The word "juice" comes from Old French in about 1300; it developed from the Old French words "jus, juis, jouis", which mean "liquid obtained by boiling herbs". The "Old French jus "juice, sap, liquid" (13c.)...[came] from Latin ius [which means] "broth, sauce, juice, soup," from PIE root *yeue- "to blend, mix food" (cognates: Sanskrit yus- "broth," Greek zyme "a leaven," Old Church Slavonic jucha "broth, soup," Russian: "ukha", Lithuanian: juse "fish soup")." The use of the word "juice" to mean"the watery part of fruits or vegetables" was first recorded in the early 14th century. Since the 19th century, the term "juice" has also been used in a figurative sense (e.g., to mean alcohol or electricity). Today, "au jus" refers to meat served along with its own juice, commonly as a gravy.
Juice is prepared by mechanically squeezing or macerating (sometimes referred to as cold pressed) fruit or vegetable flesh without the application of heat or solvents. For example, orange juice is the liquid extract of the fruit of the orange tree, and tomato juice is the liquid that results from pressing the fruit of the tomato plant. Juice may be prepared in the home from fresh fruit and vegetables using a variety of hand or electric juicers. Many commercial juices are filtered to remove fiber or pulp, but high-pulp fresh orange juice is a popular beverage. Additives are put in some juices, such as sugar and artificial flavours (in some fruit juice-based beverages); savoury seasonings (e.g., in Clamato or Caesar tomato juice drinks). Common methods for preservation and processing of fruit juices include canning, pasteurization, concentrating, freezing, evaporation and spray drying.
Although processing methods vary between juices, the general processing method of juices includes:
Washing and sorting
Straining, filtration and clarification
Filling, sealing and sterilization
Cooling, labeling and packing.
After the fruits are picked and washed, the juice is extracted by one of two automated methods. In the first method, two metal cups with sharp metal tubes on the bottom cup come together, removing the peel and forcing the flesh of the fruit through the metal tube. The juice of the fruit then escapes through small holes in the tube. The peels can then be used further, and are washed to remove oils, which are reclaimed later for usage. The second method requires the fruits to be cut in half before being subjected to reamers, which extract the juice.
After the juice is filtered, it may be concentrated in evaporators, which reduce the size of juice by a factor of 5, making it easier to transport and increasing its expiration date. Juices are concentrated by heating under a vacuum to remove water, and then cooling to around 13 degrees Celsius. About two thirds of the water in a juice is removed. The juice is then later reconstituted, in which the concentrate is mixed with water and other factors to return any lost flavor from the concentrating process. Juices can also be sold in a concentrated state, in which the consumer adds water to the concentrated juice as preparation.
Juices are then pasteurized and filled into containers, often while still hot. If the juice is poured into a container while hot, it is cooled as quickly as possible. Packages that cannot stand heat require sterile conditions for filling. Chemicals such as hydrogen peroxide can be used to sterilize containers. Plants can make anywhere from 1 to 20 tonnes a day.