why do foods containing fats and oils change thier smell and taste if left unused for a long time
Answers
Answer:
BCZ THE FOOD BECOME CONTAMINATED DUE TO RANICIDITY FOLLOW
Answer:
The oils and fats undergo a process called rancidification. Neutral or good tasting oils and fats undergo chemical reactions which produce new chemicals with off-tastes and disagreeable smell. Such spoiled food is called "rancid." There are two main reactions: Hydrolysis reacts triglycerides with water to produce fatty acids; and the double bonds in unsaturated fats react with oxygen in the air to produce aldehydes and ketones. Rancidification can be slowed by refrigeration, freezing, keeping the food dry, tightly sealing against air, and keeping the food dark. Anti-oxidation chemicals can be added to preserve the food. Unfortunately, none of these preservation methods can truly stop the rancidification process, simply because food naturally contains some amount of water and oxygen that cannot be removed. Occasional consumption of mildy rancid food is unlikely to have any negative impact on health. Rancidification can destroy vitamins, reducing nutritional value.