摘要：Whey protein concentrate (WPC) is a nutritious ingredient and has gained popularity to be used in many traditional and novel food products. It typically has a shelf-life of 9 to 18 months when stored at room temperature. Fresh manufactured WPC could have a bland or slightly dairy, whey flavor. However, recognizable off-flavor can be developed during storage and this off-flavor becomes one of the major factors limiting its application in delicate formula. To understand the off-flavor development during the storage, WPC 80 and Instantized WPC 80 samples were stored at 35, 40 and 45 °C for a period of 15 weeks. Selected volatile compounds including dimethyl disulfide, pentanal, hexanal, heptanal, 2-heptanol, 2-octanone, octanol, 1-octen-3-ol, 1-nonanol and 2-nonanol were analyzed using headspace solid-phase microextraction gas chromatography. The results showed that the concentrations of most of these compounds considerably increased during storage, especially when stored at 45 °C. Instantized WPC showed higher lipid oxidation compounds than regular WPC while removal of oxygen reduced their formation.
关键词：whey protein concentrate;volatile formation;solid phase microextraction;gas-chromatography
