Explain why ...?

Explain why pork and fish stored in brine and fruit stored in syrup will not turn bad?





Explain why when the wall of the chilli is sliced into strips and the chilli is soaked in tap water, the chilli will form a hibiscus-like flower.

Explain why ...?
why does food turn bad? it is usually because of the reaction with bacteria and the food. the examples cited (brine and syrup) all have low water concentration and are extremely concentrated. as a result any bacteria present cannot survive as bacteria has a higher water potential then the surrounding fluid used fro preservative. because of this a concentration gradient is set and water moves out of the bacteria cell killing it.





for your second question we have to ask ourselves why we observe the change only in cut chillies? this is because upon cutting the chilli into strips the cells are exposed. when the strips are placed in water, again a concentration gradient is set up and water diffuses from the bowl where the tap water is (high water concentration) to the exposed cells in the chilli (low water concentration).





plant cells, as you should know, are unique form animal cells as they contain cell walls that exerts a force when the cell is turgid. because of this the cells that are now filled with water cannot burst and this causes the hibiscus-like shape to form.





both questions have their answers firmly rooted in diffusion (or osmosis to be more precise since we are discussing the movement of water molecules across a partially permeable membrane).
Reply:stuff gets preserved in brine and sugar syrup, making them less attractive to fungus and bacteria because the water content in the meat and fruits is drawn out.





as for the chili, osmosis occurs. but at different rates, the cells on the outside of the chili is waterproof while those on the inside are not. so they expand at different rates and curl out.
Reply:Osmosis will draw water out of bacteria killing them.


I dunno what the chilli thing is you mention.
Reply:Well, it's sterilized.





As for the pork and fish in brine, the brine is like vinegar. It's a very good preservative. Bacteria can't live in it easily. Therefore, if there's no bacteria, then the meat won't go bad. It also helps keep it moist.





As far as the syrup and the fruit, I'm not all that sure this is a preservative. I mean, if you buy a can of fruit, it's preserved by the airtight seal of the can. If that seal breaks, then the fruit will spoil, regardless of if it has syrup or not. That's why you don't buy cans with dents in them.





I've never heard of this or seen this chili thing you're asking. However, I know this can be done with other vegetables. If you cut the skin and soak it, the inside of the vegetable will absorb the water, causing it to expand. The skin doesn't absorb the water. Since the skin has holes in it, the insides will expand out of these holes, creating a flower-like shape.
Reply:I know the answer to only part of your question..the part about pork and fish being stored in brine..to explain in detail...brine is a concentrated salt solution.salt forms ions when it dissolves in water...and each of these ions attract a small number of water molecules around themselves...so the theory is that if you add enough salt to the water, the ions will eventually draw out water from inside the bacteria present in the meat, thus killing them...since no bacteria is there to spoil the meat, it remains good....I'm not sure, but perhaps the same thing happens with sugar.
Reply:Osmosis. Pork, fish, fruit (including microorganisms on them) loose water in more concentrated solutions and dried chili absorb it, because it has higher concetration of minerals and similar compounds.
Reply:Brine is salt water. When salt concentration is high, this leads to osmosis of water out of bacteria cells, as a result, the bacteria becomes dessicated and dies.


The same applies for syrup, because syrup has a high sugar concentration, therefore it also leeches water from bacteria cells.


Naturally if bacteria dies, there is nothing to act on the food and so they will not turn bad.


When the chilli strips are soaked in water, the chilli cells absorb water and becomes turgid. The outer end of the chilli has a thicker cell wall and so displays turgidity, while the inner part displays flaccidity. Basically, the thicker outer portion will expand more than the inner portion and so thei chilli 'opens'
Reply:No bacteria can formed in brine solution and hene



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