Intensive pulsed light pretreatment combined with controlled temperature and humidity for convection drying to reduce browning and improve quality of dried shiitake mushroom.

BACKGROUND The change of surface color caused by browning during the drying process of shiitake mushroom seriously affects its market circulation. Intensive pulsed light (IPL) as a non-heat treatment method can reduce enzyme activity by changing the enzyme structure. Therefore, in this study, the use of IPL pretreatment before drying was aimed to reduce the adverse reactions caused by browning reaction during the drying processing of shiitake mushroom. RESULTS Shiitake mushroom pretreated with IPL energy of 400 J for 25 pulse numbers reduced the initial PPO enzyme activity, the browning index (BI) and browning degree (BD) values by 42.83 %, 43.02 % and 47.54 %, respectively. The IPL pretreatment enhanced the polysaccharides and reducing sugars contents (RSC) while it reduced 5-hydroxymethylfurfural (5-HMF) generation in the dried shiitake mushroom. The pretreatment also improved the surface color, the antioxidant activity and retained the umami taste characteristics in the dried shiitake mushroom. CONCLUSION The IPL pretreatment combined with the controlled temperature and humidity for convection drying could be a suitable method to improve the quality of dried shiitake mushroom. Therefore, this study provides a new pretreatment method for materials that are prone to browning during drying. This article is protected by copyright. All rights reserved.