Signs of Spoilage in Foods

Signs of Spoilage in Foods

The spoilage signs vary with the type of foods, causes of spoilage and environment.

Signs of spoilage: Spoilage gener-ally seen are softening, hardening, discol-ouration, mould growth, fermentation, drying, oozing out of liquid, off odours such as mouldy, alcoholic or putrid and presence of insects.

The following gives the spoilage indica-tors in different categories of food:

1. Cereals and pulses: Although the foods do not spoil easily, the following signs could be noted if spoilt.

·        Musty odour and off flavor.

·        Presence of weevils, beetles, moths and worms.

·        Clumping of whole grains.

·        Presence of dirt, mud and stones.

2. Vegetables and fruits: These show the following signs of spoilage:

·        Presence of mould, leading to rot.

·        Green leafy vegetables are wilted and limp.

·        Discolouration and mushy texture.

·        Presence of insects and worms.

·        Green potatoes, sprouted potatoes and over mature vegetables.

·        Skin or peel is damaged or bruised.

3. Milk and milk products: These prod-ucts which get spoilt may show one or more of the following changes:

·        Change in taste to sour or bitter.

·        Milk, buttermilk or curds have a frothy, bubbly surface.

·        Change in smell.

·        Rope formation.

·        Discolouration.

·        Fat separates out into clumps.

·        Milk curdles when heated.

·        Butter tastes rancid.

·        Cheese and curd develop off odour and mould growth.

4. Meat and poultry: Spoilt meat shows the following signs

·        Discolouration.

·        Putrid smell.

·        Slimy appearance and feel.

Organ meats such as liver, kidney and brain are more perishable than muscle meat due to the presence of fat.

5. Fish: Spoilt fish shows the following signs:

·        Dull or sunken eyes.

·        Gills are grey or green.

·        Off odour.

·        Flesh separates from bone and is flabby.

·        Loose scales.

·        Shellfish claws and tail lose their spring.

6. Eggs: Spoilt eggs will float when dropped in water. The signs of spoilt egg are:

·        Cracked shell.

·        Leaking contents.

·        Exposed egg yolk.

·        Eggs should be checked for blood spot, meat spot, foul odour or other con-taminations.

7. Cooked foods: Cooked foods must be consumed immediately and the left overs should be stored carefully. Cooked foods have high risk of getting spoilt.

8. Canned foods: Generally canned foods have longer shelf life and the chance of getting spoilage is possible when bac-teria enters the can. Sometimes the acid from food reacts with the iron of the container and the canned foods get spoiled. The signs of spoilage in canned foods are:

·        Puffy, swollen appearance of cans.

·        Leaky, corroded or rusty cans.

·        Contents spurt out when the can is opened.

·        Contents smell putrid.

·        Brine or syrup looks cloudy, bubbly, slimy or mouldy.

·        Contents are discoloured.

In case any one or more signs are noted it should be discarded without tasting the contents.

9. Frozen foods:

It is very difficult to identify the spoil-age in frozen foods unless there is change in colour or smell. If following precau-tions are taken, food borne illness can be prevented.

·        Do not use frozen foods if there is off smell, taste or discolouration.

·        Do not re-freeze food which has been thawed.

·        Thaw only required amount.

·        Do not purchase damaged packages.

·        Do not keep frozen foods out of the freezer for long before cooking.

·        Do not accept food which has a large quantity of ice crystals formed inside the packet.

Food that is decayed is easier to recognize than spoilt by microorganisms. Always the spoilt foods should be discarded and should not be consumed so as to prevent food poisoning and infections.