Freeze Dry at Home - best at home skin care devices

In response to one of the instructures threads I met on 2009, I decided to test if there was any idea for home freeze ophil (freeze dryer)could work?
I don't have a vacuum pump or a precision condensing or cooling device.
I have worked with desiccant in the lab and I thought if I could get a vacuum chamber at the steam point of the water, I would probably keep it below that point with no water salt.
This article: my research gave me two interesting facts that led me to my final project design: 1.
Freeze-drying is the result of a combination of negative pressure and temperature.
The drying speed depends on both. 2.
The burning of the refrigerator, and the annoying ice accumulation behind the refrigerator, are the results of the same process ---
That is, water vapor that leaves or forms solid ice. This freezer-
Combustion evaporation is called sublimation, and the ice accumulation in the opposite freezer is called deposition.
Now, it reminds me that if I can reduce the pressure in the sealed container to the steam pressure point and keep it there, I can achieve the delicious taste of frozen dried fruit behind the refrigerator.
Scientifically speaking, the problem is steam pressure.
The steam pressure depends on the temperature and pressure.
The steam pressure of our berries will tend to be equal to the pressure and temperature in the room.
This roughly means that passively dry food will only be as dry as the environment.
This makes it more difficult to dry something further. (
Water keeps flowing out of the fruit, increasing the pressure. )
This can be solved by placing desiccant in low humidity
The pressure vessel absorbs the steam and actively extracts the steam from the food you want to dry.
However, this means that the steam leaves the food and enters the desiccant at a much slower rate than the active vacuum system (
Traditional vacuum lyophilzer).
After testing how much vacuum it can pull, I chose to save the hand pump using wine in my first experiment (
See below).
There are many other similar systems on the market. -
It is usually marked as an instant marination container or a vacuum bag system. Materials: (1)
Vacuum Chamber: instant stewing using vacuum. It's expensive.
Using ball valves and sealable containers, people can easily make their own. (1)
Vacuum Source: hand pump is easy to obtain, but lower pressure can be achieved using other methods. (1)
Calcium chloride powder: the weight of the sample you want to use is about twice that of the original, but not to hurt. (1)
Separation plate: This prevents the mixing of desiccant and sample, and does not mess up the final product. (1)
You want to freeze the dry samples.
* Calcium chloride is a food safety additive when you make sure there is no desiccant in the food, but the taste is disgusting.
Silicone can also be used, but I have not tried it, it is more expensive and not as powerful as desiccant. Method: 1.
Prepare the sample by cutting it into thin strips or small pieces.
This will make the process go faster. 2.
Flash the frozen slices, if possible, to prevent ice nuclear and preserve the cell wall. 3.
Prepare the container by pouring double-weight desiccant at the bottom. 4.
Place the separation tray and place the sample for removal from the desiccant.
Leave the space for desiccant to expand, just like when absorbing water. 5.
Seal the lid and remove the air from the container.
The more air you drain, the faster the process will be. 6.
Put it in the coldest place in the deep refrigerator or refrigerator.
A lower temperature prevents the nucleus and also prevents a solution of high sucrose (ice cream)
Will deform when the temperature is too high
30 C due to very complex reasons related to residual water as a plasticizer. 7.
Put a day in the fridge and re-
Vacuum and then leave for a week or so or until your sample is dry.
This will vary depending on the sample, temperature, pressure and desiccant.
This is an intermediate step in which a different container is prepared to accept a vacuum valve for the wine.
Standard ball valves could have been used, but this method is easier with wine pumps and wine preservation valves.
When determining what to freeze and dry, consider it.
Make sure you follow the following guidelines to speed up drying and quality: 1.
Less samples or thinner slices work best.
Cutting the sample into thin slices will increase the speed of steam sublimation.
There are several samples that can reduce the pressure lost due to the sublimation of water vapor. 2.
Freeze quickly or use freezers with lower temperatures.
The faster you freeze the sample, the smaller the ice crystal body.
Old ice cream is a good example.
If a warm refrigerator is reinvented, it will become cold and rough.
Fast freezing helps with sublimation and texture retention.
This is my main limit at home and the reason why my end result looks screaming and dry on the edge.
I would like to include a few photos before and after calcium chloride.
Note that this is the same amount and expands after absorbing the water vapor in the strawberry.
Unfortunately for science, I didn't weigh back and forth because I didn't have a scale that was accurate enough.
If someone wants to continue this experiment by themselves with a pressure gauge and scale, an accurate sublimation rate measurement can be determined.
I would like to thank Dear visitors for reading my guidance carefully and I hope that as a community we can continue to make food science awesome!