Taro Mucilage: Extraction, Characterization, and Application in Cosmetic Formulations VANIELE BUGONI MARTINS, JULIANA GIANTINI DA SILVA CARVALHO, GABRIELLI ALINE PIETRO BOM, MÁRIO ANTÔNIO ALVES DA CUNHA, JULIO CESAR KLEIN DAS NEVES, MARINA LEITE MITTERER DALTOÉ, and CRISTIANE REGINA BUDZIAK PARABOCZ, De partamento de Química, Universidade Tecnológica Federal do Paraná, Via do Conhecimento, Pato Branco 85503-390, Brasil (V.B.M., J.G.D.S.V.C., G.A.P.B., M.A.A.D.C., M.L.M.D., C.R.B.P.), Depa rtamento Acadêmico de Mecânica, Universidade Tecnológica Federal do Paraná, Rua Dep. Heitor Alencar Furtado, Curitiba 81280-340, Brasil (J.C.K.D. N.) Accepted for publication February 11, 2021. Synopsis T aro muci lage, a hydrocolloid present in the rhizome of Colocasia esculenta (L.) Schott, was extracted and characterized by infrared spectroscopy, X-ray diffraction, scanning electron microscopy, thermal analysis, and proximal composition. In addition, cosmetic formulations based on extracted mucilage were developed and studied. The mucilage presented a semicrystalline structure with high thermal stability, the presence of granules along its surface area, and good emulsifying activity. High physical–chemical stability was also found in the mucilage and the cosmetic formulations during storage. All cream samples presented pseudoplastic behavior, with a fl ow behavior index lower than 1, which is a desirable characteristic for cosmetics, as it improves its applicability. The mucilage demonstrates potential for application in cosmetic products, and its commercial use as an ingredient in cosmetics could be a strategic tool for the creation of a new product chain and adding value to the culture of Colocasia0 esculenta. INTRODUCT I ON Colocasia esculenta (L.) Schott is a plant native to the humid tropical regions of Asia, belonging to the Araceae family, which is composed of at least 100 genera and more than 1,500 species. The plant has rhizomes with a high carbohydrate content (90–95%), pro- tein (2.9–4.9%), fi ber, and mucilage (1,2). The most widely cultivated varieties include Colocasia esculenta var esculenta and Colocasia esculenta var antiquorum. The fi rst has a large central corm with suckers and stolons, and the second is the eddoe type, which has a small central corm and a large number of smaller cormels (3). Address all correspondence to Cristiane Regina Budziak Parabocz at cristianerb@utfpr.edu.br. J. Cosmet. Sci., 72, 279–291 (May/June 2021) 279

In Brazil , Colocasia esculenta, popularly known as taro, is cultivated mainly in the South- Central regions, and the cultivars are classifi ed as domesticated or wild depending on the calcium oxalate content present. The rose variety also named rose or pork yam is classifi ed as wild and is used in swine feed (4,5), although still little exploited commercially. Taro is one of the oldest crops in the world used as food, and it has the potential to produce reasonable yields under conditions where most crops would fail, and this makes it a food security crop (6). The cultivation of this crop is generally carried out by small farmers and has great importance for the livelihood of many subsistence farmers in some developing countries, playing relevant economic and nutritional roles (3,6). The mucil age contained in the rhizomes of the plant could be investigated for technological applications as an emulsifying hydrocolloid. Mucilages are hydrocolloids found in vegetables as products of plant metabolism and are molecules derived from the polymerization of mono- saccharides which often have uronic acids in their constitution. These hydrocolloids form viscous masses or gels in the presence of water, and may have an amorphous (7–9) or semicrys- talline structure (10). In this context, they act as thickeners, binders, suspending agents, emulsifi ers, gelling agents, and stabilizers (11), presenting unique rheological properties (2,12). Some mucilages have been used as excipients in the production of cosmetics, pharma- ceuticals, foods, textiles, paints, and stationery, replacing the synthetic excipients and emulsi- fi ers (8,13). They are biocompatible, biodegradable, nontoxic, less expensive than synthetic products, and available in nature. It is important to highlight the recent trend and interest in relation to the use of herbal products and the replacement of synthetic additives by natural products (14,15). In previous research, sensory aspects in the use of Colocasia esculenta mucilage as an emulsifying agent in cosmetic emulsions were studied, and the results showed a potential use in cosmetic emulsions with good acceptance by consumers (16). Now, with a focus on chemical and physicochemical aspects, the pink variety Colocasia escu- lenta (L.) Schott mucilage was extracted and characterized by different analytical techniques. In addition, this hydrocolloid was studied for the fi rst time as an ingredient for cosmetic formulations, and its properties have been compared with a commercial biopolymer. MATERIAL AND METHODS MUCILAGE EXTRACTION The mucil age of the rose variety Colocasia esculenta (TM) was extracted from the rhizome of the plant. The rhizomes were washed, weighed, and peeled, and a portion of 300 g was mixed with 100 mL water and triturated in an industrial blender for 3 min. The crushed biomass was fi ltered through polyester cloth, frozen and dehydrated by lyophilization (LIO- TOP L108, Liobras, Brazil), and then stored in polyethylene pots in a desiccator until use. MUCILAGE CHARACTERIZATION X-ray dif fraction analysis (XRD) was performed using a Rigaku diffractometer (Minifl ex 600, Rigaku, Japan) with a copper radiation source (CuKα: 1.5418 Å), 40 kV voltage, 15 mA and readings performed in the range of 3–60° (2θ), step width of 0.02° (2θ), and scanning speed of 2° per minute. JOURNAL OF COSMETIC SCIENCE 280