Effect of screening and subculture on the production of betaxanthins in Beta vulgaris L. var. ‘Dark Detroit’ callus culture G. Trejo-Tapia a , J.B. Balcazar-Aguilar b , B. Martínez-Bonfil a , G. Salcedo-Morales a , M. Jaramillo-Flores c , M.L. Arenas-Ocampo a , A. Jiménez-Aparicio a, ⁎ a Centro de Desarrollo de Productos Bióticos, Instituto Politécnico Nacional, P. O. Box 24, Yautepec, 62731, Morelos, México b Instituto Tecnológico de Zacatepec, P. O. Box 45, Zacatepec, 62780, Morelos, México c Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional. Carpio y Plan de Ayala s/n, Col. Santo Tomás, México, 11340, Distrito Federal, México Received 13 February 2007; accepted 27 April 2007 Abstract Plant cell culture is an innovative technology to produce a variety of substances including natural dyes. Betaxanthins are considered food-safe nutraceutics pigments because exhibit antiradical and antioxidant activity. An important obstacle for developing large-scale production systems based in plant cells has been the instability of metabolite accumulation. In this work, a protocol was established to obtain yellow callus of B. vulgaris var. ‘Dark Detroit’. Homogeneous and heterogeneous pigmented callus were obtained with yellow, red, orange and colorless phenotype. Particular attention was done to isolate and establish a yellow line. After continuous screening of the more intense yellow callus it was possible to increase the betaxanthins production 1.8-fold after 48 subcultures. Spectrophotometric and chromatographic analysis of the pigments, confirmed the presence of betaxanthins. HPLC analysis indicated two mainly distinct betaxanthins, vulgaxanthin I and II. B. vulgaris yellow callus line did not loose pigment production ability as a result of long-term subculture. © 2007 Elsevier Ltd. All rights reserved. Keywords: Betaxanthins production; Beta vulgaris; Callus culture; Long-term subculture Industrial relevance: The stable B. vulgaris cell culture technology developed could be an alternative process to obtain betaxanthins as nutraceutic pigments. 1. Introduction Natural pigments derived from plants are valuable as color additives for foods, pharmaceutical products and cosmetics. Since color plays a decisive role in consumer acceptance of food, to meet consumer expectations numerous additives are added to restore the initial appearance or for color reinforce- ment. The demand of natural colors has increased because they are safe in contrast to synthetic dyes (Delgado-Vargas, Jiménez- Aparicio, & Paredes-López, 2000). Betalains are nitrogenous plant pigments characteristic of the order Caryophyllales. The main structural characteristic com- mon to all betalains is betalamic acid, which is condensed with cyclo-DOPA to form the red colored betacyanins, or with different amino acids and amines in yellow betaxanthins (Strack, Vogt, & Schliemann, 2003). Betalains are considered as food- safe colorants, water soluble and do not need chemical modification for dispersion in a wide range of products and do not provide non-desirable flavors to foods. Specifically, there is a growing interest in betaxanthins because of their antiradical and antioxidant activity (Cai, Sun, & Corke, 2003; Kanner, Harel, & Granit, 2001; Tesoriere, Butera, Allegra, Fazzari, & Livrea, 2005). Also, betaxanthins can be use as a mean of introducing essential amino acids in the diet (Delgado-Vargas et al., 2000). Plant cell culture has been considered as an alternative to produce a wide variety of secondary metabolites which are difficult to obtain by chemical synthesis including natural dyes (Knorr et al., 1990; Zhong, 2001). There are studies on the Available online at www.sciencedirect.com Innovative Food Science and Emerging Technologies 9 (2008) 32 – 36 www.elsevier.com/locate/ifset ⁎ Corresponding author. Tel.: +52 735 39 4 20 20; fax: +52 735 39 4 18 96. E-mail address: aaparici@ipn.mx (A. Jiménez-Aparicio). 1466-8564/$ - see front matter © 2007 Elsevier Ltd. All rights reserved. doi:10.1016/j.ifset.2007.04.009