NEWS LETTER Fresh Story Vol. 37 Jul 2021
Papers
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* Contact: Future Strategy Department (+82-62-610-1835, jiseok@wikim.re.kr)
| No. | Type | Title | Journal | Publication date | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | SCIE | Correlating capsaicinoid levels and physicochemical properties of kimchi and its perceived spiciness | Foods | Jan. 4 | |||||||||||
| We investigated whether the physicochemical properties of kimchi affect the spicy taste of capsaicinoids perceived by the tasting. The physicochemical properties such as pH, titratable acidity, salinity, free sugar content, and free amino acid content were evaluated, and the spicy strength grade was determined by selected panel to analyze the correlation between these properties. We observed a strong correlation between spiciness intensity ratings and capsaicinoid content, with a Pearson’s correlation coefficient of 0.78 at p ≤ 0.001. However, other specific variables may have influenced the relationship between spiciness intensity and total capsaicinoid content. Partial correlation analysis indicated that the free sugar content most strongly affected the relationship between spiciness intensity and capsaicinoid content, showing the largest first-order partial correlation coefficient (rxy/z: 0.091, p ≤ 0.01). | |||||||||||||||
| 2 | SCIE | Alteration of the gut microbiota in post-weaned calves following recovery from bovine coronavirus-mediated diarrhe | Journal of Animal Science and Technology | Jan. 31 | |||||||||||
| Bovine coronavirus (BCoV) is associated with severe diarrhea, dehydration, and depression, which result in significant economic damages in the dairy and beef cattle industries worldwide. In this study, fecal specimens were collected from 10 post-weaned calves, before and after 2 months of fluid therapy, and the samples were used for microbiota analysis. Beta-diversity analysis exhibited significant differences in gut microbiota compositions between calves with diarrhea and those in the recovered state. These results suggest that structural changes of the gut microbiota after recovery from BCoV infection correlate with changes in physiological parameters. In conclusion, our data provide evidence of gut microbiota-composition changes and their correlations with the physical profiles of post-weaned calves, before and after fluid therapy for BCoV-related diarrhea. | |||||||||||||||
| 3 | SCIE | Effect of ascorbic acid and citric acid on the quality of salted Chinese cabbage during storage | Food Science and Biotechnology | Feb. 6 | |||||||||||
| Changes in color, browning indices, enzyme activity, and physical and chemical quality during the storage period were investigated to assess the effectiveness of storage period extension along with the addition of ascorbic acid (AA) and citric acid (CA) to salted Chinese cabbage (kimchi cabbage). After 16 days of storage, the change in chromaticity value showed treatment with 0.5% CA showed the lowest change in the brown index during the storage period. The control showed the highest residual activity of polyphenol oxidase among control, AA, and CA-treated salted cabbage. AA and CA treatment effectively inhibited the initial populations of microorganisms including total aerobic bacteria, lactic acid bacteria, and yeast and molds in salted Chinese cabbage (kimchi cabbage) during storage. Further, the texture, i.e., hardness, chewability, and elasticity, tended to decrease with increasing storage. These results suggest that treatment with AA could help maintain the quality of salted Chinese cabbage (kimchi cabbage) during the storage period. | |||||||||||||||
| 4 | SCIE | Alteration of gut microbiota after antibiotic exposure in finishing swine | Frontiers in Microbiology | Feb. 12 | |||||||||||
| Subclinical doses of antimicrobials are commonly used in the swine industry to control infectious diseases and growth performance. Accumulating evidence suggests that swine administered with antibiotics are susceptible to disease development due to disruption of the beneficial gut microbial community, which is associated with host immune regulation, nutrient digestion, and colonization resistance against pathogens. In this study, we found that finishing swine administered with lincomycin showed gut dysbiosis and increased diarrhea incidence compared with control swine. The relative abundance of detrimental microbes was increased in the feces of lincomycin-administered finishing swine, but that of bacteria associated with fiber degradation was decreased. Moreover, administration of lincomycin significantly increased the enrichment of metabolic pathways related to pathogenicity and deficiency of polysaccharide degradation. These results suggest that lincomycin treatment could cause severe disruption of the commensal microbiota in finishing swine. | |||||||||||||||
| 5 | SCIE | Deodorization films based on polyphenol compound rich natural deodorants and polycaprolactone for removing volatile sulfur compounds from kimchi | Journal of Food Science | Feb. 13 | |||||||||||
| As natural polyphenols have been known to have the deodorizing activity, the deodorizing properties and mechanisms of action of polyphenols, the main constituents of green tea extract (GTE), black tea extract (BTE), and grape seed extract (GSE), against volatile sulfur compounds (VSCs) in kimchi were investigated. Six VSCs were targeted and detected to be in high abundance in kimchi. The deodorizing activity (%) toward VSCs was found to be in the following order: GSE (58.4 to 91.8) >GTE (37.6 to 73.8) >BTE (28.4 to 60.3). This was attributed to the high phenolic (892.6 ± 10.5 mg GAE/g) and flavonoid (666.5 ± 23.9 mg CE/g) contents in GSE, that is, polymeric proanthocyanidins (85.97%). Particularly, the hydroxyl groups in the polyphenols showed deodorizing activity against VSCs via a sulfur-capture reaction. For packaging applications, deodorization films based on GSE and polycaprolactone were developed, and the GSE/polycaprolactone 20% films exhibited strong deodorizing effects (54.9 to 99.8%) against kimchi VSCs. | |||||||||||||||
| 6 | SCIE | Free amino acid and volatile compound profiles of Jeotgal alternatives and its application to kimchi | Foods | Feb. 15 | |||||||||||
| Jeotgal containing abundant free amino acids plays an important role in the unique savory taste (umami) and flavor in kimchi. However, it is also responsible for the unpleasant fishy smell and high salt content of kimchi. Therefore, the present study aimed to identify alternative jeotgal sources and investigate the fermentation properties of jeotgal alternatives added to kimchi. The tomato hot-water extract (TH2) and dry-aged beef hot-water extract (DBH) were selected as jeotgal alternatives for kimchi preparation based on their glutamic acid contents. Characteristics of kimchi with TH2 alone (JA1) and TH2 and DBH in combination (1:1, JA2) were compared with kimchi prepared using commercially available anchovy fish sauce (CON). The pH of JA1 and JA2 was slightly decreased during fermentation, whereas the salinity was significantly lower than CON (p < 0.05). Notably, the most effective factor of the savory taste of kimchi, glutamic acid contents of JA1 and JA2 were significantly higher than that of CON (p < 0.05). In conclusion, JA1 showed slower fermentation with lower salinity and higher glutamic acid content than CON. Overall, this study showed that JA1 derived from TH2 could improve the taste and quality of kimchi by increasing glutamic acid content and decreasing the unpleasant flavor. | |||||||||||||||
| 7 | SCIE | Omics in gut microbiome analysis | Journal of Microbiology | Feb. 23 | |||||||||||
| Our understanding of the interactions between microbial communities and their niche in the host gut has improved owing to recent advances in environmental microbial genomics. Integration of metagenomic and metataxonomic sequencing data with other omics data to study the gut microbiome has become increasingly common, but downstream analysis after data integration and interpretation of complex omics data remain challenging. Here, we review studies that have explored the gut microbiome signature using omics approaches, including metagenomics, metataxonomics, metatranscriptomics, and metabolomics. We further discuss recent analytics programs to analyze and integrate multi-omics datasets and further utilization of omics data with other advanced techniques, such as adaptive immune receptor repertoire sequencing, microbial culturomics, and machine learning, to evaluate important microbiome characteristics in the gut. | |||||||||||||||
| 8 | SCIE | Calf diarrhea caused by prolonged expansion of autochthonous gut Enterobacteriaceae and their lytic bacteriophages | mSystems | Mar. 2 | |||||||||||
| Calf diarrhea is the leading cause of death of neonatal calves worldwide. Several infectious and noninfectious factors are implicated in calf diarrhea, but disease control remains problematic because of the multifactorial etiology of the disease. The major finding of the current study centers around the observation of microbial compositional and functional dysbiosis in rectal samples from diarrheic calves. These results highlight the notion that gut inflammation followed by a prolonged expansion of autochthonous Enterobacteriaceae contributes to the onset of calf diarrhea. Moreover, this condition possibly potentiates the risk of invasion of notorious enteric pathogens, including Salmonella spp., and the emergence of inflammation-resistant (or antibiotic-resistant) microbiota via active horizontal gene transfer mediated by lytic bacteriophages. | |||||||||||||||
| 9 | SCIE | Anaerocolumna sedimenticola sp. nov., isolated from fresh water sediment | Antonie van Leeuwenhoek | Mar. 17 | |||||||||||
| Strain CBA3638T was isolated from the Geum River sediment, Republic of Korea. The cells of strain CBA3638T were Gram-stain-positive, strictly anaerobic, rod-shaped, and 0.5-1.0 μm wide, and 4.0-4.5 μm long. Optimal growth occurred at 37 °C, pH 7.0, and 1.0% (w/v) NaCl. Based on the 16S rRNA gene sequence, the phylogenetic analysis showed that strain CBA3638T belongs to the genus Anaerocolumna in the family Lachnospiraceae, and is most closely related to Anaerocolumna cellulosilytic a (94.6-95.0%). The DDH value with A. cellulosilytica SN021T showed 15.0% relatedness. The genome of strain CBA3638T consisted of one circular chromosome that is 5,500,435 bp long with a 36.7 mol% G + C content. The genome contained seven 16S-5S-23S rRNA operons and one antibiotic resistance-related transporter gene (mefA). Quinones were not detected. The predominant cellular fatty acids were C16:0 and C14:0 and the polar lipids were diphosphatidylglycerol, phosphatidylcholine, and uncharacterised polar lipids. Based on the polyphasic taxonomic analysis, we propose strain CBA3638T as a novel species in the genus Anaerocolumna, with the name Anaerocolumna sedimenticola sp. nov. The type strain is CBA3638T (= KACC 21652T = DSM 110663T). | |||||||||||||||
| 10 | SCIE | Growth inhibitory effect of garlic powder and cinnamon extract on white colony-forming yeast in kimchi | Foods | Mar. 18 | |||||||||||
| White colony-forming yeast (WCFY), also referred to as film forming yeast or spoilage yeast, that appear on the surface of kimchi can deteriorate the sensory properties of kimchi, such as odor and texture. Thus, the aim of this study was to develop a method to inhibit the formation of the white colony in kimchi. Thereafter, the anti yeast activity of freeze-dried garlic powder (FGP) and cinnamon ethanol extract (CEE) was evaluated against WCFY using the agar-well diffusion assay. Following the direct application of FGP and CEE to the surface of the kimchi, the inhibitory effects on white colony were determined. In particular, the mixture of 10% FGP and 1.75% CEE, which was manufactured considering the influence of sensory properties in kimchi, exhibited anti yeast activity against all WCFY. Furthermore, the application of the FGP and CEE mixture supplemented with 0.02% xanthan gum to kimchi to enhance adhesion to the kimchi surface, led to a delay in the formation of a white colony on the surface of the kimchi by an average of 17 d at 10 ℃ compared to the control group. Collectively, the use of a FGP, CEE, and xanthan gum mixture could be an effective method for the inhibition of white colony formation on the surface of kimchi, extending its shelf life. | |||||||||||||||
| 11 | SCIE | Production, characterization, and antioxidant activities of an exopolysaccharide extracted from spent media wastewater after Leuconostoc mensenteroides WiKim32 fermentation | ACS Omega | Mar. 18 | |||||||||||
| White colony-forming yeast (WCFY), also referred to as film forming yeast or spoilage yeast, that appear on the surface of kimchi can deteriorate the sensory properties of kimchi, such as odor and texture. Thus, the aim of this study was to develop a method to inhibit the formation of the white colony in kimchi. Thereafter, the anti yeast activity of freeze-dried garlic powder (FGP) and cinnamon ethanol extract (CEE) was evaluated against WCFY using the agar-well diffusion assay. Following the direct application of FGP and CEE to the surface of the kimchi, the inhibitory effects on white colony were determined. In particular, the mixture of 10% FGP and 1.75% CEE, which was manufactured considering the influence of sensory properties in kimchi, exhibited anti yeast activity against all WCFY. Furthermore, the application of the FGP and CEE mixture supplemented with 0.02% xanthan gum to kimchi to enhance adhesion to the kimchi surface, led to a delay in the formation of a white colony on the surface of the kimchi by an average of 17 d at 10 °C compared to the control group. Collectively, the use of a FGP, CEE, and xanthan gum mixture could be an effective method for the inhibition of white colony formation on the surface of kimchi, extending its shelf life. | |||||||||||||||
| 12 | SCIE | Effect of high hydrostatic pressure (HHP) and supercooling storage in leaf mustard (Brassica juncea L.) kimchi: Modelling of microbial activity and preservation of physicochemical properties | LWT-Food Science and Technology | Mar. 19 | |||||||||||
| Kimchi products have a short shelf life due to continuous bacterial growth and fermentation. Herein, the microbiological and physicochemical properties of leaf mustard (Brassica juncea L.) kimchi were evaluated after high hydrostatic pressure (HHP) treatment (400 and 600 MPa for 5 min) and storage under supercooling (˗4.5 ℃) or refrigeration (4 and 8 ℃) conditions. Moreover, predictive models describing the growth kinetics of total lactic acid bacteria (TLAB) in leaf mustard kimchi were constructed. Treatment with 600 MPa reduced the total LAB and coliform counts in the samples before storage to 1.30 and > 1 log CFU/g, respectively. Supercooling storage prevented microbial growth for 30 days and allowed the maintenance of the titratable acidity, reducing sugar content, instrumental colour, total phenolic content, and antioxidant capacity of the samples. The Logistic and Gompertz models were relatively more acceptable to predict the growth behaviour of TLAB in leaf mustard kimchi treated/non-treated with 400 MPa during supercooled or refrigerated storage. Altogether, these findings suggest that HHP treatment combined with supercooling storage conditions that delay O2 and CO2 concentration changes in packaged kimchi's headspace could help maintain the initial microbiological and physicochemical qualities of leaf mustard kimchi. | |||||||||||||||
| 13 | SCIE | ODFM, an omics data resource from microorganisms associated with fermented foods | Scientific Data | Apr. 26 | |||||||||||
| ODFM is a data management system that integrates comprehensive omics information for microorganisms associated with various fermented foods, additive ingredients, and seasonings. The ODFM archives genome, metagenome, metataxonome, and (meta)transcriptome sequences of fermented food-associated bacteria, archaea, eukaryotic microorganisms, and viruses; 131 bacterial, 38 archaeal, and 28 eukaryotic genomes are now available to users. The ODFM provides both the Basic Local Alignment Search Tool search-based local alignment function as well as average nucleotide identity-based genetic relatedness measurement, enabling gene diversity and taxonomic analyses of an input query against the database. Genome sequences and annotation results of microorganisms are directly downloadable, and the microbial strains registered in the archive library will be available from our culture collection of fermented food-associated microorganisms. The ODFM is a comprehensive database that covers the genomes of an entire microbiome within a specific food ecosystem, providing basic information to evaluate microbial isolates as candidate fermentation starters for fermented food production. | |||||||||||||||
| 14 | SCIE | Salicibibacter cibarius sp. nov. and Salicibibacter cibi sp. nov.,two novel species of the family Bacillaceae isolated from kimchi | Journal of Microbiology | May 3 | |||||||||||
| To date, all species in the genus Salicibibacter have been isolated in Korean commercial kimchi. We aimed to describe the taxonomic characteristics of two strains, NKC5-3T and NKC21-4T, isolated from commercial kimchi collected from various regions in the Republic of Korea. Cells of these strains were rod-shaped, Gram-positive, aerobic, oxidase- and catalase-positive, non-motile, halophilic, and alkalitolerant. Both strains, unlike other species of the genus Salicibibacter, could not grow without NaCl. They showed 97.1% 16S rRNA gene sequence similarity to each other and were most closely related to S. kimchi NKC1-1T (97.0% and 96.8% similarity, respectively). The genomic G + C content of strains NKC5-3T and NKC21-4T was 44.7 and 44.9 mol%, respectively. Based on phenotypic, genomic, phylogenetic, and chemotaxonomic analyses, strains NKC5-3T (= KACC 22040T = DSM 111417T) and NKC21-4T (= KACC 22041T = DSM 111418T) represent two novel species of the genus Salicibibacter, for which the names Salicibibacter cibarius sp. nov. and Salicibibacter cibi sp. nov. are proposed. | |||||||||||||||
| 15 | SCIE | Inactivation of bacteria causing soft rot disease in fresh cut cabbage using slightly acidic electrolyzed water | Food Control | May 4 | |||||||||||
| Slightly acidic electrolyzed water (SAEW), an efficient non-thermal microbial inactivation technique, has been broadly applied to control food safety and quality. This study aimed to evaluate the bactericidal effects of SAEW treatments on fresh cut cabbage and to assess the optimal treatment conditions for inactivating Pectobacterium carotovorum subsp. carotovorum (PCC), which is among the most common causes of soft rot in cabbage. The optimal treatment condition for disinfection of PCC with SAEW treatment comprised 22.17 ppm of free available chlorine in the SAEW and an exposure time of 180 s at 10°C. The optimized SAEW treatment was verified experimentally on fresh cabbage with an observed reduction value of 5.94 ± 0.07 log10 CFU/g, which was similar to the predicted reduction value (6.21 log10 CFU/mL) in the suspension test. Taken together, these results indicate that SAEW can efficiently inactivate PCC cells in fresh cut cabbage. Moreover, the response surface quadratic polynomial equation is applicable for predicting the effect of SAEW treatments on PCC contamination in fresh cabbage production, processing, and distribution. | |||||||||||||||
| 16 | Non-SCI | Nitrogen fertilization and physiological disorders of spring kimchi cabbage during cold storage | Food Engineering Process | Feb. | |||||||||||
| Ammonium (NH4+-N) and nitrate-nitrogen (NO3-N) fertilizers were spread 30 kg/10a and 60 kg/10a, respectively, as additional fertilizers in nitrogen fertilization to investigate their effects on spring kimchi cabbage's physiological disorders during cold storage. The initial weight of spring kimchi cabbage after harvesting was 3.80 kg with two-fold O3-N, whereas it was 3.22 kg with one-fold NO3-N. After 90 days of cold storage, the total loss ratio became lower as the nitrogen fertilizer ratio increased. The pH increased, reducing sugar content decrease during the storage. Black speck occurrence became higher as the nitrogen fertilizer increased. Mid-rib brown stain and soft rot were observed slightly in kimchi cabbage regardless of the nitrogen fertilizer ratio. Two-fold NO3-N fertilization showed a positive effect on increasing weight and reducing kimchi cabbage loss, but it exhibited a negative effect on the black speck. The method and content of nitrogen fertilization of spring kimchi cabbage may be adjusted according to the usage and storage periods. | |||||||||||||||
| 17 | Non-SCI | Kimchi for vegetarians: Korean buddhism’s proposal for vegetarian temple kimchi | Culture and Convergence | May 24 | |||||||||||
| This study proposes Korea’s “temple kimchi” as a vegetarian kimchi dish that can be eaten not only by the growing number of vegans but also by a small number of extreme vegetarian consumers with varying degrees of vegetarianism. It surveyed and structured recipes for vegetarian cabbage kimchi, diced radish kimchi, and bachelor kimchi by Buddhist monk DaeAn, a temple food master, and examined the response to whether the temple kimchi made is acceptable to the British. Furthermore, it identified its suitability as a healthy vegetarian diet. Through this, it is expected to serve as an opportunity to recognize temple kimchi as vegetarian kimchi, contributing to the expansion of the global kimchi market, from general kimchi consumers and salted seafood enthusiasts to vegans. | |||||||||||||||
| 18 | Non-SCI | Effects of cooling rate on quality characteristics of spring kimchi cabbage (Brassica campestris L. ssp. Pekinensis) during cold storage | Food Engineering Process | May 31 | |||||||||||
| For long-term storage, kimchi cabbage (KC) should be maintained at a low temperature immediately after harvest; however, a sudden change in temperature during storage may lead to chilling injury in KC. The optimal cooling rate is important for the long-term storage of KC. To identify the optimal cooling rate, KC was cooled at different cooling rates (1℃, 2℃, 4℃, 6℃, 8℃, and 24℃/day), and then stored at 1℃ for 90 days. Thereafter, weight, trimming, total loss, pH, free sugar content, and total bacterial count changes were measured. Spring KC stored at the cooling rate of 6℃/day presented a lower total loss and better sensory properties than KC stored at other cooling rates; thus, 6℃/day is an appropriate cooling rate for long-term storage of KC. | |||||||||||||||
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