1. S.L.R. Jayanayake
AG/11/FT/010
Seminar in Food Science and Technology
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2.  Historical background
 Introduction to fresh water fish
 Smoke curing
 Liquid smoke
 Preservative activity
 Sensory Attributes
 Advantages and disadvantages
 Conclusions
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3.  Fire place of cave men
 Stored meat and fish
 Good flavor
 Long shelf life
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4. Lives in
 Low salinity waters
 Rivers, reservoirs, lakes and ponds
Commonly
 Carps, trout, tilapia and eels
 Local varieties
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5. Nutritional value
 As a protein source
 Rich in minerals
 Beneficial fatty acids
Economical
 Low cost
 Important to the development of regional economy
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6. Highly perishable
 75% moisture
 Rich in nutrients
 Desirable pH for microbes
Seasonal excessive production
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7.  Drying
 Salting
 Pickling
 Freezing
 Canning
 Smoking
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8. Flavoring ,cooking and preserving
by exposing to smoke.
Pre treatments
◦ Gutting
◦ Salting
Post treatments
◦ Drying
◦ Packaging
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9. Two phases
1. Particle phase
2. Vapor phase
Main compounds
◦ Alkyl esters
◦ Carboxylic acids
◦ Polycyclic Aromatic Hydrocarbons (PAH)
◦ Phenolic compounds
◦ Resin acids and terpenoids
◦ Alkanes, alkenes and other aromatic compounds
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10.  PAHs are potentially carcinogenic
 Safety problems
 Sanitation problems
 Problems in process control
 Uneven treatment
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11. Production
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Wood Smoke
Extraction or
Distillation
Condensation
Separation of
Hazardous Compounds
Liquid Smoke

12. Antimicrobial activity
◦ Phenolic compounds
◦ Carbonyls
◦ Organic acids
Antioxidant activity
◦ Phenolic compounds
◦ Hydroquinone
◦ Formic, benzoic and salicylic acids
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13. Smoke flavorings
◦ Carboxylic acids
◦ Carbonyl compounds
o Sweet
o Flowery and fruity aromas
◦ Phenolic compounds
o Smokey
o Spicy flavors
Color
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14.  Low health risks
 No need to generate smoke in
fish processing plant
 Easy to control process
 Only liquid smoke is not
sufficient to preserve fish
 Dryers are needed
 Cost of production may be high
Advantages Disadvantages
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15.  Liquid smoke can be used with hurdle concept.
 Produce good quality fish preserves with acceptable sensory
properties.
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17.  High activity
 Pseudomonas spp
 Moderate activity
 Moraxella, Acinetobactor,
 Low activity
 Aerobacter, Lactobacillus, Flavobacterium, Micrococcus, Bacillus and
Staphylococcus
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18. Chemicals Particle phase concentration (mg/kg wood burned) Vapor phase concentration (mg/kg wood burned)
Alkanes C2-C7 0.47-570 1.01-300
Alkenes C2-C7 0.57-280 92-1300
Carboxilic Acids 0.24-5410 120-9200
Alkyl esters 6200-755000 2.4
Methoxilated phenolic compounds 28-1000 1200-1500
Polycyclic Aromatic Hydrocarbons (PAH) 5.1-32000 43.4-355
Sugar derivatives 1.4-12600
Coumarins and flavonoids 0.71-12
Phytosteroids 1.7-34
Resin acids and terpenoids 1.7-41000 21-430
Other subsitudel aromatic compounds 5.0-120000 110-3600
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19. Year Off shore mt. Coastal mt. Inland aqua
culture mt.
Total mt.
2010 129,840 202,400 52,410 384,670
2011 160,270 220,990 59,560 440,820
2012 159,680 257,540 68,950 486,170
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