Antihypertensive Effect of Milk Fermented by Lactiplantibacillus plantarum K79 on Spontaneously Hypertensive Rats.

The aim of this study is to investigate whether milk fermented by Lactiplantibacillus plantarum K79, which exhibits angiotensin-converting enzyme inhibitory activity, has an effect on lowering the blood pressure of hypertensive rats and to investigate biomarker changes in their blood. Experimental group: normal group (NG, Wistar-Kyoto rats): distilled water, control group [NCG, spontaneously hypertensive rats (SHR)]: distilled water, high treatment group (HTG, SHR): 500 mg/kg/day, medium treatment group (SHR): 335 mg/kg/day, low treatment group (SHR): 170 mg/kg/day, positive control group (PCG, SHR): Enalapril, 10 mg/kg/day. The experimental animals used in this study were divided into groups composed of 8 animals. In terms of weight change, a significant difference was observed between the NG and the SHR group, but there was no significant difference between the SHR group. After 8 wk of feeding, blood pressure was lowered more significantly in the HTG (209.9±13.3 mmHg) than in the NCG (230.8±7.3 mmHg). The treatment group has an effect of lowering blood pressure by significantly suppressing blood pressure-related biomarker protein expression than NG. The results obtained can be used as an antihypertensive material in a variety of food raw materials.

Engineering Bacillus subtilis J46 for efficient utilization of galactose through adaptive laboratory evolution.

Efficient utilization of galactose by microorganisms can lead to the production of valuable bio-products and improved metabolic processes. While Bacillus subtilis has inherent pathways for galactose metabolism, there is potential for enhancement via evolutionary strategies. This study aimed to boost galactose utilization in B. subtilis using adaptive laboratory evolution (ALE) and to elucidate the genetic and metabolic changes underlying the observed enhancements. The strains of B. subtilis underwent multiple rounds of adaptive laboratory evolution (approximately 5000 generations) in an environment that favored the use of galactose. This process resulted in an enhanced specific growth rate of 0.319 ± 0.005 h-1, a significant increase from the 0.03 ± 0.008 h-1 observed in the wild-type strains. Upon selecting the evolved strain BSGA14, a comprehensive whole-genome sequencing revealed the presence of 63 single nucleotide polymorphisms (SNPs). Two of them, located in the coding sequences of the genes araR and glcR, were found to be the advantageous mutations after reverse engineering. The strain with these two accumulated mutations, BSGALE4, exhibited similar specific growth rate on galactose to the evolved strain BSGA14 (0.296 ± 0.01 h-1). Furthermore, evolved strain showed higher productivity of protease and ß-galactosidase in mock soybean biomass medium. ALE proved to be a potent tool for enhancing galactose metabolism in B. subtilis. The findings offer valuable insights into the potential of evolutionary strategies in microbial engineering and pave the way for industrial applications harnessing enhanced galactose conversion.

Consumer Preference of Traditional Korean Soy Sauce (Ganjang) and Its Relationship with Sensory Attributes and Physicochemical Properties.

This study aimed to investigate the physicochemical characteristics, sensory attributes, and consumer acceptance of the Certification of Quality of Traditional Food (CQT) ganjang samples produced in different provinces of Korea. Wide variations in physicochemical properties were found among the samples, especially in lipids, total nitrogen, acidity, and reducing sugar. Traditional fermented foods are known to be closely tied to regional features, but the composition and characteristics of CQT ganjangs might be influenced much more by individual ganjang producers than by region. Preference mapping was performed to understand consumer behavior towards ganjang, and most consumers tended to have similar preferences, implying shared a common sensory ideal. The results of the partial least squares regression revealed drivers of liking for ganjang among sensory attributes, free amino acids, and organic acids. Overall, sensory attributes such as sweetness and umami were positively associated with acceptability, while the terms related to fermentation were negatively associated. In addition, amino acids, such as threonine, serine, proline, glutamate, aspartate, and lysine, and organic acids, such as lactate and malate, were positively associated with consumer acceptance. The important implications of the findings of this study for the food industry can be utilized to develop and optimize traditional foods.

The Effect of Vacuum Films on Physicochemical and Microbiological Characteristics of Hanwoo (Korean Native Cattle).

The objective of this study was to investigate the physicochemical and microbiological characteristics of round of Hanwoo by vacuum packaging film materials, polyvinylidene chloride (PVDC) and ethylene vinyl alcohol (EVOH). The packaged beef samples were stored in refrigerated conditions (2±1°C) for 12 weeks. Physicochemical analysis with pH, surface color, thiobarbituric acid reactive substances (TBARS) values, and volatile basic nitrogen (VBN) values and microbiological analysis with aerobic plate count (APC) and metagenomic analysis of packaged beef samples were performed. The pH and surface color did not change substantially during the 12 weeks and EVOH-packaged beef tended to be lower than those of PVDC-packaged beef. PVDC- and EVOH-packaged samples showed low TBARS and VBN values below standard limits. APC did not exceed 7 Log CFU/g for both samples during storage. In metagenomic analysis, Firmicutes and Lactobacillaceae were dominant phylum and family of the PVDC- and EVOH-packaged beef. In both packaged samples, Dellaglioa algida was the dominant species during storage, with the notable difference being the presence of Lactococcus piscium. Therefore, this study provided the information on the quality of vacuum-packaged beef according to different vacuum films for long-term refrigerated storage.

Characteristics of Bacterial Strains with Desirable Flavor Compounds from Korean Traditional Fermented Soybean Paste (Doenjang).

To identify and analyze the characteristics of the microorganisms involved in the formation of the desirable flavor of Doenjang, a total of 179 strains were isolated from ninety-four Doenjang collected from six regions in South Korea, and fourteen strains were selected through a sensory evaluation of the aroma of each culture. The enzyme activities of amylase, protease and lipase was shown in the various strains. Bacillus sp.-K3, Bacillus sp.-K4 and Bacillus amyloliquefaciens-J2 showed relatively high protease activity, at 317.1 U, 317.3 U and 319.5 U, respectively. The Bacillus sp.-K1 showed the highest lipase activity at 2453.6 U. In the case of amylase, Bacillus subtilis-H6 showed the highest activity at 4105.5 U. The results of the PCA showed that Bacillus subtilis-H2, Bacillus subtilis-H3, and Bacillus sp.-K2 were closely related to the production of 3-hydroxy-2-butanone (23.51%~43.37%), and that Bacillus subtilis-H5 and Bacillus amyloliquefaciens-J2 were significantly associated with the production of phenethyl alcohol (0.39% and 0.37%). The production of peptides was observed to vary among the Bacillus cultures such as Val-Val-Pro-Pro-Phe-Leu and Pro-Ala-Glu-Val-Leu-Asp-Ile. These peptides are precursors of related volatile flavor compounds created in Doenjang via the enzymatic or non-enzymatic route; it is expected that these strains could be used to enhance the flavor of Doenjang.

Physiological Characteristics and Anti-Diabetic Effect of Pediococcus pentosaceus KI62.

The purpose of this study is to examine the physiological characteristics and anti-diabetic effects of Pediococcus pentosaceus KI62. The α-amylase and α-glucosidase inhibitory activity of P. pentosaceus KI62 was 94.86±3.30% and 98.59±0.52%, respectively. In MRS broth containing 3% maltodextrin inoculated by P. pentosaceus KI62, the amounts of short chain fatty acids (SCFA) were propionic acid 18.05±1.85 mg/kg, acetic acid 1.12±0.07 g/100 mL, and butyric acid 2.19±0.061 g/kg, and those of medium chain fatty acids (MCFA) were C8 0.262±0.031 mg/kg, C10 0.279±0.021 mg/kg, and C12 0.203±0.009 mg/kg. Compared to sixteen antibiotics, P. pentosaceus KI62 had the highest sensitivity to penicillin-G and rifampicin, as well as the highest resistance to vancomycin and ampicillin. The strain also showed higher leucine arylamidase and valine arylamidase activities than other enzyme activities, but it did not produce ß-glucuronidase which is carcinogenic enzymes. The survival rate of P. pentosaceus KI62 in 0.3% bile was 91.67%. Moreover, the strain showed a 98.63% survival rate in pH 2.0. P. pentosaceus KI62 exhibits resistance to Escherichia coli, Salmonella Typhimurium, Listeria monocytogenes, and Staphylococcus aureus at rates of 29.41%, 38.10%, 51.72%, and 50.47%, respectively. P. pentosaceus (23.31%) showed a similar adhesion ability to L. rhamnosus GG, the positive control (24.49%). These results show that P. pentosaceus KI62 has possibility as a probiotic with anti-diabetic effects.

Effect of Starch Noodle (Dangmyeon) and Pork Intestines on the Rehydration Stability of Korean Blood Sausage (Sundae).

This study was conducted to examine the effects of starch noodles (dangmyeon; SNs) with different starch sources and porcine intestines (PIs) with different pH on the rehydration stability of Korean blood sausage (sundae). Mungbean SN3 and PI3 (pH 9.18) showed significantly higher values of 80.69%-91.67% and 79.66%-80.98%, respectively, regardless of the drying methods (hot air, vacuum and freeze drying) (p<0.05). A number of larger pores were observed only in the cross-section of the freeze dried SN and PI through SEM. SN2 (potato starch) and PI3 (pH 9.18) showed lower expansion (*ΔL 6.90 mm) and higher expansion ratio (*ΔL 26.29 mm), respectively, after rehydration of freeze dried sample (p<0.05). From the application of SN2 (potato starch) and PI (0.5%-2.0% Na-pyrophosphate) to freeze dried sundae manufacturing, higher rehydration stability of more than 91.5% was obtained. These results suggested that potato SN and treatment of PI with Na-pyrophosphate is useful for desirable rehydration stability of freeze dried sundae.

Short communication: Physicochemical features and microbial community of milk kefir using a potential probiotic Saccharomyces cerevisiae KU200284.

The aim of this study was to analyze the ß-glucan contents, physicochemical features, and microbial communities in milk kefir prepared using Saccharomyces cerevisiae KU200284 isolated from cucumber jangajji, a fermented vegetable commonly eaten in Korean. Three types of milk kefir were manufactured, with (1) activated kefir grain, (2) activated kefir grain with commercial S. cerevisiae BOF, and (3) activated kefir grain with S. cerevisiae KU200284. ß-Glucan contents of milk kefir using kefir grain and kefir grain with S. cerevisiae strains BOF and KU200284 were 8.29, 8.59, and 8.57%, respectively. The pH, titratable acidity, viscosity, Brix level, and alcohol contents of milk kefir using kefir grain with S. cerevisiae strains were acceptable compared with milk kefir using only kefir grain. In milk kefir produced using kefir grains and S. cerevisiae strains, 16S rRNA reads showed representative strains of Lactobacillus kefiranofaciens (>72% relative abundance) and Acetobacter fabarum (>16% relative abundance). In particular, milk kefir using kefir grain with S. cerevisiae KU200284 had the highest relative abundance of L. kefiranofaciens. In addition, the internal transcribed sequence (ITS) rRNA reads in tested milk kefir showed representative strains of Kluyveromyces marxianus (>52% relative abundance) and Saccharomyces cerevisiae (>16% relative abundance). In contrast, milk kefir using S. cerevisiae strains had higher relative abundance of S. cerevisiae (>37%). The ß-glucan production, physicochemical properties, and microbial community profiling indicate that S. cerevisiae KU200284 could be used in functional dairy products as a starter culture.

Comparative Study on the Characteristics of Weissella cibaria CMU and Probiotic Strains for Oral Care.

Probiotics have been demonstrated as a new paradigm to substitute antibiotic treatment for dental caries, gingivitis, and chronic periodontitis. The present work was conducted to compare the characteristics of oral care probiotics: Weissella cibaria CMU (Chonnam Medical University) and four commercial probiotic strains. Survival rates under poor oral conditions, acid production, hydrogen peroxide production, as well as inhibition of biofilm formation, coaggregation, antibacterial activity, and inhibition of volatile sulfur compounds were evaluated. The viability of W. cibaria CMU was not affected by treatment of 100 mg/L lysozyme for 90 min and 1 mM hydrogen peroxide for 6 h. Interestingly, W. cibaria produced less acid and more hydrogen peroxide than the other four probiotics. W. cibaria inhibited biofilm formation by Streptococcus mutans at lower concentrations (S. mutans/CMU = 8) and efficiently coaggregated with Fusobacterium nucleatum. W. cibaria CMU and two commercial probiotics, including Lactobacillus salivarius and Lactobacillus reuteri, showed high antibacterial activities (>97%) against cariogens (S. mutans and Streptococcus sobrinus), and against periodontopathogens (F. nucleatum and Porphyromonas gingivalis). All of the lactic acid bacterial strains in this study significantly reduced levels of hydrogen sulfide and methyl mercaptan produced by F. nucleatum and P. gingivalis (p < 0.05). These results suggest that W. cibaria CMU is applicable as an oral care probiotic.