteract free radical damage in the human body; however, its antimicrobial properties, particularly against bacteria and yeasts, are relatively low compared with other natural extracts.

Research suggests that Citrus Aurantium Amara may have therapeutic potential, particularly in treating or preventing infectious diseases. Its essential oil has been studied for its effects against antibiotic-resistant microorganisms.

Traditional Medicine

In traditional Chinese medicine and other cultural practices, Citrus Aurantium Amara is used for its health-promoting properties. It's believed to aid in digestion, relieve abdominal pain, and help with other ailments.

Medical

Some studies have explored the anti-obesity effects of Citrus Aurantium Amara. Compounds like neohesperidin and naringin, found in the plant, have shown potential in weight management and obesity treatment (1).

Citrus Aurantium Amara is used in extract, essential oil, and powder form for the treatment of various diseases. One of its components, synephrine a primary proto alkaloid similar to ephedrine but producing different effects, is commonly included in dietary supplements and medicines for weight management, appetite control, sports performance, energy, and cognition (2). Synephrine exhibits cardiovascular activity but lacks the undesirable effects attributable to ephedrine. 

Extracts, oils, and powders of Citrus Aurantium Amara are used in pharmaceutical and nutraceutical preparations for their antioxidant and antimicrobial properties (3).

Food and Nutraceutical

Beyond its use in traditional medicine, Citrus Aurantium Amara is gaining attention in the food and nutraceutical industries. Its rich composition of bioactive compounds makes it a valuable ingredient for developing health supplements and natural preservatives.

It is used as a fresh fruit, natural food additive, natural flavor.

Cosmetics

Fragrance. It plays a very important role in the formulation of cosmetic products as it provides the possibility of enhancing, masking or adding fragrance to the final product, increasing its marketability. It is able to create a perceptible pleasant odour, masking a bad smell. The consumer always expects to find a pleasant or distinctive scent in a cosmetic product. 

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

CAS    68916-04-1   72968-50-4 generic

Citrus Aurantium Amara studies

References_____________________________________________________________________

(1) Shen CY, Wan L, Wang TX, Jiang JG. Citrus aurantium L. var. amara Engl. inhibited lipid accumulation in 3T3-L1 cells and Caenorhabditis elegans and prevented obesity in high-fat diet-fed mice. Pharmacol Res. 2019 Sep;147:104347. doi: 10.1016/j.phrs.2019.104347. Epub 2019 Jul 14. PMID: 31315066.

(2) Stohs SJ, Ray SD. Review of Published Bitter Orange Extract and p-Synephrine Adverse Event Clinical Study Case Reports. J Diet Suppl. 2020;17(3):355-363. doi: 10.1080/19390211.2019.1577936. 

Abstract. p-Synephrine is the primary active ingredient in bitter orange (Citrus aurantium) extract and is present in other citrus species. This review summarizes all known case reports that have been published regarding adverse events associated with multi-ingredient dietary supplements containing bitter orange extract. A common characteristic of all the case studies was the assumption that if bitter orange extract is listed on the label of the product it is the most likely cause of any adverse effect, although in no case was the presence of p-synephrine determined or a direct link demonstrated. No case study reviewed the existing published literature, and all failed to note that numerous clinical studies have not demonstrated adverse effects at commonly used doses. Most studies did not indicate the composition of the product involved, and no study analyzed the product in question. In no case was a direct correlation between the event and p-synephrine made. Although p-synephrine and ephedrine have some structural similarity, the structural differences result in markedly different pharmacokinetic, physiological, and pharmacological effects, and thus the effects produced by ephedrine cannot be extrapolated to p-synephrine.

(3) 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).