Assessment of heat treatment of dairy products by MALDI-TOF-MS

✍ Scribed by Jasmin Meltretter; Inès Birlouez-Aragon; Cord-Michael Becker; Monika Pischetsrieder

• Publisher: John Wiley and Sons
• Year: 2009
• Tongue: English
• Weight: 538 KB
• Volume: 53
• Category: Article
• ISSN: 1613-4125
• DOI: 10.1002/mnfr.200900008

✦ Synopsis

Abstract

The formation of the Amadori product from lactose (protein lactosylation) is a major parameter to evaluate the quality of processed milk. Here, MALDI‐TOF‐MS was used for the relative quantification of lactose‐adducts in heated milk. Milk was heated at a temperature of 70, 80, and 100°C between 0 and 300 min, diluted, and subjected directly to MALDI‐TOF‐MS. The lactosylation rate of α‐lactalbumin increased with increasing reaction temperature and time. The results correlated well with established markers for heat treatment of milk (concentration of total soluble protein, soluble α‐lactalbumin and β‐lactoglobulin at pH 4.6, and fluorescence of advanced Maillard products and soluble tryptophan index; r=0.969–0.997). The method was also applied to examine commercially available dairy products. In severely heated products, protein pre‐purification by immobilized metal affinity chromatography improved spectra quality. Relative quantification of protein lactosylation by MALDI‐TOF‐MS proved to be a very fast and reliable method to monitor early Maillard reaction during milk processing.