Entrepreneurs turn to industrial-scale food drying, but costs are prohibitive

For the past nine years, Sohel Rana has been running a fruit business, mainly selling mangoes and other summer fruits. While he sells 5,000 maunds of fresh mangoes every season, 30% of the total yield goes to waste. 

"Starting from the green unripe mangoes to the ripe ones; storms, bad weather and pests lead to the wastage," said the fruit trader from Naogaon.  

To reduce the waste and get the most out of the yield, Sohel has resorted to the use of a hybrid dryer or food dehydrator. The dryer runs on solar panels during the day and at night, it can run on an electric heater. This way, the dryer runs 24 hours, drying fruits, vegetables and leafy greens. 

"We have estimated that for every batch, we can dry up to 500 kg of mangoes," Sohel said. 

It has been a month and a half since he installed the dryer and up till now, Sohel has experimented with banana, tomato, neem, drumstick leaves, and some other leafy vegetables. 

"During winter, we have excellent bananas growing here. Also, tomatoes are very cheap this season. So by drying and then grinding them into fine powder, we can consume them all year. That is what we want to achieve. If we can make aamchur [dried mango powder], it can be used in smoothies, juices and even in cooking," Sohel explained. 

Like Sohel, several other businessmen are taking up drying to preserve fruits, vegetables, fish, meat, etc. Although the shutki (dried fish) industry has employed these machines for many years now, machine drying of fresh fruits and vegetables is still new.

"In our everyday culinary practice, we prefer fresh ingredients, rather than dried or preserved ones. But if this outlook towards dried and frozen food can be changed, we could reduce a lot of fresh fruit and vegetable wastage," said Professor Md Abdul Awal, a faculty member at the Department of Farm Power and Machinery, Bangladesh Agricultural University (BAU).

"Bangladesh grows some of the best mangoes, pineapples, and jackfruits in Asia. If we could process our fruits and vegetables, we could have a large export market, apart from ensuring our own food security."

Moniruzzaman, owner of online shop Fruitbd

Professor Awal has been conducting research on fruit drying since 2001, when they made a solar tunnel dryer to dry pineapples. Currently, in the BAU lab, they are working on making biodegradable packaging to conserve these dried fruits. 

According to him, drying food is not a new concept. For ages, our ancestors have used this technique to preserve food in the form of pickled and candied fruits. When refrigerators arrived, we froze fish, meat and vegetables to some extent, but only in households. 

"It's about policymaking, whether we are ready to accept a change, whether we are eager to develop a low-cost drying machine that our farmers could afford and at least ensure their food security," said Dr Awal. 

Cost remains a major barrier to entry

Md Rowshan Alamgir and his friends started a dried fish business in Cox's Bazar where they introduced an electric dryer in 2019. The dryer chamber can dehydrate up to 500 kg of fish per batch. 

"The dryer is covered and well-ventilated, helping to maintain hygiene during the fish drying process. While traditional shutki farmers dry the fish out in the open, the dryer allows us to keep the odour away, keeping the environment fresh. However, we can never beat the traditional farmers in the market as our production cost inflates due to the energy costs," said Alamgir. 

So in 2023, they halted the shutki business and took up fruit drying and freezing. 

"So far, we have worked on pineapples and it has a good shelf life. However, the market response is disappointing. No one wants to have dried fruits when they can have fresh ones, that too at a cheap price during the season," Alamgir said. 

Meanwhile, Moniruzzaman, owner of Rajshahi-based online shop Frutibd, has received funding from a Japanese company to develop a drying factory in Bangladesh. 

"They provided my farm with an industrial dryer and after completing initial tests and trials, we are hoping to start production by 2026," Moniruzzaman said. 

Fruit drying is a big business in Asian countries like Thailand, Malaysia and China. They use fruit powder in smoothies, salads and other health-focused dishes. 

"Bangladesh grows some of the best mangoes, pineapples, and jackfruits in Asia. If we could process our fruits and vegetables, we could create a large export market, beside ensuring our own food security," Moniruzzaman further said. 

Sun drying vs machine drying: What research says

"In Bangladesh, fruits are usually dried under the sun. Although sun drying is cheap, it often results in products of an inferior quality due to its dependence on weather conditions and vulnerability to the attack of insects, pests, microorganisms and dust," said Professor Awal. 

According to him, each year, a huge amount of pineapples of different varieties are produced in Bangladesh. This fruit is highly perishable and seasonal. If the excess fruits were preserved, consumers would have the taste of this seasonal fruit all-year-round. And these processed fruits could be exported to earn foreign currency. 

In 2001, a group of researchers from BAU developed a solar tunnel dryer to research pineapple drying. In this research, three sets of full-scale field-level drying runs were conducted on pineapple slices. The temperature of the drying air at the collector outlet varied from 34.1 degree Celsius to 64.0 degree Celsius during drying. 

And this dryer can be used to dry up to 150 kg of fresh pineapple. The pineapple, dried in the solar tunnel dryer, was completely protected from rain, insects and dust, and the product was of good quality. 

"This dryer can be constructed using locally available materials by local craftsmen," the research paper titled 'Solar drying of pineapples using solar tunnel dryer' states. 

Sohel Rana is using a similar dryer that he developed for his farm. "We are still running it on an experimental basis and hoping for a good mango season this year by saving on food waste," he said. He is also planning to dry jackfruits to make chips out of it. 

"There are many categories of industrial dryers available in the market, with prices ranging from Tk60,000 to several lakhs. Even if we ignore the electricity bill they generate, the initial price is unaffordable for our farmers. So, if a low-cost drying machine is developed and our farmers and entrepreneurs are provided with it, our food industry may look very different in the coming years," Professor Awal said.