Volatiles and bacterial composition of pickled bamboo shoots within 10 pre-packaged Chinese Luosifen disclosed by GC–MS, GC-IMS, and high-throughput sequencing

Abstract

Pickled bamboo shoots represent a type of fermented bamboo shoot product. In China, pickled bamboo shoots are regarded as the soul of Luosifen, which is a local specialty food in Liuzhou (Guangxi Zhuang Autonomous Region, China). To exemplify the uniqueness of the pickled bamboo shoots, we analyzed the pickled bamboo shoots within 10 pre-packaged Chinese Luosifen to determine the composition of volatiles and bacteria, and subsequently examined the correlation between them. The volatiles were identified using gas chromatography–mass spectrometry (GC–MS) and gas chromatography-ion mobility spectrometry (GC-IMS). Meanwhile, high-throughput sequencing technology was employed to investigate the bacterial composition. The results indicated that the pH values of the samples exhibited minimal variance (ranging from 3.71 to 4.53), while the total acid (measured as g lactic acid /L) varied (from 4.65 to 10.3 g lactic acid /L). Lactic acid, acetic acid, and succinic acid were the predominant organic acids. 50 volatiles were detected by HS-GC-MIS, and 108 volatiles were identified by HS-SPME-GC–MS. p-Cresol (76,541.67 < OAV < 248,166.67), acetic acid (482.31 < OAV < 1164.62), and hexanoic acid (108.33 < OAV < 1333.33) were the common distinctive volatiles among the 10 samples. Proteobacteria and Firmicutes, as the dominant phyla, were positively and negatively related to 1-butanol (R = 0.66, − 0.66), respectively. Industrial relevanceIn China, Luosifen, as a local delicacy, enjoys popularity among the public for its sour, smelly, spicy, fresh, and oily features. Among them, pickled bamboo shoots are highly sought after for their distinctive sour and refreshing flavor. Nevertheless, some individuals cannot tolerate the sour smell of pickled bamboo shoots yet still have a desire to consume Luosifen. To address this issue, it is crucial to determine what constitutes the pungent odor in pickled bamboo shoots and subsequently regulate it to meet the requirements of diverse consumers and enhance the economic benefits of the Luosifen industry. This study disclosed the stimulant flavor substances of pickled bamboo shoots in 10 pre-packaged Luosifen detected by GC–MS and GC-IMS, offering a theoretical foundation for subsequent regulation.