Classify the methods of food preservation. Explain bactericidal and bacteriostatic methods.

1. 1 · Open in two lines. Preservation methods either kill microbes (bactericidal) or stop their growth (bacteriostatic). They are also grouped by the agent they use.
2. 2 · Draw a classification chart. [Chart: preservation methods → asepsis, removal, high temperature, low temperature, drying, sugar and salt, chemicals, fermentation, smoking, irradiation]
3. 3 · Bactericidal methods.
   • Kill microbes; the food must stay sealed.
   • Sterilisation, canning, UHT, pasteurisation (disease germs), high-dose irradiation.
4. 4 · Bacteriostatic methods.
   • Stop growth; microbes revive when the hurdle is removed.
   • Refrigeration, freezing, drying, sugar, salt, acid, chemical preservatives, smoking.
5. 5 · Dose decides some methods. Heat, chemicals and irradiation kill at high levels and only hold back at low levels.
6. 6 · Hurdle technology. Mango pickle and squash combine several mild hurdles for safety and taste.
7. 7 · Nutrition link. Thawed, opened or diluted bacteriostatic foods must be handled like fresh food.
8. 8 · Close in one line. Whether to kill or only stop microbes depends on the food, the quality wanted and how long it must keep.

Scoring tip: A ten-branch chart plus the two-column comparison answers both halves of the question at a glance.