Thermal Processing

Preparation of raw material Filling Exhausting Seaming Retorting Cooling & Drying Labeling/Packaging Distribution

Exhausting in Canning Exhausting – removal of air in the food and headspace. Heat is applied causing…. – expansion of food – get rid of blocked and dissolved gas in food – reduce air in the headspace

Exhausting in Canning As the water boils in the canner, the “empty” space becomes a mixture of steam and air. The temperature of a steam/air mixture is lower than the temperature of pure steam. Venting eliminates (“exhausts”) the air so processing takes place in a pure steam environment.

Exhausting in Canning Vacuum in canned food is achieved by exhausting Vacuum- space that is free of matter Lower gas pressure – higher quality of vacuum.

Packaging of canned food Tin-plate cans

2 –piece can Eliminate long seam and one double seam Reduce possibility of 2 potential leaks

Aluminum can Advantages: Freedom from black-discoloration or rust Easier puncture opening Good selling points- no rust, easy opening, always bright Usually used for beverages

Glass containers Chemically stable Does not support microbial growth Gas does not enter Transparent – visible product is attractive Withstand thermal shock

Retortable pouch

- High shelf life of food - Tough - Resistance to puncture - Withstand high temperature - Major advantage: Thin profile and increased surface area allow rapid heat penetration. Safe 40% of retort process time, better quality (nutrition, taste, color, texture). - Green product – easier waste disposal and less energy needed

Retortable pouch 0.5 ml polyester film or in gauge aluminum foil 3 ml modified polypropylene film Laminate