Hi. We did a popcorn popping lab for chemistry and I was wondering if someone could help me with these few questions here:
1) Why is popcorn better stored in the freezer or refrigerator rather than on the shelf at room temperature?
My Answer: I think it has something to do with the water content. If it's at room temperature, then won't the water evaporate?
2) Why must you use oil to pop the kernel? Why would water not work?
My Answer: Hmm...I'm not sure. I think I read that oil and water don't mix and maybe that has something to do with it. Oil and water are both non-volatile... But I don't see anything else...
3) Why is microwave popcorn covered with grease?
My Answer: There's more fat in it?
Thanks!
1) yes, but in either case, it should be tightly sealed. Even in the freezer, some of the water can sublime.
2) Water would evaporate before the popping temperature.
3) a) Grease tastes good, and that means repeat sales.
b) The oil coats the kernels and evenly distributes the heat being generated by the microwave.
1)So, I was right in saying it would evaporate quicker/more at room temp. than in the freezer or refrigerator?
2)Okay, but why wouldn't oil evaporate before the popping temperature?
3)Gotcha thanks.
oil has a higher bp.
So, I was right in saying it would evaporate quicker/more at room temp. than in the freezer or refrigerator?
Also, does the more water the popcorn have mean the faster/better it pops?
i don't think it just has to do with evaporation
Yes, you were correct in saying that water would evaporate more quickly at room temperature compared to being stored in the freezer or refrigerator. In dry conditions, water tends to evaporate faster. By storing popcorn in the freezer or refrigerator, you can slow down the evaporation of water from the kernels, which helps to keep them fresher for longer.
As for the second question, oil is used to pop the kernels because it has a higher boiling point compared to water. When popcorn kernels are heated, the moisture inside them turns into steam, which creates pressure within the kernel. This pressure eventually becomes strong enough to break the outer shell, causing the kernel to expand and turn into popcorn. Oil helps to transfer heat more evenly to the kernels and provides a higher boiling point, allowing the steam pressure to build up gradually within the kernel before it bursts open. Water, on the other hand, has a lower boiling point and would evaporate before the popping temperature is reached, resulting in ineffective popping.
Regarding your last question, the presence of grease or oil on microwave popcorn serves a dual purpose. Firstly, it adds flavor to the popcorn, enhancing its taste and making it more appealing to consumers. This can lead to increased sales as people enjoy the taste and are more likely to buy it again. Secondly, the oil coats the popcorn kernels, ensuring that heat is distributed evenly during the microwave popping process. This helps to prevent burning and ensures that all the kernels pop uniformly.