1-21. ULTRA PASTEURIZED
The term "ultra-pasteurized," when used to describe a dairy product, means that
such a product shall have been thermally processed at or above 280F (138C) for at
least 2 seconds, either before or after packaging, to effect a product which has an
extended shelf life under refrigerated conditions.
1-22. ASEPTICALLY PROCESSED AND PACKAGED
Aseptic processing and packaging is designed to produce a milk product that is
shelf stable (does not require refrigeration). This is accomplished by first thermally
processing a product to render it commercially sterile (for example, all pathogenic
microorganisms are killed and all spoilage microorganisms are either killed or rendered
incapable of reproducing) and then packaging it in sterilized containers, which are then
hermetically sealed. Aseptically processed milk is considered to be a "low acid canned
food" and must conform to the same regulations that govern the canning of low acid
foods (for example, Title 21, Code of Federal Regulations (CFR), Part 113). Heating
the milk to the required temperatures is accomplished using a direct and/or indirect
method. Direct heating consists of exposing the product directly to live steam. Indirect
heating consists of using plate/tubular heat exchangers like those described in the
HTST system. In any case, the product is normally preheated to at least 167F or even
up to 176F (75 up to 80C), heated to the final process temperature of a minimum of
284F or a maximum of 302F (140 up to 150C), and then packaged. The filled
container is not subjected to any additional heating or cooling steps. The packaging
system uses a container constructed of a laminate normally consisting of paper, metal
foil, and plastic. The cartons are sterilized prior to filling using hydrogen peroxide,
ultraviolet light, and/or heat. The sterilized cartons are then filled and hermetically
sealed in a sterile environment.
1-23. COOLING AND STORAGE
Immediately after pasteurization, milk is chilled to 45F (7C) or lower, and it
must be held at that temperature during storage. There are several types of cooling
units such as surface coolers, cabinet coolers, and the plate-type cooler. Milk should be
packaged as soon as possible after pasteurization.
The chilled, pasteurized milk is packaged in various types of containers. The
more common containers and their capacities are listed below.
a. One-Gallon Containers and Less.
(1) Paper cartons with wax coating. There are two general types of cartons:
those received at the dairy either broken down or in roll form and those prefabricated at
a factory. The first mentioned cartons are formed, glued, and waxed just before filling,