Editing Infant formula (section)

=== Current general procedure ===
The manufacturing process may differ for different types of formula made; therefore the following is the general procedure for liquid-milk based formulas:<ref name="two" />

==== Mixing ingredients ====
Primary ingredients are blended in large stainless steel tanks and skim milk is added and adjusted to 60&nbsp;°C. Then, fats, oils and emulsifiers are added. Additional heating and mixing may be required to get proper consistency. Next, minerals, vitamins, and stabilizing gums are added at various points, depending on their sensitivity to heat. The batch is temporarily stored and then transported by pipelines to pasteurization equipment when mixing is complete.<ref name="two" />

==== Pasteurization ====
This is a process that protects against spoilage by eliminating bacteria, yeasts and molds.
It involves quickly heating and then cooling of the product under controlled conditions which micro-organisms cannot survive. The batch is held at around 85–94&nbsp;°C for approximately 30 seconds which is necessary to adequately reduce micro-organisms and prepare the formula for filling.<ref name="two" />

==== Homogenization ====
This is a process which increases emulsion uniformity and stability by reducing size of fat and oil particles in the formula. It is done with a variety of mixing equipment that applies shear to the product and this mixing breaks fat and oil particles into very small droplets.<ref name="two" />

==== Standardization ====
Standardization is used to ensure that the key parameters like pH, fat concentration and vitamins and mineral content are correct. If insufficient levels of these are found, the batch is reworked to achieve appropriate levels. After this step, the batch is ready to be packaged.<ref name="two" />

==== Packaging ====
Packaging depends on manufacturer and type of equipment used, but in general, liquid formula is filled into metal cans with lids crimped into place.<ref name="two" />

==== Heat treatment or sterilization ====
Finally, infant formulas are heat treated to maintain the bacteriologic quality of the product. This can be done traditionally by either retort sterilization or high-temperature short-time (HTST) treatment. Recently, ultrahigh-temperature treated formula has become more commonly used. If powdered formula is made, then [[spray drying]] would be required in addition.<ref name="multiple">{{cite journal | vauthors = Lönnerdal B, Hernell O | title = Effects of feeding ultrahigh-temperature (UHT)-treated infant formula with different protein concentrations or powdered formula, as compared with breast-feeding, on plasma amino acids, hematology, and trace element status | journal = The American Journal of Clinical Nutrition | volume = 68 | issue = 2 | pages = 350–356 | date = August 1998 | pmid = 9701193 | doi = 10.1093/ajcn/68.2.350 | doi-access = free }}</ref> Retort sterilization is a traditional retort sterilization method that uses 10-15mins treatment at 118&nbsp;°C.<ref name="multiple"/> Ultrahigh-temperature (UHT) is a method that uses a brief (2–3 seconds) treatment at 142&nbsp;°C. Because of the short time used, there is little protein denaturation, but the process still ensures sterility of the final product.<ref name="multiple"/>