Abstract:

In this study, 25 normal milk samples without any adulterated components were collected, and then 3 groups (50 samples/group) of adulterated milk samples were prepared by addition of different concentrations of hydrolyzed vegetable proteins (HVP, 0.3 to 50 g/kg), whey powder (0.03 to 30 g/kg), and non-dairy creamer (0.03 to 30 g/kg), respectively. A chargercoupled device (CCD) near-infrared (NIR) spectrometer (600 to 1100 nm) was applied to scan the permeable reflection spectrum, the possibility of rapid detection of adulterated components in milk was investigated, and the quantitative model between NIR spectra and contents of adulterated components was constructed by partial least squares (PLS). The results showed that the correlation coefficient for HVP detection is 0.969 and its standard error of prediction (SEP) is 0.456 g/kg, thus the precision of quantitative prediction for HVP may meet the practical measurement requirement. However, when the concentrations of adulterated components are lower than 1‰, the detection of NIR is limited and the contents of whey powder and nondairy creamer cannot be accurately predicted.

Key words: near infrared, milk, hydrolyzed vegetable proteins (HVP), whey powder, non-dairy creamer