Changes in furosine, free monosaccharides and beta-lactoglobulin during storage of dried milk products

Changes in furosine, free monosaccharides and P-lactoglobulin of dried milk products (atomised skim milk and instant skim milk product) stored under s everal conditions of temperature and water activity were studied. The main changes observed were attributable to Maillard reaction. Furosine content i ncreased during storage, mainly at the most severe conditions (30 degrees C 0.44 a(w)). Values up to 400 mg/100 g and 200 mg/100 g were obtained in at omised skim milk and instant skim milk product, respectively. In both produ cts, a substantial decrease was observed at 30 degrees C 0.44 a(w) during t he first 30 days and during all storage period in galactose and glucose lev els, respectively. Myo-inositol was found in all the samples analysed and n o changes were observed during the storage period. Although substantial mod ifications in the shape of the peaks were found, no variations in undenatur ed beta-lactoglobulin content were detected during the storage of the dried milk products at 0.33 a(w) 20 and 30 degrees C.