Antioxidant Properties Of Lemon Peel

What is an antioxidant?

To begin with this question, what is an antioxidant? It is important to know about oxidation and its process and the need of antioxidants to improve our health. The free radical that is oxygen atom with reactive properties are formed in our body as a result of various metabolic reactions. These free radicals have the ability to modify the important components of our system such as proteins, lipids and cause damage to the DNA which is called oxidative stress. Here comes our Antioxidants which plays a prominent role of capturing these free radicals and protecting us from damage and aids our system to perform the normal function.¹

Importance of Antioxidants

Studies show that Oxidative stress are primary or secondary cause of various cardiovascular diseases including atherosclerosis which is fat deposition in blood vessels causing plaque.It states that the circulating bad cholesterol or LDL (Low-Density Lipoprotein) get oxidised by free reactive oxygen species leading to lipid accumulation. The evidence shows that it causes atherosclerosis, ischemia, hypertension, and congestive heart failure. Apart from this oxidative stress is also linked with several neurological disorders such as Parkinson, Alzheimer’s, and memory loss.² Various experimental models show that free radicals are associated with different stages of cancer.The increased amount of free radical leads to cell damage and programmed cell death. Different types of cancer are due to reaction of free radicals with DNA causing mutation that is a change in DNA and affecting the normal cell cycle and causing abnormal cell growth or neoplasm.³ These findings show that oxidative stress is a key reason for various chronic health conditions and antioxidants are vital to prevent these disorders.

Overview of lemon peel as a potential source of antioxidants

Have you ever wondered that the lemon peel which we throw out as a waste has a high content of essential oils and it is rich in antioxidants? Let’s dive into the discussion. The report shows that around 54 billion tons of citrus peel waste is generated worldwide which has high content of essential oils responsible for antioxidant properties. Citrus essential oil is mainly present in the flavonoid portion of the peel and lesser quantity of leaves, flowers, fruits, and seeds. The essential oil seems to have germicidal, antioxidant, antibacterial and anticarcinogenic properties. Research shows that Citrus essential oil from the peel is a rich source of antioxidants with a total antioxidant activity of 89% for lemon peel oil. The reason for this activity is due to the mixture of bioactive compounds present in the lemon peel.⁴ 

Chemical components of lemon peel

It is seen that four hydroxycinnamic acids (caffeic, p-coumaric, ferulic and sinapic acids) in free and bound form were reported in the methanolic extracts of a variety Citrus microcarpa peel. The citrus peel represents nearly about 40–50% of the fruit mass and is a rich source of naturally occurring flavonoids. The different types of flavonoids found in citrus peel include flavones-O glycosides, flavones-C-glycosides, flavonols, and flavanones. Studies show that even there is change in flavonoids content depending on the maturation of fruits. Apart from the above mentioned chemical components citrus peel is also rich in other types of antioxidants namely, essential oils which are mixtures of volatile compounds such as aldehydes, ketones, ester, alcohol, acids.⁵

Studies and research on the antioxidant properties of lemon peel

Research studies to evaluate the antioxidant properties includes Nitric oxide radical scavenging, Reducing power determination and it showed positive results of antioxidant properties of lemon peel. The phenolic content which may be responsible for antioxidant properties was evaluated and it states that flavonoids and its structure seems to be responsible for antioxidant activity in the lemon peel.⁶ There is an interesting study which states about fresh and frozen peels of lemon for antioxidant properties. To the surprise, the frozen peel of lemon has a higher dietary antioxidant and more phenolic content and can be used as a raw material for dietary supplements.⁷ 

Role of lemon peel as an antioxidant

Essential oil present in the citrus peel is a good source of natural antioxidants that prevent oxidative stress and other diseases.The Citrus Peel Essential Oil (CPEO) is a better substitute rather than chemical antioxidant in the food process industry.8 Antioxidants shows several health related benefits which make them promising source in the pharmaceutical field and studies show that these properties are usually present in the peels rather than the pulp of fruits.It is also seen that citrus peel extract exhibited strong antioxidant effect against lipid oxidation and they can be used as a potential source in the field of medicine.⁹ Studies shows that flavonoid content from citrus peel led to better cognitive function and lowers the risk of depression and dementia.¹⁰ One such agricultural waste that finds widespread application in the cosmetic sector is citrus peel waste. Rich in antioxidants, citrus peel helps prevent oxidative damage to the skin and delays the onset of ageing and skin-related problems like wrinkles and dark spots.¹¹

Key points

• Oxidative stress is a key reason for various chronic health conditions and antioxidants are vital to prevent these disorders
• Antioxidants capture the free radicals and prevent oxidative damage to the body
• Citrus peels are rich in antioxidants with the presence of various essential oils and polyphenols
• They have various health related benefits to prevent chronic health issues

Summary

Antioxidants are vital compounds that neutralize free radicals—reactive oxygen atoms formed during metabolic reactions that can cause oxidative stress and damage proteins, lipids, and DNA. This damage is linked to various diseases, including cardiovascular conditions, neurological disorders, and cancer.

Lemon peels, typically discarded as waste, are rich in essential oils and flavonoids, making them a potent source of natural antioxidants. These compounds in lemon peel oils exhibit significant antioxidant, germicidal, antibacterial, and anticarcinogenic properties. Research confirms that lemon peel, especially when frozen, has a high antioxidant activity due to its bioactive compounds.

Antioxidants from citrus peels offer multiple health benefits, including improved cognitive function, reduced risk of depression and dementia, and protection against skin aging and damage. Thus, lemon peels can be effectively used in food processing, pharmaceuticals, and cosmetics as a natural and beneficial source of antioxidants.