Aroma profile development of intermediate chocolate products I. Volatile constituents of block-milk

Block-milk or white crumb is an intermediate product used in the manufactur e of white chocolate and milk chocolate and it is produced from a mixture o f concentrated milk and sugar. Volatile compounds of block-milk samples at different stages in the manufacturing process were investigated by dynamic headspace GC-MS. The changes in aroma profiles during processing were evalu ated using similarity indices and a multidimensional scaling technique. The se methods allow a better use of the information contained in the GC data. The results clearly point out the short intense heating step as the key ste p in the formation of the aroma profile of block-milk. During this step man y volatiles are formed due to autoxidative and Maillard reactions. This is consistent with a decrease in the lactose level concomitant with an increas e in the lactulose level following the heat treatment, as evaluated by HPLC analysis. (C) 1999 Elsevier Science Ltd. All rights reserved.