Citrus plants belong to the family Rutaceae which includes fruits such as orange, mandarin, lime, lemon, sour orange and grapefruit. These are a well known promising source of multiple beneficial nutrients for human beings. Processing of citrus by-products potentially represents a rich source of phenolic compounds and dietary fibre owing to a large amount of peel produced.
These citrus fruit residues, which are generally discarded as waste in the environment, can act as potential nutraceutical resources. Due to their low cost and easy availability, such wastes are capable of offering significant low-cost nutritional dietary supplements. The utilization of these bioactive rich citrus residues can provide an efficient, inexpensive, and environment-friendly platform for the production of novel nutraceuticals or for the improvement of older ones. This review systematically summarized the potential components present in citrus peel, which are generally discarded as waste.
Citrus peels contain high levels of antioxidants. As antioxidants, citrus peels may contribute to the protection of your DNA from cancer-causing damage. According to Medicinal Herbs & Spices, citrus peels contain greater amounts of antioxidants than vitamin E. When used in their natural form, the antioxidant effects of citrus peels are enhanced by the high levels of vitamin C found in citrus fruits.
In addition to possessing beneficial properties towards diabetes and cholesterol, citrus peels have been found to help with obesity. According to a study published in the “Journal of Clinical Biochemistry and Nutrition” on October 31, 2008, the introduction of lemon polyphenols was found to be successful in the suppression of body weight gain and body fat accumulation. The study found significant improvements in levels of serum insulin, glucose, and leptin by lemon polyphenols (found in lemon peels) which helps improve insulin resistance. This study suggests lemon polyphenols has the ability to “prevent or improve obesity and insulin resistance by modulating lipid metabolism and prevent metabolic syndrome as a representative, lifestyle-related cluster of diseases caused by an excessively high-fat diet”. Pectin, a natural fibre found in the peel helps curb cravings and diminish overactive appetites.
Citrus peels contain various flavonoids that have demonstrated effective anti-cancer properties in both in vitro and in vivo, according to a 2014 article published in “Food Science and Human Wellness”. Studies suggest compelling evidence that flavonoids in citrus peels such as Nobiletin, Hesperidin, and Citrus Peel Extract have potent anti-tumour activities in cancers of the skin, colon, prostate, lung, and liver. Nobiletin is a representative of citrus poly methoxy flavones that have shown potent beneficial activities against carcinogenesis.
Research from Japan’s Nakamura University demonstrated that citrus peel extract has the ability to block Tumor Growth on both a dose-dependent and time-dependent level. This means that the higher the dosage, the greater the inhibition with effects continuing over the duration of the treatment. Another flavonoid that is found in citrus fruit and particularly abundant in the peel is Hesperidin. Hesperidin has been shown to suppress precancerous lesions and may inhibit certain types of cancers. The limonene in citrus peel is also a Phytonutrient and has anticarcinogenic and anti-cancer properties. Limonene helps activate the body’s antioxidant detoxification enzyme system which limits the ability for growth of cancer cells while citric acid assists with the starvation of cancer cells by cutting off their energy supply.
AMNA SHEHBAZ
Faisalabad
