The most important feature of breast milk composition is that it changes according to the baby's age and condition. Breast milk is a living liquid that can meet all the needs of babies for the first six months with the superiority of the amount and bioavailability of vitamins, minerals, proteins, carbohydrates and lipids it contains. Continuing breast milk with additional nutrients after the sixth month and continuing breastfeeding until the end of the second year provides countless benefits to the baby.
According to the period in which breast milk is secreted and its composition;
✓ Colostrum: It is the milk secreted during the first five days after birth (postpartum).
✓ Transitional Milk: It is the milk secreted between the 5th and 15th days after colostrum. Its amount is higher than colostrum. While its protein content decreases, its lactose, fat and calorie content increases.
✓ Mature Milk (Ripe): It is the milk secreted after the fifteenth day.
✓ Foremilk: At the beginning of breastfeeding, it is the milk that is rich in carbohydrates and more watery.
✓ Latest milk: It is the milk that is rich in fat and satisfies the baby at the end of breastfeeding.
It is not known when this change occurs during the breastfeeding process. The important thing is that the baby benefits from both foremilk and hindmilk at once, is full, separates from the breast on its own and sleeps. In this case, it can be thought that the baby is receiving the fat-rich hindmilk.
Colostrum and its Properties
The milk secreted in the first 5 days after birth is called colostrum. Anti-infective elements, vitamin A, sodium and zinc, which are found in colostrum more than mature milk, protect the baby from infections in the first few days. Colostrum covers the baby's gastrointestinal system by forming a mucosal layer with immunoglobulins, thus protecting the newborn baby from pathogenic microorganisms from the outside environment.
Protein
Toplam protein içeriği inek sütüne oranla düşük (1,1 g/dl ve 3,2 g/dl), ancak biyolojik değeri yüksektir ve yaşamın ilk altı ayında tek başına bebeğin protein gereksinimini karşılar. Anne sütünde bulunan proteinler kazein ve whey proteinleri olup, kazein/whey proteinleri oranı 40/60’dır. Bu oran anne sütü proteini sindirilebilir olmasının ve emiliminin yüksek olmasına ve vücut proteinlerine dönüşme oranının (Net Protein Kullanımı (NPU) %100) yüksek olmasına neden olur.
Lipid
Anne sütü kalorisinin %50’sini sağlayan lipitler, anne sütünde, inek sütüne oranla daha yüksektir (4,5 g/dl ve 3,8 g/dl) ve küçük çaplı yağ globülleri halinde bulunur. Anne sütünde bulunan lipaz düşük safra düzeyinde bile yağ sindirimine yardımcı olur. Anne sütü, özellikle prematüre bebeklerin annelerinin sütü, araşidonik asit, dokzahekzaenoik asit, linolenik asit ve alfa linoleik asit gibi uzun zincirli çoklu doymamış yağ asitlerinden zengindir.