Liquid-liquid extraction coupled with gas chromatography-mass spectrometry (LLE-GC/MS) is a useful methodology for Baijiu aroma analysis. However, the background problems caused by LLE have rarely been investigated. In the present study, synthetic Baijiu was analyzed by traditional LLE-GC/MS to assess background problems, and a series of ghost peaks of some compounds were detected within the retention time of 47.0-60.0 min, including 2,4-di-tert-butylphenol (2,4-DTBP), palmitic acid and oleanitrile. 2,4-DTBP, which has a phenolic odor, is an important component in both strong and light-flavor Baijiu. Single-factor experiments confirmed that 2,4-DTBP is not a constituent of Baijiu but migrates from sodium sulphate and sodium chloride, and, high-temperature baking was an effective approach to eliminate these compounds. A combined strategy using standard cleaning coupled with high-temperature baking was proposed to reduce the background problems during LLE. Furthermore, more trace compounds could be identified through this process in the future.
Keywords: 2,4-di-tert-butyl phenol (2,4-DTBP); Aroma analysis; Background reduction; Baijiu; Liquid–liquid extraction.
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