How to lay out the answer. Follow the frame, then write it in your own words.
1 · Open in two lines. UHT (ultra-high temperature) processing heats liquid foods to 135-150 °C for a few seconds and packs them aseptically, giving a commercially sterile product.
2 · Methods.
Direct: steam injection or infusion.
Indirect: plate or tubular heat exchangers.
3 · Draw the flow. [Flow: raw milk → preheat → UHT 135-150 °C, seconds → cool → aseptic filling into sterile cartons]
4 · Aseptic packaging. Sterile product goes into sterile multilayer cartons (paperboard, polyethylene, aluminium) in a sterile zone.
5 · Advantages and limits.
Keeps for months unopened at room temperature; less cooked flavour than canning.
Costly plant; chill after opening; slight cooked taste.
6 · Nutrition link. Useful in relief camps, travel and areas without a cold chain; protein and calcium are unchanged.
7 · Close in one line. UHT gives safe, good-quality milk that needs no refrigeration until opened.
Scoring tip: Contrast UHT with in-container sterilisation in one line; it shows understanding.
