Stabilisation of vitamin A by wheat bran is affected by wheat bran antioxidants, bound lipids and endogenous lipase activity

Abstract

Food fortification is an efficient strategy to combat vitamin A deficiency. However, the stability of vitamin A during storage is low. Cereal bran can be used as a natural and affordable stabilising agent, but the mechanism behind this stabilisation remains unclear. To unravel this mechanism, vitamin A stabilisation was studied during an accelerated storage experiment (60 °C, 70% relative humidity) using a set of 30 in-house modified wheat bran samples. The characteristics of these samples were linked to vitamin A stabilisation during storage using forward regression modelling. While all wheat bran samples could stabilise vitamin A to a significant extent, the stabilising effect was more pronounced for samples with a high antioxidant capacity, high bound lipid content and low lipase activity. The main effect of lipase activity was more than thrice as large as the main effects of antioxidant capacity and bound lipid content. These results suggest that wheat bran antioxidants and bound lipids protect vitamin A from degradation during storage, while endogenous lipase activity counteracts the stabilising effect. Based on these findings, modified wheat bran mixed with vitamin A can be a cost-effective and healthy aid in food fortification by providing high vitamin A stability.