Rohan bought a packet of chips. When he opened the packet, he found that the chips smelt a bit strange. Even the taste of the chips was bad. When he asked his mother about the same, she told him that this happened due to a chemical process. Which chemical process is Rohan’s mother referring to?

Chips contain a huge amount of fat. Fats react with oxygen present in the air and get oxidised. This process is known as rancidity. Rancid fat develops a foul odour and also tastes bad. To prevent rancidity, such food items are flushed with nitrogen gas in order to remove oxygen. The chips present in the packet sometimes get exposed to oxygen and get oxidised. This may happen due to some defects in the packing.