Beyond conventional drying: improving the quality of dried Tremella fuciformis via a heat-integrated pretreatment

Why this jelly-like mushroom matters

Tremella fuciformis, often called silver ear fungus, is a popular ingredient in East and Southeast Asia, prized for its crunchy jelly texture in sweet soups and drinks. To make it safe and convenient to ship and store, it is usually dried, but common hot-air drying can leave it yellowed, tough, and slow to soften again in water. This study explores a smarter way to prepare Tremella before drying so that it keeps its bright look, pleasant bite, and fast “instant soup” convenience that many home cooks and food companies want.

A gentle warm-up before drying

The researchers tested a simple extra step called heat-integrated pretreatment, in which fresh Tremella is briefly blanched in hot water before hot-air drying. Instead of focusing only on killing microbes or stopping browning enzymes, this step is tuned to manage how water sits inside the mushroom’s natural gel-like network. The team tried different water temperatures and times, then dried all samples in the same way and compared how they looked, felt, and behaved when soaked again. They found that warming at 80 °C for 5 minutes struck the best balance between softening the tissue and avoiding damage.

How water moves inside the mushroom

Inside Tremella, long sugar chains form a sponge-like framework that holds water. If this structure collapses during drying, the pieces become dense and hard to rehydrate. Using magnetic methods that can “see” water without cutting the sample, the scientists showed that the gentle pretreatment converts some tightly held water into more mobile water while keeping the framework mostly intact. Images of the interior revealed that untreated pieces were compact and crowded, while the pretreated ones developed more pores and open pathways. This controlled loosening lets water escape more evenly during drying, instead of leaving dry crusts outside and wet pockets inside.

Faster drying and quicker soaking

Because pretreated Tremella absorbs some water and swells first, it starts the dryer with more moisture overall. Yet its opened-up structure makes it easier for that water to leave, so under the same hot-air conditions it dries efficiently and shrinks in a more regular, less damaging way. When the dried pieces were later soaked in hot water, all pretreated samples rehydrated better than the control, meaning they regained more weight and plumpness. The 80 °C for 5 minutes condition raised rehydration capacity by about three-quarters compared with normal drying, while still keeping much of the valuable polysaccharides that give Tremella its texture and health-related properties.

Better color, texture, and soup feel

Appearance is crucial for shoppers and cooks, and the heat-integrated pretreatment helped here as well. Moderately treated samples looked lighter and more appealing, with less browning than conventionally dried ones, while harsher heating at 90 °C began to wash out color and disturb structure. When the dried pieces were used to make instant Tremella soup, the pretreated versions produced thicker, more elastic liquids that behaved like a gentle gel rather than a thin broth. This shows that the inner sugar network survives the improved process well enough to rebuild a pleasant, smooth mouthfeel when cooked.

What this means for everyday products

Overall, the study shows that a short, carefully chosen warm-water step before hot-air drying can turn a fragile fresh mushroom into a dried product that soaks quickly, stays bright, and yields a satisfying, jelly-like soup. For consumers, that could mean instant Tremella desserts that are both more convenient and closer in taste and texture to the fresh version. For producers, the method offers a straightforward way to raise product quality without adding complex equipment, simply by tuning how heat and water are managed before the main drying stage.

Citation: Zhang, Y., Shi, N., Yang, C. et al. Beyond conventional drying: improving the quality of dried Tremella fuciformis via a heat-integrated pretreatment. npj Sci Food 10, 154 (2026). https://doi.org/10.1038/s41538-026-00805-8

Keywords: Tremella fuciformis, mushroom drying, rehydration, food texture, pretreatment