A new method of fruit dehydration using calcium chloride and vacuum technology may help reduce food waste and energy use while preserving nutritional and visual quality.
Many fruits are in abundance in the late summer and early fall, making it a much-anticipated time of year for jam-makers and canning enthusiasts. Traditionally, preserving seasonal fruits has allowed us to spread out their use across the year, spooning the jeweled goodness of foraged berries onto our breakfasts (or directly into our mouths) well into winter. But globally, we waste over 1.05 billion tons of food every year1, with fresh fruits and vegetables making up almost half of that amount. To address this, the food industry needs a solution that will increase shelf life without impacting nutritional quality. One option is dehydration, which is already one of the most widely used methods of food preservation. Dehydration slows down deterioration reactions and microbial growth, extends shelf life, and mitigates the risk of foodborne illnesses. Even so, it's still an energy-hungry process and requires large volumes of hot air, resulting in low energy efficiency of just 30% and notable greenhouse gas emissions.
A heatless alternative: atmospheric water harvesting under vacuum
One promising alternative dehydration method is based on an adaptation of the idea of atmospheric water harvesting (AWH) and does not require heat. In a recent study published in ACS Food Science & Technology, researchers built a heatless vacuum chamber with three levels of screens placed over a calcium chloride solution at room temperature.2 Then, they tested the chamber's dehydration effectiveness on apple and mango slices under a slight vacuum compared to standard atmospheric conditions.
This approach offers several advantages: calcium chloride is abundant, inexpensive, and nontoxic, while the recovered water can be reused for industrial or human purposes. Under vacuum conditions, tests showed that 95% of water was removed from the mango and apple slices, regardless of their distance from the solution, allowing for effective dehydration in stacked layers. In contrast, dehydration at atmospheric conditions resulted in significantly lower moisture removal in samples placed farther from the solution. The final moisture content under vacuum was comparable to that of commercial dried fruit. Analytical results confirmed that vacuum-assisted AWH preserved fruit color and slowed deterioration. Previous studies have shown that vacuum drying improves rehydration capacity, retains cellular microstructure, and reduces shrinkage.3,4
Another approach: UV-A dehydration for produce and meat
Work from the same team has explored another possible dehydration approach using a combination of low relative humidity air flow at room temperature and exposure to UV light, specifically ultraviolet-A. When tested on potatoes, analyses confirmed substantial preservation of the physical and chemical integrity of even under prolonged storage, and with significantly higher total phenolic concentrations than the raw samples.5 This method can also be used for drying meat, with tests showing beef jerky dehydrated using UV-A had comparable fat content and fatty acid composition to that dried in the oven, demonstrating that this method could be viable for jerky production.
Future directions and broader implications for global hunger and food security
For both techniques, further research is warranted to assess shelf stability and consumer acceptability, but these novel dehydration methods could pose great value for reducing both food waste and energy use compared to current methods. Such innovations are essential for advancing the United Nations' Sustainability Development Goal of Zero Hunger, which aims to achieve food security, improve nutrition, and promote sustainable agriculture. According to the Food and Agriculture Organization, meeting the needs of a projected 9 billion people by 2050 will require a 70% increase in global food production.
Chemistry plays a pivotal role in this effort, from enhancing crop resilience to developing sustainable packaging and fortified foods. To learn more about how chemistry is driving progress toward Zero Hunger, read our recent blog post and explore impactful research surrounding this topic area below.
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Chemistry Against Hunger: Enhancing Food Security
Chemistry plays a key role in improving food production, protecting crops, and promoting sustainable practices to eliminate world hunger. Explore noteworthy research highlighting chemistry’s impact in supporting sustainable agriculture and enhancing food security.
References
- https://www.unep.org/news-and-stories/press-release/world-squanders-over-1-billion-meals-day-un-report
- Roberts, M. S. et al. Dehydration of Mango and Apple through Atmospheric Water Harvesting under Vacuum. ACS Food Sci. Technol. 2025, 5, 8, 3201–3209.
- Ahmad, F. and Zaidi, S. Postharvest Quality Evaluation of Pineapple during Drying. ACS Food Sci. Technol. 2022, 2, 3, 592–603.
- Leelawat, B. and Taikerd, T. Effect of Drying Methods and Conditions on the Physicochemical Properties of Young Jackfruit-Based Chicken Meat Analogs. ACS Food Sci. Technol. 2024, 4, 11, 2682–2689.
- Roberts, M. S. and Bastarrachea, L. J. Ultraviolet-A Light Dehydration of Purple Potatoes. ACS Food Sci. Technol. 2023, 3, 4, 710–716.
- Alruzzi, M. A. et al. Impact of UV-A Light Dehydration on the Physicochemical Characteristics of Beef Jerky. ACS Food Sci. Technol. 2025, 5, 3, 1174–1182.
