Effect of the shelf life on 5-hydroxymethylfurfural content of whey protein concentrates

In this study, whey protein concentrates (WPC) samples were stored for 2 years and analyzed for hydroxymethylfurfural (HMF) content. Apparent density and moisture content were found to be similar to those reported in the literature. The amount of HMF in samples varied from 9.86 to 26.59 mu mole 100 g(-1) at the start of shelf life. Having been stored for two years, HMF values of the WPC examined ranged from 39.53 to 89.24 mu mole 100 g(-1) at the storage temperature of 20 degrees C. It was found that HMF and moisture levels of WPC were significantly affected by shelf life. However, the apparent density values of WPC did not change significantly and were not affected by the storage period. It is concluded that adulteration of WPC can be detected on the basis of HMF content. HMF level of WPC should be further considered as a criterion in the specification of WPC.