Volatile and non-volatile compounds of shiitake mushrooms treated with pulsed light after twenty-four hour storage at different conditions

TLDR

Pulsed light is used to stimulate vitamin D₂ in mushrooms, yet its impact on other volatile and non‑volatile compounds and the role of post‑treatment storage conditions remain unclear. This study examined how four storage conditions (ambient/4 °C with/without oxygen) affect vitamin D₂, phenolics, antioxidant capacity, and volatile profiles in pulsed‑light‑treated shiitake mushrooms after 24 h. The authors compared vitamin D₂, total phenolic content, DPPH and CUPRAC antioxidant capacities, individual phenolics, and volatile compounds in PL‑treated mushrooms stored under the four conditions for 24 h. Storage conditions markedly altered phenolic and antioxidant levels—gallic, caffeic, and quercetin, as well as CUPRAC—where PL‑treated mushrooms showed higher values than controls, with gallic appearing only under vacuum and caffeic reduced under vacuum, and volatile compound profiles also varied with storage.

Abstract

Pulsed light (PL) is currently done for the stimulation of vitamin D2 in mushrooms. Most studies done on mushrooms have focused on the effect of different PL intensities on vitamin D2 synthesis. Apart from vitamin D2 stimulation, PL may affect the content of other volatile or non-volatile compounds. Additionally, conditions at which mushrooms are stored after PL treatment might have an impact on the content of different mushroom compounds. The aim of the current study was to investigate the effect of different storage conditions (ambient temperature in the presence of oxygen, 4 °C in the presence of oxygen, ambient temperature under vacuum, and 4 °C under vacuum) on vitamin D2, total phenolic content (TPC), antioxidant capacity (i.e., 2,2-diphenyl-1-picrylhydrazyl (DPPH) and cupric ion reducing antioxidant capacity (CUPRAC)), as well as individual phenolic and volatile compounds of PL-treated mushrooms, after 24 h storage. Storage conditions significantly affected TPC, CUPRAC, gallic acid, caffeic acid, chlorogenic acid, and quercetin contents. Gallic acid, caffeic acid, and quercetin contents, as well as CUPRAC values were higher in mushrooms treated with PL than the control. Gallic acid was detected only in samples stored under vacuum either at ambient temperature or at 4 °C. On the other hand, caffeic acid content was lower in the samples stored under vacuum than those stored in the presence of oxygen, regardless of temperature. Finally, storage conditions significantly affected the contents of volatile compounds of PL-treated mushrooms.