Freeze Dryer Machine For Home

Buying a Home Freeze-Dryer: What to Know Before You Go

Foods that are freeze-dried are extremely loved by backpackers and chefs These days, freeze dryers are now available to home users. The ads are captivating. The possibilities are limitless: food from the future with the click of a button! Don't ever waste food again! Glamorous, welcoming, and New Age - the scream to Americans who are addicted to their devices.
However, is a home-based freeze-dryer the best choice best suited to your needs? Here's some facts to dispel the marketing noise and offer some reason for the advantages and disadvantages of having a home-based freeze-dryer.

The Science Behind Freeze Drying

What is freezing?

As per the FDA: "Lyophilization or freeze drying is a method in which water is extracted from a substance after it has been frozen and put under a vacuum, permitting the ice to transform into vapor directly without the need to go through a liquid phase. The process is composed of three distinct, unique and interdependent processes: freezing secondary drying (sublimation) and secondary drying (desorption)" (FDA Inspection Guides 7/93, revised 2014). Freeze drying makes use of the principle of science known as "sublimation," the direct change of a solid from gas by the removal of the ice (the the solid) out of food frozen items as water vapour (a gas). By sublimation, food is left with the original taste, texture, flavor and nutrients when it is rehydrated.
Freeze drying is broken into two basic processes that are freezing and vacuum drying. The food items are then frozen below the temperature of 0degF. The colder the freezer, the more efficient the subsequent stage will be. After being frozen, food items are then dried by vacuum. The air and the water gas (gas) is removed from food processors with the vacuum pump. This also includes the removal of water vapor that once was within the food. After these two steps have been correctly done, the food will be dry enough to allow safe storage at temperatures at room temperature.

Are freeze-dried foods safe to eat?

Yes, If...

1. The two sub-processes of the vacuum drying and freezing, are properly executed:

1. The process of freezing must be swift and the vacuuming process should leave just a trace of moisture.

2. For instance, chilling food safely is defined as achieving 41 degrees Fahrenheit (refrigeration temperature) within 4 to 6 hours or less. Pre-refrigerated and frozen foods can be put in the freezer dryer to lessen the chance of causing harm.

3. Drying foods safely is described by reaching "a safe residual moisture level." To establish what this is at the home level, the majority of Cooperative Extension resources suggest that foods should be dried until a "crisp" or "breakable" texture. However, foods that have high sugar levels such as fruits can be pliable however, they are not sticky when properly dried (Andress, Harrison, Reynolds and Williams Reynolds, 2014)

2. The proper food handling methods were used during cooking the meal prior to freezing drying. The process of freezing does not kill bacteria.

What is the fate of microorganisms during the process of freeze drying?

Nothing. The microorganisms are still active, but dormant even in the extreme conditions of freezing drying. Scientists actually use the laboratory method that freeze-drys to keep microorganisms in future research since microorganisms are able to be rehydrated for a long time (see Kuletskaya & Netrusov, 2011). So, when you are cooking at home and freezing raw food, the microorganisms in those food items are alive, and then are activated upon rehydration. Food items traditionally cooked prior to consumption must be cooked prior to eating to be eaten as a food item that has been freeze dried. Examples include raw meats, raw seafood, eggs that are raw and food items that contain the raw ingredients.

Can freeze-dried foods be vacuum packaged safely?

Yes. If the food has dried to a minimal residual moisture, then vacuum packaging is secure. Be aware that vacuum packaging isn't an actual food safety procedure. Actually, the removal of oxygen from the package could create a greater issue for the botulism bacterium to multiply and produce toxins if it is in an atmosphere that is moist. Fortunately, with no water (water) it is unlikely that the botulism bacterium (and all yeast, bacteria and molds) can't expand. Thus, it is appropriate to put food items that have been properly dried or frozen in vacuum containers or containers with oxygen absorber packets in the.

Advantages and Disadvantages

Advantages of Freeze-drying

• Simple preparation: Food preparation for freezing is done similar to how food preparation is done for normal freezing. After washing and getting rid of the blemishes, cook most vegetables and pretreat fruit in order to avoid the browning of meats; they can be frozen-dried raw or cooked. Casseroles are often made from prepared food items. Put the item on the trays, then press the button to begin the machine.

• Freeze drying: can preserve food items that other preservation methods can't include egg or dairy products.

• Freeze drying: can replace the pressure canning process used for low acid food items.

• storage: When finished, freeze dried items are shelf stable, light, compact, and suitable for longer preservation methods. The most conservative estimates for food safety of food products that are commercially "canned" in metal-Mylar-type pouches are between 8 and 10 years (Jahner and Number (2008)). This doesn't address the quality of the food after this time, but only that of food safety. But, there is no data that is available on the shelf-life of frozen dried products at home, since the manufacturer of the first home freeze-dryer launched sales in the year 2013.

• Nutrients: Nutrition labels of commercially frozen dried broccoli, pineapple as well as cooked chunks of chicken are compared well with the nutritional data from commercially frozen food products (see the USDA Food Composition Database).

• The taste: Freeze-dried products rehydrate more thoroughly than dehydrated ones thus the taste and texture are more fresh with a frozen product rather than a dehydrated item.

• Price: Home freeze-dried foods are considerably less expensive than those that are commercially frozen. In addition to electricity and supplies costs, commercial businesses typically charge approximately 85% more than the home-produced item (Jessen, 2018,).

Disadvantages of Freeze-drying

• Cost. The machine is not the only cost (starting at around $2,000 and rising to more than $10,000 for smaller commercial machines) isn't the only expense. The ongoing expense of equipment and supplies should be taken into consideration.

• The cost for 60 1-gallon mylar bags containing 60 300 cc oxidizer packs cost $24 at Amazon (October 2018,). The oxidizer packets can be used for a single-use item, but mylar bags can be trimmed into smaller pieces and used again.

• The price of oil for vacuum pumps is around $20 per gallon, but the oil can be cleaned and reused. A pump that is oil-free is an option, but it will incur the initial cost of
  The price is $1600 (Harvest Right, November 2018) when you purchase the machine.

• Reports about the price of electricity are varying. One customer in the East Coast said her electricity cost increased by $20 to $30 per month during her high use (Merrill 2018 Personal correspondence). Customers in the Intermountain West estimated between $2 and $5 in electricity costs per batch
  (Jessen, 2018).

• Alternatives: Consumer options for the appliance are at present limited. There are a few manufacturers of "home" freeze dryers, lab freeze dryers are designed for research purposes, and therefore could not work as well for food use, and the smaller commercial "pilot study" freeze dryers tend to be more expensive than those designed for use in homes. Furthermore, commercial and laboratory freeze dryers usually come with more sophisticated software which significantly increases the cost. But, they are all choices for those who wish to search for the best product.

• The size of the machine: This isn't a small appliance, as is evident from the table below, which includes specifications from a renowned "home" freeze dryer manufacturer:

• Installation of the unit. This appliance cannot be placed on the ground: in part because it has to be elevated to allow the tubing for melting ice to be able to drain into a container beneath it, as well as to be accessible to the vacuum pump and on/off switches of the appliance.

• Temperature: Freeze dryers, as with all machines, operate best in temperatures ranging from 45o to 85o F. The machine's pump sends out heat, therefore it is essential to place the dryer in a location that has plenty of air circulation (Harvest Right, n.d.).

• Sound: When the vacuum pump is turned on, the level of noise is 62-67 decibels. The noise level of a vacuum cleaner's noise level is 70 decibels. (EpicenterBryan 2018, 2018; and iac Acoustics IAC Acoustics, 2018,).

• Time: A typical batch takes between 20 and forty hours (Harvest Right, 2018). Foods that are extremely dense and that are high in sugar will are more difficult to prepare Fresh pineapple is ready in 48 and 52 hours.

• The quantity of batches: The mid-sized machine can handle between 7 and 10 pounds of food items. A bushel of pears weighs 48 pounds. In a 24-hour processing time, plus a 3 hour defrost period to get the machine ready for a new batch, it could take more than a week to freeze dry one bag of peaches. It is assumed that the peaches will be stored for at least a week.

• Find out the distinctions between dehydrated and freeze dried food in this article. 

• Freeze dried vs dehydrated foods A Comparative Summary
  Conclusions
  Think about the following questions when you are considering buying a freeze-dryer:

• What is the final purpose of your product? Backpacking? Dinner with the family? The Apocalypse?

• What's the most delicious? Certain foods might be more appealing to you when preserved with traditional methods, while other foods may be more appealing when preserved with freezing dry. Be aware of what your personal preferences are in order to judge the effectiveness of having an at-home freeze-dryer. Trying some commercially frozen foods could help you in this endeavor.

• Does freeze-drying work within your budget? And does it fit into your home?

• It's enjoyable to experiment using new methods of preservation However, you must be aware of the points of purchase for consumers above. Be aware before you make a purchase.
  References

• Andress, E. L., Harrison, J.A., Reynolds, S., Williams, P. (2014). Drying. In, so easy to store, sixth edition (Bulletin 989). Athens, Georgia: Cooperative Extension/The University of Georgia/Athens, College of Family and Consumer Sciences, College of Agricultural and Environmental Sciences.

• EpicenterBryan. (2017, December 14). Vacuum pumps for Harvest Right freeze dryers. Retrieved from https://theepicenter.com/blog/oilless-maintenance-free-harvest-right-freeze-dryer-pump/

• Harvest Right. (2018). Harvest Right Owner's Manual. Retrieved from http://www.acrossintl.com/Files/HR_FreezeDryer_Manual.pdf

• iac acoustics, (2018). Comparative noise examples. Retrieved from http://www.industrialnoisecontrol.com/comparat ive-noise-examples.html

• Jahner, B,. & Nummer, B.A. (2008). Food storage: Canned items. Utah State University Extension Fact Sheet. Retrieved from https://extension.usu.edu/foodstorage/howdoi/canned

• Jessen, C. (2018). Freeze drying food items. Unpublished presentation given at the Annual Conference of Utah Extension Association of Family and Consumer Sciences, Kaysville, Utah.

• Kupletskaya, M.B., & Netrusov, A.I. (2011). The viability of lyophilized microorganisms following 50 years of storage. Microbiology, Vol. 80, No. 6, 850-853. Pleiades Publishing.

• U.S. Food & Drug Administration. (2014). Lyophilization of Parenteral (7/93) (FDA Guide to Inspections of Lyophilization of Parenterals). Retrieved from https://www.fda.gov/ICECI/Inspections/Inspecti onGuides/ucm074909.htm#_top