The loss of available lysine content of milk powder equilibrat at all aw studied followed better linear relationships when ln(100*Lt/L0) was plotted against time than when of 100*Lt/L0 was
plotted. Therefore, the of loss available lysine followed pseudo first order kinetics at all temperatures and aw values analyzed, as previously reported for a milk-like system stored at similar conditions of temperature and aw (Malec et al., 2002).