Abstract:

Microbiological and spectrophotometric methods were respectively used to determine the contents of niacin and
zeaxanthin in maize kernels of 123 from 3 200 inbred lines to study the effects of maize type, kernel color and kernel type
on the contents of both phytochemicals in maize as well as their correlation. The results showed that the niacin content
of maize was in the range of 0.57–4.80 mg/100 g; the niacin content of waxy maize was much higher than that of normal
maize, the niacin content of white maize was higher than that of yellow maize, and the niacin content of purple maize was
between those of white maize and yellow maize. No significant differences in niacin contents were found among different
kernel types and among different kernel types with the same kernel color. The zeaxanthin content of maize varied from 0.35
to 4.03 mg/kg. The zeaxanthin content of waxy maize was much lower than that of normal maize, the zeaxanthin content of
white maize was lower than that of yellow maize, and the zeaxanthin content of purple maize was between those of white
maize and yellow maize. No significant differences in zeaxanthin contents existed among different kernel types and among
different kernel types with the same kernel color. These results indicated that the different maize types and kernel colors of
maize significantly affected the contents of niacin and zeaxanthin, whereas the main effect of kernel type and its interactive
effect with kernel color were not significantly different. Moreover, there was a moderate but significant negative correlation
between niacin content and zeaxanthin content in maize (r = - 0.361, P < 0.01), indicating that the higher the niacin content,
the lower the zeaxanthin content. These findings could provide a reference for the reasonable application of maize kernels
and the improvement of maize breeding.

Key words: maize, niacin, zeaxanthin