Rancidity occurs when lipids in certain foods undergo oxidation reactions due to factors like light, oxygen, trace elements, salt, water, bacteria, and molds. This produces compounds that cause odors and off-flavors, making the food stale. Foods high in lipids that are prone to rancidity include potato chips, butter, meat, cod liver oil, and dry fruits. Rancidity can be prevented by using antioxidants, vacuum packaging, refrigeration, inert gas packaging, and storing foods in a dark place to reduce oxidation reactions. Rancid fat can destroy vitamins and cause issues like anemia, dermatitis, diarrhea, and cancer.

1. Rancidity
-Chemistry

2. Rancidity
• Condition reached in certain food as the lipid material (fat) undergoes
oxidation reactions producing aldehydes, hydroxyl acids, keta
acids, and other compounds which are responsible for the odor and
off-flavor producing stale food
• Factors causing rancidity– Light
– Oxygen
– trace elements (ie. Iron, zinc)
– salt
– water
– bacteria
– molds

3. Food high in lipids
• Potato chips
• Butter
• Meat
• Cod-liver oil
• Dry fruits

4. Potato chips
• Ingredients :
–
–
–
–
–
–
–
–
–
Potato
Edible vegetable oil
Spices & Condiments
Salt
Black salt
Sugar
Tomato powder
Citric acid
Tartaric acid

5. Butter
• Ingredients :
– Butter
– Common salt
– Permitted natural color
(Annatto)

6. Meat
• Ingredients :
– Meat
– Water
– Soya protein
– Bread crums
– Edible common salt
– Spices
– Edible vegetable oil

7. Cod liver oil
• Ingredients :
– Cod liver oil
– Glycerin
– Gelatin
– water

8. Dry fruits
• Ingredients :
– Dry roasted nuts
– Sea salt
– Gum acacia
– Rice syrup
– Cane sugar

9. Harmful effects of rancid food
• Rancid fat can destroy
vitamins, which could lead to
deficiency
– Anemia
– hair loss
– Dermatitis
• diarrhea
• kidney and liver bleeding
• gastric papilloma
• reproductive failure and loss of
offspring
• cancer

10. Prevention
Using inert
gases in
packaging
• Antioxidants are added to some foods
to slow down oxidative deterioration
– BHA—Butylated Hydroxy-Anisole
– BHT—Butylated Hydroxy-Toluene
Using antioxidants
Refrigeration
Ways to
prevent
rancidity
(BHA, BHT)
• Vacuum packaging to keep oxygen out
• Adding inert gas such as nitrogen to the
bag to replace the oxygen
• Refrigeration will reduce the rate of
most reactions that take part in rancidity
• Packing food protected from light
Vacuum
packaging
Storing in a
dark place

11. Thank you
By:- Rachit Bhalla
X-B