KMUTT Propels “Low-Pressure Superheated Steam Drying” Technology: Elevating Thai Fruits to Crispy, Healthy Snacks with Zero Oil

If someone told you that dried fruit could be as crispy and delicious as deep-fried potato chips without using a single drop of oil, you might be skeptical. However, the premium snack brand “Pure D” has turned this into reality, powered by over 20 years of deep-tech research from King Mongkut’s University of Technology Thonburi (KMUTT).

While drying fruits to extend shelf life is common, traditional methods often fall short. Prof. Dr. Sakamon Devahastin, from the Department of Food Engineering at KMUTT, explains that the industry typically relies on two methods: Hot Air Drying, which often results in dark, tough, and non-crispy textures; and Freeze Drying, which preserves color but creates a foam-like texture that melts instantly in the mouth, stripping fruits of their unique physical identity.

The “Fry with Steam” Innovation

To overcome these limitations, the research team developed “Low-Pressure Superheated Steam Drying (LPSSD).” This technology addresses major pain points through two key mechanisms:

1. Oxygen-Free Environment: Since the process occurs without oxygen, chemical reactions that destroy color and nutrients are prevented. The products retain their vibrant natural colors and full nutritional value.
2. Internal Boiling: The superheated steam causes the water inside the fruit cells to “boil from within” rapidly. This expansion puffs up the fruit’s structure before it sets, creating a “crispy” texture identical to fried snacks but completely oil-free.

“It’s essentially frying the fruit using steam,” says Prof. Dr. Sakamon. “The result is a snack that is crispy but not hard, maintaining the original aroma and flavor of each fruit variety without any additives.”

A 20-Year Journey to Commercial Success

The path to success was not easy. Starting with almost no existing global knowledge on the subject, the team spent two decades building their own expertise, resulting in over 25 academic publications. The ultimate test came in 2017 when scaling the lab prototype to an industrial level. Despite initial setbacks, three years of systematic data collection and mechanical adjustments—supported by private sector partnership—finally made the technology factory-ready.

This breakthrough led to the launch of “Pure D,” a healthy snack brand that uses 100% Thai raw materials with no added sugar, no oil, and no preservatives.

Beyond a single brand, this technology provides Thailand with a “new competitive edge” in the global food market. Instead of competing on price, Thai agricultural products can now compete through high-end technology that preserves quality, flavor, and health benefits for modern consumers.