New insights into the drying technology of Pleurotus eryngii: Effects on protein structure, properties and product flavor analysis

Abstract

Drying techniques have been widely used in food macromolecule modification, sterilization, and other fields. However, comparisons about the effects of different heat treatments on the structural and functional properties of proteins have yet to be elucidated. In this study, we compared the effects of boiling water, microwave, hot air, and infrared pretreatment on the structural and functional properties of P. eryngii (Pleurotus eryngii) proteins (PEP), with the addition of low-temperature hot air drying (Fresh-H) and vacuum freeze drying (VFD) as controls. The flavor of apricot mushroom products was also analyzed. The results showed that the PEP from boiling water pretreatment combined with hot air drying (BPHD) maintained high surface hydrophobicity, turbidity, particle size, and zeta potential. Microwave pretreatment combined with hot air drying (MPHD) of PEP had higher water and oil-holding properties, crystallinity, hydrolysis, and antioxidant capacity. Meanwhile, both MPHD and infrared pretreatment combined with hot air drying (IPHD) maintained higher emulsification, foaming, and free amino acid content. There were large differences in the types and contents of volatile compounds in P. eryngii with different treatments, providing more options.

Keywords: Drying methods; Pleurotus eryngii protein; Protein structure.