J. Cosmet. Sci., 69, 363–370 (September/October 2018) 363 Fragrance Retention in Virgin and Bleached Caucasian Hair ANDRÉ MEDICE, CAROLINA LOURENÇO, REBECA GASPARIN, ADELINO NAKANO, and ANITA J. MARSAIOLI, Campinas State University, Campinas, Brazil, 13083-970 (A.M., A.J.M.), Global Hair Care Center, Symrise, Brazil, 06715-725 (C.L., R.G., A.N.) Synopsis Human hair, when bleached, undergoes oxidation of melamine granules and its structural proteins. This work aims to compare fragrance retention in both virgin and bleached hair, taking into consideration the interactions between fragrance compounds and hair before and after chemical modifi cation. The bleaching process of straight dark brown Caucasian hair was carried out using a 4.5% wt. hydrogen peroxide solution at pH 9.5. Fragrance raw materials were incorporated in a shampoo formulation and applied on hair by washing, followed by rinsing. Hair was then let to dry under controlled conditions of temperature and humidity and the volatiles were collected by solid-phase microextraction and quantifi ed by Gas Chromatography Mass Spectrometry (GC-MS). The more bleached the hair, the higher is the amount of sorbed substances during shampoo washing because of a higher number of holes in the hair structure, which increases its sorption capacity. Besides that, the impairments caused by oxidative reaction of hair surfaces are responsible for the faster evaporation of fragrant compounds and this behavior was compared with the loss of moisture of untreated and bleached hair. INTRODUCTION Fragrances play a decisive role in cosmetics and are often the main characteristic that distinguishes a product from their competitors (1). Hair perfume perception is a very important attribute when creating shampoo fragrances. The consumers expect their hair to be perceived as clean and fresh and this impression is closely linked to the longevity of the fragrance on the hair (2). Moreover the cost of fragrance in the consumer product is not negligible, so each ingredient in the perfume has to be effi cient, be cost-effective, and contribute to the overall consumer satisfaction (1). Therefore, this industry con- stantly strives for fragrance improvement and to make them cost-effective, longer lasting, and relevant to the values of the brand (2). The primary purpose in bleaching human hair is to lighten the hair by partial or com- plete oxidative degradation of the natural color pigment. For this, severe reaction con- ditions are required for destruction of the chromophoric groups of hair melanin. The Address all correspondence to Carolina Lourenco at email@example.com. In memoriam: Inés Joekes, Campinas State University, Campinas, Brazil.
JOURNAL OF COSMETIC SCIENCE 364 bleaching reagents most often used are aqueous solutions of hydrogen peroxide adjusted to pH values between 9 and 11. In bleaching compositions, persulfate salts are often added as accelerators (3,4). A published work on hair fragrance persistence from Blakeway and Seu-Salerno (5) ob- served the high affi nity of amyl salicylate to virgin hair remaining for over 24 h after deposition. According to the authors, the fragrance transference to hair occurs as a parti- tion mechanism of organic molecules from water phase to hair keratin, a mainly nonpolar support, and the fragrance persistence on hair depends on the molecule polarity. The present article contributes to the comprehension of the capacity of fragrance deposition on bleached hair by washing in comparison with the virgin hair and compares the fragrance liberation after drying to the desorption of moisture on hair before and after bleaching. MATERIALS AND METHODS SAMPLES Caucasian virgin dark brown hair, 25-cm long, was purchased from International Hair Importers (New York, NY). The hair tresses were washed with a 2.0% w/w sodium lauryl sulfate aqueous solution and left to dry at room temperature for at least 24 h. BLEACHING TREATMENT Hair tresses underwent bleaching for 10, 20, and 40 min with a hydrogen peroxide solu- tion (4.5% v/v pH = 9.5 at 55°C), consisting of 15% (w/w) of ammonium persulfate, and 70% of distilled water. The pH was reached using a concentrated sodium hydroxide solution (6). After the bleaching treatment, the samples were rinsed with tap water for 2 min and left to dry at room temperature. DIFFERENTIAL SCANNING CALORIMETRY (DSC) ANALYSIS Amounts of 5–7 mg of hair, approximately 0.5-cm long, were cut and placed in pressure- resistant stainless steel capsules. Fifty microliters of deionized water was introduced. The instrument used was DSC 4000 (PerkinElmer, Waltham, MA). The temperature range was from 70°C to 180°C, with a heating rate of 5°C min-1. The samples of hair were stored overnight at an environment with 20°C ± 2°C and 50% ± 5% of relative humidity to ensure constant water content. The capsules were sealed and stored for 24 h before test run. FLUORESCENCE MICROSCOPY Small portions of hair fi bers, about 3 cm long, collected from the swatches were embedded in acrylic resin. Sectional 10-μm cuts were processed with the use of a microtome. The cuts were exposed to rhodamine B (Sigma-Aldrich, St. Louis, MO) solution (10 μg mL-1)
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