Microorganisms In Foods Research Articles

The Swab, the Drip, or the Meat? Comparison of Microbiological Sampling Methods in Vacuum-Packed Raw Beef.

Historically, there has been a concern for the detection and enumeration of microorganisms in foods, and numerous methods have been developed to determine their microbiological conditions. The present study aimed to compare the numbers of microbes recovered with three sampling methods: drip, excision, and swabbing in vacuum-packed beef. The sampling methods were evaluated in terms of the viable numbers of Enterobacteriaceae, lactic acid bacteria (LAB), Brochrothrix thermosphacta, Salmonella spp., and yeasts and moulds (Y&M). The numbers of B. thermosphacta, Salmonella spp., Enterobacteriaceae, LAB, and M&Y recovered with the drip method were significantly higher (p < 0.05) than those from the other two methods. Regarding excision and swabbing, the recovery of B. thermosphacta and Enterobacteriaceae was higher (p < 0.05) with the excision method than swabbing, while there were no statistical differences (p > 0.05) between both methods for Salmonella spp., LAB, and Y&M. In conclusion, the drip method can recover up to two logarithms more than the other techniques in vacuum-packed meat; hence, it should be considered when designing and implementing sampling systems for the meat industry.

Use of Ozone to Reduce the Proportion of Mesophilic and Psychrotrophic Bacteria Among Aquatic Organisms: A Systematic Review and Meta‐Analysis

ABSTRACTMesophilic and psychrotrophic bacteria are agents of spoilage in aquatic organisms. Aquaculture aims to provide safe and nutritious foods from microbiological, physico–chemical, and sensory perspectives. Ozone (O3) is a gas used as an efficient antimicrobial agent for inactivating microorganisms in various foods. Therefore, this study aimed to determine whether O3 is effective in reducing or eliminating mesophilic and psychrotrophic bacteria in fish and seafood. To this end, a systematic review was performed to evaluate the data obtained from published primary studies. Articles were retrieved from the PubMed, Web of Science, Scopus and SciELO databases, and papers published between 2002 and 2024 were considered. A total of 1415 studies were identified, 11 of which met all eligibility criteria and were included in the meta‐analysis. The results indicated that O3 reduced mesophilic and psychrotrophic bacteria counts by 0.31 log CFU g−1 in fish and seafood. Significant heterogeneity persisted in the data set even after separation into subgroups, indicating that the studies were significantly diverse in terms of methodology. Therefore, the data obtained in this meta‐analysis indicates low inactivation of the microorganisms studied using O3. However, more research into the O3 treatment of aquatic organisms should be encouraged, since the included studies had methodological variations in the forms of O3 used, and investigated species, since all species have their own specificities.

Sources of Lipopeptides and Their Applications in Food and Human Health: A Review.

Lipopeptides (LPs) are widely sourced surface-active natural products with a wide range of functions and low toxicity, high potency, and good biodegradability. In this paper, we summarize, for the first time, the plant, animal, microbial, and synthetic sources of LPs. We also introduce the applications of LPs in food and human health, including (1) LPs can inhibit the growth of food microorganisms during production and preservation. They can also be added to food packaging materials for preservation and freshness during transportation, and can be used as additives to improve the taste of food. (2) LPs can provide amino acids and promote protein synthesis and cellular repair. Due to their broad-spectrum antimicrobial properties, they exhibit good anticancer effects and biological activities. This review summarizes, for the first time, the sources of LPs and their applications in food and human health, laying the foundation for the development and application of LPs.

Rapid detection of food microorganisms from the perspective of cellular and molecular biomechanics leveraging biotechnology and computer vision

Rapid detection of food microorganisms from the perspective of cellular and molecular biomechanics leveraging biotechnology and computer vision

CRISPR/Cas12a-powered universal platform with dual-signal readout for isothermal and sensitive detection of pathogenic microorganisms in foods

CRISPR/Cas12a-powered universal platform with dual-signal readout for isothermal and sensitive detection of pathogenic microorganisms in foods

Progress in the Mechanism and Application of Microorganisms in Traditional Fermented Foods

Progress in the Mechanism and Application of Microorganisms in Traditional Fermented Foods

Enhanced Fermentation of Pu-Erh Tea with Aspergillus niger: Quality and Microbial Community Analysis.

Post-fermented Pu-erh tea (PFPT) is a microbial fermented tea characterized by unique sensory attributes and multiple health benefits. Aspergillus niger is the dominant fungus involved in the fermentation process and plays a significant role in imparting the distinct characteristics of PFPT. To investigate the role of Aspergillus niger in the fermentation of Pu-erh tea, this study inoculated unsterilized sun-dried green tea with Aspergillus niger isolated from Pu-erh tea to enhance the fermentation process. Metabolites and microbial communities in sun-dried green tea (CK), fortified fermented tea (TF), and naturally fermented tea (NF) were analyzed using non-targeted metabolomics, 16S rDNA, and internal transcribed spacer sequencing. Non-targeted metabolomics revealed that Aspergillus niger significantly altered the metabolite profile of the tea samples, identifying a total of 200 different metabolites, with 95 showing significant increases and 105 significant decreases, predominantly enriched in metabolic pathways associated with amino acid biosynthesis and degradation. High-throughput sequencing revealed that although the relative abundance of the fungal community remained largely unchanged, the inoculation of Aspergillus niger significantly increased the abundance of Bacillales and Pseudomonas within the bacterial community, thereby influencing the dynamic balance of the microbial ecosystem. Collectively, the inoculation of Aspergillus niger altered the composition of the microbial community and metabolic activities, resulting in changes to the content of amino acid-dominated metabolites, thereby enhancing the flavor profile and overall quality of Pu-erh tea. These findings provide important insights for optimizing the production processes of Pu-erh tea and the application of microorganisms in other fermented foods.

Tinjauan Analisis Manfaat dan Dampak Sinar UV-C dalam Bidang Pangan dan Pertanian

UV-C light exposure has been widely applied in food and agriculture to improve product quality, safety, and durability. UV-C light has short wavelengths that are effective in inactivating pathogenic microorganisms in food and plant products, thereby reducing the risk of contamination and extending product shelf life. In agriculture, the application of UV-C light to crops can increase crop resistance to pests and diseases, and stimulate certain physiological responses that support growth.

Industrial Production of Functional Foods for Human Health and Sustainability.

Functional foods significantly affect social stability, human health, and food security. Plants and microorganisms are high-quality chassis for the bioactive ingredients in functional foods. Characterised by precise nutrition and the provision of both nutritive and medicinal value, functional foods serve a as key extension of functional agriculture and offer assurance of food availability for future space exploration efforts. This review summarises the main bioactive ingredients in functional foods and their functions, describes the strategies used for the nutritional fortification and industrial production of functional foods, and provides insights into the challenges and future developments in the applications of plants and microorganisms in functional foods. Our review aims to provide a theoretical basis for the development of functional foods, ensure the successful production of new products, and support the U.N. Sustainable Development Goals, including no poverty, zero hunger, and good health and well-being.

Microorganisms in Fermented Foods and Their Effects on the Human Body

In recent years, microorganisms in fermented foods have shown an important role in regulating human health. Studies have shown that probiotics have significant health benefits in fermented foods, such as improving gut health, stimulating immune function, and promoting metabolism, and mental health. Specifically, lactic acid bacteria in yogurt can increase the number of beneficial bacteria in the intestines and reduce the growth of pathogenic bacteria, and yeasts such as Saccharomyces cerevae have multiple health effects on intestinal microbiota protection and anti-inflammation. In addition, various enzymes and metabolites produced by Aspergillus during fermentation process can improve the nutritional value of food. However, although lots of research has been done, the understanding of the microbial mechanism under different fermentation conditions is still insufficient. In this article, the types and influencing factors of microorganisms in yogurt, wine and seasoner were reviewed. The effects of temperature, pH value, fermentation time and other conditions on microbial activity and product quality were analyzed. The results showed that suitable fermentation conditions could significantly increase microbial activity, improve product flavor and health function, and provide a theoretical basis for optimizing the production process of fermented food. The article provides a theoretical basis for improving the fermented food production process, thus helping to improve product quality and market competitiveness. However, this article has some limitations like the lack of understanding of interactions between different microorganisms. Future research should focus on examining the collaborative relationship between these microbes to improve the health benefits and production efficiency of fermented foods.

A Mathematical Model for the Combination of Power Ultrasound and High-Pressure Processing in the Inactivation of Inoculated E. coli in Orange Juice.

The mathematical modeling of a combination of non-thermal technologies for E. coli inactivation is of great interest for describing the dynamic behavior of microorganisms in food, with the goal of process control, optimization, and prediction. This research focused on the design and implementation of a mathematical model to predict the effect of power ultrasound (US), high-pressure processing (HPP), and the combination of both non-thermal technologies on the inactivation kinetics of E. coli (DSM682) inoculated in orange juice. Samples were processed by US, HPP, and a combination of both technologies at varying process parameters, and a mathematical model for microbial inactivation was developed using a System Dynamics approach. The results showed that the combination of these technologies exhibited a synergistic effect, resulting in no detectable colony-forming units per mL of juice. The developed model accurately predicted the inactivation of E. coli following the combination of these technologies (R2 = 0.82) and can be used to predict microbial load reduction or optimize it based on process parameters. Additionally, combining both techniques offers a promising approach for extending the shelf life of fresh juices using non-thermal stabilization technology.

Antimicrobial activity evaluation of combinations of essential oils, thymol and R-limonene against food-borne pathogens and spoilage agents

Antimicrobial activity evaluation of combinations of essential oils, thymol and R-limonene against food-borne pathogens and spoilage agents

Designing variable flexible sampling systems for verifying harmful microorganisms in food

Designing variable flexible sampling systems for verifying harmful microorganisms in food

Mechanistic insights into soy sauce flavor enhancement via Co-culture of Limosilactobacillus fermentum and Zygosaccharomyces rouxii

Mechanistic insights into soy sauce flavor enhancement via Co-culture of Limosilactobacillus fermentum and Zygosaccharomyces rouxii

Exploration of Alicyclobacillus spp. Genome in Search of Antibiotic Resistance.

The study investigates the antibiotic resistance (AR) profiles and genetic determinants in three strains of guaiacol-producing Alicyclobacillus spp. isolated from orchard soil and pears. Their phenotypic characteristics, such as spore formation; resistance to different factors, including drugs or disinfectants; or production of off-flavor compounds, can affect the taste and aroma of spoiled products. Food and beverages are potential vectors for the transfer of antibiotic resistance genes, which is a growing health concern; thus, microorganisms in food and beverages should not be a potential source of drug resistance to consumers. Whole-genome sequencing (WGS) was utilized to identify antibiotic resistance genes, metabolic pathways, and elements associated with guaiacol and halophenol production. Minimum inhibitory concentration (MIC) testing revealed that all strains were susceptible to eight out of nine tested antibiotics (ampicillin, gentamycin, kanamycin, streptomycin, clindamycin, tetracycline, chloramphenicol, and vancomycin) but exhibited high resistance to erythromycin. Analysis indicated that the erythromycin resistance gene, ribosomal RNA small subunit methyltransferase A (RsmA), was intrinsic and likely acquired through horizontal gene transfer (HGT). The comprehensive genomic analysis provides insights into the molecular mechanisms of antibiotic resistance in Alicyclobacillus spp., highlighting the potential risk of these bacteria as vectors for antibiotic resistance genes in the food chain. This study expands the understanding of the genetic makeup of these spoilage bacteria and their role in antimicrobial resistance dissemination.

Step-by-Step Metagenomics for Food Microbiome Analysis: A Detailed Review.

This review article offers a comprehensive overview of the current understanding of using metagenomic tools in food microbiome research. It covers the scientific foundation and practical application of genetic analysis techniques for microbial material from food, including bioinformatic analysis and data interpretation. The method discussed in the article for analyzing microorganisms in food without traditional culture methods is known as food metagenomics. This approach, along with other omics technologies such as nutrigenomics, proteomics, metabolomics, and transcriptomics, collectively forms the field of foodomics. Food metagenomics allows swift and thorough examination of bacteria and potential metabolic pathways by utilizing foodomic databases. Despite its established scientific basis and available bioinformatics resources, the research approach of food metagenomics outlined in the article is not yet widely implemented in industry. The authors believe that the integration of next-generation sequencing (NGS) with rapidly advancing digital technologies such as artificial intelligence (AI), the Internet of Things (IoT), and big data will facilitate the widespread adoption of this research strategy in microbial analysis for the food industry. This adoption is expected to enhance food safety and product quality in the near future.

Sensitive and rapid detection of three foodborne pathogens in meat by recombinase polymerase amplification with lateral flow dipstick (RPA-LFD)

Foodborne illnesses, caused by harmful microorganisms in food, are a significant global health issue. Current methods for identifying these pathogens are both labor-intensive and time-consuming. In this research, we devised a swift and precise detection technique using recombinase polymerase amplification combined with a lateral flow dipstick (RPA-LFD) for three foodborne pathogens found in meat. By employing a dedicated detection device, RPA-LFD allows for the rapid analysis of DNA from Escherichia coli O157 (E. coli O157), Salmonella, and Shigella-pathogens that are prohibited in food. The detection thresholds for E. coli O157, Salmonella, and Shigella are 0.168fg/μl (1.04CFU/ml), 0.72fg/μl (27.49CFU/ml), and 1.25fg/μl (48.84CFU/ml), respectively. This method provides a short detection window, operates at low temperatures, follows simple procedures, and exhibits high sensitivity. Our study establishes the RPA-LFD method for simultaneously identifying the nucleic acid of three foodborne pathogens, offering an efficient solution for quickly identifying multiple contaminants.

Encapsulated pomegranate peel extract as a potential antimicrobial ingredient from food waste.

Pomegranate peel waste is a valuable reservoir of heat-sensitive total hydrolysable tannins (THT), with potential applications in food and pharmaceuticals. Preserving THT is challenging due to degradation post-extraction. We explore ionic gelation as an encapsulation method to optimize THT utilization. Through external gelation, we optimized the process variables using Box-Behnken design. At 40 g kg-1 sodium alginate, 25 g kg-1 calcium chloride, and 300 g kg-1 pomegranate peel extract (PPE), we achieved an 83.65% encapsulation efficiency. Compared to spray drying, external gelation demonstrated superior performance, with enhanced release percentages and stability. Physical, phytochemical, and release profiles of encapsulates were extensively analysed. External gelation achieved an 87.5% release in 30 min, outperforming spray-dried counterparts (69.7% in 25 min). Encapsulated PPE exhibited robust antibacterial activity against Staphylococcus aureus (ATCC 25923) in powdered infant formula, with a 32 ± 0.01 mm zone of inhibition and 300 μg mL-1 minimum inhibitory concentration. Insights into S. aureus growth curves underlined the mechanism of action via membrane potential alterations. The results of carried investigations also showed that the antibacterial activity of the encapsulated PPE extracts against the targeted organism was identical to the antibacterial activity exhibited by synthetic antibiotics used generally to kill microorganisms in food. Therefore, from the findings, it can be concluded that the PPE encapsulate produced using the external gelation technique at the optimized condition displayed superior storage stability possessing strong antimicrobial activity when compared to encapsulate produced using the spray drying technique. External gelation emerges as a potent technique for developing effective encapsulates enriched with natural antimicrobials or antibiotics. This approach holds promise for applications in food, pharmaceuticals, and nutraceuticals, enhancing stability and efficacy while reducing reliance on synthetic antibiotics. © 2024 Society of Chemical Industry.

Methicillin-Resistant Staphylococcus aureus (MRSA) in Dairy Products and Bulk-Tank Milk (BTM).

In order to contribute to an assessment of the role of food in the risks of transmission of methicillin-resistant Staphylococcus aureus (MRSA), a review was undertaken of research on this microorganism in milk and dairy products published from January 2001 to February 2024. A total of 186 publications were selected, 125 for dairy products and 61 for bulk-tank milk (BTM). MRSA was detected in 68.8% of the research into dairy products and 73.8% of investigations relating to BTM, although in most studies the prevalence was less than 5%. Of the set of S. aureus strains isolated, approximately 30% corresponded to MRSA. The foods most extensively contaminated with this microorganism were raw milk and some types of soft cheese. Determination of the mecA gene on its own is known not to suffice for the detection of all MRSA strains. The great diversity of techniques used to study MRSA in milk and dairy products made it difficult to draw comparisons between studies. It would thus be advisable to develop a standardized protocol for the study of this microorganism in foods.

Evaluation of strain variability of food microorganisms in response to decontamination by pulsed electric fields and thermal treatments

Evaluation of strain variability of food microorganisms in response to decontamination by pulsed electric fields and thermal treatments