The basic composition of any infant formula consists of:
The proportion, the quality, and the processing of these elements determine the overall quality of the food. Since an infant formula may be the only source of nutrition for a new born infant, the choice of these criteria is vital - and so is the choice of equipment supplier of the complete process line for baby food.
All major infant formula producers have developed their own brands with specific compositions. However, several legislations (Codex, USFDA, EU, FS Australia and New Zealand, China) provide the regulatory frame for the composition of infant formulas and follow-up formulas.
Learn more about the processing equipment that can mix, evaporate, and dry all the ingredients needed to produce an infant formula/baby food powder with correct properties for the end user, the baby.
As in human milk, the bulk of an infant formula is composed of carbohydrates (usually about 55 % of the solids). In infant formula, the lactose is often partially or completely replaced by hydrolysed starch (i.e. maltodextrin). Generally, the higher carbohydrate content, the higher the solids content that can be fed to the spray dryer. The addition of cooked starch results in thickening of the reconstituted formula. This will have an influence on the solids content that can be fed to the spray drying plant.
Protein is composed of many amino acids: 9 of which are indispensable, cannot be synthesized by the human body, and have to be supplied in adequate proportions by the food. The amino acid profile and the energy supplied by proteins of human milk provide the “golden standard” for any formula. For an equal energy value, the infant formula must contain an available quantity of each indispensable amino acid at least equal to that of human breast milk.
After cow's milk protein, soy protein is the most widely used protein for infant formula. The protein has to be isolated from the soy bean in order to get rid of undesirable components such as oligosaccharides, fibers, saponins and phytoestrogens. The amino acids profile of soy protein is deficient in sulphur containing amino acids, and L-Methionine enrichment is therefore required.
Another aspect of proteins is their potential allergenicity. A growing proportion of infants show a certain degree of allergenicity to foreign protein, e.g. cow, goat, or soy. A reduction of the risk of allergic reactions to cow’s milk protein can be achieved by hydrolysing the proteins to smaller peptides (e.g. Hypo-Allergenic formulae).
High total protein content will result in a high viscosity of the formulation to be dried. The total solids content will therefore have to be reduced.
Lipids constitute the main energy supply of infant formulas. In many infant formulas, the lipids are a mixture of milk fat and vegetable oils. The quality of the lipids is expressed by their fatty acid composition, the degree of saturation, and the content of trans fatty acids. In most countries the oils of vegetable origin are enriched with long-chain poly-unsaturated fatty acids (LC-PUFA) containing oils.
Due to the high degree of instauration of these oils, special care has to be taken in order to avoid fat oxidation and rancidity. Generally, high lipid content in the formula will result in a low viscosity of the feed to the dryer. The total solids content can thus be increased.
As for proteins, fats and carbohydrates, minerals also play an important role in the nutrition of infants. K, Na, Ca, Mg, P and Cl are referred to as minerals, whereas Fe, Cu, Zn, Se, Mn and I are referred to as micro- or trace elements. Minerals are generally referred to as having no influence on the subsequent drying.
- Water soluble vitamins: B1, B 2, B 3, B5, B6, B12, C, Folic acid, Biotin
- Fat soluble vitamins: A, D, E, K1
Fat soluble vitamins can be encapsulated, which makes them granular and Cold Water Soluble. In this way all vitamins can be blended and used as pre-blend with an analysis certificate allowing a simplified control for each batch to be spray dried. Vitamins have no influence on the operation of the spray dryer.
The basic ingredients in infant formulae/Baby food are made up by mixing the following:
Typical raw materials in different proportions to compare the final formulae.
- Milk (skimmed or full fat, liquid or powder, cow or buffalo)
- Casein (acid or K / Ca neutralised)
- Whey protein (concentrate/isolate, partially demineralised)
- Carbohydrates: lactose, sucrose, maltodextrin and corn syrup (powder or syrup)
- Vegetable oils, anhydrous butter oil, cream
- Emulsifiers/Stabilizers: lecithin (soy), mono- and diglycerides
- Mineral salts (K, Na, Ca and Mg as carbonates, citrates, phosphates, chlorides)
- Micro-nutrients (e.g. vitamins, amino acids, KI, FeSO4, ZnSO4, CuSO4)
When the milk source is fresh milk, it should be cooled before standardisation of fat content, pasteurized and cold stored in silo tanks. From these tanks it will be pumped to the wet mixing with the dry ingredients.
Oils are supplied either in drums or in bulk from insulated tank lorries. The oil is pumped to storage tanks. Depending on the melting point of the oil, the tanks can be provided with double jacketing. If milk, either liquid or in powder form, is not available, anhydrous butter oil can be used. In order to prevent oxidation of the (poly-unsaturated) oils, the oil tanks are usually equipped with an inert gas (N2) supply.