A Comparative Study on the Structural Properties and Lipid Profile of Mushroom (<i>Pleurotus ostreatus</i>) Powder Obtained by Different Drying Methods

Abstract

Mushroom powders, as functional food ingredients, have attracted much attention in recent years. In the present study, four drying methods, i.e., freeze drying (FD), hot air drying (HAD), microwave drying (MWD), and sun drying (SD), were investigated to determine the effects on the structure and lipid profile of mushroom powder. The morphology of the mushroom powder was studied by using X-ray microtomography. The surface of the particles was studied by using scanning electron microscopy. The identification of lipophilic components was carried out by using gas chromatography in a powder extract obtained under in vitro conditions simulating digestion. The FD powder extract, with the widest range of particle size distribution (17.7–2270.3 µm), represented flake shapes with a porous structure. In addition, particles with minimal sizes (17.7–35.4 µm) were recorded only in the FD powder extract. Among the samples, the representation of large granules (1135.5–2270.3 µm) was ranked in the order: MWD FD > HAD > SD. Based on the content of linoleic acid, the samples were ranked in the order HAD Pleurotus ostreatus) powder and its lipophilic component. The new information obtained will contribute to better management of mushroom raw materials in terms of optimization, taking into consideration the manufacturer’s interest in the technological and functional properties of mushroom powders as a food ingredient or biologically active substance for the production of nutraceuticals.

Keywords

• freeze drying
• hot air drying
• microwave drying
• sun drying
• <i>Pleurotus ostreatus</i>
• mushroom powder