Food HygieneUnit 1: Food Inspection Topic: Inspection of food items Practical 7
Food Inspection • An effective food safety system is important. • Inspections are required of • Systems • Processes • Facilities • Products
Importance of food Inspection • Protect the health of populations • Ensure compliance with standards • Prevention/control of FBI • Ensure social stability • Promote and maintain trade relations
Food Inspection • The critical examination of food using various methods/techniques: • Observation- blemish, dents, leaks • Palpation – spoilage of fish • Incision- cutting into meats • Auscultation – shaking and listening • Percussion - tapping cans • Organoleptic – smell, taste
Labelling Criteria • Name of product • Brand name • Weight/volume of product • Manufacturer/Distributor • Ingredients • Dates
Product Dating • “Sell by” date • tells the store how long to display the product for sale. Product should be purchased ahead of this date to allow time for consumption • “Best if used by” date • recommended for best flavour or quality; not a purchase or safety date. • “Use by” date • last recommended date for use of the product while at peak quality; this is determined by the manufacturer of the product. • “Expiry” date • Recommended by the manufacturer, safety of the product cannot be guaranteed beyond the indicated date.
Fish What factors are responsible for fish spoilage? Under what conditions do you purchase fresh fish?
Fish Freshly caught fish relatively wholesome Deterioration of quality commence upon leaving water Principal of condemnation is decay Fish Spoilage • Microbiological Reasons • Chemical Reasons • Physiological Reasons
Microbiological Reasons for fish Spoilage • Several spp. of microbes are always present in surface slime and intestinal tract • Bacteriostasis in live fish • Flesh of life healthy fish sterile • Upon death microbes multiply rapidly and attack tissues • Since microbes survive at low temperatures in the ocean, can resist refrigeration temperatures • Need to store below 4.4 C upon being caught
Physiological reasons for fish spoilage • Glycogen depletion in muscles • Little glycogen available to be converted to lactic acid • Limited lactic acid to retard microbial growth
Chemical Reasons for fish spoilage • Enzymatic action on certain constituent of fish • Autolysis or self digestion • Undesirable chemical substances produced by the growth and activities of bacteria • One such substance is tri-methyl amines • Responsible for the fishy odour in spoilt fish • Oxidation - rancidity
Fish Inspection • 1. Oganoleptic • Appearance • Odour 2. Palpate – consistency • A sand paper feel denotes staleness • Lack of moisture at the surface • Lack of firmness of flesh and elasticity • Odour should not be fishy
Fish Accept • 4.4 C or lower • Bright red closed gills • Bright clear, bulging eyes • Firm flesh • Firmly attached scales with moderate amount of slime • Mild ocean/seaweed smell • Blood along the b-bone in visceral cavity bright red • Body stiff and tail rigid • Surrounded in crushed self draining ice • Carcass sinks in water Reject • >4.4 C • Pale pink, dull gray gills, slimy • Dull, sunken, cloudy, red rimmed eyes • Dull flesh with missing scales • Soft flesh, leaves imprints • Lifts from backbone easily • Bone alone the b-bone cavity dark to black with foul odour • Limp pliable body • Strong fishy or ammonia smell • Yellow slime • Carcass floats in water
Keeping quality • The less fish is handled the longer it will remain wholesome • Keep fish embedded in finely shaven ice • Fish fillet, sliced fish or fish with exposed surface should not come in direct contact with ice or water • Will result in more rapid spoilage, change in flavour and appearance
EGGS • Eggs usually mean those of hens but may include those of ducks and turkeys also. • Made up of three main parts: • Shell • White (albumen) • Yolk
Parts of the egg Shell • Composed mainly of calcium carbonate • May be brown or white depending on the breed of chicken • Quality, flavour, cooking characteristics and nutritional value not affected by colour Air Cell • Pocket of air formed at large end of egg • Caused by contraction of the contents during the cooling process • Increase in size as the egg ages Shell membrane • There are 2 - inner and outer shell membrane • Surround the albumin • Provide protective barrier against bacterial penetration • Air cell forms between these 2 membranes
Parts of the egg Albumen (white) • Major source of protein and riboflavin Chalazae • Twisted, cord-like strands of egg white • Anchor yolk in centre of egg • Prominent chalazae indicative of freshness Vitelline (Yolk) Membrane • Closer seal which holds the yolk in place Germinal Disc Yolk • Colour varies with feed • Colour doesn’t indicate nutritive value • Major source of vitamins, mineral and fat; and ~1/2 of the protein
Air Cell • Empty space between the white and the shell at the large end of the egg. • As a freshly laid egg is cooled, the contents contract and the inner membrane separates from the outer membrane forming an air cell. • As the egg ages, moisture and carbon dioxide leave through the pores and air enters to replace them causing the airspace to get larger. • Air cell is visible at the flattened end of a peeled boiled egg.
The shell has an air space of less than 1/4” deep The air space gets larger with time Air Space in Egg
Blood Spots • Also called meat spots • Found on egg yolk and results from the rupture of blood vessels on the yolk during the formation of the egg or in the oviduct. • Candling can reveal eggs with blood spots • As the egg ages, the yolk takes up water from the albumen and dilutes the blood spots, hence blood spots indicate a fresh egg. • Eggs with spots are fit for consumption.
Bloom • Freshly laid eggs have a dull appearance • The coating or covering on the egg that seals the pores. • Prevents bacteria from getting into the egg and reduces moisture loss • Washing removes the bloom • Protection can be restored from a light coat of mineral oil.
Conditions that render egg unsound • MICROBIAL • Mold (penicillum, cladosporum) • Pseudomonas – causing black rot or green rot • Avian TB (rare) • Salmonella – from faeces of the bird
Conditions that render egg unsound • PHYSICAL • Cracked eggs – will decompose quickly • Storage position – storage for a long time in inverted or horizontal position causing adherence of yolk to shell • Evaporation – resulting in enlarged airspace
Conditions that render egg unsound • CHEMICAL • Mainly due to enzymic action • Enzymes cause eggs to become watery. • Loss of CO2 changes pH and causes a transfer of water from the white to the yolk. • The yolk of a freshly laid egg will stand in a viscous white.
As an egg ages, several changes occur: • Water moves from the white to the yolk • The yolk structure weakens • The egg whites becomes thinner • The air space increases • Bacteria may enter through the shell • A “bad egg” smell occurs due to the production of H2S and other compounds
Testing Egg for freshness • Shaking • Candling • Immersion/Brine test • Yolk Index Test
Testing Egg for Freshness • Shaking • Fresh eggs make no sound • Stale eggs make a sloppy sound Candling • Hold egg before powerful light source • Egg quality judged by transparency • While rotating egg yolk, albumen and air space are visible • Albumen is translucent without spots Stale Egg • Albumen becomes dark and opaque • Yolk less visible • Enlarged air space • Blood spots due to the growth of microbes/ cracks can be detected
Testing Eggs for freshness • Immersion/ Brine test • Involves floating egg in water • 10% solu. (2oz salt to 1pt water) • Fresh egg sinks • Stale egg float in varying positions • Shrinkage of the albumen • Carbon dioxide and moisture levels, • Replaced by air through pores in egg shell • Increased air space
Testing Egg for freshness Yolk Index Test • Dividing the height by the diameter of yolk • Cracking egg on a plate Fresh Egg • Rounded yolk • Stands up in the viscous white Stale Egg • Yolk flattens • weakening of the vitelline membrane • Absorption of water from albumen • Thin liquified albumen • Degeneration of the gelatinous structure • Difficult to separate yolk from albumen • Sour odour detected
Evidence of Unsoundness in Egg • Degree of suitability of the yolk • Adherence of yolk to shell • Dark spots • Disintegration • Colour changes • Depth of air space • >1/4” • Presence of blood spots • Presence of discoloured albumen • Evidence of the embryo • Presence of cracks in the shell • Unpleasant odour
Inspection of Egg Accept • 4.4C or lower • No odour • Clean • Unbroken • Firm yolk Reject • >4.4C • Sulphur smell/off odour • Dirty • Broken/cracked
Examination of Egg • Colour change, Odour change, packaging, temperature, physical contamination • Liquid Egg • <4.4C • In tack packages • No signs of thawing • Dehydrated Egg • No caking
Meat Accept • 4.4C or below • Beef -bright, cherry red; aged beef may be darker in colour; vacuum packed may appear purple in colour • Lamb – light red • Pork – light pink, firm white fat • Texture – firm and spring back when touched • No odour • Package clean and in tact Reject • Above 4.4 C • Beef –brown or green • Lamb – brown, whitish surface covering the lean meat • Pork – excessively dark colour, soft or rancid fat • Texture – slimy, sticky or dry • Sour/rancid odour • Package – broken cartons. Dirty wrappers, torn packaging, vacuum packaging with broken seals
Poultry Accept • Below 4.4 C • No discolouration • Texture – firm and springs back when touched • No odour • Package – surrounded by crushed self draining ice Reject • >4.4 C • Purple or green discolouration around neck; dark wing tips • Stickiness under wings or around joints • Abnormal/unpleasant odour
Smoked fish Accept • Fresh clean, smoky smell • Firm, dry free from blood stains Reject • Sweaty, soft, slimy flesh • Mould growth • Uncharacteristic smell
Salted Fish Accept • Fresh, firm, clear, dry • Stored in cool dry place • Should be protected from all sources of contamination Reject • Soft, moist flesh • Pink/green fungal growth • Foul odour • Improperly stored • Maybe infested with Lasioderma or other pests
Pickled Fish Accept • Fish covered with liquor • Firm fish • Free from blood stains and broken pieces Reject • Fish partially covered wit liquor • Fish covered with muddy liquor • Fish with a foul/rancid odour • Blood stained flesh, discoloured • Fish broken in pieces
Shellfish • Mollusks – soft bodied, protected by hard shell • Oysters, mussels, clam • Crustaceans – body encased in hard, close fitting shell. • Possess legs, flesh firmer than mollusks • Lobster, crab, shrimp
Shellfish - Oyster • Most widely consumed mollusks • Require 4-6 years to maturity • Thrive best in brackish water • Can breed in water highly polluted with sewage • Oyster reflect the bacteriological quality of water • Oyster can self cleanse in chlorinated water
Shell fish - oyster Accept • Tightly closed unbroken shell • Outside clean • Pleasant odour • Sink in water • Liquor pH 6-7 • If shucked - <4.4 C Reject • Opened shell- don’t close when tapped • Unpleasant odour • Excessive dirt and slime • Sticky or dry • Floats in water • Liquor pH more acidic • If shucked - >4.4 C
Lobster Accept • Muscular activities in tail • Odour free • Free of dirt and slime • If scalded alive- shell will have pink colour Reject • No resistance in tail • Discolouration under tail • Slimy exudate under claws • Dark colour of the shell when scalded • Foul odour
Crab Accept • Should be accepted alive • Very active • No offensive odour Reject • Offensive odour • Sluggish • dead
Frozen processed foods Accept • Solid frozen • -14 to -21 C • Ice soft and flaky • In tack packaging • Clean packages Reject • Evidence of thawing • Fluids or frozen liquid in case bottom • Ice crystals • Water stains • Damaged packages • Unfrozen foods • > 14 C- icecream
Reduced Oxygen Packaged Food Accept • 4.4 C or lower unless otherwise specified by the manufacturer • If frozen – frozen • Packages in tact • Use by date evident • Acceptable colour Reject • >4.4 C, unless otherwise specified • If frozen- not frozen • Torn or leaking packages • Pass use by date • Unacceptable colour, slime, bubbles, and excessive liquid
DairyMilk, butter, cheese Accept • <4.4C • Clean, unbroken packages • Fresh characteristic smell • Milk: sweetish flavour • Butter: sweet flavour, uniform colour, firm texture • Cheese: typical flavour, texture and uniform colour Reject • >4.4C • Dirty, broken packages • Milk: sour, bitter or moldy taste, ropiness, discolouration, off- odour • Butter: sour, bitter; mold growth; uneven colour, rancid smell • Cheese: unnatural mold, uneven colour, abnornmal flavour and texture
Cheese Blue Cheese Asiago Cheese
UHT Foods Accept • In tack package • In tack seal • <4.4C when opened • Proper labels • Use by date Reject • Leaking, punctured • Leaking packages • Dirty packages • >4.4C after opened • No label • No use by date
Fresh Fruits & Vegetable • General rejection criteria • Insect infestation • Evidence of mold • Damaged surfaces • Wilting and Mushiness • Discolouration & dull appearance • Unpleasant odours • Unpleasant taste
Ackee Freshly picked mature ackee • Introduced 1778 – West Africa • Noted- 1875 • 1st documented- 1904 • Hypoglycin cpd. Responsible for ackee poisoning • “Jamaica Vomiting Sickness Syndrome”