Effects of Light on Riboflavin and Ascorbic Acid in Freshly Expressed Human Milk

Abstract

Millions of dollars each year is spent funding dairy research to better understand every aspect of milk processing, storage, handling, and shelf life. The dairy industry has shown that in animal milks vitamin C is photo-oxidized when exposed to light, which can cause a cascade of other nutrients that may be affected. Expressed human breast milk has had limited research published, mainly recommendations for storage duration secondary to bacterial growth, with scant research on nutrient quality during handling compared to the animal models. In this study, freshly expressed human milk was placed in containers of varying color/UV sensitivity and exposed to light over 6 hours. The laboratory analysis showed riboflavin and ascorbic acid concentrations rapidly decreased in clear containers. The containers wrapped in foil and those of amber color appear to have prevented the photo-oxidation of riboflavin and ascorbic acid. The concentrations of riboflavin and ascorbic acid consistently decreased over a relatively short space of time when stored in translucent containers. The control of photo-oxidation is an important component of maintaining nutrient quality, particularly in foods intended for infants. Minimizing light exposure would provide protection to the nutrients that are susceptible to oxidation. More research is needed to update recommendation for handling expressed human milk to ensure integrity of fragile nutrients in expressed human milk. The authors concluded that amber and other darkened containers that can prevent photo-oxidation of the breast milk could prevent degradation of certain nutrients in stored expressed human milk and possibly the shelf-life. While more research is needed to further identify harmful and helpful aspects of breast milk storage, these findings can establish a foundational understanding and new perspective on human breast milk handling.