Quality changes of oak mushroom (Lentinus edodes) sealed with various film during cold storage

Hyowon Park*, Chul-Woo Kim, Rhim Ryoo, and Uk Lee

(Division of Forest Special Products, National Institute of Forest Science, Suwon 16631, Korea)

Abstract: Oak mushroom, which grows on oak trees and has a medium brown color with an umbrella-shaped cap is one of the most popular edible mushroom in Korea. Since mushrooms are fast respiring, and start deterioration immediately after harvest, extension of postharvest storage while preserving product quality would be beneficial for mushroom industry as well as consumers. The aim of the present study was to evaluate the influence of various film packaging on quality and sensory characteristics of oak mushrooms. Mushrooms were packed with 6 fruit per each container and then sealed with three types microperforated films, which have different oxygen transmission rate (OTR) [A; control (PET), B; 5,000 cc·m-2·day·atm, C; 20,000 cc·m-2·day·atm, D; 80,000 cc·m-2·day·atm], and stored at 3±1 °C for 28 days. The concentration of CO2 inside each container was 0.2, 21.2, 16.3 and 10.1%, respectively, which remained lower as the OTR was higher during storage. Weight loss of A (control) rapidly increased to 14.7%, while B-D treatments showed 0.8, 0.8 and 1.4% after 17 days of storage. Browning index in A showed continuously higher value than every type of perforated films (B-D) during storage period. In sensory evaluation, especially off-odor index (0-10) was significantly decreased to 6.9 on B and 7.7 on C while 9.2 on D after 10 days of storage. Marketability of mushroom, which includes appearance, texture, off-odor and overall preference index was maintained 6 days for A and B, 8 days for C and 13 days for D. These results demonstrated that 1) mushroom avoids PET container due to prevent weight loss and color changes, 2) the OTR affects a significant effect on the quality and sensory of oak mushroom and 3) sealing with lower OTR films accumulates CO2 in the mushroom during storage, which leads to loss of quality due to off-odor. In short, film D prolong marketability for 5 days compared to A. To preserve optimum quality of oak mushroom, using 80,000 cc·m-2·day·atm film was recommended for sealing package.

key words: modified atmosphere packaging, microperforated film, oak mushroom, storage, weight loss