Abstract: The change of volatile flavor substances in nano-film packaged Hypsizygus marmoreus was studied in this work. The mushroom was packaged with a new polypropylene nano-film (0.05 mm) and stored at 4 ℃ for up to 12 days. During this period, the volatile components were analyzed by headspace solid phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS), and the characteristic flavor components were determined by relative odor activity value (ROAV) and principal component analysis (PCA). A total of 66 volatile components were identified during storage, including 23 aldehydes, 22 alcohols, 10 ketones, 3 esters, 4 carboxylic acids and 4 furans. The total content of volatile compounds showed a trend of first decreasing and then increasing, with values of 98 927, 28 079 and 89 021 μg/kg on days 0, 6 and 12, respectively. ROAV analysis showed that n-octyl aldehyde, 1-octene-3-ketone and 1-octene-3-alcohol were the characteristic flavor components of H. marmoreus, and 2-pentyl furan also contributed greatly to the flavor of H. marmoreus. Trans-2-octenal played a key role in the formation of the flavor of fresh H. marmoreus. Trans, trans-2,4-nondienal and 3-octyl were the key substances for the flavor deterioration of H. marmoreus. PCA analysis showed that aldehydes and alcohols were the most important flavor contributors. It can be concluded that samples of H. marmoreus from different storage periods could be distinguished according to the change of volatile components, which may provide the basis for rapid quality detection, flavor identification and shelf life prediction.

Key words: nano-film; Hypsizygus marmoreus; storage and preservation; volatile flavor components; gas chromatography-mass spectrometry