Fish Processing, Value Addition and Marketing
What the exam tests
Processing and marketing questions test preservation principles, quality control, value addition and channels. You should know why fish spoils quickly and how drying, salting, chilling, freezing and canning slow spoilage.
Core rules
- Fish spoils fast because of high moisture, neutral pH, enzymes and bacteria.
- Chilling slows bacterial growth; freezing stops growth but does not sterilise. Maintain the cold chain without breaks.
- Drying removes water; salting lowers water activity; smoking adds heat and antimicrobial compounds.
- Good quality raw fish, clean water, hygienic handling and proper packaging are essential.
- Value addition includes fish pickle, cutlets, dried fish, surimi, fish meal and ready-to-cook products.
- HACCP identifies hazards and critical control points; records must be kept.
Worked example
10 kg fresh fish at 75 percent moisture contains 2.5 kg dry matter. If dried to 15 percent moisture, final weight = 2.5 / 0.85 = 2.94 kg. Reasoning: dry matter is conserved; final weight is dry matter divided by the dry-matter fraction. This explains the large weight loss in drying.
Traps
Do not say freezing kills all bacteria. Do not ignore temperature abuse in the cold chain. Do not confuse moisture percentage with water activity. Do not dry fish on the ground or in unhygienic conditions.
Key facts
Dried fish is a major Assam product. Packaging protects against moisture and insects. Labels should show species, weight and date.