Effect of glutinous rice flour on chemical and physical qualities of crispy grey oyster mushroom sheets

Abstract

The grey oyster mushroom (Pleurotus ostreatus (Jacq. ex Fr.) Kummer) is an economically important mushroom species in Thailand. Developing grey oyster mushrooms into crispy snack products is therefore an interesting opportunity. This study aimed to investigate the effects of glutinous rice flour on selected qualities of crispy grey oyster mushroom sheets. A completely randomized design (CRD) was applied, studying glutinous rice flour at levels of 0, 5, 10, 15, and 20% (w/w). The study revealed that moisture content, water activity (aw), hardness, fracturability, and color values were significantly different (P≤0.05). Increasing the amount of glutinous rice flour led to a decrease in moisture content and aw , with the sample containing 10% glutinous rice flour exhibiting the lowest moisture (2.97%) and aw (0.174). An increase in flour content resulted in higher hardness and fracturability values. The samples exhibited hardness ranging from 0.69 to 1.83 N and fracturability from 0.52 to 1.31 N. Regarding color attributes, lightness (L*) increased as the glutinous rice flour content increased, indicating a slightly lighter appearance of the product. Minor changes were observed in a* and b* values. The findings from this study can be applied to the development of crispy grey oyster mushroom sheet snacks as healthy alternatives, with desirable textural and physical qualities that align with consumer preferences.