Determination of Carotenoids in Yellow Maize, the Effects of Saponification and Food Preparations

Abstract

Maize is an important staple food consumed by millions of people in many countries. Yellow maize naturally contains carotenoids which not only provide provitamin A carotenoids but also xanthophylls, which are known to be important for eye health. This study was aimed at 1) evaluating the effect of saponification during extraction of yellow maize carotenoids, 2) determining the major carotenoids in 36 genotypes of yellow maize by high-performance liquid chromatography with a C30 column, and 3) determining the effect of cooking on the carotenoid content of yellow maize. The major carotenoids in yellow maize were identified as all-trans lutein, cis-isomers of lutein, all-trans zeaxanthin, alpha- and beta-cryptoxanthin, all-trans beta-carotene, 9-cis beta-carotene, and 13-cis beta-carotene. Our results indicated that carotenoid extraction without saponification showed a significantly higher yield than that obtained using saponification. Results of the current study indicate that yellow maize is a good source of provitamin A carotenoids and xanthophylls. Cooking by boiling yellow maize at 100 degrees C for 30 minutes increased the carotenoid concentration, while baking at 450 degrees F for 25 minutes decreased the carotenoid concentrations by almost 70% as compared to the uncooked yellow maize flour.

Carotenoid Retention of Biofortified Provitamin A Maize (Zea mays L.) after Zambian Traditional Methods of Milling, Cooking and Storage

“…No consistent trend was observed for the cis-isomers after boiling. Muzhingi et al 22 also reported similar results on retention levels above 100% for all individual carotenoids, except for β-cryptoxanthin (92%), for yellow maize boiled for 1 h at 100°C.…”

Accruing genetic gain in pro-vitamin A enrichment from harnessing diverse maize germplasm

“…Some of the promising lines had high provitamin A content by accumulating mainly higher levels of b-carotene at the expense of the synthesis of other carotenoids while others contained high provitamin A by accumulating high levels of both carotenes and xanthophylls. These lines will be useful not only for the development of hybrids and synthetics with high concentration of carotens and xanthopylls but also for elucidating the mechanisms that regulate the synthesis of more substrates upstream in the carotenoid biosynthetic pathway and the resulting increased flux downstream Table 3 Provitamin A contenet and grain yields of the best five synthetic varieties (OPV) and hybrids selected from each of the two regional trials evaluated at four to six locations in 2013, 2014 and 2015 Even though significant progress has been made in boosting provitamin A to higher levels in tropical maize, studies have demonstrated that the loss in provitamin A during storage, milling, and preparation of diverse traditional foods may reach up to 70% (Muzhingi et al 2008;Mugode et al 2014;Pillay et al 2014;De Moura et al 2015). Also, the extent of loss in provitamin A carotenoids exhibits a broad range of variation among maize genotypes in these studies.…”

A single extraction and HPLC procedure for simultaneous analysis of phytosterols, tocopherols and lutein in soybeans

“…Direct saponification of a food sample is commonly performed in alcohol. However, the harsh conditions of saponification may reduce the recovery of labile carotenoids and tocopherols (Feltl, Pacakova, Stulik, & Volka, 2005;Muzhingi et al, 2008;Oliver & Palou, 2000;Ryyanen, Lampi, Salo-Vaananen, Ollilainem, & Piironen, 2004). Thus, a protective antioxidant is an essential component of the saponification procedure.…”