Time resolved fluorescence of cow and goat milk powder

Milk powder is an international dairy commodity. Goat and cow milk powders are significant sources of nutrients and the investigation of the authenticity and classification of milk powder is particularly important. The use of time-resolved fluorescence techniques to distinguish chemical composition and structure modifications could assist develop a portable and non-destructive methodology to perform milk powder classification and determine composition. This study goal is to differentiate milk powder samples from cows and goats using fluorescence lifetimes, The samples were excited at 315 nm and the fluorescence intensity decay registered at 468 nm. We observed fluorescence lifetimes of 1.5 +/- 0.3, 6.4 +/- 0.4 and 18.7 +/- 2.5 ns for goat milk powder; and 1.7 +/- 0.3, 6.9 +/- 02 and 29.9 +/- 1.6 ns for cow's milk powder. We discriminate goat and cow powder milk by analysis of variance using Fisher's method. In addition, we employed quadratic discriminant analysis to differentiate the milk samples with accuracy of 100%. Our results suggest that time-resolved fluorescence can provide a new method, to the analysis of powder milk and its composition. (C) 2016 Elsevier B.V. All rights reserved.