Carotenoid content of extruded and puffed products made of colored-grain wheats

Wheat is a relevant source not only of essential macronutrients but also of many other health-promoting phytochemicals (carotenoids, anthocyanins, tocols, phenolic acids, etc.). Colored-grain wheats were used for extrusion and kernel puffing. The total content of carotenoids (sum of lutein, zeaxanthin, antheraxanthin, alpha and beta carotene, and xanthophyll esters) decreased significantly due to extrusion (to 25.7%) and puffing (to 31.6%), compared to the content in the raw material. Zeaxanthin was shown to be the most stable among all detected carotenoids (30.8 and 48.7% was preserved). The results of the performed analyses have not confirmed greater stability of xanthophyll esters against higher temperatures (decrease to 29.5 and 22.1%). Both technologies induced E-to Z-isomerization of all-E-lutein and puffing also of all-E-zeaxanthin. Higher concentrations of 13 -Z and 9-Z-zeaxanthin were identified in puffed grains (2x and 37x on average). To preserve more carotenoids, it is appropriate to look for a more suitable food processing technology.

Automated summary

Wheat is a rich source of essential macronutrients and health-promoting phytochemicals, but the content of carotenoids significantly decreases during extrusion and puffing processes. Among all detected carotenoids, zeaxanthin was found to be the most stable, while xanthophyll esters did not show greater stability at higher temperatures.