RESUMO Objetivo: avaliar o efeito do agente espessante na osmolalidade do leite humano e da fórmula infantil em relação às concentrações e ao efeito do tempo. Métodos: foram realizados 6 ensaios para avaliar a osmolalidade, ao natural e com espessamento, da fórmula infantil, leite humano ordenhado cru e pasteurizado. O cereal de arroz foi usado como agente espessante (nas concentrações de 2%, 3%, 5% e 7%). A osmolalidade foi aferida pelo The Advanced TM Micro Osmometer Model 3300 após a preparação das amostras por um período de 0-60 minutos. As diferenças significantes foram avaliadas por meio de Anova. Resultados: observou-se variação da osmolalidade no leite humano pasteurizado nos tempos observados e nas concentrações. O leite humano cru apresentou variação nos tempos e nas concentrações 5 e 7%, quando comparado ao leite não espessado. A fórmula infantil não mostrou diferenças na osmolalidade com relação ao tempo. No tempo zero, apresentou variações entre as concentrações de 2, 3 e 5%. Nos demais tempos, houve diferença na osmolalidade entre as amostras com concentração de 5% e a fórmula não espessada. Conclusão: a osmolalidade das dietas analisadas variou conforme o tempo e as concentrações para o leite humano e a formula infantil. No entanto, estas variações se mantiveram dentro dos parâmetros preconizados, indicando que o cereal de arroz é um espessante seguro para a alimentação de lactentes com disfagia orofaríngea leve ou moderada.

ABSTRACT Purpose: to evaluate the effects of a thickening agent on the osmolality of human milk and on an infant formula, with respect to concentration and time. Methods: six trials were performed to evaluate the osmolality of a natural and thickened infant formula, raw human milk, and pasteurized human milk. Rice cereal was used as a thickening agent (at concentrations of 2%, 3%, 5%, and 7%). Osmolality was measured using the Advanced Micro Osmometer Model 3300 after sample preparation periods of 0-60 minutes. Statistical evaluations were performed using ANOVA. Results: pasteurized human milk exhibited time- and concentration-dependent variation in osmolality. The osmolality of raw human milk differed among time points and between the samples with 5% and 7%, when compared to the non-thickened milk. The infant formula did not show differences in osmolality with respect to time. At time zero, there were differences in osmolality between the infant formula samples with 2%, 3%, and 5% thickener. At other time points, there were differences in osmolality between the sample with a 5% thickener and the non-thickened formula. Conclusion: the osmolality of diets varied over time and according to the concentration of thickener in human milk and the infant formula. However, the observed variation remained within the recommended parameters, indicating that rice cereal is a safe thickener for the feeding of infants presented with mild or moderate oropharyngeal dysphagia.

RESUMO Objetivo: analisar o leite humano e a fórmula láctea infantil com a viscosidade modificada. Métodos: foram realizados três estudos considerando a viscosidade e efeito do tempo na fórmula nas concentrações 2, 3 e 5% e no leite humano cru e pasteurizado nas concentrações 2, 3, 5 e 7% na temperatura de 37ºC pelo tempo de 60 minutos. O cereal de arroz foi utilizado como agente espessante. A viscosidade foi avaliada pelo viscosímetro do tipo Copo Ford e as amostras analisadas em quatro intervalos de tempo. Diferenças significativas foram avaliadas por meio do teste da Anova. Resultados: não foram observadas diferenças significativas da viscosidade em relação ao tempo para as concentrações de 2, 3 e 5%. Observou-se diferença na viscosidade entre leite humano e fórmula nas concentrações de 2% e 5%, 2% e 7%, 3% e 5%, e 3% e 7%, independente dos intervalos de tempo considerados. Conclusão: o estudo aponta para a necessidade de diferentes concentrações para leite humano e formula. O cereal de arroz apresenta-se como opção terapêutica adequada para os recém-nascidos com disfagia nas concentrações de 2, 3, 5 e 7% pelo seu efeito na viscosidade e redução do fluxo, desde que se observe o tempo de mamada.

ABSTRACT Purpose: to analyze the modification of the viscosity of human milk and infant formula. Methods: three studies were performed to assess the viscosity and effect of time on infant formula with a thickener, at concentrations of 2, 3, and 5%, as well as raw and pasteurized human milk at concentrations of 2, 3, 5, and 7% at 37ºC, for 60 minutes. Rice cereal was used as a thickening agent. The viscosity was evaluated using a Ford Cup-type viscometer, and the samples were analyzed at 20-minute intervals. Significant differences were assessed using the ANOVA test. Results: no significant differences in viscosity were observed over time in concentrations of 2, 3, and 5%. There was a difference in the viscosity between human milk and infant formula, in concentrations of 2% and 5%, 2% and 7%, 3% and 5%, and 3% and 7%, independently of the time intervals evaluated. Conclusion: the findings of this study demonstrate the need for different concentrations of the thickening agent for human milk and infant formula. Rice cereal is a suitable therapeutic option for newborns presented with dysphagia in concentrations of 2, 3, 5, and 7%, due to its effect on the viscosity and flow reduction, provided that the feeding time is considered.

Neonatal nutrition is an important subject in health in the short, medium and long term. In preterm newborns, nutrition assumes a predominant role for the child's overall development. Babies with uncoordinated swallowing or respiration may not have the necessary oral abilities to suck the mother's breast and will need to implement different feeding practices; one of them is changing the consistency of the milk offered. Objectives: Determine viscosity variations of untreated human and pasteurized milk without and with thickening to adapt the diet to the needs of dysphagic infants hospitalized in the Neonatal Intensive Cara Unit (NICU). Material and Methods: The authors altered the viscosity of natural infant powdered milk and, after thickening, determined and adopted a thickening standard for human milk. Untreated human and pasteurized milk was thickened in concentrations of 2%, 3%, 5% and 7% and the viscosity were determined every 20 minutes for a period of 60 minutes at a temperature of 37ºC. Results: The infant lactose formula thickened at concentrations of 2% and 3% produced viscosities of 8.97cP and 27.73 cP, respectively. The increases were significantly different after 1 hour. Inversely, untreated human milk at 2%, 3%, 5% and 7% produced diminished viscosity over time; the changes were more accentuated in the first 20 minutes. In pasteurized human milk, the 2% concentration had no variation in viscosity, but with the 3%, 5% and 7% concentrations, there was a significant decrease in the first 20 minutes with stability observed in the subsequent times. Conclusion: In powdered milk, the viscosity increases over time; the viscosity in human milk diminishes. The results point out the importance not only of considering the concentration of the thickener but also the time being administered after its addition to effectively treat dysphagic infants.