Freeze-drying or lyophilization is a dehydration technique where ice is sublimed from the material directly to a gas, under pressure, and with a small amount of heat. In comparison to other drying or dehydration processes, freeze-drying has become a feasible method of processing heat sensitive and high-quality products. The sublimation process, which helps the direct transition of water from solid to vapor without a liquid phase helps to preserve most of the initial raw material’s properties such as appearance, shape, taste, color, and flavor. In addition, freeze-dried products have a high rehydration capacity compared to other dried products.
Irrespective of all its advantages, freeze-drying is still not used widely on an industrial scale in India. Due to its cost, its use in the food industry is restricted to high added-value products – coffee, ingredients for ready-to-eat foods (fruit, vegetables, meat, and fish), and aromatic herbs.
To learn more about this technology, we recently interacted with RajendraN HonaRao, owner and one of the directors of Gujarat-based Freeze Drying Systems. Freeze Drying Systems manufactures food freeze dryers, lyophilizer machines, and food preserving dryers. The company has two manufacturing units in Vadodara. Before starting his manufacturing plant in 1998, Rajendra worked as a freeze-drying technology consultant and manufactured machines for Saraf Food, a well-known manufacturer and supplier of dehydrated food products, fruit, vegetables, and herbs.
While sharing his journey in process and equipment manufacturing, he says, “Destiny brought me to this business. I realized that in India, we do a lot of snacking and consume junk foods. Moreover, children are not very interested in peeling fruit and eating these. Instead, they love to have something in an attractive packet. Then I decided, instead of giving them packets full of junk food, why shouldn’t we offer them something good with more nutritional value.”
Counting on the benefits of freeze-dried products, HonaRao says, “Freeze-drying works as a preservation and processing technology. Using this technique, you can process any food or vegetable without adding any preservatives, additives, and added-sugar – and as a result, you will get a product with comparable nutritional value to the original product but with longer shelf-life.”
Lab-scale to industrial processing capacity
Freeze Drying Systems manufactures machines in a variety of sizes – from laboratory scale to machines with a processing capacity of 1000 kilograms a day. The company makes six to seven models from lab scale to its bigger capacity models, including 30 kg, 60kg, 500kg, and 1000kg. HonaRao proudly says that the company has sold more the 108 units all over India to food and pharmaceutical companies. Apart from India, the company exports machines to Ghana, Ivory Coast, Uganda, Spain, and Bangladesh.
HonaRao says, “We have the domain knowledge to implement world-leading lyophilization technology in our freeze-drying machines. Our machinery can realize the beauty of this technology over all other conventional methods of drying. With these, you can process anything on the earth, such as any fruit, vegetable, spices, herbs, enzymes, extracts, confectionery items, milk, ice cream, tea, and coffee. Whereas, the other traditional processing methods have limitations of processing four or five types of materials.”
Although easy to handle and user-friendly, he admits that the affordability of these machines is a concern. “Freeze-drying compared to other drying technologies is costlier, but if we compare the nutritional benefits, this is much closer to nature. Moreover, we have refined the freeze-drying process to a point where we can supply the most efficient and economic freeze-drying plants in the market.”
“If the cost of the machine goes up, machine manufacturers find some challenges to sell it in the market, but now considering the benefits, the demand for such technologies has increased. In the last couple of years, the cost of our machinery has also come down. It could be because the duties have reduced on the imported components, and with the use of variable frequency drives, the running cost of the machines has reduced. As a result, they are coming within an affordable range,” HonaRao continues.
Preserve your produce for years
HonaRao concludes, “The government should have these machines in the food processing supply chain to help and benefit farmers by processing their produce. At present, farmers are not getting the right price for their produce, which is often wasted without reaching the consumers. Freeze drying can preserve their products for years together.”