Volatile composition and sensory profile of oyster mushroom as affected by drying method

ABSTRACT

The smell of food is one of the most important factors in assessing its quality. In this study, the influence of drying method on aroma/volatile compounds of oyster mushrooms (Pleurotus ostreatus Jacq.) was evaluated. The drying methods tested were convective drying (CD), freeze-drying (FD), vacuum microwave drying (VMD), and a combination of convective predrying and VM finish drying (CPD–VMFD). The volatile compounds were extracted by solid-phase microextraction and identified by gas chromatography–mass spectrometry. The best fitting model to describe the drying kinetics of the oyster mushroom was Henderson and Pabis model. Thirty-four volatiles in fresh oyster mushrooms were identified, with 3-octanone (2,890 µg/100 g dry basis) and 3-octanol (991 µg/100 g) being the major components. The total concentration of volatiles of fresh mushroom (4,506 µg/100 g) was drastically reduced by all drying treatments, although the highest contents were found after: (i) CPD (50°C)–VMFD (480 W) (245 µg/100 g) and (ii) VMD at 480 W (143 µg/100 g). According to the sensory data, the products dried using the treatment CPD (50°C)–VMFD (480 W) were those closer to the fresh mushrooms.

KEYWORDS:

• Descriptive sensory analysis
• hot air-drying
• mushroom drying
• Pleurotus ostreatus
• vacuum microwave drying

Abbreviations::

• ANOVA: analysis of variance
• CD: convective drying
• CPD: convective predrying
• DSA: descriptive sensory analysis
• GC–MS: gas chromatography–mass spectrometry
• HS-SPME: headspace solid-phase microextraction
• LSD: least significant difference
• RMSE: root mean square error
• RI: retention index
• FD: freeze-drying
• VD: vacuum drying
• VMD: vacuum microwave drying
• VMFD: vacuum microwave finish drying