Medice André, Lourenço Carolina, Gasparin Rebeca, Nakano Adelino
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.).
J Cosmet Sci. 2018 Sep/Oct;69(5):363-370.
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 modification. 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 quantified 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.
人类头发在漂白时，其黑素颗粒和结构蛋白会发生氧化。这项工作旨在比较天然头发和漂白头发中香料的保留情况，同时考虑化学改性前后香料化合物与头发之间的相互作用。使用4.5%（重量）的过氧化氢溶液在pH 9.5的条件下对直的深棕色白种人头发进行漂白处理。将香料原料添加到洗发水配方中，通过洗发的方式涂抹在头发上，然后冲洗。接着让头发在温度和湿度可控的条件下干燥，并通过固相微萃取收集挥发物，用气相色谱 - 质谱联用仪（GC - MS）进行定量分析。头发漂白程度越高，洗发过程中吸附的物质就越多，这是因为头发结构中的孔隙增多，从而增加了其吸附能力。除此之外，头发表面氧化反应造成的损伤导致香料化合物蒸发加快，并且将这种行为与未处理和漂白头发的水分流失情况进行了比较。
