Modifications induced by controlled storage conditions on whey protein concentrates: Effects on whey protein lactosylation and solubility

Food processing and storage conditions play an important role in product stability and quality. Chemical and structural modifications may be induced on food proteins. In this context, a study on the effect of storage conditions on milk whey proteins was performed on whey protein concentrates (WPC-35). Samples were stored up to 2 wk and up to 60 °C. Kjeldahl and SDS-PAGE analysis confirmed that the protein content was not affected. With UPLC-MS analysis, lactosylated forms of the proteins were identified and quantified. It was observed that the level of protein glycation increases due to both temperature and duration of storage. All samples were also characterised for amino acid composition and nutritional value determination. Results showed that the nutritional value of the products was not altered, in a consistent way, even in the extreme conditions applied (14 d 60 °C).