Human Milk Proteins | ScienceGate

Our knowledge related to human milk proteins is still limited. The present study determined the changes in multiple human milk proteins during the first six months of lactation, investigated the influencing factors of milk proteins, and explored the impact of milk proteins on infant growth. A total of 105 lactating women and their full-term infants from China were prospectively surveyed in this research. Milk samples were collected at 1–5 days, 8–14 days, 1 month, and 6 months postpartum. Concentrations of total protein and α-lactalbumin were measured in all milk samples, and concentrations of lactoferrin, osteopontin, total casein, β-casein, αs−1 casein, and κ-casein were measured in milk from 51 individuals using ultra performance liquid chromatography coupled with mass spectrometry. The concentration of measured proteins in the milk decreased during the first six months of postpartum (p-trend < 0.001). Maternal age, mode of delivery, maternal education, and income impacted the longitudinal changes in milk proteins (p-interaction < 0.05). Concentrations of αs−1 casein in milk were inversely associated with the weight-for-age Z-scores of the infants (1 m: r −0.29, p 0.038; 6 m: r −0.33, p 0.020). In conclusion, the concentration of proteins in milk decreased over the first six months postpartum, potentially influenced by maternal demographic and delivery factors. Milk protein composition may influence infant weights.

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Improving Rehydration Solutions With Human Milk Proteins: Are the Benefits Worth the Challenges?

Journal of Pediatric Gastroenterology and Nutrition ◽

10.1097/mpg.0b013e3180375584 ◽

2007 ◽

Vol 44 (3) ◽

pp. 298-299 ◽

Cited By ~ 1

Author(s):

Steven A Abrams ◽

David C Hilmers

Keyword(s):

Human Milk ◽

Milk Proteins ◽

Rehydration Solutions

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Simultaneous pasteurization and homogenization of human milk by combining heat and ultrasound: effect on milk quality

Journal of Dairy Research ◽

10.1017/s0022029909990483 ◽

2010 ◽

Vol 77 (2) ◽

pp. 183-189 ◽

Cited By ~ 38

Author(s):

Charles Czank ◽

Karen Simmer ◽

Peter E Hartmann

Keyword(s):

Human Milk ◽

Milk Proteins ◽

Food Preservation ◽

Secretory Iga ◽

Bioactive Components ◽

Laser Scattering ◽

Milk Samples ◽

Donor Human Milk ◽

Preservation Technique ◽

Ultrasound Effect

The combination of ultrasound and heat (thermoultrasound) is an emerging food preservation technique that retains higher quantities of bioactive components compared with current thermal pasteurization practice, but has not yet been assessed for pasteurizing human milk. Artificially contaminated human milk samples were treated with ultrasound (20 kHz, 150 watts) with and without heating. The retention of four human milk proteins was quantified by biochemical assay and laser scattering particle sizing was used to determine the extent of homogenization. While ultrasonic treatment was effective at inactivating Escherichia coli (D4 °C=5·94 min), Staphylococcus epidermidis exhibited resistance (D4 °C=16·01 min). Thermoultrasonic treatment was considerably more effective (Esch. coli D45 °C=1·74 min, D50 °C=0·89 min; Staph. epidermidis D45 °C=2·08 min, D50 °C=0·94 minutes) with a predicted retention (2·8 min treatment, 50°C) of secretory IgA lysozyme, lactoferrin and bile salt stimulated lipase of 91, 80, 77, and 45%, respectively. Homogenization of the milk samples occurred after 5 min and 2 min of ultrasonic and thermoultrasonic treatment, respectively. Thermoultrasonic treatment is an effective method for pasteurizing donor human milk and retaining a greater proportion of bioactive components compared with current practices. However, further studies are required to assess the practicality of applying this technique routinely to donor human milk.

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Summary-The Early Feeds: Human Milk Versus Formula and Bovine Milk

PEDIATRICS ◽

10.1542/peds.75.1.157 ◽

1985 ◽

Vol 75 (1) ◽

pp. 157-159

Keyword(s):

Breast Milk ◽

Human Milk ◽

Whey Proteins ◽

Bovine Milk ◽

Milk Proteins ◽

Human Infant ◽

Postnatal Life ◽

Human Breast Milk ◽

Nonprotein Nitrogen ◽

Casein Protein

Adaptations of the gastrointestinal tract and the immune system that take place during the first year of postnatal life are of great importance, initially facilitating the transition between gestation and lactation, ultimately supporting independent postnatal life. When considering feeding options during the early periods, the roles of human milk, commercially prepared formula, and bovine milk must be evaluated in light of recent knowledge of these adaptations. Since infant feeding practices and the biologic capabilities of infants themselves vary significantly, the question arises as to what is "acceptable" v what is "optimal." NUTRITIONAL PROTEINS At present, evaluations of the amount of protein required for infant growth are based on clinical studies of largē populations and include a "margin of safety" to meet the needs of the individual infant. Based on the assumption that the milk of a given species is best adapted to the nutrient requirements of the young of that species, human infant protein requirements are determined by the protein contribution of human breast milk. Breast-milk proteins are defined broadly as either whey or casein protein with an approximate ratio of 70:30, respectively. The casein portion is divided into three subgroups: α,β and κ casein. Whey proteins are divided into six major subgroups: α-lactalbumin, β-lactoglobulin; lactoferrin; serum-albumin; lysozyme, and immunoglobulins A, G, and M. Numerous nonprotein nitrogen substances including taurine exist as well. Protein Availability Protein concentration of breast milk is approximately 1.2 g/dL when measured as total nitrogen. Nearly 25% of this is nonprotein nitrogen, much of which may not be used for nutritional purposes.

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