Citrus Sphaerocarpa peel water is a hydrosol obtained from the peel of the Citrus Sphaerocarpa fruit, commonly known as "kabosu" in Japan. This water-based extract retains many of the bioactive compounds found in the peel, such as vitamins, flavonoids, and trace amounts of essential oils, providing it with antioxidant, soothing, and moisturizing properties. It is used in skincare and haircare formulations to hydrate, refresh, and protect the skin and hair while offering a mild, refreshing citrus scent. Citrus Sphaerocarpa peel water is particularly valued for its gentle, non-irritating nature, making it ideal for sensitive skin.
Chemical Composition and Structure
Citrus Sphaerocarpa peel water contains water-soluble compounds such as flavonoids, small amounts of essential oils like limonene, and trace elements that are beneficial to the skin. While the concentration of active ingredients is lower compared to the essential oil, the peel water still provides antioxidant and soothing effects. The hydrosol also contains vitamins like vitamin C, contributing to its brightening and revitalizing properties.
Physical Properties
Citrus Sphaerocarpa peel water is a clear, water-like liquid with a subtle citrus fragrance. It is water-soluble and easily incorporated into aqueous-based formulations like toners, mists, and lotions. The hydrosol is light and non-greasy, making it suitable for leave-on skincare products. Its mild, refreshing scent provides a pleasant sensory experience without overwhelming the formula.
Production Process
The production of Citrus Sphaerocarpa peel water involves the following steps:
Harvesting: The Citrus Sphaerocarpa fruits are harvested when ripe.
Peel Distillation: The peels are steam-distilled to extract the water-soluble compounds, producing the hydrosol that contains trace amounts of essential oils and beneficial plant compounds.
Filtration and Packaging: The resulting peel water is filtered to remove any solid particles and then packaged for use in various cosmetic and personal care formulations.
Applications
Skincare: Citrus Sphaerocarpa peel water is widely used in toners, mists, and lotions due to its hydrating and refreshing properties. It helps to soothe the skin, improve moisture retention, and offer a mild antioxidant boost. Its gentle nature makes it suitable for sensitive skin and products aimed at hydration and rejuvenation.
Haircare: In haircare products, Citrus Sphaerocarpa peel water is used to hydrate the scalp and hair, providing a lightweight moisture boost without weighing down the hair. Its refreshing properties help cleanse and revitalize the scalp.
INCI Functions:
Skin conditioning agent - Humectant. Humectants are hygroscopic substances used to minimise water loss in the skin and to prevent it from drying out by facilitating faster and greater absorption of water into the stratum corneum of the epidermis. The epidermis is the most superficial of the three layers that make up the human skin (epidermis, dermis and hypodermis) and is the layer that maintains hydration in all three layers. In turn, the epidermis is composed of five layers: corneum, the most superficial, lucidum, granulosum, spinosum and basale. Humectants have the ability to retain in the stratum corneum the water they attract from the air and have the function of moisturising the skin. It is better to use them before emollients that are oil-based.
- Medical: Consumed to aid digestion and improve overall health due to its high antioxidant capacity (1). The hexane extract of Citrus sphaerocarpa seems to suppress lipid accumulation (2).
Aromatherapy and Refreshing Mists: The subtle, refreshing citrus scent of Citrus Sphaerocarpa peel water makes it ideal for use in refreshing facial mists, body sprays, or aromatherapy products, offering a gentle and natural fragrance.
Sensitive Skin Formulations: Due to its mild and soothing properties, Citrus Sphaerocarpa peel water is frequently included in formulations designed for sensitive skin, providing gentle hydration and antioxidant benefits without irritation.
Environmental and Safety Considerations
Citrus Sphaerocarpa peel water is considered safe for use in cosmetic formulations. It is non-irritating and non-sensitizing, making it ideal for sensitive skin types. Its water-based nature and low concentration of essential oils reduce the risk of photosensitivity compared to citrus essential oils, though sun protection is always recommended when using citrus-based products.
From an environmental perspective, Citrus Sphaerocarpa peel water is derived from a natural and renewable resource, making it a sustainable ingredient. The production process typically involves repurposing peels, minimizing waste and environmental impact.
References__________________________________________________________________________
(1) Tomiyama K, Aoki H, Oikawa T, Sakurai K, Kasahara Y, Kawakami Y. Characteristic volatile components of Kabosu (Citrus sphaerocarpa Hort. ex Tanaka). Nat Prod Commun. 2011 Mar;6(3):403-8.
Abstract. The volatile components of both peel and juice of Japanese citrus, Kabosu (Citrus sphaerocarpa Hort. ex Tanaka) were investigated using SAFE (Solvent Assisted Flavor Evaporation) technique after solvent extraction. In this study, wine lactone, rose oxide, (2E)-4,5-epoxy-2-decenal, mintsulfide, and indole were newly identified from Kabosu. AEDA (Aroma Extract Dilution Analysis) of the oxygenated fraction of the peel extract showed high FD (Flavor Dilution) factors for linalool, (2E)-4,5-epoxy-2-decenal, octanal, (4Z)-decenal, beta-citronellol, geraniol, and wine lactone, while wine lactone, linalool, eugenol, geraniol, and (2E)-4,5-epoxy-2-decenal from the juice extract. The enantiomeric distribution of linalool, cis-rose oxide, beta-citronellol, and wine lactone were also determined using a multidimensional chiral GC/MS.
Akakabe Y, Sakamoto M, Ikeda Y, Tanaka M. Identification and characterization of volatile components of the Japanese sour citrus fruit Citrus nagato-yuzukichi Tanaka. Biosci Biotechnol Biochem. 2008 Jul;72(7):1965-8. doi: 10.1271/bbb.80144.
Abstract. A total of 39 aroma compounds were detected in the essential oil of Citrus nagato-yuzukichi Tanaka (nagato-yuzukichi) by gas chromatography-mass spectrometry (GC-MS). The essential oil was characterized by a high percentage of monoterpene hydrocarbons (12 components, 90.52%). The composition pattern of essential oil in C. nagato-yuzukichi was fairly similar to that of Citrus sudachi Hort. ex Shirai (Sudachi). Principal component analysis (PCA) of data obtained with an electronic nose indicated a variation of each oil along PC1. The oils of Citrus junos Tanaka (Yuzu) and Citrus sphaerocarpa Tanaka (Kabosu) showed a clear upward displacement as compared with those of C. nagato-yuzukichi and C. sudachi. However, in PC2, the oils of C. nagato-yuzukichi and C. sudachi showed a displacement in a negative direction and a positive one respectively.
(2) Zang L, Kagotani K, Hayakawa T, Tsuji T, Okumura K, Shimada Y, Nishimura N. The Hexane Extract of Citrus sphaerocarpa Ameliorates Visceral Adiposity by Regulating the PI3K/AKT/FoxO1 and AMPK/ACC Signaling Pathways in High-Fat-Diet-Induced Obese Mice. Molecules. 2023 Dec 9;28(24):8026. doi: 10.3390/molecules28248026.
Abstract. Obesity is an emerging global health issue with an increasing risk of disease linked to lifestyle choices. Previously, we reported that the hexane extract of Citrus sphaerocarpa (CSHE) suppressed lipid accumulation in differentiated 3T3-L1 adipocytes. In this study, we conducted in vivo experiments to assess whether CSHE suppressed obesity in zebrafish and mouse models. We administered 10 and 20 μg/mL CSHE to obese zebrafish juveniles. CSHE significantly inhibited visceral fat accumulation compared to untreated obese fish. Moreover, the oral administration (100 μg/g body weight/day) of CSHE to high-fat-diet-induced obese mice significantly reduced their body weight, visceral fat volume, and hepatic lipid accumulation. The expression analyses of key regulatory genes involved in lipid metabolism revealed that CSHE upregulated the mRNA expression of lipolysis-related genes in the mouse liver (Pparα and Acox1) and downregulated lipogenesis-related gene (Fasn) expression in epididymal white adipose tissue (eWAT). Fluorescence immunostaining demonstrated the CSHE-mediated enhanced phosphorylation of AKT, AMPK, ACC, and FoxO1, which are crucial factors regulating adipogenesis. CSHE-treated differentiated 3T3L1 adipocytes also exhibited an increased phosphorylation of ACC. Therefore, we propose that CSHE suppresses adipogenesis and enhances lipolysis by regulating the PI3K/AKT/FoxO1 and AMPK/ACC signaling pathways. These findings suggested that CSHE is a promising novel preventive and therapeutic agent for managing obesity.
Citrus Sphaerocarpa Peel Water 
