[Free amino acids of various lacteal formulas used in Spain].

A comparative study has been made upon free amino-acids in human milk, cow's milk and some infant formulas commercialized in Spain. The contents of free amino-acids in human milk is significantly increased when compared to those of raw of UHT sterilized cow's milk and to those of infant formulas. The concentrations of alanine are significantly lower in cow's milk and in infant formulas compared to human milk. The same occurs with branched chain amino-acids, glutamic acid, serine, threonine and taurine. On the contrary, the levels of free cysteine are significantly higher in cow's milk and in infant formulas. The concentrations of free amino-acids determined in different infant formulas on sale in Spain are rather similar between each others, being the cuantitative pattern very different from that determined in human milk.