Food hygiene unit 1 food inspection
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Food Hygiene Unit 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

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Food Hygiene Unit 1: Food Inspection

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Food hygiene unit 1 food inspection

Food HygieneUnit 1: Food Inspection

Topic: Inspection of food items

Practical 7

Food inspection

Food Inspection

  • An effective food safety system is important.

  • Inspections are required of

    • Systems

    • Processes

    • Facilities

    • Products

Importance of food inspection

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 inspection1

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

Labelling Criteria

  • Name of product

  • Brand name

  • Weight/volume of product

  • Manufacturer/Distributor

  • Ingredients

  • Dates

Product dating

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.

Food hygiene unit 1 food inspection


What factors are responsible for fish spoilage?

Under what conditions do you purchase fresh fish?

Food hygiene unit 1 food inspection


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

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

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

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

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

Food hygiene unit 1 food inspection



  • 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


  • >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

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

Food hygiene unit 1 food inspection


  • 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 an egg

Parts of an Egg

Parts of the egg

Parts of the egg


  • 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 egg1

Parts of the egg

Albumen (white)

  • Major source of protein and riboflavin


  • 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


  • 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

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.

Air space in 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

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.



  • 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

Conditions that render egg unsound


    • Mold (penicillum, cladosporum)

    • Pseudomonas – causing black rot or green rot

    • Avian TB (rare)

    • Salmonella – from faeces of the bird

Conditions that render egg unsound1

Conditions that render egg unsound


    • 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 unsound2

Conditions that render egg unsound


    • 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

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

Testing Egg for freshness

  • Shaking

  • Candling

  • Immersion/Brine test

  • Yolk Index Test

Testing egg for freshness1

Testing Egg for Freshness

  • Shaking

    • Fresh eggs make no sound

    • Stale eggs make a sloppy sound


  • 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

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 freshness2

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

    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

    Inspection of Egg


    • 4.4C or lower

    • No odour

    • Clean

    • Unbroken

    • Firm yolk


    • >4.4C

    • Sulphur smell/off odour

    • Dirty

    • Broken/cracked

    Examination of egg

    Examination of Egg

    • Colour change, Odour change, packaging, temperature, physical contamination

    • Liquid Egg

      • <4.4C

      • In tack packages

      • No signs of thawing

    • Dehydrated Egg

      • No caking

    Food hygiene unit 1 food inspection



    • 4.4C 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


    • 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




    • Below 4.4 C

    • No discolouration

    • Texture – firm and springs back when touched

    • No odour

    • Package – surrounded by crushed self draining ice


    • >4.4 C

    • Purple or green discolouration around neck; dark wing tips

    • Stickiness under wings or around joints

    • Abnormal/unpleasant odour

    Smoked fish

    Smoked fish


    • Fresh clean, smoky smell

    • Firm, dry free from blood stains


    • Sweaty, soft, slimy flesh

    • Mould growth

    • Uncharacteristic smell

    Salted fish

    Salted Fish


    • Fresh, firm, clear, dry

    • Stored in cool dry place

    • Should be protected from all sources of contamination


    • Soft, moist flesh

    • Pink/green fungal growth

    • Foul odour

    • Improperly stored

    • Maybe infested with Lasioderma or other pests

    Pickled fish

    Pickled Fish


    • Fish covered with liquor

    • Firm fish

    • Free from blood stains and broken pieces


    • Fish partially covered wit liquor

    • Fish covered with muddy liquor

    • Fish with a foul/rancid odour

    • Blood stained flesh, discoloured

    • Fish broken in pieces



    • 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

    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

    Shell fish - oyster


    • Tightly closed unbroken shell

    • Outside clean

    • Pleasant odour

    • Sink in water

    • Liquor pH 6-7

    • If shucked - <4.4 C


    • 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




    • Muscular activities in tail

    • Odour free

    • Free of dirt and slime

    • If scalded alive- shell will have pink colour


    • No resistance in tail

    • Discolouration under tail

    • Slimy exudate under claws

    • Dark colour of the shell when scalded

    • Foul odour

    Food hygiene unit 1 food inspection



    • Should be accepted alive

    • Very active

    • No offensive odour


    • Offensive odour

    • Sluggish

    • dead

    Frozen processed foods

    Frozen processed foods


    • Solid frozen

    • -14 to -21 C

    • Ice soft and flaky

    • In tack packaging

    • Clean packages


    • 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

    Reduced Oxygen Packaged Food


    • 4.4 C or lower unless otherwise specified by the manufacturer

    • If frozen – frozen

    • Packages in tact

    • Use by date evident

    • Acceptable colour


    • >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

    Dairy milk butter cheese

    DairyMilk, butter, cheese


    • <4.4C

    • Clean, unbroken packages

    • Fresh characteristic smell

    • Milk: sweetish flavour

    • Butter: sweet flavour, uniform colour, firm texture

    • Cheese: typical flavour, texture and uniform colour


    • >4.4C

    • 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



    Blue Cheese

    Asiago Cheese

    Uht foods

    UHT Foods


    • In tack package

    • In tack seal

    • <4.4C when opened

    • Proper labels

    • Use by date


    • Leaking, punctured

    • Leaking packages

    • Dirty packages

    • >4.4C after opened

    • No label

    • No use by date

    Fresh fruits vegetable

    Fresh Fruits & Vegetable

    • General rejection criteria

      • Insect infestation

      • Evidence of mold

      • Damaged surfaces

      • Wilting and Mushiness

      • Discolouration & dull appearance

      • Unpleasant odours

      • Unpleasant taste



    Freshly picked mature ackee

    • Introduced 1778 – West Africa

    • Noted- 1875

    • 1st documented- 1904

    • Hypoglycin cpd. Responsible for ackee poisoning

    • “Jamaica Vomiting Sickness Syndrome”



    • Two toxic substances can be extracted from the fruit

      • Hypoglycin A & Hypoglycin B

    • Hypoglycin A, can be found in the aril of the fruit

    • Unripe fruit has a higher concentration of hypoglycin (x20)

    • Seed and membrane at the base of the seed are always poisonous




    • Hypoglycin A is an unusual amino acid

    • Has the ability to significantly reduce blood glucose levels and induce hypoglycemia

    • Depletion of glucose reserves and the inability of cells to regenerate glucose leads to hypoglycemia.




    Potential risk behaviours for ackee poisoning include the following:

    • Consumption of unripe ackee fruit

    • Consumption of ackee that has been forcibly opened

    • Reuse of the water in which an unripe ackee has been cooked

    Stages in maturity of ackee

    Stages in maturity of ackee

    • Bearing seasons

      • January to March

      • June to August

    • Fruits bear in clusters, turn red on reaching maturity

    • Split open along the seams with continuedexposure to the sun

    Ackee maturity guide

    Ackee maturity guide


      • small, hard, immature, and unopened. Unsuitable for processing or eating.


      • Slightly open, pod lobes split, seed and aril visible

      • (Warning: At this stage, the hypoglycin (toxin) is at a dangerously high level. Fruit can be reaped for racking but not for processing or eating.


      • Fully opened pod: seed and aril clearly visible. Suitable for processing and eating.


      • Advanced Shrivelling of pod, onset of spoilage, aril begins to decay or rot.

    Ackee maturity guide1

    Ackee maturity guide

    • Fruit Maturity

    • Ackee takes 7-8 weeks to attain full maturity

    • During weeks 2-3 of fruit development, the fruit doubles in size, after which the fruit increases at a much slower rate

    • At full maturity the fruits are pear shaped and acquire a red or a yellow tinge with red colouration

    • The pods then open revealing the seeds and 3 fleshy arilli

    Inspection of canned foods

    Inspection of canned foods

    • Canning is a widely used method of food preservation so the inspection of canned foods is unavoidable.

    • At least 10%of consignment should be inspected

      • If >2.5% rejected – action

    Canned foods

    Canned Foods

    It is important to:

    • Identify the can contents

    • Identify the brand

    • Identify the weight

    • Condition on the can

  • Four methods of inspection can be utilized

    • Observation

    • Palpation

    • Percussion

    • auscultation

  • Canned foods1

    Canned Foods

    Normal Can

    • Clean appearance

    • Rust free

    • Dent free

    • Stain free

    • Has slightly concave ends

    • Sound Seams

    • Leak free

    • Labelled

    • Use by date

    Abnormal Can

    • Rusty can

    • Dented

    • Bulging (“blown”)

    • Leaking

    • unlabelled

    Good can

    Good can



    • Look for rusts, leaks, dents, holes, swelling, soldering defects and presence or absence of labels.


    • Swollen cans are referred to as “blown”

    • Blowing is due to gas production from microbial action or chemical reaction

    • Check labels or bottom of cans for product dating



    • Degrees of swelling can be detected by palpation, i.e., pressing the can between the fingers and thumb of both hands.

    • If air is inside, it will respond to pressure.

    • Flipper – earliest stage of spoilage where the can appears normal, but pressure on one end will cause a bulge in the other end. When pressure is release, end regains its normal appearance.

    • Springer – more advanced spoilage where pressure on one end causes the other end to bulge permanently.



    • Bulging does not always mean that the contents are decomposing, it may be due to:

      • Insufficient vacuuming

      • Overfilling

      • Chemical reaction between can and food (hydrogen swell)

    • These conditions cannot be determined unless the can is opened, so err on the side of safety and condemn all blown cans.



    • Employment of this method provides a useful indication of quality.

    • Sound cans will emit a dull note when tapped

    • If gas is present in a can, it will have a higher, drum like pitch when knocked



    • This is applicable to canned foods that were not packed with liquid, e.g., meats.

    • If the contents have deteriorated, a liquid will be present.


    • Canned foods can deteriorate without gas production (flat sour)

      • This cannot be detected without opening

    • On the basis of the condition of the can, you make your judgment – pass or condemn.

    Bad cans

    Bad Cans

    Bad cans1

    Bad Cans

    • A. Bulge or swollen at one or both ends

    • B. Cans dented at seams

    • C. Can showing signs of leaking

    • D. Rusty cans



    • Acceptance /rejection criteria for:

      • Prepare an inspection form to be used at a receival area of a large restaurant. Design the form in a manner such that there are clear acceptance rejection criteria for any food of choice.

        Due: Next Practical session

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