Ultra-performance liquid chromatography (UPLC) quantification of carotenoids in durum wheat Influence of genotype and environment in relation to the colour of yellow alkaline noodles (YAN)

Carotenoids are the main compounds responsible for the yellow colour of durum wheat semolina and flours However the concentration of carotenoids in wheats depends on genotype and growing environments The total pigment and carotenoid concentration of four durum wheat varieties (AC Avonlea Commander AC Navigator and Strongfield) and two common wheat varieties (AC Barrie and AC Snowbird) which were grown in different locations in Saskatchewan Canada (Taber Regina and Swift Current) were determined using the AACC International approved method and ultra-performance liquid chromatography (UPLC) A fast (within 6 min) and sensitive method for separation of carotenoids extracted from durum wheat flours was developed using UPLC The results show that Commander and AC Navigator varieties exhibited higher total pigments and lutein concentration than the other wheats Wheat grown in Taber and Swift Current regions had higher total pigments and lutein concentration than those grown at Regina Although carotenoids in wheat extracts possessed antioxidant properties there was no significant correlation between antioxidant capacity and the concentration of carotenoids in the extracts (r(2) = 0 13) The carotenoid extracts from AC Barrie exhibited the highest DPPH radical scavenging while AC Avonlea showed the lowest The concentration of extracted lutein highly correlated (r(2) = 0 93) with the yellowness b value of the yellow alkaline noodles whereas the correlation between lutein concentration and noodle redness a or brightness L values were not as strong (r(2) = 075 or 058 respectively) Thus the high concentration of lutein in the durum wheats contributes to the desirable greater yellowness of yellow alkaline noodle an important key to making a healthy yellow alkaline noodle without artificial yellow agent (C) 2010 Elsevier Ltd All rights reserved