Food Dehydration, The Full Process, And Advantages of Dehydrated Food!
Food Dehydration
1. What is Dehydrating Food?
Drying (dehydrating) food is one of the oldest and easiest methods of food preservation. Dehydration is the process of removing water or moisture from a food product. Removing moisture from foods makes them smaller and lighter. Food Dehydration
Dehydrated foods are ideal for backpacking, hiking, and camping because they weigh much less than their non-dried counterparts and do not require refrigeration. Drying food is also a way of preserving seasonal foods for later use. Food Dehydration
2. How Dehydration Preserves Foods:
- Foods can be spoiled by food microorganisms or through enzymatic reactions within the food.
- Bacteria, yeast, and molds must have a sufficient amount of moisture around them to grow and cause spoilage.
- Reducing the moisture content of food prevents the growth of these spoilage-causing microorganisms and slows down enzymatic reactions that take place within the food.
- The combination of these events helps to prevent spoilage in dried food.
3. The Basics of Food Dehydration:
Three things are needed to successfully dry food at home:
- Heat, hot enough to force out moisture (140°F), but not hot enough to cook the food.
- Dry air, to absorb the released moisture.
- Air movement, to carry the moisture away.
Foods can be dried using three methods:
- In the sun requires warm days of 85°F or higher, low humidity, and insect control; recommended for dehydrating fruits only.
- In the oven.
- Using a food dehydrator electric dehydrators take less time to dry foods and are more cost-efficient than an oven.
4. Preparing Fruits And Vegetables For Drying:
- Many fruits and vegetables can be dried. (Table 1) Use ripe foods only.
- Rinse fruits and vegetables under cold running water and cut away bruised and fibrous portions. Remove seeds, stems, and – or pits.
“Vegetables And Fruits” Table No 1:
Fruits and Vegetables Suitable for Drying |
|
---|---|
Fruits | Vegetables |
Apple | Beets |
Apricots | Carrots |
Bananas | Sweetcorn |
Cherries | Garlic |
Coconuts | Horseradish |
Dates | Mushrooms |
Figs | Okra |
Grapes | Onions |
Nectarines | Parsnips |
Peaches | Parsley |
Pears | Peas |
Pineapples | Peppers (red, green, and chili) |
Plums | Potatoes |
Pumpkin |
Most vegetables and some fruits (Table 2 and 3) should undergo a pretreatment, such as balancing or dipping. Blanching is briefly precooking food in boiling water or steam, and it is used to stop enzymatic reactions within the foods. Blanching also shortens drying time and kills many spoilage organisms.
The Food Drying Process, Fruits, Vegetables, And Meats:
1. Timing:
Drying times vary based on a few factors:
I. Humidity:
Check your local weather service to determine the day’s humidity level. The closer the humidity level is to 100%, the longer it will take food to dry.
II. Moisture Content:
The actual amount of water in the food you are drying is also a major consideration. Remember, the water content of a fruit or vegetable can vary due to growing season, rainfall and environmental factors, as well as the ripeness of the food.
III. Slicing:
The amount of water in the food can vary due to the growing season’s rainfall, environmental factors, and the ripeness of the food. This will affect drying times. If you wash produce before dehydrating, make sure you towel off excess water prior to drying.
2. Cleaning:
Wipe dehydrator with a damp cloth and warm, soapy water. Rinse well. Trays can be placed on the top rack of the dishwasher. Removable mesh inserts can be soaked in warm, soapy water. Wipe down with a damp sponge. The door can be cleaned using warm, soapy water. Wipe down with a damp sponge.
3. Blanching:
A treatment using boiling water or steam. Also known as checking or crazing. Use on tough-skinned or fruits with a natural protective wax-like graph, plums, cranberries, etc. This method reduces the drying time significantly.
Steps For Blanching:
A. Steam blanching (fruit and vegetables):
- Use a steamer or a deep pot with a tight-fitting lid that contains a wire basket or could fit a colander or sieve so steam can circulate around the vegetables.
- Add several inches of water to the steamer or pot and bring to a rolling boil.
- Loosely place fruits – vegetables into the basket, no more than 2 inches deep.
- Place basket into the pot (fruits – vegetables should not make contact with water).
- Cover and steam until fruits – vegetables are heated for the recommended time (Tables 2 and 3).
- Remove basket or colander and place it in cold water to stop cooking.
- Drain and place fruits – vegetables on the drying tray.
B. Water blanching (vegetables only):
- Use a blancher or a deep pot with a tight-fitting lid.
- Fill the pot two-thirds full with water, cover, and bring to a rolling boil.
- Place vegetables into a wire basket and submerge them into the boiling water for the recommended time (Table 2).
- Remove vegetables and place them in cold water to stop cooking.
- Drain and place vegetables on a drying tray.
C. Syrup blanching (fruits only):
- Combine 1 cup sugar, 1 cup light corn syrup, and 2 cups water in a pot.
- Add 1 pound of fruit.
- Simmer 10 minutes (Table 3).
- Remove from heat and keep fruit in syrup for 30 minutes.
- Also, remove the fruit from syrup, rinse, drain, and continue with the dehydration step.
4. Dipping:
Dipping is a pretreatment used to prevent fruits such as apples, bananas, peaches, and pears from turning brown (Oxidizing). Ascorbic acid, fruit juices high in vitamin C (lemon, orange, pineapple, grape, etc.), or commercial products containing ascorbic or citric acid may be used for dipping.
Sodium Bisulfite:
Available directly through Excalibur. It is the most effective and least expensive anti-oxidant. Use only food-safe grade. When mixed with water, this is the liquid form of sulfur. Before using, check with your physician regarding allergies.
Fruits:
Mix 1-1/2 tablespoons of Sodium Bisulfate in 1-gallon of water. Soak fruit slices for 5 minutes. Rinse.
Vegetables:
Recommended for steam blanching only. Also highly recommended for vegetables to be stored in excess of 3 months. Add 1 teaspoon of Sodium Bisulfate to each 1 cup of steam water and blanch.
Ascorbic Acid-Citric Acid Dip:
Available directly through Excalibur. A simple form of Vitamin C. Found in all citrus fruits. Soak prepared produce in a solution of 2 tablespoons of powder to 1 quart of water for 2 minutes.
Fruit Juice Dip: Food Dehydration
A natural anti-oxidant. Stir 1 cup of citrus juice into 1 quart of lukewarm water. Soak prepared produce for 10 minutes. NOTE: Fruit juice is only 1/6 as effective as pure Ascorbic Acid and may add taste to your food.
Honey Dip:
A common treatment for dried fruits sold in the grocery store or in health food stores. This will make fruit considerably sweeter and add calories as well. Dissolve 1 cup of sugar in 3 cups of hot water. Cool mixture to lukewarm. Add 1 cup of honey. Dip fruits in small batches. Remove with a slotted spoon and drain thoroughly before dehydrating.
For example,
- Dipping sliced fruit pieces in a mixture of ascorbic acid crystals and water (1 teaspoon ascorbic acid crystals per 1 cup of water),
- Or dipping directly in fruit juice for 3 to 5 minutes will prevent browning.
- Fruits may also be blanched as a means of treatment.
“Vegetables” Table No 2:
Blanching and Drying Times for Selected Vegetables |
||||
---|---|---|---|---|
Vegetable | Blanching | Drying time (hrs) |
||
Method | Time (mins) |
|||
Beets | cook before drying | 3½–5 | ||
Carrots | steam | 3–3½ | 3½–5 | |
water | 3½ | |||
Corn | not necessary | 6–8 | ||
Garlic | not necessary | 6–8 | ||
Horseradish | not necessary | 4–10 | ||
Mushrooms | not necessary | 8–10 | ||
Okra | not necessary | 8–10 | ||
Onions | not necessary | 3–6 | ||
Parsley | not necessary | 1–2 | ||
Peas | steam | 3 | 8–10 | |
water | 2 | |||
Peppers | not necessary | 2½–5 | ||
Potatoes | steam | 6–8 | 8–12 | |
water | 5–6 | |||
Pumpkin | steam | 2½–3 | 10–16 | |
water | 1 | |||
Dried vegetables should be brittle or crisp. |
I. Drying Fruits and Vegetables:
1. Natural sun-drying: Food Dehydration
Sun drying is recommended for drying fruit only. Sun drying is not recommended in cloudy or humid weather.
The temperature should reach 85°F by noon, and the humidity should be less than 60 percent. Outdoor dehydration can be difficult in Virginia and other southern states due to high humidity. All food that is dried outdoors must be pasteurized.
- Dry in the sun by placing slices of food on clean racks or screens and covering with cheesecloth, fine netting, or another screen. Food will dry faster if racks are placed on blocks and the rack is not sitting on the ground.
- If possible, place a small fan near the drying tray to promote air circulation.
- Drying times will vary (Tables 2 and 3).
- Turn food once a day. Dry until the food has lost most of its moisture (fruits will be chewy).
- Fruits should be covered or brought in at night to prevent moisture from being added back into the food.
2. Drying with a food dehydrator:
- Place food dehydrator in a dry, well-ventilated, indoor room.
- Arrange fruits or vegetables in a single layer on each tray so that no pieces are touching or overlapping.
- Dehydrate at 140°F.
- Check food often and turn pieces every few hours to dry more evenly.
- See Tables 2 and 3 for drying times.
3. Oven drying: FOOD DEHYDRATION
Dry food in an oven that can be maintained at 140°F. Leave door 2 inches to 3 inches ajar. Place a fan in front of the oven to blow air across the open door.
- Spread the food in a single layer on racks or cookie sheets.
- Check food often and turn pieces every few hours to dry more evenly.
- Drying time will vary (Tables 2 and 3). Do not leave the oven on when no one is in the house.
“Oven drying is not recommended in households where children are present”
When food is dehydrated, 80 percent of the moisture is removed from fruits and up to 90 percent of the moisture is removed from vegetables, making the dried weight of foods much less than the fresh weight (Table 4).
“Fruits” Table No 3: FOOD DEHYDRATION
Blanching and Drying Times for Selected Fruits |
|||
---|---|---|---|
Fruit | Blanching | Drying time(hrs) | |
Method | Time (mins) | ||
Apple | steam | 3–5 | 6–12 |
syrup | 10 | ||
Apricots | steam | 3–4 | 24–36+ |
syrup | 10 | ||
Bananas | steam | 3–4 | 8–10 |
syrup | 10 | ||
Cherries | syrup | 10 | 24–36 |
Figs | not necessary | 6–12 | |
Grapes: seedless | not necessary | 12–20 | |
Nectarines | steam | 8 | 36–48 |
syrup | 10 | ||
Peaches | steam | 8 | 36–48 |
syrup | 10 | ||
Pears | steam | 6 | 24–36+ |
syrup | 10 | ||
Pineapples | not necessary | 24–36 | |
Plums | not necessary | 24–36 | |
|
II. Pasteurizing Sun-Dried Fruits:
All sun-dried fruits must be pasteurized to destroy any insects and their eggs. This can be done with heat or cold. To pasteurize with heat,
- Place dried food evenly in shallow trays no more than 1 inch in depth.
- Fruits should be heated at 160°F for 30 minutes.
- To pasteurize with cold, fruits can be placed in the freezer at 0°F for 48 hours.
III. Conditioning Dried Fruits:
Dried fruits must be conditioned prior to storage. Conditioning is the process of evenly distributing moisture present in the dried fruit to prevent mold growth. Condition dried fruit by:
- Placing it in a plastic or glass container, sealing, and storing it for 7 days to 10 days.
- Shake containers daily to distribute moisture.
- If condensation occurs, place the fruit in the oven or dehydrator for more drying and repeat the conditioning process.
“Fresh Fruits” Table No: 4:
Fresh Fruits
|
Dehydrated Weight
|
Apple | 2 |
Peaches | Peaches 1½–2½ |
Pears | 2¼ |
Prunes-plums | 2¼ |
Fresh vegetables (20 lbs) |
Dehydrated weight (lbs) |
Snap beans | 1¾ |
Beets | 2 |
Carrots | 1¾ |
Onions | 2½ |
Squash (summer) | 1½–2 |
Tomatoes | ¾ |
IV. Storing Dried Fruits and Vegetables:
The ideal temperature for food storage is 50˚ – 60˚F / 10˚ – 16˚C. Use containers safe from moisture and insects. Glass jars with tight lids, sealed bags, and vacuum-sealed bags are recommended. You can store bags in metal coffee cans or cookie tins.
Cool-dried food should be placed in:
- A closed container that has been washed and dried before storing it.
- Home canning jars are good containers for storing dried foods.
- Store in a cool, dry, and dark place.
- Dried foods can maintain quality for up to a year depending on the storage temperature.
- The cooler the storage temperature, the longer dehydrated foods will last.
V. Reconstituting Dried Fruits and Vegetables:
Reconstituting foods adds yet another dimension to the versatility of daily food preparation. Properly dried food, rehydrate well. They will retain much of the aroma, flavor, minerals, and vitamins.
Here are some common reconstituting methods. It is important to not add salt, sugar, or spiced during the first 5 minutes of reconstitution.
1. Electric Steamer: Food Dehydration
Place food in a rice bowl and cover it with liquid. Follow the directions provided with your steamer’s operating manual for reconstituting fruits and vegetables.
2. Soaking:
Place dried food in a shallow pan. Cover with liquid. Allow 1 to 2 hours for the rehydration process to occur.
3. Boiling Water ‘Vegetables’:
Place 1 cup of dried vegetables in 1 cup of boiling water. Soak for 5 to 20 minutes. Fruits: Place 1 cup of dried fruit and 1 cup of boiling water into a pan. Let simmer until tender.
4. Cooking:
For vegetable sides, fruit toppings, or compotes: Use 1 part liquid to 1 part dried food. For food used in soufflés, pies, and quick bread, add 2 parts of liquid to 3 parts of dried food. When cooking fruits, place them into a saucepan with boiling water, turn the heat to low. Simmer 1 to 15 minutes or until tender.
To prevent the growth of microorganisms,
- Dried fruits and vegetables should be reconstituted in the refrigerator.
- One cup of dried fruit will yield approximately 1½ cups of reconstituted fruit.
- One cup of dried vegetables will yield approximately 2 cups of reconstituted vegetables.
- Reconstituted fruits and vegetables should be cooked in the water in which they were soaking.
VI. Jerky:
Making Safe Jerky:
Jerky can be made from almost any lean meat, including pork, venison, and smoked turkey. Jerky made from meat is of particular concern because dehydrators rarely reach temperatures beyond 140°F. This temperature is not high enough to kill harmful microorganisms that may be present on meat. Before dehydration, precook meat to 160°F and precook poultry to 165°F. For best results, precook meat by roasting in the marinade.
A. Meat preparation To prepare meat for jerky:
make sure that safe meat handling procedures are followed.
- Clean: Wash hands with soap and running water for at least 20 seconds before and after handling raw meat. Use clean utensils.
- Chill: Store meat or poultry refrigerated at 40°F or below prior to use. It is important to thaw frozen meat in the refrigerator.
Never thaw meat on countertops. Slice partially frozen meat into strips no thicker than ¼ inch. Trim and discard any fat. Meat can be marinated for flavor and tenderness.
B. Drying meats:
- Drain strips on a clean, absorbent towel.
- Place strips in a single layer, making sure they don’t touch or overlap.
- Dehydrate at 140°F until a test piece will crack, but not snap when bent.
- Remove dried strips from rack and cool.
If the meat strips were not heated to 160°F in marinade prior to drying, you may want to do this in an oven after drying. Place the dried strips on a baking sheet and cook at for 275°F, or until meat reaches 160°F. This process adds an additional safety step to the process. Food Dehydration Food Dehydration
C. Storing meat jerky:
Meat strips should be packaged in glass jars or heavy plastic storage bags. Jerky can be stored at room temperature for 2 weeks in a sealed container. For the longest shelf life, flavor, and quality jerky, store in the refrigerator or freezer. Food Dehydration
5. Advantages of Dehydrating Vegetables:
- 1. Dehydrating vegetables with your dehydrator will only affect the nutritional value minimally: Fiber, Vitamin A, and C, magnesium, selenium, and carbohydrates are only a few of the nutrients that will remain in dehydrated food.
- 2. Dehydrated food also has the extra benefit of it being chemical and pesticide-free: Vegetables and other foods can be preserved and stored safely. You will be able to buy or harvest vegetables in bulk without having to worry that they will go rotten.
- 3. Dehydrated vegetables have a longer shelf life: Dehydrated vegetables have a longer shelf life than even canned vegetables as long as the container you are keeping your dehydrated vegetables in is properly sealed.
- 4. Dehydrated vegetables will retain their flavor: You can use your dehydrated vegetables as delicious and healthy lunchbox snacks and are great to take along when going camping.
- 5. Dehydrated vegetables can be rehydrated by simply adding water: This will make soup preparation so much easier when you do not have the time to clean and chop up vegetables.
- 6. Dehydrated vegetables can be packed in when you are going hiking and will take up basically no space.
Also,
- 7. During natural disasters, you will have the comfort of knowing that you will be able to use your dehydrated vegetables when no other food is available.
- 8. Buying ready-made dehydrated vegetables can be an expensive excursion.
- 9. By making your own in your dehydrator you will save cost.
- 10. You will not need to use your freezer to store your dehydrated vegetables.
- 11. It takes less time and effort to dehydrate your vegetables than if you would or freeze them.
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Disclaimer: “Nothing in this article makes any claim to offer cures or treatment of any disease or illness. If you are sick please consult with your doctor.”
References
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