Abstract
According to the study on the shiitake phenolase in a previous paper, a few attempts for the prevention of the browning of defrosting shiitake were carried out.
Sodium hydrosulfite prevented the browning (Fig. 1), but the usage of sulfite for fresh vegetables was prohibited in Japan from Oct. 1969.
Blanching at 90°C, 5min. also prevented the browning (Fig. 2) ; however, the marked deterioration of both texture and flavor was observed.
As shown on Fig. 3, the authors have found that CO gas can successfully be used to prevent browning (2 hrs. 50min.).
Moreover, it was noticed that the extent of browning varied widely with the samples obtained at different places and dates, it seemed to depend chiefly on the content of polyphenols (Fig. 4) ; and the main polyphenols as substrate in shiitake were chlorogenic acid type.
