Differences-Differences-Principles-Assays-j

For higher macronutrient levels, a trend to greater differences between the HMA and the laboratory method was seen, particularly in samples with high fat concentration. The intra-assay variation for the HMA for all macronutrients was less than 4%. It is concluded that that with appropriate sample preparation, the mid-infrared HMA can provide a practical measurement of macronutrients in human milk.Compartmentalization and quantitation of protein in human milk.Human milk protein was determined by three colorimetric methods and by Kjeldahl analysis. The distribution of nitrogen (N) and protein was determined within various milk compartments.

Total N, whey, casein, nonprotein nitrogen (NPN), cell N and N in the fat fraction were analyzed by micro-Kjeldahl analysis after a series of centrifugation and ultracentrifugation separations. Fresh milk samples (colostrum, transitional milk and mature milk) were centrifuged at 0 X g to separate milk cells and at X g to skim the milk. Decelled milk and skimmed milk were ultracentrifuged at 189 X g to separate fat and casein micelles from whey. NPN was analyzed after trichloroacetic acid precipitation. Whole milk, decelled milk, skimmed milk and whey were analyzed for protein with the Lowry method, modified for fat-containing samples, the Bradford dye-binding assay (Bio-Rad) and the Pierce bicinchoninic acid (BCA) assay. Cell nitrogen had a tendency to be lower in mature milk than in colostrum. Colostrum contained only 6% casein protein, whereas mature milk contained 13%.

Fat from skimming was lower in N than fat from ultracentrifugation. Average NPN levels were similar for milk from all three lactation periods, and constituted % of colostrum N and 25% of mature milk N. Protein determined by the Bio-Rad method on whole milk samples had the lowest variability (square root MSE) when correlated to Kjeldahl values. Lactose-N-neotetraose had lower variability when analyzing whey and skimmed milk than when analyzing whole milk. The Lowry method and the Bio-Rad method had low variability for whey and skimmed milk samples, but the Lowry method yielded analytical values closest to Kjeldahl protein values. Fucosylated oligosaccharides overestimated Kjeldahl protein by %.Design and characterization of a human milk product for the preterm infant.

Biomolecular, and Chemical Science, The University of Western Australia, BACKGROUND It is necessary to fortify human milk to promote optimal growth of the very preterm infant. However, the addition of non-human milk components to human milk is not ideal because of the risk of feeding intolerance and necrotizing enterocolitis. Human milk products (HMP) are an alternative to commercially available fortifiers, but their preparation is likely to result in modifications to the qualities of human milk.METHODS Ten batches of HMP were prepared with the aim of meeting a desired proteinenergy ratio of 3 g of protein0 kcal. Ultrafiltration was used to produce a skim milk concentrate, to which cream was then added to produce the final HMP. Characterization of HMP and human milk fortified with commercial human milk fortifiers (Nutriprem [Cow & Gate, Limerick, Ireland] and S-26 SMA human milk fortifier [Wyeth Nutrition, Baulkham Hills, NSW, Australia]) included quantifying macronutrient content, osmolality, microbial content, and particle RESULTS Average proteinenergy ratio of the final batch was 23 +-. g of protein0 kcal, equating to an inaccuracy of 2% relative to the desired ratio of 3 g of protein0 kcal.

Significantly greater fat (P 1), lower lactose (P 01), and lower osmolality (P 01) were characteristic of the HMP compared to human milk fortified with either commercial fortifier. Microbial growth occurred during preparation of HMP but did not exceed (5) colony-forming unitsmL, and pasteurization of human milk prevented CONCLUSIONS HMP can be designed to accurately target the protein and energy requirements of the preterm infant, but modifications of the macronutrient, biochemical, structural, and microbial characteristics of human milk may affect Multiple enzymic activities of human milk lactoferrin.Kanyshkova TG(1), Babina SE, Semenov DV, Isaeva N, Vlassov AV, Neustroev KN, Lactoferrin (LF) is a Fe3+-binding glycoprotein, first recognized in milk and then in other human epithelial secretions and barrier fluids. Many different functions have been attributed to LF, including protection from iron-induced lipid peroxidation, immunomodulation and cell growth regulation, DNA binding, and transcriptional activation. Its physiological role is still unclear, but it has been suggested to be responsible for primary defense against microbial and viral infection.