Poultry muscle

• Much higher white muscle fiber type content than mammals. This results in rapid rigor development
  (normal time for rigor ~1-1 ½ hr).
• Few problems are associated with palatability, however, toughness may occur in some birds due to
  cold shortening, lack of aging period or improper cooking.

Preservation and storage

A)Packaging

• Most chicken marketed fresh
• Most turkey marketed frozen
• Fresh products are normally packaged in a O2 impermeable film. Frozen products use a similar film.
• Most of the spoilage is due to aerobic microflora.
• In recent years controlled atmosphere storage has received a great deal of consideration by the poultry
  industry as it enhances the shelf life to 20 days.

B)Refrigeration/freezing

• Fresh poultry is normally processed and shipped in ice alternative would include refrigeration systems
  that run >28 F and or CO2 snow.
• Freezing is handled using various techniques are normally the best.
  

C)Thermal processing

• Commercial precooking systems normally use low temperature and long time for cookery to reduce cooking
  loss and to maintain palatability.
• USDA requires internal temperature of 71 C for uncured poultry and 68 C for cured ones.

D)Chemical deterioration during storage

• Auto oxidation (rancidity) warmed over flavor.
• Poultry deposit unsaturated fats that are very susceptible to autooxidation.
• Turkey is more susceptible to auto oxidation than chicken because they store less Vitamin E in their lipid.
• Supplemental vitamin E has little or no effect on warmed over flavor. This is due to warmed over flavor
  developing from membrane lipids and vitamin E is normally not stored at this level.

E)Processing and fabrication

• Processing sequence is shackling, stunning, bleeding, scalding, washing, evisceration, cleaning and chilling.
• Birds are normally chilled rapidly USDA requires 40 C internally within 4- 8 hr.
• Processed products are cured whole birds/parts. The problem associated with these products is of cure color
  development due to low myoglobin content.
• Cooked /smoked whole birds/parts.
• Loaves/ rolls involve binding pieces together and includes skins and broth. Bind problems may occur if frozen
  products are utilized because freezing damags some proteins.
• Comminuted meat products – USDA permits upto 15% poultry meat in comminuted red meat products like
  franks and bologna.
• Poultry franks often display inferior texture due to high water/protein ratio and/or poor quality protein
  (mechanically deboned meat).
• Fermented products – require longer drying period to achieve desired moisture/ protein ratio

Fish

• Fishes are cold blooded vertebrates.
• Fish muscle is biochemically similar to mammals.
• They have lower amount of connective tissue ( 3- 4% of the proteins).
• Fish proteins breakdown more rapidly than mammals.
• Cold water fish are less stable.
• Fish muscle have certain associated problems like endogenous enzymes, free amino acids and small
  peptides etc.
• The functional properties have limited use as restructured fish products. they have reasonable emulsifying
  capacity.
• Fish is marketed upto 40% fresh, 30 % as frozen and canned, 15% as cured, and 10 – 15 % of fish is sold
  as comminuted or sectioned and formed products.
• limited use of fish as restructured or sausage products in the U.S.
• Protein extractability and binding strength of fish muscle is normally related to the moisture/ protein ratio
  and the quality of fish being used.
  
• Lipids from fish contain high levels of polyunsaturated fatty acids.
• The stability of fish lipids is short due to their poly - unsaturated nature.
• Shell fish usually have high levels of cholesterol; however, other fish is similar to red meat products.
• Preservation and spoilage of fish –
  i)Most spoilage of fish is due to bacterial breakdown. Bacterial breakdown is very similar to the
  red meats and the microbial flora is similar.
  ii) One spoilage characteristic found in fish and not in muscle foods is trimethylamine formation.
  This odoriferous amine is responsible for the fish smell associated with spoiling fish. The amount
  of trimethylamine formation is often used as an index of fish quality.
  iii) Scombroid poisoning is another problem associated with fish in which the histidine gets
  converted to histamine which causes allergic reactions in consumers.
  iv) fish meat has high level of polyunsaturated fatty acids.
  v) Cholesterol content is very high in shell fish.
  vi) Chilling of fish immediately after harvest is very important part of preservation. methods include
  ice or ice water to maintain the quality of the product until it is processed temperatures near freezing
  are normally used.
  vii) Frozen storage requires low temperature – 10 F for extended shelf life. A host of freezing
  techniques are used, but rapid techniques are commonly employed.
  viii)Freezing can alter protein functionality which reduces extractability and bind.
  ix)Lipid oxidation may occur and if temperatures are not maintained ( – 10 F ) trimethylamine
  formation.
• Processing of fish for making surimi–
  

Process for making fibrous, flake, chunk and composite molded products

paste(a) (b) Straight mold Molded(c)

Surimi+ water + flavor enhancer salt shellfish meat Starch and/or egg white (a)silent cutter meat pump Feeder Nozzle (extrusion) Conveyor belt gas Steam Gas Cooling Strip cutter Strings (d) (b)mixer former (c)composite mold Molded steam cooking(e) packaging

(d)Rope former Wrapper Obliquecut straight cut Flake chunk---------------------- Stick (e)Fibrous