Investigation of different cold adaptation abilities in Salmonella enterica serotype Typhimurium strains using extracellular metabolomic approach.

This study explored the extracellular metabolomic responses of three different Salmonella enterica serotype Typhimurium (S. Typhimurium) strains-ATCC 13311 (STy1), NCCP 16964 (STy4), and NCCP 16958 (STy8)-cultured at refrigeration temperatures. The objective was to identify the survival mechanisms of S. Typhimurium under cold stress by analyzing variations in their metabolomic profiles. Qualitative and quantitative assessments identified significant metabolite alterations on day 6, marking a critical inflection point. Key metabolites such as trehalose, proline, glycerol, and tryptophan were notably upregulated in response to cold stress. Through multivariate analyses, the strains were distinguished using three metabolites-4-aminobutyrate, ethanol, and uridine-as potential biomarkers, underscoring distinct metabolic responses to refrigeration. Specifically, STy1 exhibited unique adaptive capabilities through enhanced metabolism of betaine and 4-aminobutyrate. These findings highlight the variability in adaptive strategies among S. Typhimurium strains, suggesting that certain strains may possess more robust metabolic pathways for enhancing survival in refrigerated conditions.

Structural and Functional Changes in Soybean Protein via Remote Plasma Treatments.

To the best of our knowledge, few studies have utilized cold plasma to improve soybean protein extraction yield and the functional properties of soybean protein. In this study, we aimed to assess the benefits of remote plasma treatments on soybean with respect to the utilization of soybean protein. This study involved two different sample forms (whole and crushed beans), two different plasma chemistry modes (ozone and nitrogen oxides [NOx = NO + NO2]), and a novel pressure-swing reactor. Crushed soybeans were significantly affected by NOx-mode plasma treatment. Crushed soybeans treated with NOx-mode plasma had the best outcomes, wherein the protein extraction yield increased from 31.64% in the control to 37.90% after plasma treatment. The water binding capacity (205.50%) and oil absorption capacity (267.67%) of plasma-treated soybeans increased to 190.88% and 246.23 % of the control, respectively. The emulsifying activity and emulsion stability slightly increased compared to those of the control. The secondary structure and surface hydrophobicity were altered. The remote plasma treatment of crushed soybeans increased soybean protein extraction yield compared to plasma-treated whole beans as well as untreated beans and altered the structural and physicochemical properties of soybean proteins.

The inactivation efficacy of plasma-activated acetic acid against Salmonella Typhimurium cells and biofilm.

AIM: This study aimed to examine the inactivation efficacy of plasma-activated acetic acid (PAAA) against Salmonella Typhimurium cells and biofilm and elucidate underlying chemical inactivation pathway. METHODS AND RESULTS: PAAA was prepared by discharging plasma to 20 ml of 0.2% (v/v) acetic acid (AA) for 20 min (2.2 kHz and 8.4 kVpp). The count of cells and biofilms decreased by 5.71 log CFU ml-1 and 4 log CFU/cm2 after 10 min of treatment with 0.2% PAAA and 0.4% PAAA compared with control group (without any treatment), respectively. In 0.2% PAAA, the concentrations of hydrogen peroxide (H2 O2 ) and nitrate anions were directly proportional to the plasma discharge time, whilst nitrite anion (NO2 - ) was not detected. However, the pH values of both 0.2% PAAA and plasma-activated water were inversely proportional to the plasma discharge time. Treatment with catalase, L-histidine, D-mannitol and sodium azide inhibited the antibacterial activity of PAAA. CONCLUSION: H2 O2 , singlet oxygen, hydroxyl radical and NO2 - are involved in the generation and decomposition of peroxynitrous acid generated from PAAA functioned as intermediate agent, which could diffuse through cell membranes of bacteria and induce cell injury. SIGNIFICANCE AND IMPACT OF STUDY: This study provides the understanding of efficacy and selectivity of PAAA which could be a novel decontamination agent.

Effect of Penicillium candidum and Penicillium nalgiovense and their combination on the physicochemical and sensory quality of dry-aged beef.

This study was designed to investigate the effect of starter culture on the improvement of physicochemical and sensory properties of dry-aged beef. Penicillium nalgiovense and Penicillium candidum were used as single starter cultures and mixed suspensions (1:1) to determine the effect of mixed starter culture. Starter cultures were spray-inoculated on the surface of beef samples, and samples were dry-aged for 0, 7, 10, 14, and 21 days. Dry-aged samples were then analyzed for microbial population, physicochemical properties (pH, water content, and color), proteolytic activity on sarcoplasmic and myofibrillar proteins, and flavor compounds (free amino acids, nucleotides, and volatile compounds). The microbial activities of starter cultures affected the physicochemical traits and enhanced sensory quality. Penicillium candidum particularly influenced proteolytic activity and volatile compounds, whereas P. nalgiovense affected free amino acid and nucleotide content, with the most significant effect on day 7. Combination of the two strains resulted in different patterns when compared to the single strains. Therefore, the inoculation of mold starter cultures significantly affected the physicochemical properties and improved the sensory qualities of dry-aged beef, and the effect differed between single and mixed strains.

Molecular hybridization based on (-)-epigallocatechin gallate as a new class of antiglycation agents.

(-)-Epigallocatechin gallate (EGCG) and olivetol hybrid molecules 1-4 were conveniently synthesized using dielectric barrier discharge plasma irradiation. The structures of these unprecedented hybrid molecules were determined by interpretation of spectroscopic data. The unusual hybrid 1 showed improved antiglycation potency toward the advanced formation of glycation end products than the original EGCG and olivetol. The novel hybrid 1 is an interesting new class of antiglycation candidate that requires further investigation.

Synergistic bactericidal effect of clove oil and encapsulated atmospheric pressure plasma against Escherichia coli O157:H7 and Staphylococcus aureus and its mechanism of action.

We investigated the bactericidal effect of clove oil and encapsulated atmospheric pressure plasma (EAP), individually or in combination, against Escherichia coli O157:H7 and Staphylococcus aureus. The bactericidal effect of the combined treatment was also investigated in inoculated beef jerky. For both pathogens, clove oil and EAP single treatments resulted in less than 3.0-log reductions, whereas the combined treatment resulted in more than 7.5-log reductions. The disc-diffusion assay and gas chromatography-mass spectrometry showed no changes in both the clear zone diameter and chemical composition of clove oil before and after the EAP treatment. Significant changes in cell membrane permeability and cell morphology resulting from the combined treatment of clove oil and EAP were evidenced by increased in UV absorption of cell supernatants, increased cell staining with propidium iodide, and changes in cell structure revealed by transmission electron microscopy. The synergistic bactericidal effects of clove oil and EAP against both pathogens were also observed in inoculated beef jerky, but the treatments were less effective against S. aureus, presumably due to thicker peptidoglycan layer. Experiments also demonstrated that the synergistic bactericidal effects between clove oil and EAP are due to clove oil increasing the susceptibility of the bacteria to subsequent EAP treatment, and does not involve alteration of the antibacterial activity of clove oil by EAP.

Muscle stem cell isolation and in vitro culture for meat production: A methodological review.

Cultured muscle tissue-based protein products, also known as cultured meat, are produced through in vitro myogenesis involving muscle stem cell culture and differentiation, and mature muscle cell processing for flavor and texture. This review focuses on the in vitro myogenesis for cultured meat production. The muscle stem cell-based in vitro muscle tissue production consists of a sequential process: (1) muscle sampling for stem cell collection, (2) muscle tissue dissociation and muscle stem cell isolation, (3) primary cell culture, (4) upscaled cell culture, (5) muscle differentiation and maturation, and (6) muscle tissue harvest. Although muscle stem cell research is a well-established field, the majority of these steps remain to be underoptimized to enable the in vitro creation of edible muscle-derived meat products. The profound understanding of the process would help not only cultured meat production but also business sectors that have been seeking new biomaterials for the food industry. In this review, we discuss comprehensively and in detail each step of cutting-edge methods for cultured meat production. This would be meaningful for both academia and industry to prepare for the new era of cellular agriculture.

Novel Hybrid Molecules Based on (-)-Epigallocatechin Gallate as Potent Anti-adipogenic Agents.

A series of novel (-)-epigallocatechin gallate (EGCG)-phloroglucinol hybrid compounds 1-4 has been successfully synthesized by employing a simple and efficient methodology using a dielectric barrier discharge (DBD) plasma irradiation. The new hybrid structures were determined by interpretation of spectroscopic data, with the absolute configurations being established by analysis of the circular dichroism (CD) spectra. The novel hybrids 1 and 2 showed highly improved anti-adipogenic potencies toward both pancreatic lipase and preadipocytes differentiation in 3T3-L1 compared to the original EGCG and phloroglucinol. A novel hybrid 1 represent an interesting subclass of anti-adipogenic candidates that need further research.

Characteristic Metabolic Changes of the Crust from Dry-Aged Beef Using 2D NMR Spectroscopy.

Two-dimensional quantitative nuclear magnetic resonance (2D qNMR)-based metabolomics was performed to understand characteristic metabolic profiles in different aging regimes (crust from dry-aged beef, inner edible flesh of dry-aged beef, and wet-aged beef striploin) over 4 weeks. Samples were extracted using 0.6 M perchlorate to acquire polar metabolites. Partial least squares-discriminant analysis showed a good cumulative explained variation (R2 = 0.967) and predictive ability (Q2 = 0.935). Metabolites of crust and aged beef (dry- and wet-aged beef) were separated in the first week and showed a completely different aspect in the second week via NMR-based multivariable analyses. Moreover, NMR-based multivariable analyses could be used to distinguish the method, degree, and doneness of beef aging. Among them, the crust showed more unique metabolic changes that accelerated proteolysis (total free amino acids and biogenic amines) and inosine 5'-monophosphate depletion than dry-aged beef and generated specific microbial catabolites (3-indoxyl sulfate) and γ-aminobutyric acid (GABA), while asparagine, glutamine, tryptophan, and glucose in the crust were maintained or decreased. Compared to the crust, dry-aged beef showed similar patterns of biogenic amines, as well as bioactive compounds and GABA, without a decrease in free amino acids and glucose. Based on these results, the crust allows the inner dry-aged beef to be aged similarly to wet-aged beef without microbial effects. Thus, 2D qNMR-based metabolomic techniques could provide complementary information about biochemical factors for beef aging.

Status of meat alternatives and their potential role in the future meat market - A review.

Plant-based meat analogues, edible insects, and cultured meat are promising major meat alternatives that can be used as protein sources in the future. It is also believed that the importance of meat alternatives will continue to increase because of concerns on limited sustainability of the traditional meat production system. The meat alternatives are expected to have different roles based on their different benefits and limitations. Plant-based meat analogues and edible insects can replace traditional meat as a good protein source from the perspective of nutritional value. Furthermore, plant-based meat can be made available to a wide range of consumers (e.g., as vegetarian or halal food products). However, despite ongoing technical developments, their palatability, including appearance, flavor, and texture, is still different from the consumers' standard established from livestock-based traditional meat. Meanwhile, cultured meat is the only method to produce actual animal muscle-based meat; therefore, the final product is more meat-like compared to other meat analogues. However, technical difficulties, especially in mass production and cost, remain before it can be commercialized. Nevertheless, these meat alternatives can be a part of our future protein sources while maintaining a complementary relationship with traditional meat.

Association of the thyroid hormone responsive spot 14 alpha gene with growth-related traits in Korean native chicken.

OBJECTIVE: Thyroid hormone responsive spot 14 alpha (THRSP) has been used to investigate the regulation of de novo lipogenesis because the variation of THRSP mRNA content in the tissue affects directly the ability of that tissue to synthetize lipids. Also, this gene responds to thyroid hormone stimulation and high level of carbohydrate feeding or insulin-injection. This study was carried out to investigate variations within THRSP and their effects on body and carcass weights in Korean native chicken (KNC). METHODS: A total of 585 chickens which represent the five lines of KNC (Black, Gray-Brown, Red-Brown, White, and Yellow-Brown) were reared and body weight data were recorded every two weeks from hatch until 20 weeks of age. Polymerase chain reaction- restriction fragment length polymorphism, DNA chips for Agilent 2100 Bioanalyzer, and Fluidigm Genotyping Technology, were applied to genotype selected markers. A linear mixed-effect model was used to access association between these single nucleotide polymorphism (SNP) markers and growth-related traits. RESULTS: A total of 30 polymorphisms were investigated in THRSP. Of these, nine SNPs for loci were selected to perform association analyses. Significant associations were detected between g.-49G>T SNP with body weight at 20 weeks of age (BW20), g.451T>C SNP with growth at 10 to 12 weeks of age (GR10-12), and g.1432A>C SNP with growth at 14 to 16 weeks trait (GR14-16) and body weight at 18 weeks of age (BW18). Moreover, diplotype of the THRSP gene significantly affected body weight at 12 weeks of age (BW12) and GR10-12 traits. Diplotype of ht1/ht2 was favorable for BW12 and GR10-12 traits. CONCLUSION: These results suggest that THRSP can be regarded as a candidate gene for growth traits in KNC.

Controversy on the correlation of red and processed meat consumption with colorectal cancer risk: an Asian perspective.

This study aimed to investigate the relationship between meat intake and colorectal cancer risk from an Asian, particularly Korean, perspective. A report by the International Agency for Research on Cancer (IARC) published in 2015 concluded that intake of processed and red meat increases the risk of developing colorectal cancer. We conducted an in-depth analysis of prospective, retrospective, case-control and cohort studies, systematic review articles, and IARC monograph reports, which revealed that the IARC/WHO report weighted the results of studies based in Western countries more and that the correlation between intake of processed meat products and colorectal cancer incidence in Asians is not clearly supported. Among 73 epidemiological studies, approximately 76% were conducted in Western countries, whereas only 15% of studies were conducted in Asia. Furthermore, most studies conducted in Asia showed that processed meat consumption is not related to the onset of cancer. Moreover, there have been no reports showing significant correlation between various factors that directly or indirectly affect colorectal cancer incidence, including processed meat products types, raw meat types, or cooking methods. Further epidemiological studies taking each country's food culture into consideration are required to reliably elucidate the effects of processed meat product intake, especially on cancer incidence.

Prospective Applications of Cold Plasma for Processing Poultry Products: Benefits, Effects on Quality Attributes, and Limitations.

Eliminating the pathogens from the chicken egg and meat is of supreme value for food scientists. In this regard, researchers have explored the potential applications of cold plasma, as a promising technique, to increase the profitability of poultry farming and safety of the poultry products. In the present study, an overview of the conducted research on plasma treatment of poultry products is presented to highlight the potential benefits of this emerging technology for the food and poultry industries. The potential negative effects of plasma treatment on the quality attributes of the product are also discussed. Moreover, the limitations of this technology and considerations for its commercial applications are illustrated. Furthermore, the needs for future research in this area of science are pointed out. Several studies have confirmed the applicability of cold plasma for egg and chicken decontamination. Considering the number of the recently conducted research and on-going advances in plasma science, this technique may assist food producers in enhancing the poultry product safety in the near future.

Cold Plasma for Effective Fungal and Mycotoxin Control in Foods: Mechanisms, Inactivation Effects, and Applications.

Cold plasma treatment is a promising intervention in food processing to boost product safety and extend the shelf-life. The activated chemical species of cold plasma can act rapidly against micro-organisms at ambient temperatures without leaving any known chemical residues. This review presents an overview of the action of cold plasma against molds and mycotoxins, the underlying mechanisms, and applications for ensuring food safety and quality. The cold plasma species act on multiple sites of a fungal cell resulting in loss of function and structure, and ultimately cell death. Likewise, the species cause chemical breakdown of mycotoxins through various pathways resulting in degradation products that are known to be less toxic. We argue that the preliminary reports from cold plasma research point at good potential of plasma for shelf-life extension and quality retention of foods. Some of the notable food sectors which could benefit from antimycotic and antimycotoxin efficacy of cold plasma include, the fresh produce, food grains, nuts, spices, herbs, dried meat and fish industries.

Effect of Dietary Red Meat on Colorectal Cancer Risk-A Review.

Heme iron overload has been implicated as the main cause of the increased risk of cancer due to the consumption of red meat. However, fish and shellfish, teas, and spices contain up to five times more iron than red meat. There is insufficient evidence that iron intake in dietary red meat is the primary causal factor for colorectal cancer. In addition, harmful substances produced during the preparation of red meat, including heterocyclic amines (HCAs), polycyclic aromatic hydrocarbons (PAHs), N-nitroso compounds, and acrylamide, are extrinsic factors that increase carcinogenicity. HCAs are produced during the cooking of red meat, poultry meat, and fish. PAHs may also be produced during the cooking of diverse food groups, such as dairy products, fruits, vegetables, and cereals. The average daily intake of red meat among Korean individuals is 62 g; the amount of PAHs entering the body via red meat is less than the average amount of PAHs the body is exposed to in the air. Therefore, it is difficult to conclude that dietary red meat is the main cause of colorectal cancer. Rather, there may be an intricate influence of multiple factors, including fruit and vegetable intake, alcohol consumption, smoking, overweight, obesity, and stress.

Isolation and identification of angiotensin I-converting enzyme inhibitory peptides derived from thermolysin-injected beef M. longissimus.

OBJECTIVE: This study identified angiotensin I-converting enzyme (ACE) inhibitory peptides in beef M. longissimus injected with thermolysin (80 ppm) and stored for 3 days at 5°C. METHODS: Crude peptides (molecular weight <3 kDa) were obtained from the thermolysin hydrolysate and separated into seven fractions. Fraction V showing the highest ACE inhibitory activity was further fractionated, yielding subfractions V-15, V-m1, and V-m2, and selected for superior ACE inhibitory activity. Finally, twelve peptides were identified from the three peak fractions and the ACE inhibitory activity (IC50) of each peptide was evaluated. RESULTS: The Leu-Ser-Trp, Phe-Gly-Tyr, and Tyr-Arg-Gln peptides exhibited the strongest ACE inhibitory activity (IC50 values of 0.89, 2.69, and 3.09 mM, respectively) and had higher concentrations (6.63, 10.60, and 29.91 pg/g; p<0.05) relative to the other peptides tested. CONCLUSION: These results suggest that the thermolysin injection process is beneficial to the generation of bioactive peptides with strong ACE inhibitory activity.

Comparison of reducing sugar content, sensory traits, and fatty acids and volatile compound profiles of the longissimus thoracis among Korean cattle, Holsteins, and Angus steers.

OBJECTIVE: This study was performed to compare fat content, reducing sugar contents, sensory traits, and fatty acid (FA) and volatile compound profiles in longissimus thoracis (LT) among Korean cattle (KC), Holstein (HO), and Angus (AN) steers. METHODS: Twelve LT samples (about 500 g each) of KC with an average age of 31±0.42 months, an average carcass weight of 431±12.5 kg, and a quality grade (QG) of 1+ were obtained from the joint livestock products market. Twelve LT samples of HO cattle with an average age of 24±0.54 months, an average carcass weight of 402±7.81 kg, and a QG of 2 were also obtained from the same market. Twelve LT samples of AN steers with an average age of about 20 months and a QG of choice were purchased from a beef delivery company. After slaughter, samples were kept at 4°C for 42 days and prepared for immediate analysis or stored at appropriate conditions. The chemical composition, color, pH, shear force, collagen content, reducing sugars, sensory evaluation, FA composition, and volatile compound content for each LT sample were analyzed. RESULTS: The LT of KC had the highest (p<0.05) fat content, the highest reducing sugar content, and the highest scores in the sensory evaluation (flavor, tenderness, juiciness, and overall acceptance). All the sensory traits were positively correlated (p<0.001) with intramuscular fat and reducing sugar content. Several FAs and volatile compound profiles varied among the breeds. KC LT had the highest (p<0.05) concentrations of acetaldehyde, 3-methyl butanal, and 3-hydroxy-2-butanone, and these volatile compounds were positively correlated (p<0.05) with all the sensory traits. CONCLUSION: Variations in fat content and reducing sugar contents and FA and volatile compound profiles may contribute to differences in the sensory quality of LT among breeds.

A green chemical oligomerization of phloroglucinol induced by plasma as novel α-glucosidase inhibitors.

A new facile method was developed for simple green synthesis of methylene-bridged phloroglucinol oligomers using nonthermal dielectric barrier discharge (DBD) plasma in methanolic solution. The chemical structures of these newly generated oligomers 2-5 were determined by interpretation of the spectroscopic data, and the inhibitory activity toward α-glucosidase of all isolates was evaluated. The unusual phloroglcuinol pentamer 5 connected by four methylene linkages showed a much higher potential inhibitory effect against α-glucosidase than the other generated oligomers 2-4 and appeared to be a promising lead for development as a potential antidiabetic agent. Abbreviations: T2DM, type2 diabetes mellitus; DBD, dielectric barrier discharge; HPLC, high-performance liquid chromatography; IC50, 50% inhibition concentration; NMR, nuclear magnetic resonance; FABMS, fastatom bombardment mass spectrometry.

Use of alternative curing salts for processing salamis.

OBJECTIVE: This study was performed to determine effects of different curing salts on the quality of salamis and to assess feasibility of using NaCl-alternative salts. METHODS: Various types of curing salts (KCl or MgCl2) as well as NaCl (sun-dried or refined) were incorporated for processing of salamis. The proximate composition, fatty acids, nucleotide-related compounds, and free amino acids of the salamis were analyzed during 40 days of ripening. RESULTS: The substitution of NaCl by KCl caused higher fat and ash content, but lower moisture content of the salami after 20 days of ripening (p<0.05). Compared with the sun-dried NaCl, use of KCl in salami also led to greater inosine 5'-monophosphate whereas refined NaCl had more inosine (p<0.05). KCl-added salami also had a higher C12:0, C17:1, and C20:0 than other types of salami (p<0.05). MgCl2-added salami had higher content of free amino acids compared to the other salamis (p<0.05). CONCLUSION: Alternative curing salts such as KCl and MgCl2 could substitute NaCl in consideration of quality factor of a fermented meat product. Especially replacement of NaCl with KCl will be a suitable strategy for developing relatively low sodium salami products without compromising product quality.

Identification of quantitative trait loci for the fatty acid composition in Korean native chicken.

OBJECTIVE: Fatty acid composition is one of the most important meat quality traits because it can contribute to functional, sensorial, and nutritional factors. In this study, quantitative trait locus (QTL) analyses for fatty acid composition traits were investigated in thigh and breast meat of Korean native chicken (KNC). METHODS: In total, 18 fatty acid composition traits were investigated from each meat sample using 83 parents, and 595 F1 chicks of 20 week old. Genotype assessment was performed using 171 informative DNA markers on 26 autosomes. The KNC linkage map was constructed by CRI-MAP software, which calculated genetic distances, with map orders between markers. The half-sib and full-sib QTL analyses were performed using GridQTL and SOLAR programs, respectively. RESULTS: In total, 30 QTLs (12 in the thigh and 18 in the breast meat) were detected by the half-sib analysis and 7 QTLs (3 in the thigh and 4 in the breast meat) were identified by the full-sib analysis. CONCLUSION: With further verification of the QTL regions using additional markers and positional candidate gene studies, these results can provide valuable information for determining causative mutations affecting the fatty acid composition of KNC meat. Moreover, these findings may aid in the selection of birds with favorable fatty acid composition traits.