A Natural Source of Antioxidant Compounds and Its Potential Health Benefits
Isha B. Gajjar
MSc Nutrition and Dietetics (in progress)
4 Oct 2026 · 6 min read
Orange peel is commonly discarded as household food waste, although it contains a wide range of biologically active compounds. The peel of sweet orange (Citrus sinensis) is particularly rich in flavonoids, phenolic compounds, polymethoxylated flavones and volatile constituents. These compounds have attracted scientific interest because of their antioxidant and other biological activities (Singh et al., 2020). One simple way of utilising orange peel is to prepare an infusion, commonly known as orange peel tea. However, it is important to distinguish the demonstrated biological activity of orange-peel extracts from the potential effects of drinking a homemade tea.
Nutritional and Bioactive Composition of Orange Peel
Citrus peels contain substantially higher concentrations of several phenolic compounds than the edible pulp (Ghasemi et al., 2009; Singh et al., 2020). Major flavonoids reported in citrus peel include hesperidin, naringin, narirutin and hesperetin, while polymethoxylated flavones such as nobiletin and tangeretin are characteristic compounds of citrus peel (Khan et al., 2014). Phenolic acids, including caffeic, ferulic, p-coumaric and sinapic acids, also contribute to the bioactive profile of the peel (Singh et al., 2020).
Orange peel also contains essential oils, with limonene being one of the major volatile constituents responsible for its characteristic citrus aroma. The chemical composition can vary according to orange variety, maturity, geographical origin, agricultural practices and processing conditions.
Hesperidin is particularly important because it is a major citrus flavanone and has been extensively investigated for its antioxidant and anti-inflammatory properties. Experimental studies suggest that hesperidin and its aglycone hesperetin can influence oxidative-stress-related pathways and cellular antioxidant defences (Parhiz et al., 2015).
Antioxidant Properties of Orange Peel
Antioxidants are compounds capable of reducing oxidative reactions by scavenging reactive species or by supporting endogenous antioxidant defence mechanisms. Oxidative stress occurs when the production of reactive oxygen species exceeds the capacity of biological antioxidant systems to neutralise them.
The antioxidant activity of orange peel has been demonstrated using several experimental methods. Common chemical assays include DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS (2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid)) radical-scavenging assays. Studies investigating citrus peel extracts have generally demonstrated substantial antioxidant capacity, which has been associated with their high concentration of phenolic compounds and flavonoids (Ghasemi et al., 2009; Singh et al., 2020).
Research specifically examining sweet-orange peel has identified hesperidin, hesperetin, nobiletin and tangeretin in water extracts (Z. T. Chen et al., 2012). Experimental findings indicated that these compounds were associated with protection against experimentally induced oxidative stress in cultured cells, including effects on reactive oxygen species and endogenous antioxidant-related mechanisms.
These findings support the scientific basis for considering orange peel a source of antioxidant phytochemicals. Nevertheless, antioxidant activity measured in a laboratory extract should not automatically be interpreted as an equivalent physiological effect after consuming orange peel tea.
Potential Health Benefits
1. Support against oxidative stress
The polyphenols present in orange peel can exhibit radical-scavenging and other antioxidant activities. Hesperidin and related citrus flavonoids have been investigated for their ability to modulate oxidative-stress pathways and cellular antioxidant defences (Parhiz et al., 2015).
Regular consumption of foods containing polyphenols contributes to overall dietary antioxidant exposure. However, the amount of these compounds transferred into a cup of orange peel tea depends on factors such as peel quantity, particle size, water temperature, steeping time and the specific orange variety.
2. Potential cardiovascular relevance
Citrus flavonoids have been investigated for their possible effects on vascular and cardiovascular biomarkers. In a four-week randomised crossover study in healthy, slightly overweight men, a hesperidin drink lowered blood pressure and improved post-meal blood-vessel reactivity compared with a placebo drink (Morand et al., 2011).
However, these findings should not be interpreted as evidence that orange peel tea itself prevents cardiovascular disease. A systematic review of hesperidin in orange juice reported that overall effects on chronic-disease biomarkers were relatively weak, highlighting the need for further research (Tadros & Andrade, 2022).
3. Possible anti-inflammatory activity
Laboratory research has demonstrated anti-inflammatory activity associated with several citrus flavonoids, including hesperidin, hesperetin and polymethoxylated flavones. Experimental studies have investigated pathways involving inflammatory mediators such as NF-κB, iNOS and COX-2 (X. M. Chen et al., 2017; Parhiz et al., 2015).
Nevertheless, laboratory findings cannot be directly translated into clinical benefits from drinking orange peel tea. Human evidence remains considerably more limited (Lorzadeh et al., 2019).
4. Food-waste valorisation
Beyond its nutritional interest, orange peel also has value for food utilisation and sustainability. Citrus processing generates considerable quantities of peel and other by-products. Because these materials contain valuable phenolic compounds and essential oils, their incorporation into foods and beverages may contribute to food-waste reduction and the development of functional food ingredients (Singh et al., 2020).
How to Prepare Orange Peel Tea
To prepare a simple infusion, wash an orange thoroughly and use clean peel from a suitable food source. Place approximately 2–3 small strips of peel in 250 mL of freshly boiled water and allow it to steep for about 5–10 minutes. The peel can then be removed before consumption.
A small amount of the white pith can be retained because it contains flavonoids, although too much pith may increase bitterness. Orange peel can also be dried, powdered and stored in an airtight container for later use.
For improved flavour, orange peel can be combined with ingredients such as ginger, cinnamon or mint. The resulting beverage should be considered a flavonoid-containing herbal infusion rather than a medicinal preparation.
Important Considerations
Although orange peel contains numerous bioactive compounds, more is not necessarily better. The concentration and bioavailability of compounds in homemade tea are variable, and the human health effects of orange peel tea specifically have not been established to the same extent as the effects of isolated citrus compounds or standardised extracts.
Individuals with citrus allergy should avoid orange peel preparations. People taking regular medications should also seek professional advice if they intend to consume concentrated citrus preparations, particularly because certain citrus fruits, such as grapefruit and Seville orange, are known to interact with some medications.
Conclusion
Orange peel is more than a discarded part of the fruit; it is a source of flavonoids, phenolic compounds, polymethoxylated flavones and volatile constituents with demonstrated antioxidant activity. Hesperidin, nobiletin, tangeretin and other phytochemicals have been investigated extensively in experimental research, providing a scientific basis for interest in citrus-peel utilisation.
Orange peel tea can therefore be viewed as a simple and sustainable way of incorporating citrus-derived phytochemicals into the diet. However, evidence for the antioxidant activity of orange-peel extracts should not be confused with proof of specific therapeutic effects from a cup of tea. Further human studies are needed to determine the actual bioavailability, effective intake and health effects of orange peel tea. For now, its most defensible role is as a flavourful, plant-based beverage that contributes dietary phytochemicals while helping to valorise an otherwise underutilised food by-product.
Glossary
21 terms
- Aglycone
- The form of a flavonoid without its attached sugar; hesperetin is the aglycone of hesperidin. ↑ Back to text
- Bioavailability
- The share of a compound that is absorbed and reaches the bloodstream, where it can have an effect. ↑ Back to text
- COX-2
- An enzyme that makes prostaglandins, signalling molecules that drive inflammation and pain. ↑ Back to text
- Cultured cells
- Cells grown in a lab dish, used to study a compound's effects before testing in animals or people. ↑ Back to text
- DPPH and ABTS assays
- Test-tube methods that measure how well a substance neutralises a coloured free radical, used to compare antioxidant capacity. ↑ Back to text
- Endogenous antioxidant defences
- The body's own antioxidant systems, such as enzymes that break down reactive oxygen species. ↑ Back to text
- Flavanone
- A group of flavonoids typical of citrus fruit, which includes hesperidin and naringin. ↑ Back to text
- Flavonoids
- A large family of plant compounds, found in fruit, vegetables and tea, studied for their antioxidant activity. ↑ Back to text
- Limonene
- The main compound in orange peel oil, and the source of most of its citrus smell. ↑ Back to text
- NF-κB
- A protein complex inside cells that switches on many genes involved in inflammation. ↑ Back to text
- Oxidative stress
- An imbalance in which reactive oxygen species are produced faster than the body can neutralise them. ↑ Back to text
- Phytochemicals
- Compounds made by plants that aren't essential nutrients but may affect health. ↑ Back to text
- Polymethoxylated flavones
- Flavonoids found almost only in citrus peel, such as nobiletin and tangeretin. ↑ Back to text
- Randomised crossover study
- A trial in which each participant gets both the treatment and the comparison, in random order, with a break in between. ↑ Back to text
- Reactive oxygen species
- Unstable oxygen-containing molecules made during normal metabolism that can damage cells in excess. ↑ Back to text
- Systematic review
- A review that finds and assesses all the studies on a question using a set, transparent method. ↑ Back to text
- Valorisation
- Turning a waste product or by-product into something useful or valuable. ↑ Back to text
References
- Chen, X. M., Tait, A. R., & Kitts, D. D. (2017). Flavonoid composition of orange peel and its association with antioxidant and anti-inflammatory activities. Food Chemistry, 218, 15–21. https://doi.org/10.1016/j.foodchem.2016.09.016
- Chen, Z. T., Chu, H. L., Chyau, C. C., Chu, C. C., & Duh, P. D. (2012). Protective effects of sweet orange (Citrus sinensis) peel and their bioactive compounds on oxidative stress. Food Chemistry, 135(4), 2119–2127. https://doi.org/10.1016/j.foodchem.2012.07.041
- Ghasemi, K., Ghasemi, Y., & Ebrahimzadeh, M. A. (2009). Antioxidant activity, phenol and flavonoid contents of 13 citrus species peels and tissues. Pakistan Journal of Pharmaceutical Sciences, 22(3), 277–281.
- Khan, M. K., Zill-E-Huma, & Dangles, O. (2014). A comprehensive review on flavanones, the major citrus polyphenols. Journal of Food Composition and Analysis, 33(1), 85–104. https://doi.org/10.1016/j.jfca.2013.11.004
- Lorzadeh, E., Ramezani-Jolfaie, N., Mohammadi, M., Khoshbakht, Y., & Salehi-Abargouei, A. (2019). The effect of hesperidin supplementation on inflammatory markers in human adults: A systematic review and meta-analysis of randomized controlled clinical trials. Chemico-Biological Interactions, 307, 8–15. https://doi.org/10.1016/j.cbi.2019.04.016
- Morand, C., Dubray, C., Milenkovic, D., Lioger, D., Martin, J. F., Scalbert, A., & Mazur, A. (2011). Hesperidin contributes to the vascular protective effects of orange juice: A randomized crossover study in healthy volunteers. The American Journal of Clinical Nutrition, 93(1), 73–80. https://doi.org/10.3945/ajcn.110.004945
- Parhiz, H., Roohbakhsh, A., Soltani, F., Rezaee, R., & Iranshahi, M. (2015). Antioxidant and anti-inflammatory properties of the citrus flavonoids hesperidin and hesperetin: An updated review of their molecular mechanisms and experimental models. Phytotherapy Research, 29(3), 323–331. https://doi.org/10.1002/ptr.5256
- Singh, B., Singh, J. P., Kaur, A., & Singh, N. (2020). Phenolic composition, antioxidant potential and health benefits of citrus peel. Food Research International, 132, Article 109114. https://doi.org/10.1016/j.foodres.2020.109114
- Tadros, F. J., & Andrade, J. M. (2022). Impact of hesperidin in 100% orange juice on chronic disease biomarkers: A narrative systematic review and gap analysis. Critical Reviews in Food Science and Nutrition, 62(30), 8335–8354. https://doi.org/10.1080/10408398.2021.1927976
Content on Nutri-Verse is general information, not personal medical or dietary advice. Health disclaimer