393 Effect of the Process of Dyeing a Natural Fiber Fabric Using Watery Extract of Cochineal G. Arroyo-Figueroa a and G.M.L Ruiz-Aguilar Departamento de Ingeniería Agroindustrial Universidad de Guanajuato Salvatierra, Guanajuato Mexico A.L. Vigueras-Guzmán and L. Portillo Departamento de Botánica y Zoología Universidad de Guadalajara Guadalajara, Jal. Mexico H. Arroyo-Figueroa Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, D.F. Mexico Mexico G. González-Sánchez Centro de Investigación de Materiales Avanzados Chihuahua, Chih. Mexico Keywords: carmine, Dactylopius coccus, natural pigment, textile industry, mordanting Abstract A natural ideal pigment to replace the synthetic colorings and to be used in textile industry is the insect Dactylopius coccus Costa. This pigment is generally used for artisanal textiles. It is necessary to carry out research that allows the employment of this natural pigment in textile industries. With the aim to determine the effect of the dyeing process in cotton fabric, using as pigment the extract of cochineal, eight tests of dyeing were carried out changing in each one the concentration of the mordant used during the process. The eight dyed fabrics were analyzed in a scan electronic microscope. Also the original fabric without any process was analyzed, the washed fabric and the pre-mordanting fabric in their three phases (1 st , 2 nd and 3 rd mordanting stages). No differences were observed between the micrographies of the fabric after the stage of wash with regard to the original fabric; nevertheless, there were differences between the micrographies from the first phase of mordanting up to the stage of dyeing, with regard to the original fabric. On the other hand microscopic difference did not differ among each of the fabrics dyed in eight tests. At the same time, in order to observe other differences among the eight fabrics, their colors were measured and absorbance was determined. Presenting the major dark-red tone, the fabric dyed with the process of test 3, and this fabric allowed crossing a medium intensity of light. The dyed fabric that allowed crossing the minor intensity of light was that obtained with test 5, being very close to the result of test 8. INTRODUCTION Fibers are organized in natural, synthetic and artificial. Among natural fibers are those that are obtained from seeds, stems or leaves (Hollen et al., 2005). Cotton is a plant fiber that is obtained from seeds; it is a cellulose fiber (94% cellulose) which basic unit is glucose, constituted by a great quantity of chains of glucose, polymer of sugar, its chemical reactivity is related to the groups hydroxy (-OH), which constitute the glucose (Hollen et al., 2005). The physical structure that characterizes this fiber is a kind of folds which produce one twisted structure forming a natural waviness (Hollen et al., 2005). Cotton belongs to the Gossypium genus that many years before the discovery of America, the aborigines cultivated, harvested and processed (Arroyo, 2008). The cultivated species G. herbaceum, G. hirsutum and G. barbadense produce short, medium and large fibers, respectively (Vigueras and Portillo, 2004). Cotton is native to Mexico where it has been cultivated for ages (Takahashi, 2003). Synthetic materials have substituted notably the fibers of plant and animal origin for the manufacture of textiles (Esparza, 1999). a gabiaf@yahoo.com.mx Proc. 7 th International Congress on Cactus Pear and Cochineal Eds.: A. Nefzaoui et al. Acta Hort. 995, ISHS 2013