Light wavelength effects on a lutein-fortified model colloidal beverage.

The effect of light on a model colloidal beverage system containing whey protein, lutein, and limonene was investigated. Changes in volatile chemistry were evaluated under accelerated conditions (12 h, 25 °C) at selected wavelengths regions (395, 463, 516, 567, and 610 nm absorbance maxima) using a photochemical reactor. The most damaging wavelengths to lutein stability were UV (200-400 nm) and 463 nm wavelengths. Hexanal formation was highest in the control beverage when exposed to full spectrum light and UV (200-400 nm) wavelengths. Hexanal also was formed in the lutein-fortified beverage under full spectrum light and UV (200-400 nm) wavelengths but to a significantly lesser degree. Limonene degraded significantly under all treatment conditions, with most degradation occurring during full spectrum light exposure. Lutein fortification did not completely protect limonene from degradation.