Apple pomace, a by-product of juice and cider production, is rich in dietary fiber, polyphenols, and other valuable nutrients, making it a promising ingredient for food applications. Its high fiber content contributes to improved water retention and viscosity, enhancing the structure and texture of food products by increasing thickness, moisture stability, and mouthfeel, especially in baked goods, meat analogues, and dairy alternatives.

The aim of the study was to investigate the impact of hydrothermal treatment parameters on the technological and functional properties of powder obtained from dried apple pomace based on the characteristics of the pulp rehydrated from it. This was tested in terms of texture properties, particle size, water holding capacity, bioactive compounds, and antioxidant activity.

The results showed that treatment at temperatures ranging from 60°C to 90°C for 1 to 10 minutes improved the water-holding and binding capacity of the apple pomace powder, which was associated with the loosening of the material’s structure. However, increasing the temperature negatively affected the polyphenol content and antioxidant activity of the resulting pulp due to the heat sensitivity of bioactive compounds. Higher processing temperatures also enhanced the texture-forming properties of the pulp. The duration of the hydrothermal treatment had a less significant effect, although a tendency was observed for reduced bioactive properties and increased water retention with longer processing times (1–10 minutes). The findings confirm that the parameters of the hydrothermal rehydration process determine the technological usefulness of dried apple pomace powder and should be optimized depending on its intended function in food products. Higher temperatures and longer durations are recommended for texture improvement, while lower temperatures should be used to preserve bioactive compounds.