4th lecture Signs of spoilage in fresh and dry food

4Signs of Spoilage

in Fresh and Dry FoodBy:

Dr. Waleed FoadMSc.Public Health in Nutrition

Clinical Nutrition SpecialistEuropean Society of Gastrointestinal

Endoscopy (ESGE)Member of the American Society of

Nutrition Email: [email protected]

Signs of Spoilagein Fresh and Dry Food

Vary with type of Food

Generally: Change in Texture: Softening or Hardening Change in Colour: e.g. Discolouration, Mould Growth Change in Smell e.g. Putrid, alcoholic, acidic.. Oozing out of fluid. Fermentation or curding. Presence of visible foreign material e.g. Insects, mould, metals

Spoilt FishShows one or more of the Following: Gills are Gray or green. Dull or Sunken eyes. Bad Smell. Is Flabby and Flesh Separates from

the bone. When outer surface is pressed, finger

depression remains in flesh. Few scales are left on fish

Good Looking Gills Fish

Spoilt Fish

Spoilt Meat and PoultryWhen Surface area is increased, Spoilage

becomes more easier.Organ meats (as Liver, Kidney and Brain) are

more perishable than muscle meat.Signs of Spoilage: Discoloration. Bad Smell. Slimy appearance Flabby texture Microbial growth (colonies)

Spoilt Meat

Spoilt Poultry

Milk and Dairy productsShows spoilage signs of one or more of

the Following: Change in taste to sour or bitter milk. Frothy or bubbly surface of milk. Curd formation (mostly when heated) Butter tastes rancid. Cheese develop off odours, mould

growth and become slimy.

Spoilt Milk and Dairy products

Bread ,Cereals and pulsesThese food types don’t spoil easily

When spoilt, signs as the following may appear:

Musty odour and off taste Presence of pests or insects, e.g. Beatles,

worms,...etc Clumping of whole grains. Contamination with dirt, mud and stones Mould over growth.

Spoilt Cereals and pulses

Food contaminated by pests (A Mouse)

Vegetables and FruitsWhen spoilt or contaminated, signs as the

following may appear: Presence of mould (some times rottening) Presence of insects, e.g. Beatles,

worms,...etc Green leafy vegetables are wilted or

shrunk Discolouration and altered texture. Skin or peel is bruised or damaged. Contamination with dirt, mud and stones

Spoilt Vegetables and Fruits

Food contaminated by pests (Frogs)

Eggs

Recognizing 2 different issues:1. Fresh from Stale (non-Fresh) eggs.2. Spoilt eggs

Eggs

The Egg Shell integrity is the main protector against Spoilage and the main Spoilage indicator in the whole egg

Generally, Safe Eggs are:1. Kept refrigerated, and2. are not broken,3. Used with in 1 month of the Package

date.

Testing Eggs: 1

1- See Package Date

Eggs that are kept refrigerated and are not broken should be good for at least 1 month beyond the Package date.

Testing Eggs: 22- Hold the egg up to your ear and shake it,

listening for a sloshing sound As the egg ages, moisture and carbon dioxide escapes through the shell, the yolk and white begin to dry out and shrink, and the air pocket in the egg becomes bigger.A larger air pocket gives the egg more room to move

around inside the shell and create a sloshing sound.A sloshing egg only indicates that the egg is old and does

not mean the egg is unsafe for consumption.http://www.ochef.com/789.htm

Testing Eggs: 33- Place the egg in a bowl or a glass of cold water and

see if it floats. There is a tiny air pocket inside eggs, and over time more air passes through their porous shells and into the egg.

If the egg lays on its side on the bottom of the bowl, it is at peak freshness.If the egg stands upright on one end but is still touching

the bottom, it is aging but is still safe to eat.

http://www.ochef.com/789.htm http://simmerandboil.cookinglight.com/2013/08/28/can-i-use-expired-eggs/

#sthash.k0mefnAr.dpuf

Testing Eggs: 3 cont.3- Cold water Float test.

If the egg is floating, it is not a fresh egg. Stale (non-Fresh) eggs float in Water.This does not necessarily mean it’s bad or unsafe to eat. You should

test the egg by cracking it open and looking for (or smelling) signs that it has gone bad

http://www.ochef.com/789.htm

Testing Eggs: 44- Break and Smell

Break the egg open and notice if it smells. Best indicator of a bad egg.A bad egg will have a pungent, foul odor when you break it open.The sulfurous smell will be obvious as soon as the egg is cracked (and possibly before), and the egg should be thrown out. A bad egg will have this foul smell, regardless of whether it is

raw or cooked http://cooking.stackexchange.com/questions/47036/egg-safety-when-to-

eat-and-when-to-not-eat http://www.fsis.usda.gov/wps/portal/fsis/topics/food-safety-education/

get-answers/food-safety-fact-sheets/egg-products-preparation/shell-eggs-from-farm-to-table/CT_Index#32

Testing Eggs: 55- Break and See Texture.

Crack the egg open on a plate and check the quality of the yolk and white.

Testing Eggs: 5 (cont.)

5- Break and See Texture.An Old Egg spreads or seems a little watery has a

thinner white. An Old Egg yolk is flat and breaks easily, and moves

around easily.

http://www.fsis.usda.gov/wps/portal/fsis/topics/food-safety-education/get-answers/food-safety-fact-sheets/egg-products-preparation/shell-eggs-from-farm-to-table/CT_Index#32

Testing Eggs: 66- Break and See color.

Break the egg open and notice its color. The color of the yolk, in shades of yellow or orange, has nothing to do with freshness of the egg. Instead, inspect the egg white, or albumen.

http://www.fsis.usda.gov/wps/portal/fsis/topics/food-safety-education/get-answers/food-safety-fact-sheets/egg-products-preparation/shell-eggs-from-farm-to-table/CT_Index

Testing Eggs: 6 (cont.)6- Break and See color.

Egg white, or albumen. If it is pink or green, the egg has been contaminated

by bacteria and is not safe to eat.If black or green spots, it has been contaminated by

fungus and should be thrown away.A cloudy white indicates a very fresh egg. A clear

white means the egg is older (but may still be edible)


Testing Eggs: 6 (cont.)6- Break and See color.

Egg yellow, or yolk: If the yolk of a hard-cooked egg has a green ring around it, this means

the egg has been overcooked or was cooked in water with a high iron content. This egg is still safe to eat.

If there is a blood or meat spot in the egg, it is still safe to eat and does not mean the egg is contaminated or has gone bad. A blood spot occurs when a blood vessel ruptures when the egg is forming and has nothing to do with freshness.



Spoilt Eggs

Suspicion should raise when:1. Cracked Shell2. Leaking Contents.3. Egg yolk is exposed.4. Shell has an obvious discoloured dirty shell.5. Bad Smell.6. Eggs kept out of refrigerator for 2 hours or more,

after being refrigerated. Once an egg has cooled in your refrigerator, it is important

to keep it at the same temperature. A cold egg in a warmer environment begins to sweat, which

can encourage bacteria to grow on the outside of the egg. Because the egg shell is porous, it is sometimes possible for the bacteria on the shell to pass into through and contaminate the egg.

http://www.eggsafety.org/blog/safe-handling/224-safely-store-your-eggs

Spoilt Eggs

Questions?For Further Support:

Dr. Waleed FoadEmail: [email protected]

Health & Medicine

4th lecture Signs of spoilage in fresh and dry food