Upcycled citrus fruit waste holds potential for cosmetics industry, flags research

18 Mar 2022 --- Multiple researchers suggest citrus waste can be used in perfumery and cosmetics due to its valuable bioactive compounds and phytochemicals. Researchers in India outline various upcycling opportunities to industry from citrus peels, seeds and pomace.

Citrus peel waste is extensively used in the cosmetic industry, flag the researchers. The peel has been researched to be effective for hyperpigmentation and aging skin.

Citrus seed oil is proposed to be used as an ingredient for medicinal soaps as it exhibits “remarkable anti-microbial, anti-fungal, anti-parasitic and antioxidative properties.”

Skin whitening properties
The researchers explain that Citrus reticulata Blanco peel extract showed “anti-collagenase and anti-elastase potential” with “high antioxidant and anti-enzymatic activity” in in-vitro tests. The anti-aging extract was derived using soxhlation. 

“The antioxidants present in citrus peel help in delaying skin aging and aids in reducing oxidative damage as well as skin-related issues such as acne, wrinkles and dark spots.” Citrus waste can be used for natural ingredients in cosmetics, medicines, packaging materials and biofuels, suggest researchers.  

For instance, the alcoholic extract of Citrus reticulata peels was tested in-vitro, where it was suggested to be used in anti-wrinkle skincare formulas.

Additionally, the California navel orange peel (Citus sinesis L.) was noted for its “high anti-tyrosinase activity leading to lowering melanin pigment,” thus, showing potential to be used in skin whitening cream, the study suggests. 

The paper also shares that anti-tyrosinase (inhibiting browning) activity was found in orange (Citus sinesis L.) peel extract; thus, formulating a whitening cream can prevent the accumulation of melanin pigments.

“Orange peel showed significant anti-tyrosinase property with an IC50 [potency] value of 255.10 µg/ml. Whitening cream developed using the orange peel waste (2%) weight by weight could reduce melanin pigment by 17.33%.” 

However, the researchers suggest that further research is required to test the effectiveness of citrus peel waste for skincare and hyperpigmentation. 

Health-promoting properties
“Citrus peels offer vast potential for valorizing natural antioxidants, pectin, enzymes and essential oils,” suggest the researchers. They are also rich sources of Vitamin C, folic acid, potassium and pectin.  “China, India, Nigeria, Brazil, and Mexico are the major citrus-growing countries globally,” find researchers.

According to researchers, citrus fruits have gained interest due to their high polyphenols, mainly flavonoids and antioxidant content. 

“Flavanones such as naringin and hesperidin are usually found in tissues and peels of citrus fruits, displaying numerous therapeutic advantages due to their antioxidative, anti-inflammatory, and anti-carcinogenic properties.”

The researchers describe citrus as commercially grown fruits with an “excellent repository of phytochemicals and biologically active compounds with health-promoting properties.” 

Apart from health benefits, the researchers say that their essential oils make them suitable to incorporate in cosmetic products.

Citrus seeds for medicinal soap
In addition, citrus seeds are recognized as a source of natural oil. Seeds are used in the cosmetic industry to prepare soaps, body lotions, body sprays and other cosmetic products. 

Citrus sinensis seed oil was extracted by soxhlet and saponified using a natural lye solution to create medicinal soaps. The extract contained linoleic acid (36%) and oleic acid (27%). 

Therefore the research paper suggests that the use of naturally available citrus seed and peel oil can reduce the exposure to synthetic chemicals and be a better use of waste. 

Extracting essential oils
The researchers describe essential oils as: “aromatic liquids that contain an assembly of volatile compounds.” A study suggests that essential oil extracted from citrus peels is used for flavors and fragrances.

A solvent-free microwave extraction technique of essential oils from Citrus limon peel resulted in the recovery of limonene (1.26%). 

Supercritical fluid method for oil extraction from Citrus limon peels resulted in a greater yield of d-limonene (4.5%). Using the same method, another study found that CO2 extraction from mandarin (Citrus unshiu Kuno) peel resulted in a “high limonene yield of 30.65% at 300 bar pressure .” 

Firmenich details conscious perfumery targets for 2030 featuring renewable fragrances in recent perfumery news. The company also unveiled its 2022 perfumery collection featuring green chemistry ingredients. 

Meanwhile, Symrise and Antofénol collaborated for clean beauty by leveraging eco-extraction for natural products.

Edited by Venya Patel