Importance of drying in support of human welfare

There is a great challenge in feeding the world's growing population. By the year 2100, there is an 80% probability that the world's population will increase from the current 7.2 billion to between 9.6 billion and 12.3 billion. In addition, due to rising incomes and urbanization, food consumption patterns around the world are shifting to more resource-intensive, animal-based foods, among other factors. As a result of increasing temperatures and declining precipitation over tropical, subtropical and semiarid regions, corn, wheat, rice, and other primary crops are expected to yield lower yields in the near future; climate change, particularly extreme weather, will likely have a significant impact on global food security in the near future.

It is imperative that major changes are made to the current practices of food production, storage, distribution, and consumption in order to ensure food security. An essential processing operation for the safe storage of agricultural products and food, it contributes significantly to enhancing global food security. By removing the moisture to a safe level, drying can prevent the growth and reproduction of microbial proliferation, mitigate moisture-mediated deteriorative biochemical reactions, reduce packaging, transportation, storage and processing costs, thereby reducing postharvest losses, extending shelf life and increasing value. It is noteworthy that it is possible to enhance food quality cost-effectively by drying sustainably under optimal operating conditions in well-designed dryers with smaller physical and energy footprints. Globally, this requires an inter- and multi-disciplinary approach to research and development. International cooperation and networking can lead to innovation and cost reduction. Mathematical modeling can be used to design and scale up various dryer types in order to increase efficiency and reduce life cycle costs.

Inadequate and improper drying can result in serious losses. As a result of insufficient drying and microbial spoilage, China loses as much as 21 million tons of grain annually, which accounts for 4.2% of the country's total grain output. This is more than four times the amount of grain harvested each year, which poses a serious threat to China's food security. Other parts of the world have experienced similar results. In addition, inadequate drying can lead to serious food safety issues, which pose a threat to the health of the general public and national security. Statistics from the Food and Agricultural Organization (FAO) indicate that about 25% of agricultural products are contaminated with mycotoxins as a result of inadequate or improper storage conditions, and that 2% of agricultural products lose their nutritional and economic value as a result of pollution, resulting in economic losses of hundreds of billions of dollars.

Aflatoxin development is the most prevalent problem in food products. The compounds in question are highly toxic and carcinogenic, as well as resistant to degradation under normal food processing conditions. In the International Agency for Research on Cancer (IARC), aflatoxin B1 is classified as a Group 1 carcinogen. Globally, it is estimated that up to 28% of liver cancers are caused by aflatoxin pollution. Insufficiently dried foods, such as peanuts, maize, spices, and herbs, are most likely to develop this condition.

The role of drying in sustainable global development is crucial. In most countries, it consumes 7-15% of the total industrial energy consumption. Considering the huge total energy consumption of a dryer and the low energy utilization efficiency of the current dryer of only 25-50%, efficient drying can and should play a crucial role in achieving low carbon and sustainable development as well as curbing climate change. In fact, even small improvements in the energy efficiency of drying can lead to huge energy savings through process optimization, employing multi-stage drying, intermittent drying as well as using energy saving technologies via the use of renewable energy sources on a larger scale.

As one of the oldest methods for preserving food and the most frequently employed industrial operation, it has been considered a mature and well-developed technology. For a long time, the investment in drying research has been far lower than it should be. This is because of the contribution of drying research to national food security, human health and global sustainable development. Although thi