Kinetics of Quality Degradation and Water Removal During Air Drying of Osmodehydrated Oyster Mushrooms Impregnated with Rosa damascena Distillation By-Products

Mushrooms are a valuable food in the human diet due to their superior nutritional properties. However, mushrooms' short shelf life presents a challenge for their commercial application. Mushrooms' air drying kinetics were determined, and the impact of prior osmotic dehydration was quantitatively evaluated. Additionally, the sustainable utilization of <i>Rosa damascena</i> distillation wastewater, rich in phenolics, was explored. Samples were impregnated with hypertonic solutions including rose wastewater, glycerol, salt and calcium chloride, and air-dehydrated at 40, 55, and 70 °C. Texture and color changes were determined during drying. Seven acknowledged mathematical models were successfully applied to describe the drying kinetics, with the effect of process temperature being incorporated into the drying constant. The simplest first-order model is deemed adequate for describing moisture reduction and quality degradation. Pretreatment significantly reduced the drying time to reach a final moisture content of 10% w.b, especially at 70 °C, where the reduction obtained was more than 40% (5 h for untreated vs. 2.5 h for pretreated samples). At the end of drying, pretreated samples reached lower values of water activity and maintained their color better (25-50% improvement). This study aims to provide a basis for producing a novel, mushroom-based, nutritionally fortified dry snack, following results confirmed by a sensory examination.