Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 10/9/2006
Publication Date: 10/9/2006
Citation: Vazquez-Carrillo, M.G., Salinas-Moreno, Y., Flores-Gomez, L., Palacios-Rojas, N., Scott, M.P. 2006. Anthocyanin content and antioxidant activity in maize (Zea mays L.) races [abstract]. 4th International Congress on Pigments in Food:Pigments in Food - A Challenge to Life Sciences. Poster.
Technical Abstract: There are maize kernels of different colors including black, blue, red, orange, white and brown. Use of blue and red maize kernels has been increasing, especially in Mexico and Central America, (Betrán et al., 2000). Anthocyanins are the pigments responsible for the blue, black, red and brown colours of the kernels. They are important as natural colorants (Mazza et al., 1993), antioxidants, anti-mutagenic and are anti carcinogenic. Twelve maize races were used in this study, three Mexican ones and nine obtained from the Regional Plant Introduction Station, Ames, Iowa, USA. A Hunter Lab MiniScan XE Plus colorimeter was used for color determination. Total anthocyanin content was quantified in raw kernel flour using a conventional spectrophotometric method (Salinas et al., 2005). The chromatographic profile of the anthocyanins from each sample was obtained with HPLC. The anthocyanins were identified using commercial standards of cyanidin 3-glucoside, pelargonidin 3-glucoside and malvidin 3-glucoside. Antioxidant activity was measured in flours of raw grain according to the protocol described by Soler-Rivas et al. (2000). Ari-USA had the highest proportion of anthocyanins (2612 mg kg-1 flour), being more than two-fold higher than a previously reported value for maize kernels (Salinas et al., 2005). The Mexican races samples showed anthocyanin levels higher than previously reported for the same races collected in other Mexican states (Espinosa, 2003) Table 1. Samples Ari and Arequipa, showed similar anthocyanin profiles (Figure 1). Thirteen peaks were observed, including cyanidin-3-glucoside (1), pelargonidin 3-glucoside (3) and malvidin 3-glucoside (5). Picks 6-10 are unknown but most probably they are acylated anthocyanins (Harbone and Self, 1987). Cyanidin-3-glucoside was in higher proportion in blue kernels. In the red kernels of Gto1 and IA18, up to 17 peaks were observed, with pelargonidin 3- glucoside being dominant. In samples IA19 and IA3 (red pericarp and yellow endosperm), cyanidin 3-glucoside was found in high proportion and acylated anthocyanins were 66 and 61%, respectively. Antioxidant activity varied from 90 to 60 reduced DPPH percentages. In general, blue kernels had the highest antioxidant activity, follow by the violet kernels and red kernels. The differences among samples could be due to other flavonoids present in the kernels that also contribute to the antioxidant activity (Yan-Hwa et al., 2000). The highest anthocyanins content was found in black kernels. When pigments were located in both pericarp and aleurone layer, the higher anthocyanins content were found in black, blue and red kernels. The anthocyanin profile for black and blue kernels were similar, with cyanidin-3-glucoside being in higher content. Red kernels did not show any specific anthocyanins which could be used their identification. Ari USA maize is a great source of acylated anthocyanins.