Effect of lactic acid fermentation of red beetroot juice on volatile compounds profile and content

Abstract

The study aimed to evaluate the effect of lactic acid fermentation on the profile and content of volatile organic compounds (VOCs) in red beetroot juice. Red beetroot juice was fermented by three different amounts (1%, 2%, and 2.5%) of three various Lactobacillus strains (L. acidophilus ATCC 8014, L. brevis Lbbr 12A, L. plantarum ATCC 3543) for 24 h. The head-space micro-extraction (HS-SPME) with gas chromatography–mass spectrometry (GC–MS) was implemented to qualify and quantify the VOCs presence in samples: fresh juice, two controls incubated at 30 and 37 °C, and nine fermented juice samples. A total number of 100 volatiles were identified in the analyzed juice samples, which were classified into 18 chemical groups. Fermented juice samples were characterized by a greater variety of VOCs than unfermented juice samples. In fermented juice samples, 17 to 38 compounds were identified, while in unfermented juice samples, it was 13–15 compounds. The highest number of VOCs was found in juice fermented by L. plantarum (33–38 volatiles) and the lowest in fresh juice (13 volatiles). Total relative content of VOCs ranged from 84.00 (fresh juice) to 881.31 µg/mL (control, 30 °C). On the other hand, the highest relative content of VOCs among fermented juice samples was noticed in the juice fermented by a 1% addition of L. plantarum. According to this study, it can be said that 24-h lactic acid fermentation of red beet juice allows forming a significant amount of volatilized molecules. Therefore, the relatively high content of volatiles can increase potentially the aroma attractiveness of red beetroot juice.