food hygiene unit 1: food inspection topic: inspection of food items practical 7
TRANSCRIPT
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 wholesomeDeterioration of quality commence upon leaving waterPrincipal 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 an Egg
Parts of the eggShell 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 eggAlbumen (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 placeGerminal 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.
Air Space in Egg
– The shell has an air space of less than 1/4” deep
– The air space gets larger with time
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
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
ShakingFresh eggs make no soundStale eggs make a sloppy sound
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
Asiago CheeseBlue 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 Introduced 1778 –
West Africa Noted- 1875 1st documented- 1904
Hypoglycin cpd. Responsible for ackee poisoning
“Jamaica Vomiting Sickness Syndrome”
Freshly picked mature ackee
Ackee 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
Source: http://www.scq.ubc.ca/the-ackee-fruit-blighia-sapida-and-its-associated-toxic-effects/
Ackee 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.
Source: http://www.scq.ubc.ca/the-ackee-fruit-blighia-sapida-and-its-associated-toxic-effects/
Ackee
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
Bearing seasons– January to March– June to August
Fruits bear in clusters, turn red on reaching maturity
Split open along the seams with continued exposure to the sun
Ackee maturity guide 1) SMALL UNOPENED
– small, hard, immature, and unopened. Unsuitable for processing or eating.
2) SLIGHTLY OPENED – 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.
3) FULLY OPENED – Fully opened pod: seed and aril clearly visible. Suitable for
processing and eating. 4) ADVANCED SHRIVELLING
– Advanced Shrivelling of pod, onset of spoilage, aril begins to decay or rot.
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
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 FoodsIt 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 FoodsNormal 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
Observation Look for rusts, leaks, dents, holes, swelling,
soldering defects and presence or absence of labels.
CANS WITHOUT LABELS MUST BE CONDEMNED
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
Palpation 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.
Palpation 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.
Percussion 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
Auscultation 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. DO NOT USE THIS METHOD FOR FOODS
PACKED IN LIQUID 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 A. Bulge or swollen at one or both
ends B. Cans dented at seams C. Can showing signs of leaking D. Rusty cans
Assignment 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