Screening sweetcorn for enhanced zeaxanthin concentration.
BACKGROUND
New varieties of fruits and vegetables, with higher carotenoid levels, are being developed to improve the potential health benefits to consumers. To assist the development of a new variety of high zeaxanthin sweetcorn, an analytical screening method was developed, including chromameter measurement of hue angle and optimized extraction for HPLC, and applied to 385 lines of a breeding population and six commercial varieties.


RESULTS
Saponification had no effect on carotenoid extraction. In the breeding population, carotenoid levels had a wide range with the highest levels of zeaxanthin being 11.9 mg kg(-1) fresh weight, which was at least six times greater than the tested commercial varieties. The regression of hue angle versus zeaxanthin was described by the equation, hue angle = 76.16 + 4.50 x exp(-0.24 x zeaxanthin) + 11.73 x exp(-0.24 x zeaxanthin), r(2) of 0.59. The top 6% of lines, with regards to zeaxanthin (zeaxanthin + beta-cryptoxanthin + beta-carotene) and total carotenoids, all had hue angles <or=84.1 degrees.


CONCLUSIONS
The use of a hue angle of 85 degrees as a maximum cut-off for liquid extraction will allow for much increased efficiency in screening further germplasm for high zeaxanthin lines. There appears to be significant opportunity to further increase the zeaxanthin concentration by selecting for lines which preferentially channel carotenoid synthesis towards zeaxanthin.
Fanning
Kent J
KJ
Innovative Food Technologies, Primary Industries and Fisheries, Department of Employment, Economic Development and Innovation, 19 Hercules Street, Hamilton, Queensland, Australia, 4007. kent.fanning@deedi.qld.gov.au
Martin
Ian
I
Wong
Lung
L
Keating
Veronique
V
Pun
Sharon
S
O'Hare
Tim
T
D000383:Agriculture / Q000379:methods; D000704:Analysis of Variance; D002851:Chromatography, High Pressure Liquid; D003132:Commerce; D065366:Cryptoxanthins; D005638:Fruit / Q000737:chemistry* / Q000235:genetics; D005838:Genotype; D008954:Models, Biological; D010936:Plant Extracts / Q000737:chemistry*; D012044:Regression Analysis; D012503:Saponins / Q000378:metabolism; D024341:Xanthophylls / Q000032:analysis*; D003313:Zea mays / Q000737:chemistry* / Q000235:genetics; D065146:Zeaxanthins; D019207:beta Carotene / Q000032:analysis
D065366:Cryptoxanthins; D010936:Plant Extracts; D012503:Saponins; D024341:Xanthophylls; D065146:Zeaxanthins; D019207:beta Carotene