Comparing freeze-drying to other drying and preservation methods

In today’s article we will look at other food drying methods and compare freeze drying with air drying, spray drying and convection drying.

Air drying is a natural drying method that is carried out by exposing food to air. This method is simple and inexpensive, but it is not very efficient and can alter the taste and aroma of the food.

• Simplicity: Air drying is a simple method that does not require specialised equipment.
• Economy: Air drying is an economical method.
• Versatility: Air drying can be used to dry a wide variety of foods.

• Inefficiency: Air drying is an inefficient method that can take days or weeks to dry food.
• Alteration of flavour and aroma: Air drying can alter the flavour and aroma of food.
• Loss of nutrients: Air drying can lead to loss of nutrients from the food.

1. Select food: Food should be fresh and clean.
2. Cutting food: Food should be cut into small pieces so that it dries faster.
3. Placing food on a rack: Food should be placed on a rack to allow air to circulate on all sides.
4. Placing the rack in a dry and ventilated place: The rack must be placed in a dry and ventilated place for the food to dry properly..
5. Check food regularly: Food should be checked regularly to ensure that it is drying properly.

• Fruits: apples, pears, plums, etc.
• Vegetables: tomatoes, peppers, onions, etc.
• Meat: beef, pork, poultry, etc.
• Fish: salmon, tuna, etc.
• Herbs and spices: basil, coriander, parsley, etc.

Spray drying is a rapid drying method that is carried out by spraying food with a jet of hot air. This method is efficient and preserves the nutrients in the food, but may alter the texture of the food.

• Efficiency: Spray drying is an efficient method that can dry food in a matter of minutes.
• Preservation of nutrients: Spray drying allows the nutrients in the food to be preserved.
• Versatility: Spray drying can be used to dry a wide variety of foods.

• Texture alteration: Spray drying alters the texture of the food, making it harder.
• Cost: Spray drying is an expensive method.
• Specialised equipment: Spray drying requires specialised equipment with qualified facilities and personnel.

1. The products are prepared: the product to be dried must be washed and cut into small pieces.
2. Adding water: Food should be added to a tank of water to soften it.
3. Atomising food: Food should be atomised with a jet of hot air.
4. Recovering food: Dried food should be recovered from the drying equipment.

• Fruits: strawberries, raspberries, blueberries, etc.
• Vegetables: tomatoes, peppers, onions, etc.
• Meat: beef, pork, poultry, etc.
• Fish: salmon, tuna, etc.
• Herbs and spices: basil, cilantro, parsley, etc.

Convection drying is a drying method that is carried out by exposing food to a flow of hot air. This method is efficient and preserves the nutrients of the food, but alters its taste and aroma as well as its properties.

• Efficiency: Convection drying is an efficient method that can dry food in a matter of hours.
• Preservation of nutrients: Convection drying preserves the nutrients in the food.
• Versatility: Convection drying can be used to dry a wide variety of foods.

• Alteration of flavour and aroma: Convection drying can alter the flavour and aroma of food, making it drier and less tasty.
• Cost: Convection drying is an economical method.
• Specialised equipment: Convection drying requires specialised equipment.

1. Prepare the food: Food should be washed and cut into small pieces.
2. Placing food on a tray: Food should be placed on a tray to allow air to circulate on all sides.
3. Heating the air: The air must be heated to a temperature of between 40 and 60 °C.
4. Drying food: Food should be dried for a certain period of time.

• Fruits: apples, pears, plums, etc.
• Vegetables: tomatoes, peppers, onions, etc.
• Meat: beef, pork, chicken, etc.
• Fish: salmon, tuna, etc.
• Herbs and spices: basil, coriander, parsley, etc.

The following is a list of alternative preservation methods to freeze-drying.

Freeze-drying can be compared to other preservation methods such as refrigeration, freezing and canning.

• Refrigeration: Refrigeration is a method of preservation based on keeping food at a temperature below 4 °C. This method is effective for preserving food for a short period of time, but is not suitable for preserving food that is sensitive to freezing.
• Freezing: Freezing is a method of preservation based on keeping food at a temperature below -18 °C. This method is effective in preserving food for long periods of time, but can alter the taste and flavour of the food.
• Canning: Canning is a method of preservation based on sealing food in an airtight container and subjecting it to heat treatment. This method is effective in preserving food for long periods of time, but can alter the taste and flavour of the food.

• Long shelf life: Freeze-dried foods have a shelf life of several years, even without refrigeration.
• Preservation of flavour and aroma: Freeze-drying is a process that preserves the natural flavour and aroma of foods.
• Preservation of nutrients: Lyophilisation preserves the nutrients in food.
• Texture preservation: Lyophilisation preserves the texture of the food.
• Ease of storage and transport: Freeze-dried foods are easy to store and transport.

• Cost: Freeze-drying is an expensive process.
• Specialised equipment: Freeze-drying requires specialised equipment.