Unraveling the difference in physicochemical properties, sensory, and volatile profiles of dry chili sauce and traditional fresh dry chili sauce fermented by Lactobacillus plantarum PC8 using electronic nose and HS-SPME-GC-MS

Abstract

The fermented dry chili sauce (FDCS) has the advantage of year-round production compared with the traditional fermented fresh chili sauce (FFCS). This study determined the differences in physicochemical properties, sensory, and volatile profiles between FFCS and FDCS, which Lactobacillus plantarum PC8 fermented with excellent fermentation characteristics. FDCS showed higher concentrations of amino nitrogen, malic and succinic acids, and redder color. Both FFCS and FDCS have good overall acceptability via sensory evaluation. Further, the aroma profile of FFCS and FDCS were studied using HS-SPME-GC-MS and electronic nose. The radar fingerprint chart of electronic nose showed that the W1W and W5S sensors gave higher responses to all samples. A total of 134 volatile compounds were identified in the fermented chili sauce, including 6 acids, 19 terpenes, 19 alkanes, 35 esters, 14 ketones, 8 aldehydes, 25 alcohols and 8 other compounds, of which 30 key compounds (odor activity value > 1) dominated flavor development. Pyrazine, 2-methoxy-3-(2-methylpropyl)-, linalool and d-limonene significantly contributed to the fermented chili sauce's aroma profile. However, FDCS expressed the distinctive herbal, nutty and fermented aromas characteristic, while the predominant aroma character of FFCS was spicy and fresh fruit. Overall, FDCS possessed a similar sensory profile to FFCS, but that had the special color, aromas and physicochemical characteristics, which suggested that the FDCS fermented by Lactobacillus plantarum PC8 might be an ideal chili sauce for production throughout the year. The results facilitate the full utilization of chili pepper and provide a theoretical basis for the industrial production of fermented chili sauce.