Comparison of microbial diversity and metabolites on household and commercial doenjang.

In this study, the microbial diversity, free amino acid (FAA), and biological activities of household doenjang (HDJ) from four different regions and commercial doenjang (CDJ) four manufacturers were analyzed. And volatile flavor compound (VFC) and isoflavone profiles were analyzed using gas chromatograph-mass spectrometer (GC-MS) and high performance liquid chromatography (HPLC), respectively. The major bacterial genus in 1HDJ and 2HDJ was Bacillus (97.5%), while in 3HDJ and 4HDJ, it was Enterobacter (47.5%) and Pseudomonas (80%), respectively. Tetragenococcus was the main bacterial genus of CDJ. The Zygosaccharomyces genus among yeast was comparatively high in all samples. In all samples, glutamic acid predominated among the FAAs, and the 3-methyl butanal, benzeneacetaldehyde, and diallyl disulphide were major VFCs. CDJ contained higher levels of isoflavone-glycoside and total phenolics. Except for 3HDJ and 4CDJ, the isoflavone-aglycone and total flavonoid contents were higher in HDJ. The correlation between bacterial genus and metabolited of doenjang showed that Tetragenococcus was closely related to glutamic acid, Bacillus was related to aglycones and ammonia, and Pseudomonas was highly related to isovaleric acid. While, correlation between yeast genus and metabolited of doenjang confirmed that Candida, Hanseniaspora, and Saccharomyces were related with furfural, benzeneacetaldehyde, and 3-methyl butanal, respectively. The results of this study can be utilized as basic data for the industrialization and development of doenjang.

Elucidation of phenolic metabolites in wheat seedlings (Triticum aestivum L.) by NMR and HPLC-Q-Orbitrap-MS/MS: Changes in isolated phenolics and antioxidant effects through diverse growth times.

The current research was characterized on phenolic metabolite profile including six chemical structures (phenolic acid, luteolin, orientin, apigenin, isoscoparin, and tricin) in wheat seedlings using HPLC-Q-Orbitrap-MS/MS and NMR techniques. Our study was also was the first to demonstrate fluctuations of isolated nine phenolic contents and antioxidant properties in various cultivars of this species with different growth times. The antioxidant abilities differed significantly in the 80 % methanol extracts (600 µg/mL) according to cultivar and growth time, with the highest average activities (DPPH: 82 %; ABTS: 87 %) observed after 7 days. The isolated nine compositions exhibited considerable differences in cultivars and growth times, specifically, isoorientin (6) and isochaftoside (8) were observed the most abundant average contents (99.3; 64.3 mg/100 g), representing approximately 28.3 and 18.3 % (total content: 350.8 mg/100 g). Their total phenolics showed the highest rates (420.8 mg/100 g) at 7 days, followed by 9 â†’ 5 â†’ 12 â†’ 14 days with 374.6 â†’ 366.7 â†’ 350.7 â†’ 241.1 mg/100 g, as the rank orders of antioxidant effects. These findings suggest that wheat seedlings may be a potent source of functional agents.