K. Fanning

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. CONCLUSION 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.

Zeaxanthin-Biofortified Sweet-Corn as An Enhanced Dietary Source of Macular Pigment

S Macular Carotenoids Conference Cambridge, United Kingdom, July 10-12, 2013 LUTEIN AND ZEAXANTHIN: THE AUTOBIOGRAPHY Britton G. University of Liverpool, School of Biological Sciences, Crown Street, Liverpool, United Kingdom Nature makes a great diversity of carotenoids; more than 700 different ones have been identified. In an ordinary diet, containing a good variety of fruit and vegetables, we probably ingest about 100, and 20-30 can usually be detected in the blood. And yet the macula specifically accumulates just two carotenoids, the dihydroxy xanthophylls lutein and zeaxanthin. Why and how are these two carotenoids so special? Every carotenoid has a unique structure and this determines its chemical and physical properties. Any biological function or action depends on these properties and on interactions of the carotenoid with its environment. This talk will introduce lutein and zeaxanthin (including mesozeaxanthin) and explore what their structures tell us about factors such as their shape, solubility, reactivity and stability, and interactions with light. The biological behaviour and functioning of lutein, zeaxanthin and meso-zeaxanthin must be compatible with these properties, which may be modified by the physical or molecular environment. Knowledge of these properties is therefore an essential foundation for understanding the biological significance of these particular xanthophylls, including their presence and role in the macula. We obtain lutein and zeaxanthin from natural or manufactured food, or from health supplements. The form or physical state in which the carotenoids are present in these sources is an important factor in determining bioavailability and how efficiently they may be taken up into the body and tissues. LUTEIN AND INFLAMMATION Berendschot T. University Eye Clinic Maastricht, The Netherlands Lutein selectively accumulates in the primate retina and as a major component of the macular pigment it plays an important role as a filter to prevent harmful effects of blue light (Landrum, 1997). It also protects the retina from oxidative damage by quenching free oxygen radicals (Khachik, 1997). Lutein also has anti-inflammatory properties that may be important in the prevention of Agerelated Macular Degeneration (Kijlstra, 2012). They will be discussed as well as recent studies on the role of lutein in the inflammatory pathway of the innate immune system. EFFECTS OF THE MACULAR CAROTENOIDS FROM EYE TO BRAIN, FROM INFANCY TO OLD AGE Hammond Billy R. Behavioral and Brain Sciences Program, University of Georgia, Athens, GA, USA The macular carotenoids influence many aspects of central nervous system function. These effects extend from optical filtering within the eye to physiological activity of neurons within the brain. With respect to the latter, the macular carotenoids appear to enhance chromatic contrast, increase visual range, decrease photostress recovery times, glare disability, and discomfort. Post-receptorally, they have been linked to faster visual processing speeds as assessed by numerous tasks: e.g., macular pigment optical density (MPOD) is significantly (p<0.05) related to fixed and variable reaction time, coincidence anticipation errors (estimating the arrival of a stimulus at a target location moving at varying velocity), and balance ability. Reduced processing speed is a central feature of cognitive decline and current data suggest that higher MPOD (likely a biomarker for more central levels of lutein and zeaxanthin) is related to preservation of cognitive function: e.g., our current data link (p<0.05) MPOD to executive cognitive functions in the healthy elderly and subjects with mild cognitive impairment. Taken together, the multiple effects of the xanthophylls on nervous system function seem to manifest throughout life and address vulnerabilities that also seem to change with age: e.g., increased actinic stress to the retina in infants and the elderly. REFINING THE MEASUREMENT OF MPOD BY HETEROCHROMATIC FLICKER PHOTOMETRY Bone Richard A. Department of Physics, Florida International University, Miami, USA Purpose: To design a heterochromatic flicker photometer (HFP) for MPOD measurement which minimizes the difficulties that subjects often experience with a traditional HFP, and which removes the effect of age-dependent lens yellowing upon results. Methods: MapcatSFTM is a blue/green LED-based HFP providing centrally fixated 1.5 and 15° stimuli. With the 1.5° stimulus, subjects adjust the blue intensity in the usual way to produce a flicker null. With the 15° stimulus, they adjust for elimination of flicker around the periphery. Blue and green intensities are recorded by a photo-detector. A microprocessor computes the subjects lens-corrected MPOD as well as lens optical density, LOD, at 425 nm, and lens equivalent age, LEA. Test-retest repeatability was assessed for 55 subjects. Results: Subjects found the test easy, particularly the peripheral measurement. A Bland-Altman plot of the test-retest MPOD data provided an average difference between two consecutive measurements of 0.00194, and limits of agreement (±1.96 SD) of ± 0.079. Corresponding results for LOD and LEA were -0.012±0.090 and -0.5±6.7 yr respectively. Conclusions: We have developed an HFP with novel features, notably a centrally fixated, large stimulus for the peripheral part of the test. The test-retest MPOD results for the MapcatSFTM were superior to those reported for other instruments, including those employing physical techniques. Disclosures: Science Advisory Board member, Guardion Health Sciences. LUTEIN AND ZEAXANTHIN: FROM THE RETINA TO THE BRAIN Johnson EJ. Carotenoids & Health Laboratory, Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA, USA Lutein and zeaxanthin (L/Z) may play a role in the prevention or delay the progression of cognitive decline. Among the carotenoids, L/Z are the only ones that cross the blood-retina barrier to form macular pigment (MP) in the eye. Lutein also preferentially accumulates in the human brain. To evaluate the relationship between L/Z as MP and their levels in the human brain, matched macula and brain tissue were analyzed for L/Z and significant relationships for both carotenoids were found. Therefore, MP may be a biomarker of L/Z in brain tissue. This is of interest given our work in the Health Aging and Body Composition Study in which MP levels were significantly associated with a variety of measures of cognition. Therefore, MP may be a potential biomarker of cognition. Furthermore, we found a significant relationship between serum levels of L/Z Macular Carotenoids Conference Downing College, University of Cambridge Cambridge, United Kingdom