Food Safety Problems Research Articles

Antibacterial mechanism analysis of resveratrol against Salmonella typhimurium via metabolomics.

Salmonella, a common pathogenic bacterium in food, can have a severe impact on food safety and consumer health. At present, Salmonella infection is controlled primarily by the use of antibiotics, which creates unsafe factors for food safety. Thus, finding a natural antibacterial agent is highly practical. In this study, resveratrol was screened from 17 kinds of polyphenols, and its inhibitory mechanism and effects on metabolites of Salmonella typhimurium were investigated to occur through cell wall and membrane damage and metabolomics analysis. The results revealed that the minimum inhibitory concentration of resveratrol against S. typhimurium was 250μg/mL. After treatment with resveratrol, the lag period of the strain was prolonged, and the cell wall and membrane structure were destroyed. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) further confirmed that resveratrol induced damage to the cell walls and cell membrane. The metabolic profile of S. typhimurium following resveratrol treatment was analysed by gas chromatography‒mass spectrometry. In the metabolome evaluation, we screened 23 differentially abundant metabolites, including 11 upregulated and 12 downregulated metabolites. Eight metabolic pathways of S. typhimurium, including pathways important for amino acid metabolism and the tricarboxylic acid (TCA) cycle, exhibited significant changes after resveratrol treatment. The verification results of the citric acid content, cis-aconitase activity, and ATP content further revealed that the tricarboxylic acid cycle and other related metabolic pathways of S. typhimurium were affected. These results could provide a theoretical possibility for the use of resveratrol as a plant-derived bacteriostatic for food safety problems caused by S. typhimurium. KEY POINTS: • The mechanism of bacteriostasis was studied via metabolomics • Resveratrol causes the death of Salmonella by disrupting the cell wall and membrane.

СУЧАСНІ СТРУКТУРНІ ЗМІНИ В АГРАРНОМУ СЕКТОРІ ТА ЇХ ВПЛИВ НА ПРОДОВОЛЬЧУ БЕЗПЕКУ КРАЇНИ

. In the article, the author examines the evolution of the role of food security, both at the historical stages of development and in the modern world, as well as its place in the system of ensuring economic and national security of the state. The strategic priority of agrarian policy in most countries was ensuring food security, which was understood primarily as self-sufficiency in food. This became especially relevant in the 50s of the XX century as a result of the fact that military actions violated previously imposed trade relations, and violations in this area arose under the influence of the payment crisis. The purpose of the article is an analysis of modern structural changes in the agricultural sector and their impact on the country's food security. The methodological basis of the research in the article is the scientific work of the authors in the field of economics of culture, innovation management, management in the field of culture, as well as social partnership. The research was carried out on the basis of general scientific methods of research - a systematic approach, analysis and synthesis, methods of typological and comparative analysis, empirical methods. The object of the study is the sphere of culture, which needs conditions in which organizational and financial reforms are carried out, as well as the development and application of innovative management methods. The hypothesis of the study. Currently, all developed countries of the world, including the United States, Japan, and the EU countries, have their own national programs, laws and measures to ensure national food security. Presentation of the main material. The primary tasks of the state in the sphere of regulation of agro-industrial production should be the stabilization and development of agro-industrial production, ensuring food security, improving food security of the population, maintaining economic parity between agriculture and other sectors of the economy, converging income levels of workers in agriculture and industry, protecting domestic producers in the sphere of agro-industrial production. From the point of view of welfare economics, "the problem of food safety and quality is one of the specific features of the functioning of the agricultural market, which determine its equilibrium in a Pareto inefficient state. This, in turn, is the economic basis for the need for state policy intervention in the agricultural sector and the possibility of redistributing the financial resources of society for its development. The originality and practical significance of the study. In our opinion, the existing problem of food security should be considered in the context of economic security, since it concentrates the main directions of agricultural policy and economic reforms in the current market conditions. This process reflects the real trends in the development of agricultural production, the state of the market and the position of consumers in it, determines the degree of involvement and dependence on the world food market, applies the mechanism of state strategy taking into account internal and external factors in order to create the main life support system – food security. Conclusions. Taking into account the interests of economic security and socio-political stability in society, it should be noted that the food and agricultural complexes always remain the most important sectors of the economy. The primary task is to create conditions for economic management and entrepreneurial stability in the agro-food sector of the economy and to ensure state support for producers

Характеристика антиоксидантной активности СО2- экстрактов бурых водорослей и стабилизации липидов

Vegetable oils are susceptible to oxidation during storage, which is a serious problem for shelf-life and food safety. The article describes the antioxidant properties of supercritical extracts from brown algae (Undaria pinnatifida and Costaria costata), Russian Far East. It also explains their prospects as stabilizers that preserve the quality and safety of vegetable oils by affecting the kinetics of oxidation and hydrolysis. The study featured supercritical extracts of marine brown algae Undaria pinnatifida and Costaria costata from Russian Far East. The methods involved spectrophotometry and high-performance liquid chromatography. Supercritical extracts of marine brown algae proved to be reliable sources of bioactive substances, e.g., phenolic compounds, carotenoids, and mannitol. They also possessed antioxidant properties in terms of antiradical activity, hydroxyl ion binding, superoxide radical absorption, and Fe+2 chelating. The experiments revealed nine phenolic compounds responsible for antioxidant properties. The supercritical extract of Costaria costata demonstrated a greater antioxidant effect on lipid oxidation in vegetable oils than Undaria pinnatifida. Both algae proved effective in stabilizing hydrolysis and were able to increase the shelf-life of soy and sunflower oils by three months. Supercritical extracts of Undaria pinnatifida and Costaria costata served as antioxidants to stabilize lipid oxidation in refined and unrefined soy and sunflower oils. The research revealed high approximation coefficients for regression equations describing the patterns of changes in the peroxide and acid numbers of vegetable oils stabilized with supercritical extracts of these marine brown algae.

ACCUMULATION OF HEAVY METALS IN APPLES AND PEARS FROM THE SUBURBS OF MITROVICA, KOSOVO

Intake of heavy metals through the food is a food safety problem that seriously affects consumer health. Therefore, information is needed on the intake of food contaminated with heavy metals and their concentrations, to assess the potential risk for human health. This paper aims to determine the accumulation of metals in apples and pears grown in the surroundings of Kosovska Mitrovica (Republic of Kosovo) and the bioconcentration factor (BF). With the help of the ICP-MS technique, were determined the amounts of Cu, Fe, Co, Mn, Ni, and Cr in apples and pears grown in three regions - Zvečan , Frashër, and Polski. From the conducted tests, the highest concentrations in apples and pears were determined for iron (on average 100.67 mg/kg for apples and 107.4 mg/kg for pears) and the lowest concentrations for cobalt (on average 0.13 mg/kg for apples and 0.18 mg/kg for pears). The lowest bioconcentration factor in apples is 0.01 (for Fe, Co, and Mn in all three regions), and the highest is 0.32 (for Cr in Zvečan). When determining the bioconcentration factor in pears, the lowest (0.01) was determined for iron (in all three regions) and manganese (in Zvečan and Frashër regions), and the highest bioconcentration factor was determined for copper – 0.46 (Polski region). There is a very high correlation between the values obtained for the analyzed metals in apples and pears. According to BF values, pears extract twice as much Cu and Co from the soil compared to apples, and the extraction of other metals from the soil is the same for both types of fruit.

Defense mechanisms of Salmonella against antibiotics: a review

Salmonella is a foodborne pathogenic bacterium that causes salmonellosis worldwide. Also, Salmonella is considered a serious problem for food safety and public health. Several antimicrobial classes including aminoglycosides, tetracyclines, phenols, and β-Lactams are used to treat Salmonella infections. Antibiotics have been prescribed for decades to treat infections caused by bacteria in human and animal healthcare. However, intensive use of antibiotics resulted in antibiotic resistance (AR) among several foodborne bacteria including Salmonella. Furthermore, multi-drug resistance (MDR) of Salmonella has increased dramatically. In addition to MDR Salmonella, extensively drug resistant (XDR) as well as pan drug resistant (PDR) Salmonella were reported globally. Therefore, increasing AR is becoming a serious universal public health crisis. Salmonella developed many mechanisms to ensure its survival against antimicrobials. The most prominent defense mechanisms against these antibiotics include enzymatic inactivation, expelling drugs from the cell through efflux pumps, altering the structure of drugs, and changing or protecting the targets of drugs. Additionally, the formation of biofilms and plasmid-mediated AR by Salmonella, enhancing its resistance to various antibiotics, making it a challenging pathogen in both healthcare and food industry settings. This review focuses exclusively on providing a detailed overview of the mechanisms of AR in Salmonella.

Phytochemical Characterization of Bilberries and Their Potential as a Functional Ingredient to Mitigate Ochratoxin A Toxicity in Cereal-Based Products.

Mycotoxin contamination of cereals and cereal-based products is a serious problem for food safety. Antioxidant-rich ingredients such as bilberries (Vaccinium myrtillus L., VM) may mitigate their harmful effects. Firstly, total phenolic content, antioxidant activity, and analytical phytochemical composition (hydroxycinnamic and hydroxybenzoic acids, flavanols, flavonols, and anthocyanins) were assessed in lyophilized wild bilberries from Romania. Secondly, this study evaluated bilberries' effects on reducing ochratoxin A (OTA) bioaccessibility and cytotoxicity. An in vitro digestion model was developed and applied to four different types of bread: Control, VM (2%), OTA (15.89 ± 0.13 mg/kg), and OTA (16.79 ± 0.55 mg/kg)-VM (2%). The results indicated that VM decreased OTA bioaccessibility by 15% at the intestinal level. OTA-VM digests showed improved Caco-2 cell viability in comparison to OTA digests across different exposure times. Regarding the alterations in Jurkat cell line cell cycle phases and apoptosis/necrosis, significant increases in cell death were observed using OTA digests (11%), while VM addition demonstrated a protective effect (1%). Reactive oxygen species (ROS) analysis confirmed these findings, with OTA-VM digests showing significantly lower ROS levels compared to OTA digests, resulting in a 3.7-fold decrease. Thus, bilberries exhibit high potential as a functional ingredient, demonstrating protection in OTA mitigation effects.

Foods of the Future: Challenges, Opportunities, Trends, and Expectations.

Creating propositions for the near and distant future requires a design to catch the tide of the times and move with or against trends. In addition, appropriate, adaptable, flexible, and transformational projects are needed in light of changes in science, technology, social, economic, political, and demographic fields over time. Humanity is facing a period in which science and developing technologies will be even more important in solving food safety, health, and environmental problems. Adapting to and mitigating climate change; reducing pollution, waste, and biodiversity loss; and feeding a growing global population with safe food are key challenges facing the agri-food industry and the food supply chain, requiring systemic transformation in agricultural systems and sustainable future agri-food. The aim of this review is to compile scientific evidence and data, define, and create strategies for the future in terms of food security, safety, and sufficiency; future sustainable foods and alternative protein sources; factors affecting food and nutrition security and agriculture; and promising food systems such as functional foods, novel foods, synthetic biology, and 3D food printing. In this review, the safety, conservation, nutritional, sensory, welfare, and potential challenges and limitations of food systems and the opportunities to overcome them on the basis of new approaches, innovative interpretations, future possibilities, and technologies are discussed. Additionally, this review also offers suggestions for future research and food trends in light of future perspectives. This article focuses on future sustainable foods, alternative protein sources, and novel efficient food systems, highlights scientific and technological advances and new research directions, and provides a significant perspective on sustainability.

Bactericidal effect of ultrasound on glutinous rice during soaking and its influence on physicochemical properties of starch and quality characteristics of sweet dumplings

The soaking process of glutinous rice allows the growth and reproduction of microorganisms, which can easily cause food safety problems. In this work, the effects of different ultrasonic powers (150 W, 300 W, 450 W, and 600 W) on the bactericidal effect of glutinous rice, the physicochemical properties of starch and the quality characteristics of sweet dumplings were studied. Compared with soaking for 0 and 2 h, sonication of glutinous rice after soaking for 4 h was more effective at reducing the number of microorganisms in soaked glutinous rice, and the bactericidal effect increased with increasing ultrasound intensity. After 30 min, the total number of bacteria decreased by 2.04 log CFU/g. Moreover, ultrasonic treatment destroys the grain structure of glutinous rice starch, resulting in the formation of dents and cracks on the starch surface, increasing the amylose content, improving its expansion, reducing its short-range order and relative crystallinity, and altering its gelatinization characteristics. In addition, ultrasonic treatment increased the soup transparency of sweet dumplings from 51.8 % to 63.95 %, reducing their hardness, chewiness and adhesiveness. In summary, ultrasonic treatment can not only effectively kill microorganisms in soaked glutinous rice but also improve the quality of glutinous rice dumplings by changing the physicochemical properties of glutinous rice starch. The results of this study provide theoretical support for the application of ultrasonic technology in glutinous rice food production.

Dual excitation channel ratiometric fluorescent probes for visual and fluorescent detection of anthrax spore biomarker and tetracycline hydrochloride

Long-term and excessive use of tetracycline hydrochloride (TC) can lead to its accumulation in the environment, which can cause water contamination, bacterial resistance, and food safety problems. 2,6-Pyridine dicarboxylic acid (DPA) is a major biomarker of Bacillus anthracis spores, and its rapid and sensitive detection is of great significance for disease prevention and counter-terrorism. A bifunctional ratiometric fluorescent nanoprobe has been fabricated to detect DPA and TC. 3,5-dicarboxyphenylboronic acid (BOP) was intercalated into layered europium hydroxide (LEuH) by the ion-exchange method and exfoliated into nanosheets as a fluorescent nanoprobe (PNP). DPA and TC could significantly enhance the red fluorescence of Eu3+ through the antenna effect under different excitation wavelengths, while the fluorescence of BOP can be used as a reference based on the constant emission intensity, realizing ratiometric detection. A low limit of detection (LOD) for the target (DPA: 9.7 nM, TC: 21.9 nM) can be achieved. In addition, visual detection of DPA and TC was realized using color recognition software based on the obvious color changes. This is the first ratiometric fluorescent nanoprobe based on layered rare-earth hydroxide (LRH) for the detection of DPA and TC simultaneously, which opens new ideas in the design of multifunctional probes.

Food safety, voluntary recall and firm reputation

AbstractProduct recalls are direct remedies for producers in case of food safety problems. Unlike in the United States or other developed countries, in China, voluntary recalls are rarely documented in the food sector. The purpose of this paper is to address two questions: (1) why do firms adopt different recall strategies in different countries; (2) under what circumstances can voluntary recall help firms build up their food safety reputation? Based on the theory of collective reputation, we develop a dynamic model to incorporate firms' recall strategy and investigate the impact of such a strategy on industry collective reputation. The model takes into account production hazards: producers' lapses in food safety despite good‐faith efforts. Our results show that voluntary recall helps a firm to maintain a good historical record. Hence, firms are likely to achieve a high level of collective reputation under voluntary recall. However, a firm is willing to initiate voluntary recall only if the collective reputation is high enough. This explains the current situation in China: as consumers show little trust (belief in collective reputation is low), firms cannot recover the recall loss and thus have no incentive to initiate a voluntary recall.

Research Progress of Biosensor Based on Organic Photoelectrochemical Transistor.

In order to solve the food safety problem better, it is very important to develop a rapid and sensitive technology for detecting food contamination residues. Organic photoelectrochemical transistor (OPECT) biosensor rely on the photovoltage generated by a semiconductor upon excitation by light to regulate the conductivity of the polymer channels and realize biosensor analysis under zero gate bias. This technology integrates the excellent characteristics of photoelectrochemical (PEC) bioanalysis and the high sensitivity and inherent amplification ability of organic electrochemical transistor (OECT). Based on this, OPECT biosensor detection has been proven to be superior to traditional biosensor detection methods. In this review, we summarize the research status of OPECT biosensor in disease markers and food residue analysis, the basic principle, classification, and biosensing mechanism of OPECT biosensor analysis are briefly introduced, and the recent applications of biosensor analysis are discussed according to the signal strategy. We mainly introduced the OPECT biosensor analysis methods applied in different fields, including the detection of disease markers and food hazard residues such as prostate-specific antigen, heart-type fatty acid binding protein, T-2 toxin detection in milk samples, fat mass and objectivity related protein, ciprofloxacin in milk. The OPECT biosensor provides considerable development potential for the construction of safety analysis and detection platforms in many fields, such as agriculture and food, and hopes to provide some reference for the future development of biosensing analysis methods with higher selectivity, faster analysis speed and higher sensitivity.

Microbial Volatile Organic Compounds: Insights into Plant Defense.

Volatile organic compounds (VOCs) are low molecular weight molecules that tend to evaporate easily at room temperature because of their low boiling points. VOCs are emitted by all organisms; therefore, inter- and intra-kingdom interactions have been established, which are fundamental to the structuring of life on our planet. One of the most studied interactions through VOCs is between microorganism VOCs (mVOCs) and plants, including those of agricultural interest. The mVOC interactions generate various advantages for plants, ranging from promoting growth to the activation of defense pathways triggered by salicylic acid (systemic acquired resistance) and jasmonic acid (induced systemic resistance) to protect them against phytopathogens. Additionally, mVOCs directly inhibit the growth of phytopathogens, thereby providing indirect protection to plants. Among the current agricultural problems is the extensive use of chemicals, such as fertilizers, intended to combat production loss, and pesticides to combat phytopathogen infection. This causes problems in food safety and environmental pollution. Therefore, to overcome this problem, it is important to identify alternatives that do not generate environmental impacts, such as the application of mVOCs. This review addresses the protective effects of mVOCs emitted by microorganisms from different kingdoms and their implications in plant defense pathways.

Quality Regulation in the Global “Wine Periphery”: The Case of Late Imperial Rio de Janeiro (1880–1889)

ABSTRACT This article explores the consequences of the phylloxera crisis on Rio de Janeiro’s wine market, the resulting public health debate, and the administrative problem of quality regulation and consumer protection. As a peripheral market with relatively low purchasing power, the Brazilian capital became a destination for many cheap imitation wines from Europe and also developed its own artificial wine industry. By the mid-1880s this led to a fierce competition on Rio’s wine market, which in turn provoked an unprecedented public debate about wine qualities and public health. Thus, the article shows that the problem of food safety, brought to public attention by the wine question, occupied a central place on the health agenda of the medical profession as well as the government and health authorities in late Imperial Brazil, triggering regulatory interventions that followed European models.

Application of computer information technology in food quality safety and detection

Nowadays, food safety problems have occurred frequently, and how to ensure food quality safety has become the focus of attention of the whole world. While computer information technology has become a necessary means to control food quality safety along with the continuous improvement of information degree. Computer information technology is the general term mainly used for the management and processing of information, including acquisition, processing, expression, communication, management and evaluation of information. In this paper, the application of computer information technology applied in food industry at home and abroad was mainly summarized, including query and retrieval related information of food science, stimulation of the production process to effectively control the potential risk factors, fast calculation in the process of food production and consumption, network platform design of sensory evaluation instead of complex manual work, and realization the whole process of full traceability for food industrial chain, so as to provide effective supervision channels for the government, establish food industrial traceability system, improve the information degree in food management and play the role of information technology in food safety management and realize the value.

Review on the extension of shelf life for fruits and vegetables using natural preservatives.

Fruits and vegetables are important for the nutrition and health of individuals. They are highly perishable in nature because of their susceptibility to microbial growth. Foodborne pathogens create a significant problem for consumers, food businesses, and food safety. Postharvest factors, including transportation, environment, and preservation techniques, cause a reduction in product quality. The present world is using synthetic preservatives, which have negative impacts on consumer health. Food safety and demand for healthy foods among consumers, the scientific community, and the food industry resulted in the exploitation of natural preservatives, which play an important role in their effectiveness, prolonged shelf life, and safety. Natural preservatives include plants, animals, and microbiological sources with polymers to extend shelf life, improve quality, and enhance food safety. This review specifically focuses on mechanism of action of natural preservatives, spoilage of fruit and vegetables, the importance of edible film and coating on fruits and vegetables.

Acoustofluidic one-step production of plasmonic Ag nanoparticles for portable paper-based ultrasensitive SERS detection of bactericides

SERS measurements for monitoring bactericides in dairy products are highly desired for food safety problems. However, the complicated preparation process of SERS substrates greatly impedes the promotion of SERS. Here, we propose acoustofluidic one-step synthesis of Ag nanoparticles on paper substrates for SERS detection. Our method is economical, fast, simple, and eco-friendly. We adopted laser cutting to cut out appropriate paper shapes, and aldehydes were simultaneously produced at the cutting edge in the pyrolysis of cellulose by laser which were leveraged as the reducing reagent. In the synthesis, only 5 μL of Ag precursor was added to complete the reaction, and no reducing agent was used. Our recently developed acoustofluidic device was employed to intensely mix Ag+ ions and aldehydes and spread the reduced Ag nanoparticles over the substrate. The SERS substrate was fabricated in 1 step and 3 min. The standard R6G solution measurement demonstrated the excellent signal and prominent uniformity of the fabricated SERS substrates. SERS detection of the safe concentration of three bactericides, including tetracycline hydrochloride, thiabendazole, and malachite green, from food samples can be achieved using fabricated substrates. We take the least cost, time, reagents, and steps to fabricate the SERS substrate with satisfying performance. Our work has an extraodinary meaning for the green preparation and large-scale application of SERS.

Self-assembled thymol-betaine co-crystals with controlled release and hygroscopic properties as green preservatives for aflatoxin prevention

Mycotoxins are representative contaminants causing food losses and food safety problems worldwide. Thymol can effectively inhibit pathogen infestation and aflatoxin accumulation during grain storage, but high volatility limits its application. Here, a thymol-betaine co-crystal system was synthesized through grinding-induced self-assembly. The THY-TMG co-crystal exhibited excellent thermal stability with melting point of 91.2 °C owing to abundant intermolecular interactions. Remarkably, after 15 days at 30 °C, the release rate of thymol from co-crystal was only 55%, far surpassing that of pure thymol. Notably, the co-crystal demonstrated the ability to bind H2O in the environment while controlling the release of thymol, essentially acting as a desiccant. Moreover, the co-crystals effectively inhibited the growth of Aspergillus flavus and the biosynthesis of aflatoxin B1. In practical terms, the THY-TMG co-crystal was successful in preventing AFB1 contamination and nutrients loss in peanuts, thereby prolonging their shelf-life under conditions of 28 °C and 70% RH.

Phenotypic and genotypic characterization of antimicrobial resistance of non-typhoidal Salmonella from retail meat in California

Antimicrobial resistance (AMR) is a global emerging problem for food safety and public health. Retail meat is one of the vehicles that may transmit antimicrobial resistant bacteria to humans. Here we assessed the phenotypic and genotypic resistance of non-typhoidal Salmonella from retail meat collected in California in 2019 by the National Antimicrobial Resistance Monitoring System (NARMS) Retail Food Surveillance program. A total of 849 fresh meat samples were collected from randomly selected grocery stores in Northern and Southern California from January to December 2019. The overall prevalence of Salmonella was 15.31 %, with a significantly higher occurrence in Southern (28.38%) than in Northern (5.22 %) California. The prevalence of Salmonella in chicken (24.01 %) was higher (p < 0.001) compared to ground turkey (5.42 %) and pork (3.08 %) samples. No Salmonella were recovered from ground beef samples. The prevalence of Salmonella in meat with reduced antibiotic claim (20.35 %) was higher (p < 0.001) than that with conventional production (11.96 %). Salmonella isolates were classified into 25 serotypes with S. Kentucky (47.73 %), S. typhimurium (11.36 %), and S. Alachua (7.58 %) as predominant serotypes. Thirty-two out of 132 (24.24 %) Salmonella isolates were susceptible to all tested antimicrobial drugs, while 75.76 % were resistant to one or more drugs, 62.88 % to two or more drugs, and 9.85 % to three or more drugs. Antimicrobials that Salmonella exhibited high resistance to were tetracycline (82/132, 62.12 %) and streptomycin (79/132, 59.85 %). No significant difference was observed between reduced antibiotic claim and conventional production in the occurrence of single and multidrug resistance. A total of 23 resistant genes, a D87Y mutation of gyrA, and 23 plasmid replicons were identified from resistant Salmonella isolates. Genotypic and phenotypic results were well correlated with an overall sensitivity of 96.85 %. S. infantis was the most resistant serotype which also harbored the IncFIB (pN55391) plasmid replicon and gyrA (87) mutation. Data from Northern and Southern California in this study helps us to understand the AMR trends in Salmonella from retail meat sold in the highly populous and demographically diverse state of California.

The Effectiveness of LISTEXTM P100 in Reducing the Biofilm of Listeria spp. on Steel, Plastic, and Galvanised Surfaces.

Eliminating and managing L. monocytogenes, L. welshimeri, and L. ivanovii biofilms is a significant problem for food safety, as listeriosis is among the worst foodborne illnesses. The Listex P100 bacteriophage's bactericidal and inhibitory properties have been investigated in relation to varying strains of vegetative cells and biofilms of L. monocytogenes, L. welshimeri, and L. ivanovii. The phage concentrations of 109 and 1010 PFU/ml showed strong antibacterial activity against L. monocytogenes, L. welshimeri, and L. ivanovii at both 10°C and 30°C (P<0.05). In 96- well microplate experiments, bacteriophage treatment inhibited biofilm development and reduced biofilm by up to 57.6% (P ≤ 0.05). When compared to controls, Listex P100 bacteriophage significantly reduced the populations of L. monocytogenes, L. welshimeri, and L. ivanovii biofilms on the surfaces of galvanised, stainless steel, and plastic surfaces where holes were produced and the structure of Listeria spp. was disturbed. This study clearly demonstrated that L. monocytogenes, L. welshimeri, and L. ivanovii biofilms on galvanised, stainless steel, and plastic surfaces might be removed by using Listex P100 bacteriophage.

Degradation of Di (2-ethylhexyl) phthalic acid plasticizer in baijiu by a foam titanium flow reactor attached with hairpin-like structured peptide enzyme mimics

Because of the significant environmental and health hazards imposed by di(2-ethylhexyl) phthalate (DEHP), a common plasticizer, developing safe and green techniques to degrade DEHP plasticizer is of huge scientific significance. It has been observed that environmental contamination of DEHP may also induce serious food safety problems because crops raised in plasticizers contaminated soils would transfer the plasticizer into foods, such as Baijiu. Additionally, when plastic packaging or vessels are used during Baijiu fermentation and processing, plasticizer compounds frequently migrate and contaminate the product. In this study, hairpin-like structured peptides with catalytically active sites containing serine, histidine and aspartic acid were found to degrade DEHP. Furthermore, after incorporating caffeic acid molecules at the N-terminus, the peptides could be attached onto foam titanium (Ti) surfaces via enediol-metal interactions to create an enzyme-mimicking flow reactor for the degradation of DEHP in Baijiu. The structure and catalytic activity of peptides, their interaction with DEHP substrate and the hydrolysis mechanism of DEHP were discussed in this work. The stability and reusability of the peptide-modified foam Ti flow reactor were also investigated. This approach provides an effective technique for the degradation of plasticizer compounds.