Weissella cibaria is one of the bacteria in charge of the initial fermentation of kimchi and has beneficial effects such as immune-modulating, antagonistic, and antioxidant activities. In our study, we aimed to estimate the safety of W. cibaria JW15 for the use of probiotics according to international standards based on phenotypic (antibiotic resistance, hemolysis, and toxic metabolite production) and genotypic analysis (virulence genes including antibiotic resistance genes). The results of the safety assessment on W. cibaria JW15 were as follows; (1) antibiotic resistance genes (ARGs) (kanamycin and vancomycin etc.) were intrinsic characteristics; (2) There were no acquired virulence genes including Cytolysin (cylA), aggregation substance (asa1), Hyaluronidase (hyl), and Gelatinase (gelE); (3) this strain also lacked β-hemolysis and the production of toxic metabolites (D-lactate and bile salt deconjugation). Consequently, W. cibaria JW15 is expected to be applied as a functional food ingredient in the food market.

The production of good Meju soybean paste primarily depends on the selection of raw materials and fermenting microorganisms, which together influence its characteristic metabolites, taste, and aroma. In this study, we analyzed the relationship between properties and metabolites in Meju samples fermented by Aspergillus oryzae alone or with Bacillus velezensis. We developed fast-stable processing techniques to obtain Meju from A. oryzae and B. velezensis using the inoculation method, thereby ensuring safety in the production of soybean paste. The amino-type nitrogen content increased from an initial 180–228 mg% to a final 226–776 mg% during fermentation and was higher in Meju inoculated separately with the fungi and bacteria (C group) than in Meju co-inoculated with both the starters concurrently (D group). The levels of metabolites such as glucose, myo-inositol, glycerol, and fatty acids (palmitic, stearic, oleic, and linoleic acids) in Meju fermented by A. oryzae with B. velezensis were higher than those in Meju fermented by A. oryzae alone. Fungal growth was affected by the inoculated bacteria, which often occurs during the fermentation of co-inoculated Meju.

The present study evaluated the cultural and functional characteristics of six strains of acetic-acid bacteria (AAB), namely, GHUR-A11-2, SR-A24, GY-A26, GHF-A37, JS-B7, and JS-C1, which were isolated from farm-made fermented vinegars. The six bacterial strains exhibited high acetic acid production capability via the decomposition of CaCO3, and they were identified as Acetobacter pasteurianus based on the 16S rDNA sequences. The initial pH and optimal growth temperature for acetic acid production were determined to be 4.0 and 30°C, respectively; however, some strains of AAB presented reasonable growth even at 40°C. Four bacterial strains (except SR-A24 and GHF-A37) exhibited alcohol degradation activities of more than 90%. Bacillus cereus presented high susceptibility to the antibacterial activity of the six strains of AAB. The antioxidant activity evaluated using DPPH and ABTS was 5–15 times and 4–5 times higher for the six strains of AAB than that for the control group, respectively. GHUR-A11-2, SR-A24, and JS-C1 exhibited higher ACE activities, with inhibition rates of 154%-175%, as compared to those exhibited by the positive control of 0.1% captopril (inhibition rate of 138%). Furthermore, the fibrinolysis activity of SR-A24 (93.3%) was markedly higher than that of 0.5 U plasmin. Four bacterial strains (except GHF-A37 (75.3%) and JS-B7 (68.0%)), exhibited α-glucosidase inhibition activities of more than 100%. It was concluded that the six strains of AAB exhibited excellent physiologically active characteristics, which facilitated their use as seed strains for the synthesis of high-efficiency functional vinegar by harnessing the functional characteristics that fit the scientific basis.

Fermented vinegar is prepared from grains and medicinal plants. Here, we produced vinegar from peeled and unpeeled roots of bellflowers (Platycodon grandiflorum) using Acetobacter pasteurianus A11-2 and analyzed bellflower vinegar (BV) samples using gas chromatography–mass spectrometry and quadrupole time-of-flight mass spectrometry over 15 days of fermentation to assess the quality. We also evaluated their antibacterial and immunoenhancing effects using RAW 264.7 macrophage cells. The major metabolites in BV are organic acids, with the main volatile compounds being ethyl acetate, isoamyl acetate, 1-pentanol, hydroxypropanoic acid, and malonic acid. When we fermented BV from unpeeled roots for 10 days with a starter culture, we observed significant antibacterial and immunoenhancing effects in macrophages. Therefore, we could determine the metabolite and functional differences in vinegar obtained from bellflower roots and proposed that bellflower roots with peel are an effective substrate for developing vinegar and healthy food products.

Jujube vinegar is produced using a method described in the ancient literature titled “Sangayorok”. In this vinegar production method, alcohol and acetic acid fermentation occur at the same time. This study was conducted to reproduce the traditional jujube vinegar and improve its quality. The manufacturing proess was divided into two stages of fermentation. Jujube wine was prepared using the base liquor (Mit-sool), and jujube vinegar was prepared by seed vinegar. Moreover, the optimum conditions were determined by analyzing the quality of the fermented jujube vinegar at different temperatures (20, 30, and 35°C) and initial pH conditions (pH 3, 4, and 5). We evaluated the pH, acidity, organic acid content, and antioxidant activity of the fermented jujube vinegar, and its taste was analyzed using an electronic tongue. On the 14th day of fermentation under pH 4 and at 20°C, the pH level dropped to 3.4, and the acidity was 10.4%. The total organic acid content was 6,568 mg /100 mL, of which acetic acid content was as high as 83% (5,475 mg/100 mL). Umami and sourness of the vinegar increased as the fermentation progressed. Analysis of antioxidant activity of the vinegar fermented at pH 4 and 20°C revealed that the ABTS radical scavenging activity of the jujube vinegar was 90.9%, and the total polyphenol content was 1,131.3 mg (GAE)/100 mL. These findings can form a basis for selecting optimal fermentation conditions and developing manufacturing technologies through modernized process improvements for commercialization of traditional jujube vinegar.

According to the method described in the ancient literature “Imwonsipyukji”, ‘Dochobang’ was mainly composed of lactic acid (756.81 mg/100 mL) and acetic acid (473.66 mg/100 mL) as the main organic acids on the 14th day of fermentation. The acidity of ‘Dochobang’ was 1.09%, resulting in low marketability. Therefore, this study aimed to improve the manufacturing process of peach vinegar and optimize the conditions, including temperature and initial pH, for producing high-acidity vinegar using fermented seeds. We first selected yeasts (Saccharomyces cerevisiae YM27) with excellent alcohol fermentation ability and acetic acid bacteria (Acetobacter oryzifermentans (KACC19301)) with remarkable acid-producing ability and used these in the process-improved two-stage fermentation. The experiment was conducted by 3 treatments of tepmerature(20°C, 30°C and 35°C) and initial pH(3, 4 and 5) for acetic acid fermentation. ‘Dochobang’ fermented alcohol and acetic acid at the same time by natural fermentation. on the other hand, peach wine starter and seed vinegar were added before each fermentation step to increase acetic acid production. Wines fermented at 25°C and 30°C were found to be 9% alcoholic on days sixth and nine days, respectively. Organic acid analysis revealed that the level of acetic acid in vinegar fermented at pH 4 and 20°C increased steadily until day 14 (6,171.3 mg/100 mL). The acidity was 7% on the 21st day of fermentation. Furthermore, as the fermentation progressed, the umami and sourness of the peach vinegar increased. We expect that our findings could improve the quality of peach vinegar recorded in the old literature and can be used in small-scale agricultural companies.