RESUMO
OBJECTIVE: To determine the frequency of utilization of milk surrogates as well as their protein contents and composition MATERIAL AND METHODS: Interview data on lactation patterns previously recorded (1986-1994) in Hermosillo, Mexico, were reviewed. Both human and surrogate milk fluids were tested; total protein contents were quantified by microKjeldhal and protein composition was determined by electrophoresis computer densitometry. RESULTS: Eleven milk formulas and three whole cow milks were used more frequently for infants aged 0-6 months. Total protein contents of modified and follow-up formulas were the same as reported on the label, in compliance with sanitary regulation. Casein content of human milk was 40%, and modified formulas contained 44%; follow-up formulas and whole milks were 60% and special formulas contained more than 70%. CONCLUSIONS: Products used for lactation seem to be inadequate for infant nutrition. In addition, the protein composition of some products was quite different that of human milk, and they are not proscribed from official regulation.