Seafood Processing PDF

SEAFOOD PROCESSI NG Official (Open) Official (Open) Seafood is a popular part of the diet in many countries and in some countries it constituted the main supply of animal protein Nowadays consumer are turning to fish as a healthy altern...

SEAFOOD PROCESSI NG Official (Open) Official (Open) Seafood is a popular part of the diet in many countries and in some countries it constituted the main supply of animal protein Nowadays consumer are turning to fish as a healthy alternative to red meat The effects on coronary heart disease of the n-3 polyunsaturated fatty acids found in fatty fish species have gained popularity amongst the health-conscious people particularly in affluent countries (where cardiovascular disease mortality is high) INTRODUCTION Official (Open) SEAFOOD PROCESSIN G Seafood processing plays an important role in seafood chain to ensure that our seafood harvested is safe and good for consumption. Seafood processing includes the following:  Cleaning, filleting and mincing of fish  Marinating seafood  Preparing sashimi  Freezing fish and other seafood  Opening oyster and shellfish  Smoking of salmon and other seafood  Grading, shelling & cooking of prawns and other crustaceans  Freezing seafood products (e.g. fish balls, imitation crabstick, breaded fish fillet) Official (Open) SURIMI Surimi is a Japanese word which means “minced fish meat”. It constitutes about 2 ~ 3% of world fishery supply (2 – 3 million tons of fish from around the world) It can be defined as stabilized fish myofibrillar protein and is sometimes known as “ground fish meat” or “concentrated fish protein”. It is obtained from fishes that are mechanically deboned, refined (heading, gutting and mincing), washed with water, drained, blended thoroughly with cryoprotectants, packed and frozen. It is widely used as intermediate product for variety of surimi seafood products or shellfish substitutes Official (Open) SURIMI Official (Open) SURIMI It has excellent gelling properties and can be formed into various shape. Generally, good quality surimi is odourless and has is creamy white in appearance. Surimi industry uses several fish species for surimi processing. Generally, these fishes are white fleshed fishes with low fat content. Common fish species for surimi manufacturing:  Alsaka pollock (Theragra chalcogramma) ~ North Pacific Ocean  Pacific whiting (Merluccius productus) ~ Pacific Coast of US and Canada  Blue Hake/Hoki (Macruronus navaezelandiae) ~ New Zealand and Chile  Southern blue whiting (Micromesistius australis) ~ Chile & Argentina  Northern blue whiting (M. poutassou)Thailand, Malaysia, Indonesia, ~ North Atlantic Ocean  Threadfin bream (Nemipterus spp.) Southern China and India  Big eye snapper (Priacanthus spp)  Lizard fish (Saurida spp)  Yellow croaker (Pseudosciaena manchurica) (South of Japan)  SURIMI PROCESSING: Official (Open) Raw Material De-heading & gutting Deboning (Filleting) Mincing Minced Meat Washing Refining Dewatering Leached Meat Mixing Packing Freezing Frozen Surimi Official (Open) SURIMI PROCESSING De-Heading & Gutting  To remove head, gut (viscera) using heading-gutting machine.  Gut must be removed completely as residual enzymes can cause a decrease in gel-forming ability  Kidney and peritoneal membranes (reddish) will affect appearance of the final product  After de-heading and gutting, fish are washed again with chilled water to remove loose scales, blood and pieces of gut Official (Open) SURIMI PROCESSING Deboning  Separation of meat from skin and bones using deboning machine (e.g. drum type separator: This machine can separate fish meat from fish bone, fish skin, fish tendon. Fish meat is collected in the barrel and fish bone, fish skin, fish tendon is sent out by scraper).  During deboning, plenty of water is used to separate the fillets from undesirable parts of fish Official (Open) SURIMI PROCESSING Mincing  Most deboning machines work on the principle to force soft portion of fish (e.g. flesh) through perforated plate or screen into the drum interior. The bones, hard cartilage and skin on the drum exterior are scraped away.  Diameter perforations of 3 – 4mm is optimal for quality and yield. >5mm yields larger meat particles, improve recovery yield but quality of surimi compromised due to difficulty removing sarcoplasmic protein and other impurities. 1- 2mm enhance washing but significant lost of fine meat particles during washing and resulting in lower recovery.  De-skinned and deboned fillet give cleaner minced meat since blood, membrane are removed Official (Open) SURIMI PROCESSING Washing  Involves mixing minced meat with cold water (near or below 5℃) to avoid degradation of myofibrillar protein by proteolytic enzymes..  Critical step to remove undesirable water soluble sarcoplasmic proteins (water soluble protein), blood, fat and other nitrogenous compounds  Sarcoplasmic proteins (exist in fluids in and between muscle fibre), heme proteins and many metabolic enzymes diminish the stability of functional proteins lowering gel-forming ability of surimi  Helps to increase surimi quality (e.g. colourless, odourless), concentrate functional myofibrillar protein (salt soluble protein) to enhance the functional property of surimi and extend frozen shelf life  Under-washing result in substantial loss of gel quality during storage while over-washing result in substantial loss of fine particles and excessive moisture causing difficulty in refining and dewatering of washed meat Official (Open) SURIMI PROCESSING Surimi quality other than dependent on type, freshness of fish and structure of washing unit, the degree of washing (E.g. Number of washing cycle and water/meat ratio) is important factor.  Effective washing process: water/meat ratio 2:1with typical wash ratios of 0.9 – 1.2 parts water in first wash and 0.7 - 0.8 in second wash. Due to difference in fish freshness, at-sea processors can achieve same washing effect with even lesser water.  Washing cycle about 2 – 3 times to ensure sufficient removal of sarcoplasmic proteins  Increased washing undesirable since result increase in water usage, more myofibrillar protein loss and waste disposal Official (Open) SURIMI PROCESSING Dewatering  Removing water by screening and dehydrators or centrifuging  Similar to washing cycle, it is repeated 2 - 3 times  Before last dewatering using screw press, undesirable particles (e.g. fine bones, scales and connective tissues) are removed by the refiner  Sometimes 0.1 – 0.3% salt mixture (NaCl and CaCl 2) are added during last dewatering step to facilitate the removal of water. However, addition of salt may result in protein denaturation during frozen storage. Thus, mechanical dewatering using screw press without salt help to maintain the frozen stability of surimi.  Screw press with 0.5 – 1.2mm perforation remove excess water via compression to final moisture level of 82 - 85% Official (Open) SURIMI PROCESSING Mixing  After dewatering, the meat is mixed thoroughly with cryoprotectants to ensure maximum functionality of surimi (e.g. prevent protein denaturation and aggregation)  Approx. 9% w/w of sucrose and sorbitol (either mixed or used alone) to dewatered minced leached fish meat is added as primary cryoprotectants to stablise actomyosin from stiffening.  Mixture of sodium tripolyphosphate and tetrasodium pyrophosphate (1:1) is added at 0.2 - 0.3% level acting as synergist to cryoprotectants. It acts as pH adjusting agent (shift to pH 7) to improve gel values and chelating agent to inactivates metal ions in surimi.  Silent cutter is used for mixing cryoprotectants for approx. 2- 3 minutes and temperature is kept at