Abstract: In order to investigate the influence of different salt contents on the quality of pickled peppers, this study compared the sensory quality, amino nitrogen, organic acid and total acid contents and volatile composition as determined by gas chromatography-ion mobility spectroscopy (GC-IMS) of one-year-old pickled peppers with different salt contents (6%, 9%, 12%, 15%, and 18%). The results showed that the sensory scores of the five pickled peppers were 5.75, 7.66, 8.51, 7.99, and 7.78 points, respectively. The contents of total acids in them were (5.431 ± 0.014), (4.575 ± 0.009), (4.227 ± 0.012), (4.125 ± 0.013), and (3.882 ± 0.005) g/kg, respectively, indicating a significant difference from each other (P < 0.05). The contents of amino nitrogen were (0.165 5 ± 0.000 5)%, (0.128 5 ± 0.001 2)%, (0.086 2 ± 0.000 8)%, (0.056 3 ± 0.001 0)%, and (0.033 6 ± 0.000 5)%, respectively, with a significant difference from each other (P < 0.05). A total of six organic acids were detected in all samples by high performance liquid chromatography (HPLC), namely oxalic acid, tartaric acid, lactic acid, malic acid, acetic acid, and citric acid. The contents of organic acids continued to decrease with the increase in salt content. Among them, the content of oxalic acid was the highest. Tartaric acid was not detected in the sample with salt contents equal to or greater than 12%. GC-IMS was used to analyze the difference in the volatile fingerprints of all samples, showing that higher contents of ethyl lactate, ethyl 2-hydroxy-4-methylpentanoate, isoamyl acetate, ethyl acetate, and 4-hydroxyl were found in the sample with 6% salt content. As the salt content increased, the amounts of the above substances decreased, while the amounts of other flavor substances such as ethyl acetate, ethyl 2-methylpropionate, 3-methyl-3-buten-1-ol, ethyl 2-methylbutanoate, 2-octanol, 3-methyl-1-pentanol, n-pentanol, 2,3-butanedione, 3-pentanone and 2-pentylfuran gradually increased, so that an obvious flavor difference occurred. Compared with those with other salt contents, pickled peppers with salt contents of 9%–12% had better flavor quality and could be directly used for the processing and seasoning of chopped hot pepper. The results of this study may be meaningful for guiding the processing of hot pepper.

Key words: salt content; pickled; hot pepper; volatile components; organic acid; gas chromatography-ion mobility spectrometry