Freeze Drying: The Latest Tech On The Block
Overview
Freeze Drying is a technological concept that is slowly and steadily gaining prominence. The origin dates to World War II when this technique was used to preserve plasma and penicillin. In the late 20th century, this became a method of food preservation. With tailor-made machinery, freeze-drying is much simpler nowadays.
Freeze drying, as the words denote, means the drying of food from solid to gas/ from ice to vapor (without liquifying it). It is also known as “Lyophilization” and is a dehydration process. In this process, the food is first dried under pressure to remove the water content in it. Thereafter the food is packed in air-tight containers. At the time of consumption, some warm water is added / food is slightly heated, and voila! you can then eat it!
The Process Of Freeze Drying
Freeze drying is carried out in the following manner:
- Freezing: The first step is freezing, where the food is frozen under atmospheric pressure.
- Primary drying: In this second step, the frozen free water is removed by sublimation.
- Secondary drying: In this step, which is also called desorption drying, the food is dried off the remaining humidity, thereby making it porous.
The freeze-dried food can be rehydrated just by adding water to it. Thereafter it is ready for consumption.
Benefits Of Freeze Drying
Freeze drying process has the following benefits :
- Preservation: The flavor and nutrients of the food are preserved to the maximum. There is hardly any loss of flavor or texture in this process.
- Safe: The food is safe from contaminating agents as this process does not involve the use of any hard chemicals or processes.
- Portable: The food can be easily handled, stored, or transported as the dryness reduces its volume and weight.
- Life: The shelf life of these products is twenty-five (25) years +!
- Fresh: The food remains good and does not spoil easily.
- Taste: The taste of the food remains unchanged.
- Retention: This process retains the antioxidants (anthocyanins, flavonoids, ascorbic acid/Vitamin C) in the food. These antioxidants are beneficial in fighting the effects of oxidative stress on our bodies.
- Dryness: As the food is stripped of all its water content, there is no scope for the growth of bacteria, yeast, or molds, thereby reducing spoilage.
- Consumption: The consumption is simple – just add water to it and your food is ready to eat, with the same original aroma and taste.
- Availability: Freeze drying makes the availability of certain plant-based foods that are seasonal.
- Less heating: Rehydrating the food requires minimal heat thereby conserving energy.
- Ration: This food is a must-have for hikers, trekkers, campers, space explorers, military forces, busy working professionals, students residing away from home, in remote areas, and cases of emergency and survival conditions.
Freeze Drying: Shortfalls
- Raw food: If raw food like eggs or meat is freeze-dried, there is a chance of disease-causing microorganisms surviving the process, thereby leading to food-borne diseases, if the food is consumed uncooked. So it is advisable to cook the raw food before consumption.
- Cooking: It is recommended to cook raw food well before freeze-drying it.
- Porosity: The porosity of the freeze-dried food can easily access oxygen leading to a higher level of oxidation or degradation of bioactive compounds.
- Machinery: Freeze drying is recommended to be carried out in the machines specially manufactured for the process as the foods need to be subjected to specific temperature and atmospheric pressure.
- Training: If you have acquired a freeze-drying machine for your personal use, it may be a time-consuming process as you may not be adept at its usage. You should be properly trained to use the same.
- Unsafe: Freeze drying, if attempted by you, may be unsafe, if you are unaware of the functioning of the machine and process of freeze drying.
Foods That Can Be Freeze Dried
Not all food can be freeze-dried. Listed below ae some of the foods that can be freeze dried and used.
- Fruits: Strawberries, apples, blackberries, bananas, pears, oranges, and fruit puree
- Vegetables: Carrots, asparagus, mushrooms, peppers, pumpkins, tomatoes, and most other vegetables
- Meat: Fish, beef, chicken, eggs, shrimp, turkey, pork
- Grains: Cooked rice, beans, pasta, quinoa, and polenta
- Legumes: Cooked beans, lentils, peas, tofu
- Frozen meals: Whole meals like Pad Thai, stews, chili, and snacks
- Beverages: Instant juices, coffee and tea or milk
- Spices: Ginger, oregano, mint, basil, and garlic
- Sweeteners: Maple syrup for sugar powder
Market Trends And Future Growth
The Growing Freeze-Dried Food Market in India
You must have noticed these frozen foods in supermarkets. Many Indian companies have jumped at this opportunity to cultivate the freeze-dried food market. It is slowly and steadily gaining momentum in India.
- Chericious, based in Ahmedabad, offers freeze-dried food options, including the ability to freeze-dry home-cooked meals and ship them to the USA.
- They provide a range of ready-to-eat products, including Jain options.
There are many online videos showing the easiness with which the freeze-dried food can be prepared and consumed. Examples are Chole-Kulcha (cooked chickpeas- Indian bread), Dal Makhani (cooked lentil curry), and Malabar Paratha (Malabar Indian bread) which need minimal heating and it is ready for consumption. It tastes the same as if it has been freshly prepared.
The Benefits of Freeze-Drying for Busy Professionals and Students
All in all, freeze-drying is a tried and tested healthy food preservation technique.
- Convenient for time-pressed working professionals and students.
- Provides a healthier alternative to fast food.
- Offers variety for those tired of their own cooking.
- Allows parents to ship homemade freeze-dried meals to children overseas easily.
- Ensures parents that their children are eating nutritious food.
The Expanding Applications of Freeze-Drying
The global freeze-drying equipment market is proliferating, valued at USD 1.91 billion in 2023 and projected to reach USD 4.48 billion by 2033 (Spherical Insight & Consulting).
- Freeze-drying has significant medical applications, including enhancing the effectiveness of anti-tumour drugs with freeze-dried lymph nodes (CGTN).
- The simple mantra for freeze-dried food: “Freeze it, Heat it, Eat it.”
