Question

why do not sealed packets develop foul smell even it kept for months? ​

Answer 1

Answer:

$\huge\mathfrak{\red{Answer}}$

The sealed packets do not develop foul smell even it is kept for months because the food packets are added with preservation methods such as salting, addition of excess sugar, filled with nitrogen gas and many more methods are followed.

In packets with content full of fats and oil, there is a danger of Rancidity (reaction of fats and oil with atmospheric oxygen which causes foul small and leads to bad taste) to take place, to avoid such thing from happening, the packets are filled with nitrogen gas. This is one of the preservation methods.

________________________________________________________

Other preservation methods include:

Salting. :-

Addition of salt in food is one of the used preservation methods, the microorganisms cannot survive in such an environment with.

Pasturization:-

The sudden heating and cooling of milk is also a method of preservation.

As microorganisms cannot survive sudden change in temperature.

The methods of preservation helps in preserving food from getting spoil and can be kept safe from getting spoilt by attack of microorganisms or other factors.

Answer 2

Answer:

it because of preservatives... its done by different methofs like salting, pasteurization, etc..