Rare colorless carotenoids emerge as multifunctional ingredients for beauty and health
· Medical Xpressedited by Gaby Clark, reviewed by Andrew Zinin
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Colorless carotenoids are naturally occurring compounds found in many fruits and vegetables, and are the biosynthetic precursors of familiar colored carotenoids such as lycopene and β-carotene. Despite their important biological roles, phytoene and phytofluene have received far less scientific attention because their geometric isomers are difficult to separate and purify in sufficient quantities for detailed investigation. As a result, little has been known about how individual isomers differ in their chemical characteristics and biological activities, limiting their potential development as high-value functional ingredients.
To address this challenge, a research team led by Associate Professor Masaki Honda from the Graduate School of Environmental and Human Sciences, Meijo University, Japan, collaborated with researchers Kento Nakamura and Kazumi Sawada at Harima Chemicals Group Inc., Japan. The researchers established an efficient purification strategy to isolate highly pure geometric isomers of phytoene (PT) and phytofluene (PTF), and comprehensively evaluated their structural characteristics, ultraviolet absorption properties, isomerization behavior, antioxidant capacity and skin-related biological activities. The study was published in the journal Food Research International.
Using high-purity samples, the researchers systematically compared the properties of individual isomers for the first time. Their analyses demonstrated that each isomer possesses distinct ultraviolet (UV) absorption characteristics and exhibits different responses to light- and heat-induced isomerization. Notably, PTF isomers exhibited strong UV-A shielding capacity, whereas PT isomers efficiently absorbed UV-B radiation, suggesting that combinations of these naturally occurring carotenoids could provide broad-spectrum UV protection.
They also evaluated antioxidant activity together with biological functions relevant to skin health, including anti-glycation activity associated with healthy aging and enzyme-inhibitory activities linked to skin pigmentation and elasticity. By combining chemical analyses with biological evaluation, the study provided a comprehensive understanding of how geometric structure influences the functionality of these colorless carotenoids.
"Our research was inspired by the limited understanding of individual PT and PTF isomers despite their importance as naturally occurring carotenoids," explains Dr. Honda. "By successfully isolating highly purified isomers, we were able to uncover significant differences in their UV-shielding, antioxidant and biological properties that were previously impossible to evaluate accurately," adds Nakamura.
Unlike conventional carotenoids that impart yellow, orange or red coloration, PT and PTF remain essentially colorless while retaining UV-absorbing properties and other beneficial activities. Their ability to absorb UV light while exhibiting antioxidant and skin-related biological activities suggests they could serve as multifunctional ingredients in UV-protective skin care and cosmetic formulations, skin care products, dietary supplements, functional foods and nutricosmetics. Because they have minimal impact on product color, they may be more readily incorporated into a wide range of commercial formulations than traditional carotenoids.
The findings also highlight the importance of understanding carotenoid functionality at the isomer level rather than treating each compound as a single entity. Such knowledge could enable researchers and manufacturers to select specific isomers that provide desirable biological or physicochemical properties, supporting the development of next-generation natural ingredients for food, cosmetic and health care industries.
"Understanding how individual geometric isomers contribute to biological function provides an important foundation for designing more effective natural products," says Sawada. "We hope these findings will encourage further research into colorless carotenoids and accelerate their application in health, beauty and wellness products."
Overall, this study establishes a comprehensive reference framework for understanding the physicochemical and biological properties of purified PT and PTF isomers. By demonstrating their unique UV-shielding, antioxidant, anti-glycation and skin-related activities, the research positions these colorless carotenoids as promising candidates for next-generation beauty, wellness and healthy aging applications. By revealing their isomer-specific characteristics and biological activities, the research expands the scientific understanding of colorless carotenoids and provides a foundation for developing innovative natural ingredients for future functional food and cosmetic applications.
More information
Yuki Nishimura et al, Comprehensive characterization of high-purity colorless carotenoid (phytoene and phytofluene) geometric isomers: Spectroscopic properties, isomerization behavior, antioxidant capacity, and biological activities, Food Research International (2026). DOI: 10.1016/j.foodres.2026.119474
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Skin & Hair careDermatologyHealthy agingHealthy living Provided by Meijo University Who's behind this story?
Gaby Clark
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Citation: Rare colorless carotenoids emerge as multifunctional ingredients for beauty and health (2026, July 7) retrieved 7 July 2026 from https://medicalxpress.com/news/2026-07-rare-colorless-carotenoids-emerge-multifunctional.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.