• Caused by chemical, physical and microbiological factors

• Chemical : rancidity in high fat bread products (lipid degradation)

• Physical : contamination after baking; during cooling, slicing or packaging processes and storage temperature. For example, moisture absorption. 

• Microbiological : exposed to yeast, bacterial spoilage, mold during preparation, processing, packing and storage 

• Effect:

1.  contribute to the staling process

• Shorten the shelf life.

• Bread loses nutritional value and chemical stability after baking

• Rancidity ; off odours and flavor

2. Slicing process can produce moist cut surfaces for mould to grow.

• Spoilage mould : penicillium spp.

• Production of mycotoxins 

Effect of Spoilage: Sour or off smell, hard or dry texture, or visible mold. Eating spoiled rice can cause foodborne illness, leading to nausea, cramps, and diarrhea.

Spoiled strawberries will cause health risk such as food poisoning. It lose vitamins, taste and texture.

Why Does Bread Become Stale?

✔ Moisture Loss – Bread naturally loses water content over time.

✔ Starch Retrogradation – Starch molecules rearrange and harden as bread cools.

✔ Exposure to Air – Storing bread uncovered speeds up the staling process.

✅Stale bread safe to eat as long as it does not have mold, stale bread is still edible.

How to Use Stale Bread?

1️⃣ Toast It – Heating reverses starch retrogradation, making it crispy.

2️⃣ Make Bread Pudding – Soak in milk and eggs to soften.

3️⃣ Turn into Croutons – Cut into cubes and bake for crunchy salad toppings.

4️⃣ Blend into Bread Crumbs – Use as coating for fried foods.

5️⃣ French Toast – Soaking stale bread in eggs and milk restores softness.

6️⃣ Make Garlic Bread – Add butter, garlic, and toast for extra flavor.

🔴 When Should This BreadThrow this Away?

🚫 If there is mold (green, black, or white fuzzy spots).

🚫 If it has a sour or bad smell (signs of spoilage).

Cause:

1) Microbial growth - presence of mold or fungi use the nutrients of tomatoes for their growth and reproduction

2) Enthylene production - tomatoes will produce ethylene naturally along ripening stage, then excessive ethylene cause overripening and spoilage

Effect:

1) Nutrient loss - deterioration of tomatoes leads decrease of vitamins and minerals

2) Texture changes - tomatoes become soft, mushy and wrinkled

3) Healthy risk - consumption of deteriorated tomatoes may cause foodborne illness due to toxins and harmful bacteria

Prevention:

1) Refrigeration - store tomatoes in fridge to slow down respiration rate and ethylene production

2) Proper storage - store tomatoes separately and keep them away from ethylene-producing fruits such as banana

1. Causes

a) Growth of spoilage microorganisms like Lactobacillus, Pseudomonas, and sometimes E. coli or Salmonella (if contaminated).

b) Enzymatic activity

c) Storing milk above refrigeration temperatures speeds up bacterial growth.

d) Exposure to light (especially UV) can cause oxidation of fats in milk, leading to off-flavors and nutrient loss (like vitamin B2/riboflavin)

2. Effect

a) Taste : Sour, bitter, off-flavors

b) Smell : Rotten or unpleasant odor

c) Appearance : Curdling, coagulation, discoloration

d)Texture : Lumpy or slimy

3. Prevent

a) Keep milk at 4°C (39°F) or lower

b) Heating milk to kill harmful microbes

c) Use light-blocking and airtight containers (like opaque plastic or cartons)