Impact of packaging material and storage condition on retention ofprovitamin A carotenoids and xanthophylls in yellow-seeded maize flour

Abstract

Background: Pro-vitamin A carotenoid (pVAC) rich foods are those foods that contain substancewhich can be converted within the human body into retinol. These foods also contribute to thereduction of vitamin A deficiency diseases. Yellow-seeded maize flour is a pVAC rich food.Identifying the right packaging materials and storage conditions that retain pVAC in this food isessential for their health benefits. Traditionally, maize flour is stored with different packagingmaterials to increase its shelf life. For example, previous studies have shown how during storagein different food matrices, carotenoids, including maize grains, are highly susceptible todegradation by temperature, light, and oxygen. Therefore, in this study we investigated the effectof storage packaging materials (polypropylene woven sacks-PWS, high-density polyethylenebags-HDPE, and polyvinyl plastic containers-PPC) and storage condition (temperature andrelative humidity) on retaining pVAC in yellow-seed maize flour.Methods: The yellow-seeded maize grains were collected and ground into flour. The maize flourwas divided into portions (200 g). Each portion was packed and sealed in PWS, HDPE, and PPC.The control samples (12 pieces) were stored on top of the storage box. The packed samples werestored in both the upper (12 samples) and lower (12 samples) compartment of a storage woodenbox. The interior of the upper part was lightened with aluminum foil and fitted with fluorescenttube to increase the light intensity. The lower compartment was darkened with gloss black painting. The flour samples were stored for 28 days. Samples were collected for pVAC andxanthophylls analyses at 7 day intervals using standard methods.Results: The results demonstrated how packaging in PPC and storing in a dark compartmentresulted in the highest total pVAC (92.39%) and total xanthophylls (89.44%) retention and retinolequivalent (RE) (0.40 μg/g). In contrast, packaging in HDPE and storing in lighted compartmentresulted in the lowest pVAC (44.92%) and total xanthophylls (46.76%) retention and RE (0.19μg/g).Conclusions: Packaging yellow-seeded maize flour in PPC and storing in the dark may berecommended for maximum retention of carotenoids in yellow-seeded maize flour since, as thepackaging material and storage condition resulted in the highest pVAC retention and retinol equivalent.