J. Cosmet. Sci., 68, 233–244 (May/June 2017) 233 Color profi les and stability of acylated and nonacylated anthocyanins as novel pigment sources in a lipstick model: A viable alternative to synthetic colorants ALEXANDRA WESTFALL and M. MÓNICA GIUSTI, Department of Food Science and Technology, The Ohio State University, Columbus, OH. Accepted for publication May 6, 2017. Synopsis Cosmetics, such as lipstick, can affect an individual’s perception of attractiveness and morale. Consumer concern with the safety of synthetic colorants has made the need for alternative natural color sources increasingly urgent. Our goal was to evaluate the feasibility of anthocyanin (ACN) extracts as colorants in lipstick formulations. Lipstick formulations were colored with ACN-rich materials. Accelerated environmental testing typical of the cosmetic industry were used: incubation at 20°, 37°, and 45°C for 12 weeks and temperature abuse cycles between 20°/37°C or -20°/20°C. Color (CIELab) and total monomeric ACN (pH- differential) changes were monitored to determine shelf stability of the product. All formulations exhibited acceptable color for lipsticks. Shelf stability was determined to exceed 2 year based on the accelerated testing conditions. Formulations containing cyanidin as their main ACN were the most stable (elderberry, purple corn, and purple sweet potato). ACNs could be used as suitable alternatives to synthetic colorants in lipid- based topical formulations. INTRODUCTION Color is a crucial element for the cosmetic industry because it has a direct and immediate effect on consumer self-perception of attractiveness (1). The strongest evidence for the psychological infl uence of colored cosmetics, such as lipstick, is the phenomenon of in- creased spending by women on attractiveness-enhancing products during times of economic downturn, nicknamed the “lipstick effect” (2). Lipstick has been associated with boosts in morale, as well as increased attractiveness to potential mates, since the Great Depression when lipstick sales skyrocketed unexpectedly (2). Lipsticks are typically colored with synthetic pigments such as D&C Reds #6 (CI 15850), #7 (CI 15850), #28 (CI 45410) FD&C Yellow #5 (CI 19140), and FD&C Blue #1 (CI 42090) however, consumer concerns with the safety of synthetic colorants have been growing in recent years. Eosin- and fl uorescein-based colorants used in cosmetics [D&C Red #21 (CI 45380), D&C Red #22 (CI 45380), and D&C Red #27 (CI 45410)] are often Address all correspondence to M. Mónica Giusti at giusti.6@osu.edu.

JOURNAL OF COSMETIC SCIENCE 234 associated with photosensitization-induced cheilitis or infl ammation of the mouth (3). Azo dyes are frequently associated with contact dermatitis, especially with repeat expo- sure (4). Azo dyes, such as D&C Red #6, D&C Red #7, and FD&C Yellow #5, are some of the most commonly used organic pigments in lipstick formulations (5). Carmine (CI 75470), a natural source of color in cosmetics, has also been shown to produce contact dermatitis on the lips and skin of sensitive populations (6,7). The combination of concerns with synthetic colorants and an increase in consumer demands for more “natural” ingredients in cosmetics makes fi nding plant-derived alternatives a necessity (8). One such alternative color source is a group of water-soluble fl avonoids known as antho- cyanins (ACN) (9). ACNs are responsible for many of the red, purple, and blue shades found in fruits and vegetables. Although ubiquitous in nature, there are six common aglycones, namely, cyanidin, delphinidin, malvidin, pelargonidin, peonidin, and petunidin, with various types of glycosylation and acylation. They have been frequently used in the food industry as a natural colorant source (10). Their use as alternatives to synthetic colorants, such as FD&C Red #40 (CI 16035) (11), FD&C Red #3 (CI 45430), and FD&C Blue #2 (CI 73015) (12), has also been proposed. Moreover, the interest in their use as colorants has also been fueled by a desire to fi nd uses for waste by-products of the agriculture in- dustry, such as grape skins from the wine industry (13,14). The stability and color of ACNs is infl uenced by many factors including pH, tempera- ture, light exposure, and interactions with other compounds (15). Substitutions on the B-ring of ACNs and the presence of additional hydroxyl or methoxyl groups infl uence their stability (16). However, ACN sources with additional glycosylations and acylations have been shown to exhibit high resistance to these degradation factors (11). ACNs have also gained increased interest because of their potential health benefi ts, such as their potent antioxidant properties (11). Therefore, their use in cosmetics may replace ingredients of concern to consumers with potentially health-promoting bioactive pig- ments. To date, most of the research surrounding the use of ACNs has been focused on aqueous food systems (17). The potential of certain ACN sources to match the colors typically used in lipstick formulations makes them an attractive alternative to synthetic colorants. The aim of this study was to investigate the potential use of ACN extracts as natural colorants in lipstick formulations by evaluating their ability to produce shades of lipstick of commercial relevance, as well as their color stability during accelerated environmental testing as viable alternatives to synthetic lipstick colorants. Nonacylated cyanidin–based and acylated cyanidin–based sources, such as elderberry (Sambucus nigra L.), purple carrot (Daucus dacota L), purple corn (Zea mays L.), purple sweet potato (Ipomoea batatas L.), and red cabbage (Brassica oleracea L.), were chosen because of their vast abundance in nature and high stability (18). Hibiscus (Hibiscus sabdariffa L.), a source of nonacylated delph- inidin, was chosen because of its reported high antioxidant activity (19). Red radish (Raphanus sativus L.), a source of acylated pelargonidin, was chosen because of its reported stability and potential as an alternative to synthetic red colorants (20). Strawberry (Fragaria x ananassa), a source of nonacylated pelargonidin, was used for a comparison of acylation effects in pelargonidin (21). Red grape (Vitis vinifera L.), which contains all six aglycones, was also investigated to better understand the effect of chemical structure on color stability.