History and innovation of tinned cans

Appert canning technique was improved by the work of British scientists Bryan Donkin and John Hall. They created the first tinned canned food in 1812.

The first cans were handmade of steel coated with tin. Durand’s early process produced 10 cans per day; modern can-making machines can produce 1000 or more per minutes.

Other innovations include quick-opening cans with pull tabs, as are used for soft drinks, sardines and nuts; cans that are opened with a slotted key that comes with the can, as are used for sardines and cured hams; pasteurized cans that use a propellant to dispense whipped cream and cheese spreads; and extruded or drawn cans, as are used for soft drinks, tuna and sardines.

The extruded cans has several advantages over the conventional can, a major one being the elimination of the bottom and side seams, which reduces the probability of seam failures eliminates the use of lead, (used in side seam) and permits more stable stacking in shelves, requiring somewhat less vertical space.

Two basic types of allowed metals are used in food packaging: steel and aluminium. Steel is used primarily to make rigid cans, where aluminium is used to make cans as well as thin aluminium foils and coatings.

Until a few years ago nearly all steel used for cans was coated with a thin layer of tin to inhibit corrosion; hence, the name ‘tin can’.
History and innovation of tinned cans

Hermetically sealed metal containers

The preservations of canned products require hermetically sealed cans.  Presently three types of hermetically sealed containers are recognized by the food industry:
*Rigid
*Semirigid
*Flexible containers

By the early 1900s, the manufacturing and sealing cans were accomplished by machine. The technique was developed by Peter Durand, who used tin coated iron containers in place of glass jars. He was granted a patent in 1810 for his technique of preserving foods in hermetically sealad tin cans.

Double seam made by five layers compressed 

The lid used for the cans contained a rim to which a plastic casket could be added, and rim to could be sealed tightly by machine by first crimping it over and under the flanged top of the can body and then pressing the two together by a second roller operation.

The plastic gasket made the can airtight by filling the tiny voids produced between the rim of the cover and the flange of the cans as they were brought together.  The process of creating an airtight closure by attaching the can end component to the can body is called double seaming.

This double seem is a metal-to-metal joint formed by mechanically interlocking five layers of metal together three from the can end and two from the can body.
Hermetically sealed metal containers

Cereal Processing: History of Milling

The objective of cereal milling is to remove the bran and germ from the seed and to free the endosperm. This left whole as in rice milling, ground into coarse pieces (wheat semolina, maize grits) or milled into flour.

Since prehistoric times up to the middle of the 19th century, cereal grains were ground in small mills, driven by hand, wind or water power.

The process of milling wheat into flour was revolutionized around 800 BC in Mesopotamia, when animal, water and wind power were harnessed for the first time to run the large stones used for grinding.

In ancient Rome the mill and the bakery were the very same enterprise. The grain were milled and worked up without delay to dough and bread.

The flour ground in such a mill was whole grain flour, because the complete cereal grains poured into the mill on top, came out out as flour at the bottom.

Probably the most ancient technique involves the grinder rocking backwards and forwards while grasping an ellipsoid stone in both hands which crushes the grain within a larger concave stone suits in front of the grinder.

Both upper and lower stone are usually made from a hard igneous rock such as granite or basalt to avoid the production of stone in the grinding process.

Around the Mediterranean and possibly also in China during the first half of the first millennium BC, there were two sophisticated versions of the handmill the hopper-rubber and the lever mill.

Moving to the milling process proper, it was in 1878 that Henry Simon took 19 British millers, to Hungary to view the all steel rollermill invention.

This machine became the heart of what is known as the gradual reduction system, commonly used worldwide today.
Cereal Processing: History of Milling

Process of Milk Pasteurization

Process of Milk Pasteurization
Pasteurization, named after Louis Pasteur (1622-1895), its originator, was originally used to treat wine and beer, but soon came into use to treat milk as well, when it found that heating milk for a short time to below its boiling point killed microorganisms.

Pasteurization destroys 100 percent of pathogenic bacteria, yeasts and molds and 95 to 99 percent of other, nonpathogenic bacteria.

The process of pasteurization also inactivated many of the enzymes that cause the off-flavors of rancidity.

In the United States pasteurization was championed by Alice Catherine Evans (1881-1975), a microbiologists who worked for the US department of Agriculture.

Evans suffered from a disease known as brucellosis (undulant fever) and in 1918 she discovered that brucella, the bacterium that caused her disease, could be found in cow’s milk.

Scientists eventually determined that brucella was not the only milk borne bacterium. Milk can harbor other bacteria – such as E. coli, salmonella, and listeria – which can cause harmful and even life threatening infectious in the young, the old, pregnant women and the infirm.

Indeed, unpasteurized cow’s milk was a very common cause of tuberculosis, typhoid fever and salmonellosis.

Evans advocated on behalf of pasteurization for years after her discovery. Finally in the 1930s, milk pasteurization became mandatory under US law.

The advantages to be derived from pasteurization vary with the conditions under which the milk is produced and the efficiency with which the work is conducted.

If the milk comes from dairies where disease and uncleanliness prevail, pasteurization will prolong the keeping quality of the milk and also materially lessen the danger from disease germs.

If on the other hand, healthfulness and cleanliness receive the exacting attention which prevails on certified dairy farms, nothing can be gained by subjected milk to the pasteurizing process.
Process of Milk Pasteurization

History of Aseptic Packaging

History of Aseptic Packaging
Aseptic packaging is an area of food packaging in which a food product and a package are commercially sterilized separately and combined in a commercially sterile environment.

The aseptic processing and packaging process has seen tremendous growth and remarkable advances since its inception in the 1940s.

The first invention was likely a device for carrying food. Hunters and gatherers needed to lighten the burden of bringing food back to a central camp.

These early camps were undoubtedly located near water, because the means of transporting liquid was still long way off.

As population grew and were forced to move father away from a secure source of water, the need to carry liquids became urgent. Skins and shells, followed by pottery and ceramics and then glass, metals and plastics, became the materials needed for storing, preserving and transporting liquids.

The used of glass containers for food dates back to 1200 BC. Glass proved to be particularly useful type of food packaging, because it did not react with food and was a highly effective barrier against oxygen, a common cause of food spoilage or deterioration.

Packaging food in paper began around 200 BC , when the Chinese used a type of paper made from tree bark to package foods.

Paper products evolved slowly until the late nineteenth century, when advances made during the industrial revolution helped make the production of paper bags and other products possible.

Canning truly revolutionized food packaging. There is evidence that containers made of tin-plated iron was used as early as the thirteenth and fourteenth centuries, but the use of these containers was not widespread, because they were considered poisonous to food.

In 1989 the Institute of Food Technologist an organization of food scientists devoted to improving the production and distribution of food, selected aseptic packaging as “the most significant food science innovation in the past fifty years”.

Ruben Rausing in Sweden reportedly conceived the concept for holding milk in a container made form a paperboard composite.

The original package had a tetrahedral shape and was called a Tetra Pak.

This new technology was married to aseptic technology, and a new industry was born. The box-shaped package that is so widely available is a laminate of six layers of three materials: paperboard 70% polyethylene 24%, and aluminum 6 %.

Innovations in plastic technology and plasma discharge silica coating technology offer the promise that more foods will be packaged in efficient septic packages during the twenty first century.
History of Aseptic Packaging