Professional Knowledge: Food Science, Storage and Quality Control
Food Science, Storage and Quality Control tests spoilage mechanisms, preservation, grain storage, mycotoxins, food safety systems and quality standards relevant to FCI operations.
Core rules
- Microbial growth depends on moisture or water activity, pH, temperature, oxygen and nutrients. Drying, cooling, acidification and hermetic storage reduce spoilage.
- Grain storage: clean and dry grain to safe moisture, keep cool, control insects and rodents, and monitor for hotspots. Phosphine fumigation is used under sealed conditions with safety controls.
- Quality control: use representative sampling, specification limits, GMP, HACCP’s seven principles and FSSAI/Codex-based limits.
- Mycotoxins: Aspergillus flavus can produce aflatoxin in warm, humid groundnuts and cereals. Prevention is better than removal because aflatoxin is heat-stable.
Worked example
1000 kg of wheat is at 14% moisture (wet basis) and is dried to 12%. How much water is removed?
Dry matter remains constant: 1000 × 0.86 = 860 kg. At 12% moisture, dry matter is 88% of final weight. Final weight = 860/0.88 = 977.3 kg. Water removed = 1000 − 977.3 = 22.7 kg. A common error is taking 2% of 1000 kg, or 20 kg, which ignores that the final weight is also smaller.
Traps
- Mixing wet-basis and dry-basis moisture percentages.
- Assuming fumigation removes insect fragments, dust or mycotoxins; it targets live pests.
- Treating HACCP as a product-testing scheme rather than a preventive hazard-control system.
- Ignoring temperature and humidity in warehouse ventilation.