Carotenoids and coenzyme Q10 are naturally occurring antioxidant compounds that are also found in human skin. These bioactive compounds have been the focus of considerable research due to their antioxidant, anti-inflammatory, and photoprotective properties. In this review, the current state of the art in the encapsulation of carotenoids and coenzyme Q10 in lipid nanoparticles to improve their bioavailability, chemical stability, and skin absorption is discussed. Additionally, the main findings are highlighted on the cytotoxic and photoprotective effects of these systems in the skin.

Skin health is not only significantly affected by ageing, but also by other lifestyle-related factors, such as sun exposure, exercise and eating habits, smoking or alcohol intake. It is known that the cutaneous tissue can exhibit visible signs of senescence, in the form of, for example, dull complexion, loss of firmness, or changes in pigmentation. Consumers attempt to improve skin health and appearance not only by cosmetic products, but also with the consumption of food supplements. Recently, there has been an increase in the amount of food supplements with claims that are related to skin and hair health. Nevertheless, the literature is still scarce in evidence of the efficacy of this type of products. Considering this scenario, we aim in this review to assemble studies and methodologies that are directed at the substantiation of the cutaneous health claims of food supplements. For example, we reviewed those that were indicative of antioxidant properties, improvement in pigmentation disorders, increased hydration or protection against the damages caused by ultraviolet radiation.

In this study, an analytical method based on Design of Experiments and response surface methodology for the separation of lycopene, beta‐carotene, coenzyme Q10, and lutein was developed by ultra‐high performance supercritical fluid chromatography technique. A Central Composite Design was used to evaluate the influence of temperature, pressure, and ethanol percentage on the retention and separation factors of these compounds. In the designed experiments, the temperature was varied between 25 and 50 °C (298 and 323 K), the pressure within the interval of 1500 and 2200 psi (10 and 15 MPa), and the ethanol percentage between 15 and 24 (v/v) %. Each variable was tested at 3 levels and 5 replicated central points were added. It was found for the studied system that the ethanol percentage and pressure were the parameters that most influenced the retention factors whereas the ethanol percentage, pressure, and temperature affected the separation factors. Quadratic models were necessary to describe the retention and separation of these compounds. Furthermore, interactions among the factors were observed, justifying the DOE approach used in this work. Considering the retention and separation factors, the selected operating conditions for further experiments were: 15.5 % of ethanol at 40 °C (313 K) and 1500 psi (10 MPa).

Lycopene, beta-carotene, coenzyme Q10, and lutein are minor constituents of palm oil that are removed during biodiesel production to produce light-colored oils. With the aim to investigate the recovery of these valuable compounds, a separation method was developed to quantify carotenoids and coenzyme Q10 in palm oil by ultra-highperformance supercritical fluid chromatography. Due to the presence of interferents, different clean-up procedures were evaluated; however, these approaches were ineffective and the separation method was developed without this step. The chemometric method multivariate curve resolution-alternating least squares was employed to properly quantify lycopene, beta-carotene, and coenzyme Q10 in the presence of interferents. Lutein was sufficiently resolved to be quantified by a univariate method. Lycopene concentration was below the limit of quantification 3.12 g/mL (3.12 x 10-3 kg/m 3). Beta-carotene concentration was determined as being 183.48 ±1.66 g/mL (183.48 ±1.66 x 10-3 kg/m 3). Coenzyme Q10 concentration was lower than the limit of detection 4.22 g/mL (4.22 x 10-3 kg/m 3) and lutein concentration 9.24 g/mL (9.24 x 10-3 kg/m 3) was below the limit of quantification. The study showed the analytical challenges associated with the separation and quantification of minor constituents of a highly complex matrix such as palm oil and demonstrated that the recovery of beta-carotene could be economically viable due to its wide range of application in industry.

No abstract