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Filling a commercially sterile product into a sterilised container in a sterile environment, sealing without further heat.
What lets Tetra Pak milk and juice sit unrefrigerated on a store shelf for months, then spoil within days once opened.
A short heat treatment, usually 70–100 °C, applied before freezing, drying or canning, primarily to inactivate enzymes.
The quick dip in boiling water before freezing vegetables like peas and beans, so they don't turn mushy or lose colour in the freezer.
See also: Enzymatic browning, Peroxidase test, Polyphenol oxidase
Fruit showing a sharp rise in respiration and ethylene production at the onset of ripening — banana, mango, apple, tomato — and able to ripen after harvest.
The reason bananas and mangoes can be bought unripe and left to ripen on the kitchen counter, while grapes and citrus can't.
See also: Respiration rate, Ethylene
Bulk storage in which gas composition is continuously monitored and actively corrected, used mainly for fruit such as apples.
Why apples bought from a supermarket in April can still taste crisp from an autumn harvest — kept in low-oxygen rooms that slow ripening for months.
See also: Modified atmosphere packaging, Respiration rate
A gaseous plant hormone that triggers and accelerates ripening and senescence, active at parts-per-million concentrations.
The ripening gas behind the old kitchen trick of storing bananas away from other fruit, so the whole bowl doesn't ripen and spoil together.
See also: Climacteric fruit, Controlled atmosphere storage
Dehydration by freezing the food and subliming the ice under vacuum below the triple point of water, followed by desorption of bound water.
Why instant coffee dissolves instantly, and why astronaut ice cream and lightweight camping meals keep their shape and nutrients for years.
See also: Sublimation, Spray drying, Glass transition temperature
Applying isostatic pressure of roughly 400–600 MPa to packaged food to inactivate vegetative microorganisms with little heat.
The technology behind cold-pressed juices sold with a longer shelf life than fresh juice, without heat pasteurisation.
See also: Hurdle technology, Pasteurisation
The principle that higher temperature for shorter time achieves the same microbial lethality with less loss of nutrients, colour and flavour.
The reason pasteurised milk in a carton tastes fresher and less “cooked” than boiled milk — a shorter, hotter treatment instead of prolonged boiling.
See also: UHT, z-value, Pasteurisation
Combining several mild preservation factors — pH, aw, temperature, preservatives, redox potential — so that their combined effect prevents microbial growth where none alone would suffice.
Why pickles are salty, sour and stored in oil all at once — no single barrier alone would stop spoilage, but combined they do.
See also: Water activity, Preservative
Exposure to ionising radiation — gamma, electron beam or X-ray — measured in grays, to reduce microbial load, control insects or inhibit sprouting.
The reason some imported spices, onions and potatoes are treated to kill insects and stop sprouting without heat or chemicals — look for the Radura symbol on the pack.
See also: Hurdle technology
Replacing the air in a pack with a controlled gas mixture, typically carbon dioxide, nitrogen and sometimes oxygen, then sealing without further adjustment.
The reason a packet of sliced bread, salad leaves or cut fruit in a supermarket looks puffed up with gas rather than vacuum sealed.
See also: Controlled atmosphere storage, Hurdle technology
A mild heat treatment that destroys vegetative pathogens and reduces spoilage organisms, without eliminating spores. Milk: LTLT 63 °C for 30 min, or HTST 72 °C for 15 s.
The everyday reason packaged milk, juice and beer are safe to drink without boiling, and why “raw milk” carries extra risk.
See also: Sterilisation, UHT, Phosphatase test
The rate at which harvested produce consumes oxygen and releases carbon dioxide, heat and water.
Why some vegetables like spinach wilt and spoil within a day at room temperature while others like potatoes last for months.
See also: Climacteric fruit, Controlled atmosphere storage, Q10
A heat process severe enough to destroy all microorganisms including spores, typically above 100 °C under pressure.
Ensures canned and UHT foods are completely free of microorganisms, unlike pasteurised products which still need refrigeration.
See also: Commercial sterility, Pasteurisation, UHT
Heating to roughly 135–150 °C for 2–5 seconds followed by aseptic packaging, giving a shelf-stable product without refrigeration.
What makes Tetra Pak milk shelf-stable for months without refrigeration until opened, unlike pasteurised milk which needs the fridge.
See also: Pasteurisation, Aseptic packaging, z-value, HTST principle
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