Comparison of total polyphenols, profile anthocyanins, color analysis, carotenoids and tocols in pigmented maize

Abstract

Total phenolics, flavonoids, anthocyanins, CIELAB color, tocols and carotenoids were determined in whole kernels of four different pigmented (yellow, red, blue and purple) maize genotypes. The aim of this work was devoted i) to characterize the anthocyanin profile, ii) to compare the bioactive phytochemical substances, iii) to promote the introduction of new pigmented maize genotypes. Anthocyanins detected were mainly eight: cyanidin, petunidin, pelargonidin and peonidin-3-glucoside and their malonated derivatives. Acylated anthocyanins were far more abundant than glycosilated anthocyanins. Among the pigmented maize samples, the purple kernel genotype showed the highest concentration of anthocyanins. Color analysis of individual kernels of the four maize samples showed difference between the average L*a*b* values, detecting high correlations between L*, C* and Hue. Anthocyanins were negatively significantly correlated versus L*, C* and Hue. Considerable differences in phytochemical contents were observed between the genotypes. Principal Component Analysis provided a good summary of the results; it accounted for about 91% of total variance and clearly discriminated the four genotypes based on their specific chemical composition. Purple kernel maize genotype showed a higher content of total phenolics, flavonoids, proanthocyanidin, whereas yellow maize showed higher content in carotenoids and red maize resulted dominant in total tocols.