Characteristics of Chungkookjang that Enhance the Flavor and GABA Content in a Mixed Culture of Bacillus subtilis MC31 and Lactobacillus sakei 383

Abstract

Chungkookjang has several functional properties, such as fibrinolytic activity, anticancer effects, and antioxidant effects. However, children do not like Chungkookjang because of its foul odor. A mixed culture of Bacillus subtilis MC31 and Lactobacillus sakei 383 was used to improve the production of GABA in Chungkookjang and its flavor. Most of the foul odor of Chungkookjang was removed. The slime content and viscosity of Chungkookjang fermented in the mixed culture were similar to those of commercial Chungkookjang when B. subtilis MC31 and Lactobacillus sakei 383 were inoculated in a 1:1 ratio. The maximum GABA content was obtained when Chungkookjang was fermented with B. subtilis MC31 and L. sakei 383, which was fermented at 37℃ for 72 hr. During the period of fermentation, the viable cell number of B. subtilis MC31 reached a peak (log 9.13 CFU/g) at six days, and L. sakei 383 reached a peak (log 6.78 CFU/g) at two days. The moisture, crude ash, crude protein, crude fat, and crude fiber contents were 61.71%, 2.05%, 17.54%, 8.36%, and 1.95%, respectively. The amino-type nitrogen content of Chungkookjang fermented by B. subtilis MC31 and L. sakei 383 was less than Chungkookjang fermented by B. subtilis MC31 alone. The ammonia-type nitrogen and reducing sugar content of the Chungkookjang fermented by B. subtilis MC31 and L. sakei 383 were higher than that of steamed soybean. The glutamic acid and GABA content detected with an amino acid analyzer were 1.40 mg/g and 0.47 mg/g, respectively. These results suggest that fermentation with B. subtilis MC31 and L. sakei 383 in a 1:1 ratio removes more of the foul odor and increases the GABA content compared with single fermentation.

Influence of bacteriocin-producing Bacillus strains on quality characteristics of fermented soybean product with biogenic amine-forming lactic acid bacteria

“…Amino-type nitrogen, the nitrogenous compounds (amino acids, peptides and ammonium ions) produced from decomposition of proteins by microbes or autolytic enzymes can be used as an indicator of food quality and approximate index of the protein content, related with the total amount of substances having terminal amino group. According to Korean Food Standards Codex, amino-type nitrogen, which represents the savory taste in fermented soybean foods, is required to contain at least 280 mg%/g [28]. The results obtained from our experiments were in disagreement with those published previously by Shim et al [29], who suggested that starter doenjang samples showed higher amino-type nitrogen contents than non-starter Doenjang throughout the fermentation period owing to the high enzymatic activities of the selected starter strains.…”

Optimized Production of GABA and γ-PGA in a Turmeric and Roasted Soybean Mixture Co-fermented by <i>Bacillus subtilis</i> and <i>Lactobacillus plantarum</i>

“…In foods, the GABA content varies from 0.01 _ 0.04 mg/g in white rice to 0.1 _ 1 mg/g in sprouted brown rice, 0.35 _ 2.05 mg/g in green tea, and 2.5 _ 7.0 mg/g in foods produced by lactic acid fermentation (Hwang, 2011). A study plantarum K154 to use glutamate as a substrate for producing GABA (Kim et al, 2014).…”

Physicochemical Properties and Fibrinolytic Activity of Ginseng Powder Fermented with &lt;i&gt;Bacillus subtilis&lt;/i&gt; Isolated from &lt;i&gt;Cheonggukjang&lt;/i&gt;

“…When comparing the A and B strains, the initial viscosity immediately after the Bacillus inoculation was higher in the medium inoculated by the A strain; after 3 days of fermentation, however, the initial viscosity of the B strain was 33.6 Pa.s higher compared to the A strain, meaning that the viscous substance content and the viscosity were proportional, which is thought to be a result of the production of viscous substances with polymerized fructose and glutamic acid by B. subtilis [27]. Lee et al [28] manufactured Cheonggukjang by controlling the ratio of B. subtilis and Lactobacillus sakei with an inoculation concentration of 1% and reported that the viscosity was higher with a higher ratio of B. subtilis MC31. This latter finding is consistent with the result that the viscosity increased with an increasing amount of viscous substances.…”