Soybean Paste Research Articles

Biogenic amine reduction by vasoactive amine-degrading Bacillus licheniformis CH7P22 in Enterococcus faecium-contaminated Cheonggukjang, Korean fermented soybean paste

Biogenic amine reduction by vasoactive amine-degrading Bacillus licheniformis CH7P22 in Enterococcus faecium-contaminated Cheonggukjang, Korean fermented soybean paste

Korean fermented soybean paste (Doenjang) has anti-obesity and anti-hypertensive effects via the renin-angiotensin system (RAS) in high-fat diet-induced obese rats.

The health-beneficial outcomes of doenjang, a Korean fermented food have been questioned due to its high salt content; moreover, the detailed underlying mechanisms of its health beneficial effects are not fully investigated. Thus, this study aimed to investigate doenjang's anti-obesity effects, anti-hypertensive effects, and its underlying mechanisms in high-fat diet -induced obesity. Sprague-Dawley rats fed with normal diet (ND), high-fat diet (HD), HD with 8% additive salt (HDS), or HD with doenjang containing 8% salt (HDJ) for 13 weeks. Compared to HD and HDS groups, the HDJ group had lower body and epididymal fat tissue weight gain and showed hypotrophy and hypoplasia. The RAS-related mRNA levels in the adipose tissue, including Renin and Ace were downregulated in the HDJ group compared to HD and HDS groups. Additionally, HDJ groups had significant improvements in systolic blood pressure, serum RAS-associated parameters (e.g., angiotensin II and aldosterone), renal mRNA levels related to RAS (e.g., angiotensin II receptor type 1 and 2), and aldosterone-associated mRNA expressions (e.g., mineralocorticoid receptor) in the kidney of HD-induced obese rats. Most importantly, HDS and HDJ groups showed distinct outcomes regarding adipogenesis and electrolytes metabolism, even though both diets contain a high level of salt. HDS group showed a higher epididymal fat tissue weight, mass, and adipocyte size than HDJ group. In addition, compared with HDJ group, HDS group significantly decreased the release of Na+ and K+ throughout the urine and feces. The present study addresses that doenjang has anti-obesity effects and anti-hypertensive effects by activating RAS in the adipose tissue and kidney, respectively. Additionally, this study also demonstrates that salt in doenjang and the additive salt differently influences adipogenesis and electrolytes metabolism, supporting doenjang has health advantageous effects regardless of its high salt contents.

Exploring the changes in microorganisms and metabolites during the fermentation process of traditional Chinese watermelon–soybean paste

Watermelon–soybean paste (WSP) is a traditional Chinese fermented food item. Changes in the microbial community diversity affect the final product quality. However, the correlation between microorganisms and their metabolites in WSP is not clearly understood. In this study, seven bacterial and eight fungal genera were found to be dominant during WSP fermentation using 16S rRNA and ITS gene sequencing. A total of 838 metabolites were identified using UHPLC-TOF-MS; of which, 99 were identified as differential metabolites. Correlation analysis showed that the microbial metabolic activities of Bacillus sp., Candia sp., and Kodamaea sp. were associated with amino acid production. Bacillus sp. and Aspergillus sp. correlated with dipeptide production. Metabolic pathway analysis suggested that amino acid metabolism was the most significant differential metabolic pathway, which may be related to the fermentation quality of WSP. Our study provides a new theoretical basis for improving WSP quality from the perspective of metabolomic and microbial diversity.

High-level production of poly-γ-glutamic acid by a newly isolated Bacillus sp. YJY-8 and potential use in increasing the production of tomato

Strain YJY-8, a new γ-polyglutamic acid producer, was separated from fermented soybean paste samples. The strain was identified as a genus of Bacillus by morphological and 16S rDNA sequence analysis and was named Bacillus sp. YJY-8. The optimal medium composition and cultural conditions were studied using a single-factor experiment and a response surface experiment. The optimized medium consisted of monosodium glutamate 70 g/L, glucose 54.3 g/L, glycerol 31.8 g/L, ammonium sulfate 11.1 g/L, yeast extract 3.2 g/L, tryptone 1.5 g/L, L-glutamic acid 6.8 g/L, MgSO4 7H2O 0.5 g/L, FeCl3 6H2O 0.02 g/L, KH2PO4 0.9 g/L, CaCl2 0.03 g/L, MnSO4 H2O 0.3 g/L, ammonium molybdate 0.02 g/L, pH 7.0. The optimal cultivation conditions were 35 °C and pH 7.0. Under the optimized conditions, after 48 hr of cultivation, the highest shaking flask fermentation level of γ-PGA reached 65.2 ± 0.36 g/L. In addition, through fed-batch fermentation in 30 L fermenters, the fermentation level of γ-PGA reached its highest level at 88.42 g/L and productivity was 1.23 g/(L hr) after 72 hr. Then, the effect of γ-PGA on tomato yield was investigated. At the seedling stage, the plant height and stem diameter of γ-PGA treated plants increased by 5.69 and 15.735% after spraying γ-PGA for 19 days. During the flowering and fruiting period, the stem diameter of the γ-PGA treatment group increased by 6.74%, with a maximum increase of 11.65%. The number of fruit branches increased by 0.56–16.29% and the number of fruit sets increased by 1.01–28.47%. At the fruit maturation stage, the yield of tomatoes increased by 10.51, 14.27, and 5.83%.

Identification of geographical origins of soybean pastes using headspace gas chromatography-mass spectrometry by selecting sample-descriptive components with an Incremental Association Markov Blanket

The identification of geographical origins of soybean pastes using headspace gas chromatography-mass spectrometry was attempted in this study. Since soybean paste was odor-rich, 36 components were identified in the imported and domestic soybean samples. t-Test, variable importance in projection (VIP), and Incremental Association Markov Blanket (IAMB) were employed to select proper components that could effectively discriminate the two sample groups. The discrimination accuracies were below 87.3 % when all 36 components were fed for either LDA, k-NN, or SVM. When the five t-test-selected components or six VIP score-selected components were employed, the accuracies improved to 95.2–96.2 %. The IAMB selected three different components were 3-methylbutanal, 4-methylnonane, and 2,3-pentanedione, and the correlations among their peak areas were not significant. This suggests that these three components were independently relevant for the discrimination. The accuracy obtained using these three components was superior, 97.7 %, as undescriptive and/or redundant components for the discrimination were excluded.

Flavor Characterization of Traditional Fermented Soybean Pastes from Northeast China and Korea.

This study compares the physicochemical properties, taste, and volatile compounds of Northeastern Chinese dajiang (C) and Korean doenjang (K) and distinguishes the discriminant volatile metabolites between them. The result revealed that compared to group C, group K exhibited more similar physicochemical properties and had lower pH, moisture, and amino acid nitrogen content, while demonstrating higher titratable acidity, salt content, and reduced sugar content. The electronic tongue analysis showed that the saltiness and umami of soybean pastes had high response values, enabling clear differentiation of the overall taste between the two types of soybean pastes. A total of 71 volatile substances from the soybean pastes were identified through solid-phase microextraction gas chromatography-mass spectrometry. Furthermore, orthogonal partial least squares discriminant analysis revealed 19 volatile compounds as differentially flavored metabolites. Our study provides a basis for explaining the differences in flavor difference of Northeastern Chinese dajiang and Korean doenjang from the perspective of volatile metabolites.

Effect of Peony (Paeonia ostii) Seed Meal Supplement on Enzyme Activities and Flavor Compounds of Chinese Traditional Soybean Paste during Fermentation.

Peony seed meal (PSM) is the by-product obtained from peony seeds after oil extraction. In this study, PSM was incorporated into traditional koji-making, and its impacts on koji enzyme activities and flavor compounds in final products were investigated. In the process of koji fermentation, the optimal addition ratio of PSM to soybean was determined as 7:3. Under this ratio, the maximum enzyme activities of neutral protease, amylase, and glucoamylase were 1177.85, 686.58, and 1564.36 U/g, respectively, and the koji obtained was subjected to maturation. During post-fermentation, changes in the fermentation characteristics of the paste samples were monitored, and it was found that compared to the soybean paste without PSM, the enzyme activities maintained at a relatively good level. The PSM soybean paste contained a total of 80 flavor compounds and 11 key flavor compounds (OAV ≥ 1), including ethyl isovalerate, isovaleric acid, hexanal, phenylacetaldehyde, 3-Methyl-1-butanol 4-heptanone, 2-pentylfuran, methanethiol ester caproate, isoamyl acetate, 3-methyl-4-heptanone, and isovaleraldehyde. These findings could be used to improve the quality of traditional fermented paste, enrich its flavor, and simultaneously promote PSM as a valuable resource for fermented foods.

Isolation and Characterization of Enterococcus faecium from Fermented Korean Soybean Paste with Antibacterial Effects

In the present study, a total of eight Enterococcus faecium (OQ940301, OQ940302, OQ940303, OQ940304, OQ940305, OQ940308, OQ940309, and OQ940310) were isolated from soybean paste, a traditional Korean fermented food, and evaluated for their probiotic properties. The results showed that all the E. faecium strains survived in simulated human gastrointestinal conditions (4.1–5.59 log10 CFU/mL). In addition, the range of auto-aggregation was 5–25%, the hydrophobicity was around 94%, and it exhibited significant co-aggregation ability with Salmonella enterica and Staphylococcus aureus. However, all the isolates were shown to be resistant to Gentamycin. The bacterial cell-free supernatant showed antibacterial activity against S. enterica, Escherichia coli, Bacillus cereus, Listeria monocytogenes, and S. aureus. Furthermore, E. faecium exhibited potent anti-oxidant activity by scavenging 2,2′-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) free radicals. In addition, safety was confirmed by evaluating the hemolytic activity in blood agar; none of the bacterial isolates showed hemolysis. These results demonstrated that E. faecium (OQ940301 and OQ940309) isolated from soybean paste showed a higher probiotic potential.

Black soybean cooking water (aquasoya) powder as a novel clean‐label ingredient in plant‐based vegan patties

SummaryBlack soybean cooking water (BSCW), a by‐product of the soybean paste industry, is a novel foaming and emulsifying material. Its application, however, is limited to sauces and bakery goods. To expand its use, this research explored its binding and texturising abilities on a plant‐based patty. This vegan patty was developed including methylcellulose (MC) at 3% or BSCW powder at 3, 6 and 12%, and their functional and textural characteristics were analysed. Adding BSCW powder at 12% resulted in enhanced fluid retention parameters, namely, decreased cooking loss (9.98 ± 0.72%; control: 12.64 ± 0.36%) and increased binding capacity (86.18 ± 0.47%; control: 83.26 ± 1.94%). Texturally, BSCW powder enhanced the hardness and adhesiveness of the patties. Consequently, BSCW powder could improve the characteristics of a minced‐type vegan food similar to MC constituting an alternative plant‐based ingredient that is environmentally friendly due to being sourced from an upcycled material.

Screening lactic acid bacteria and yeast strains for soybean paste fermentation in northeast of China.

Soybean paste was a traditional fermented product in northeast China, mainly fermented by molds, yeast, Bacillus, and lactic acid bacteria. In this study, the safety and fermentation ability of lactic acid bacteria and yeast strains isolated from traditional soybean paste in northeast China were evaluated, and the dynamic changes of biogenic amines, aflatoxin, total acids, amino acid nitrogen, and volatile compounds were investigated during the fermentation of the traditional soybean paste. Among the tested strains, Lactiplantibacillus plantarum DPUL-J8 could decompose putrescine by 100%, and no biogenic amine was produced by Pichia kudriavzevii DPUY-J8. Lactiplantibacillus plantarum DPUL-J8 and P. kudriavzevii DPUY-J8 with strong biogenic amine degrading capacities were inoculated into the soybean paste. After 30 days of fermentation, the content of biogenic amines and aflatoxin in the fermented soybean paste declined by more than 60% and 50%, respectively. At the same time, compared with the control group without inoculation, the contents of total acid (1.29 ± 0.05 g/100 g), amino acid nitrogen (0.82 ± 0.01 g/100 g), and volatile compounds in soybean paste fermented by L. plantarum DPUL-J8 and P. kudriavzevii DPUY-J8 were significantly increased, which had a good flavor. These results indicated that the use of L. plantarum DPUL-J8 and P. kudriavzevii DPUY-J8 as starter cultures for soybean paste might be a good strategy to improve the safety and flavor of traditional Chinese soybean paste.

Fishmeal replacement and its effects on nutrition and the physiology of Penaeus vannamei shrimp juveniles

The replacement of fishmeal with plant protein sources has been studied in Penaeus vannamei. However, it has only been studied from the point of view of protein replacement, forgetting the integral role that fishmeal plays in the nutrition of shrimp. This study aimed to determine if a supplement of dietary phosphorus can sustain the fishmeal replacement by a blend of plant protein feedstuffs, with betaine and tauren as attractants and still supporting homeostasis, growth, digestive enzymes, and lipid-soluble antioxidant systems at normal levels in juveniles of P. vannamei. A standard feed (25% fishmeal) for juvenile P. vannamei was partially replaced with a mix of plant ingredients (soybean and canola paste, soy protein concentrate, and wheat meal). These feedstuffs were supplemented with amino acids (MET, LYS, TAU) plus microencapsulated exogenous phytase, betaine, and dicalphosphate. P. vannamei juveniles (2.56 g) were maintained in 100 L fiber tanks for 70 days. Biomass was significantly affected by the treatments (P < 0.05), being better as the fishmeal was replaced in the diet and comparable to commercial feed. No significant changes were observed in blood parameters. Muscle superoxide dismutase activity was significantly affected by the diets (P < 0.05). There were adaptive changes in digestive enzymes, and homeostasis remained stable. Fishmeal replacement may depend on supplementation with taurine and soluble phosphorus, not only for performance but flesh quality, and here, the shear strength of the shrimp muscle remained within the acceptable value (69-81 mJ).

Comparative Analysis of Microbial and Mycotoxin Contamination in Korean Traditional Soybean Paste and Soy Sauce Production with and without Starter

Doenjang and ganjang are traditional, Korean fermented foods. They are manufactured by fermenting jangs, either through the traditional natural fermentation, using straw, or the commercial inoculating starter cultures. However, both Bacillus cereus and aflatoxins have been detected in jangs, compromising their safety. Aflatoxins have been detected on numerous occasions. However, studies are yet to be conducted on whether these safety issues differ depending on the manufacturing method. In this study, we evaluated whether the manufacturing methods of doenjang and ganjang alter their safety. Samples of traditional and commercial doenjang and ganjang were analyzed for aflatoxin and B. cereus contamination. Microbiome taxonomic profiling was performed to assess microbial composition. The experimental methodology involved sample collection from various stages of production, including the use of starter cultures and natural fermentation processes. Aflatoxin levels were determined using regulatory limits, and B. cereus content was evaluated against specific thresholds. Aflatoxins were detected in both traditional and commercial doenjang and ganjang, with either the total aflatoxin (15 μg/kg) or aflatoxin B1 (10 μg/kg) exceeding the regulatory limits. However, ochratoxin A was not detected in any of the samples. B. cereus was detected in some samples, within the regulatory limit (4 log CFU/g), and was not influenced by the manufacturing method. Analysis at the production stage showed that aflatoxin increased alongside the fermentation time in traditional doenjang. However, in ganjang, no significant differences were associated with the fermentation period. When using starter cultures, the fermentation period did not affect the toxin level in both foods. Both methods showed lower aflatoxin content in the initial doenjang and ganjang samples than in meju. B. cereus was not detected in either method, as its content decreased over the fermentation period. Microbiome taxonomic profiling confirmed that even when using starter cultures, B. cereus was not a dominant species and was considerably affected by the environment. Staphylococcus aureus and Pseudomonas, pathogenic in nature, were detected in products manufactured using the traditional method; hence, the potential risk of this method was higher than that of the commercial method. The experimental methodology employed in this study contributes to understanding the microbial composition and toxin contamination levels in doenjang and ganjang, contributing to the overall knowledge of their safety and quality control.

Classification of fermented soybean pastes using inductively-coupled plasma optical emission spectroscopy and multivariate data modeling

Fermented soybean paste is widely used in food sauces and stews in East Asia. The main ingredients are soybeans, salt, and water. Therefore, it provides both proteins and inorganic nutrients. Fermented soybean paste consumed in South Korea is produced in South Korea and China. In this study, for 166 fermented soybean pastes collected in Korean markets, nine inorganic elements were analyzed by inductively-coupled plasma optical emission spectroscopy (ICP-OES), and partial least squares-discriminant analysis (PLS-DA) models were developed to classify the samples with respect to their provenances. Among these elements, Mg and Sr were effective variables for discriminating between fermented soybean pastes produced in South Korea and those produced in China. The model trained using Mg and Sr exhibited a classification accuracy of 92.7%. Discrimination power of Mg was rationalized by the difference in Mg concentration between the salts used in South Korea (sea salts) and those used in China (refined salts). Our results indicated that the elemental content of fermented soybean paste was significantly influenced by the salts used as the main ingredients. The combination of ICP-OES and PLS-DA has been suggested as a reliable methodology for discriminating fermented soybean pastes produced in South Korea and those produced in China.

Use of Enzyme Mixtures in Diets Based on Animal and Plant Ingredients for Litopenaeus vannamei: Effect on Digestibility, Growth, and Enzyme Activity

The objective of this research was to determine the effect of adding a mixture of different exogenous enzymes at 0.005% (0.0025% for each enzyme; protease+xylanase [P/X], protease+cellulase [P/C], and xylanase+cellulase [X/C]) to diets, based on fishmeal (FM) or soybean paste (SP), on shrimp`s growth performance, survival, feed conversion, digestibility, and digestive capacity. Eight isoproteic experimental diets (FM, FM+P/X, FM+P/C, FM+X/C, SP, SP+P/X, SP+P/C, and SP+X/C) were evaluated with three replicates. Shrimps (1  0.2 g) were maintained in a recirculating system at 12 organisms/tank for 90 days. Significant differences (p ˂ 0.05) were found in all the productive parameters of L. vannamei. Compared with the control diets (FM and SP), shrimps fed with FM+P/C showed the highest final body weight (7.83 ± 0.34 g) and proteolytic activity (178.81 ± 24.49 U/mg protein), as well as the lowest feed conversion ratio (1.71 ± 0.01). In contrast, the SP+X/C group presented the highest lipolytic activity (0.0235 ± 0.0028 U/mg) and apparent digestibility (94.12 ± 0.09%). In accord with its omnivorous trophic habits, enzyme mixtures included in animal and plant based-diets improved different productive variables of L. vannamei, representing a nutritional alternative to optimize feed use in shrimp cultivation.

Exploring the Health Benefits of Yeast Isolated from Traditional Fermented Foods in Korea: Anti-Inflammatory and Functional Properties of Saccharomyces and Non-Saccharomyces Strains.

Traditional yeast (Saccharomyces cerevisiae) has been used for its benefits in various fermentation processes; the benefits of non-Saccharomyces yeast as a material for food, feed, and pharmaceuticals have been studied recently. This study evaluated the anti-inflammatory activity and extracellular functional characteristics of wild-type yeasts isolated from traditional fermented foods (doenjang (common name: soybean paste) and nuruk) in Korea. The viability of the yeast and lipopolysaccharide (LPS)-stimulated RAWBlue™ cells was improved, similar to unstimulated RAWBlue™ cells, and the isolates demonstrated NF-κB inhibitory activity. Yeast suppressed the nitric oxide production in LPS-stimulated RAWBlue™ cells, which was attributed to the inhibition of iNOS or COX-2 mRNA expression depending on the strain. Although there were differences depending on the strain, the production of anti-inflammatory cytokines was reduced in the yeast and LPS-stimulated RAWBlue™ cells, some of which were demonstrated at the mRNA level. In addition, the isolates exhibited high antioxidant and antihypertensive activities (similar to the positive control), which varied depending on the strain. This suggests that yeast can be used for fermentation with enhanced antioxidant and antihypertensive activities. Furthermore, the isolates inhibited the growth of pathogenic Gram-negative bacteria, indicating that yeast can inhibit food spoilage and the growth of pathogenic bacteria during fermentation. Consequently, utilizing raw materials to cultivate yeast strains could be a promising avenue for developing functional foods to prevent and treat inflammatory reactions; such foods may exhibit antioxidant, antihypertensive, and antibacterial properties.

Complete Genome Sequence of Bacillus sp. Strain KICET-1, Isolated from Soybean Paste (Doenjang).

Bacillus sp. strain KICET-1, a bacterium isolated from traditional Korean soybean paste (Doenjang) at Osong, has one 4,099,652-bp DNA chromosome. The G+C content is 46.1%, and KICET-1 shares 99.64% similarity with Bacillus velezensis CR-502T (AY603658), according to phylogenetic classification based on 16S rRNA gene sequences.

Annotation of Dipeptides and Tripeptides Derivatized via Dansylation Based on Liquid Chromatography-Mass Spectrometry and Iterative Quantitative Structure Retention Relationship.

Small peptides such as dipeptides and tripeptides show various biological activities in organisms. However, methods for identifying dipeptides/tripeptides from complex biological samples are lacking. Here, an annotation strategy involving the derivatization of dipeptides and tripeptides via dansylation was suggested based on liquid chromatography-mass spectrometry (LC-MS) and iterative quantitative structure retention relationship (QSRR) to choose dipeptides/tripeptides by using a small number of standards. First, the LC-autoMS/MS method and initial QSRR model were built based on 25 selected grid-dipeptides and 18 test-dipeptides. To achieve high-coverage detection, dipeptide/tripeptide pools containing abundant dipeptides/tripeptides were then obtained from four dansylated biological samples including serum, tissue, feces, and soybean paste by using the parameter-optimized LC-autoMS/MS method. The QSRR model was further optimized through an iterative train-by-pick strategy. Based on the specific fragments and tR tolerances, 198 dipeptides and 149 tripeptides were annotated. The dipeptides at lower annotation levels were verified by using authentic standards and grid-correlation analysis. Finally, variation in serum dipeptides/tripeptides of three different liver diseases including hepatitis B infection, liver cirrhosis, and hepatocellular carcinoma was characterized. Dipeptides with N-prolinyl, C-proline, N-glutamyl, and N-valinyl generally increased with disease severity. In conclusion, this study provides an efficient strategy for annotating dipeptides/tripeptides from complex samples.

Distribution of vitamin K_2 content in Chinese traditional fermented soybean products

To determine the content of vitamin K_2 in different types of fermented bean products and analyze the difference of vitamin K_(2 )content. A total of 98 kinds of typical fermented bean products were included in Chinese traditional fermented bean products(Douchi, Sufu, soybean paste). Process, region, sales volume, raw materials and flavor were considered, and the content of vitamin K_2 in fermented bean products was determined by high performance liquid chromatography. Chinese bean fermented foods generally contained vitamin K_2, and the subtype menaquinone-7(MK-7)was the main one. The content of vitamin K_2 in Douchi was the highest(437.55 μg/100 g), the content of vitamin K_2 in Sufu and Soybean paste were lower(7.48 μg/100 g and 2.47 μg/100 g). The content of vitamin K_2 in bacterial Douchi was higher than that in Mucor type and Aspergillus oryzae type which were 403.94, 232.98 and 81.00 μg/100 g(P<0.05). Soybean type Douchi was higher than that in black bean type of Douchi which were 610.41, 178.08 μg/100 g(P<0.05), and the content of vitamin K_2 in dry Douchi was higher than the content of vitamin K_2 in water Douchi which were 1 517.45 μg/100 g, 297.58 μg/100 g(P<0.05). However, there were no significant difference in the content of vitamin K_2 in Soybean paste and Sufu in different types and regions(P > 0.05). Vitamin K_2 is widely contained in Chinese fermented bean products, and its content is mainly affected by fermentation microorganisms and processing technology.

Effect of the Types of Starter on Microbiological and Physicochemical Properties of Dry-Cured Ham.

This study analyzed the microbiological (Lactobacillus spp., Staphylococcus spp., mold, yeast, aerobic bacteria) and physicochemical properties [pH, salinity, water activity, volatile basic nitrogen (VBN), and thiobarbituric acid reactive substances]. The starters were used by mixing Debaryomyces hansenii separated from Korean Doenjang (D) and fermented sausage (S). The starter was inoculated with dry-cured ham and aged for 6 weeks at 20°C and 25°C, respectively. The aerobic bacteria, Lactobacillus spp., and Staphylococcus spp. of D, S, and DS treatment showed significantly higher values at 25°C than at 20°C. Among them, S25 treatment showed a high tendency. At week 6, the mold of the S25 treatment was significantly higher than the S20 treatment, and the yeast was higher in 25°C than 20°C (p<0.05). The pH of all treatment groups increased with the aging period. Compared with that at 25°C, the pH was significantly higher at 20°C (p<0.05). The water activity showed a significant decrease as the aging period increased, and the treatment of D25, S20, and DS20 showed a significantly higher value at week 6 (p<0.05). Compared with that at 20°C, the VBN content was higher at 25°C. At week 6, the VBN contents of the C20, S25, and DS25 groups were higher than those of the other treatment groups. Therefore, inoculation of D. hansenii separated from fermented sausage produced in Korean starter at 25°C is expected to improve the safety of harmful microorganisms and physiochemical properties in dry-cured ham.

감태 분말 첨가 된장의 품질 특성

Doenjang (Korean soybean paste) was prepared by adding of Ecklonia cava powder (w/w 0.3.6,9%) to Meju fermented for 30℃ for 40 days. The pH level of all samples did not show any significant decrease or increase by days 20 and 30, but the pH level increased near the end of the fermentation process by day 40 compared to the early days of fermentation, with the highest pH for the control group with no added powder and the lowest for the 9% group. The titratable acidity in the 9% group was measured to be the highest, as all the samples increased from the initial fermentation on the 40th day of fermentation. At the start of fermentation, the control group showed the lowest levels of total nitrogen and amino acid content and the 9% group showed the highest. However, by day 40 of fermentation, the control group showed the highest levels and the 9% group showed the lowest levels. The nitrogen degradation rate (NDR) was increased as the fermentation process continued, the control group showed the highest levels by day 40, but the 9% group showed the lowest levels of NDR, showing a decreasing trend as more powder is added. As the fermentation process continued, the levels of reducing sugar decreased, with the control group showing the lowest level and the 9% group with the highest level. The total number of bacteria was significantly reduced from 7.12 to 8.28 log CFU/g at the beginning of fermentation to 6.00 to 6.15 log CFU/g by day 40 of fermentation. The total polyphenol content and % DPPH radical scavenging activity increased significantly with the addition of Ecklonia cava powder in both the early fermentation and the last day of fermentation, showing a higher polyphenol content on the last day of fermentation compared to the first day. In a survey of consumer preferences was showed that the control group with no addition of Ecklonia cava powder showed the highest values in appearance and aroma. However, although there were no significant differences in taste-related assessments (salty taste, umami, after taste) and overall acceptability, the preference for the group with 6% Ecklonia cava powder was the highest. Based on these findings, it was confirmed that soybean paste with 6% of Ecklonia cava powder had the best effect on the preference and functionality of soybean paste, and the possibility of manufacturing soybean paste using Ecklonia cava powder has potential in food development.