Demand For Safe Food Research Articles

Polysaccharides from pineapple peel: Structural characterization, film-forming properties and its effect on strawberry preservation

The growing demand for food safety has stimulated the development of new environmentally friendly food packaging. It is the development trend of food packaging in recent years by using natural polysaccharides as carriers and adding bioactive ingredients extracted from plants to prepare multifunctional films with antioxidant, antimicrobial and biodegradable properties. Herein, three polysaccharide components (PPE40, PPE60, and PPE80) from pineapple peel were extracted by ultrasound-assisted hot water extraction combined with gradient ethanol precipitation method, which all showed a certain scavenging activities against DPPH, ABTS, and hydroxyl radical. Then, the composite films were prepared by adding PPE40, PPE60 and PPE80 to chitosan. The results of SEM, FT-IR and XRD analysis showed that PPE40, PPE60 and PPE80 could interact with chitosan matrix. Furthermore, the addition of PPE40, PPE60, and PPE80 could improve the mechanical properties of the films, and promote the antibacterial activity of the films against B. subtilis, S. aureus and E. coli. Finally, the application of the composite films to strawberries showed that the addition of PPE40, PPE60 and PPE80 could delay the rapid decay of strawberries during storage. The results of this study showed that pineapple polysaccharides have a potential to be applied in the field of food packaging.

Advances and Drawbacks of Sous-Vide Technique-A Critical Review.

The sous-vide (SV) technique, notable for its precision and ability to preserve food quality, has become a transformative method in culinary arts. This review examines the technical aspects, applications, and limitations of SV, focusing on its impact on food safety, nutritional retention, and quality parameters across various food matrices such as meats, seafood, vegetables, and semi-prepared products. Through an extensive literature review, the study highlights the use of natural inhibitors and essential oils to enhance microbial safety and explores the nutritional benefits of SV in preserving vitamins and minerals. The findings suggest that while SV offers significant benefits in terms of consistent results and extended shelf life, challenges remain in terms of equipment costs and the necessity for specific training, and although sufficient for food preparation/processing, its effectiveness in eliminating microbial pathogens, including viruses, parasites, and vegetative and spore forms of bacteria, is limited. Overall, the research underscores SV's adaptability and potential for culinary innovation, aligning with modern demands for food safety, quality, and nutritional integrity.

Cellulose-based biomass composite films for plastic replacement: Synergistic UV shielding, antibacterial and antioxidant properties

With the gradual increase in environmental awareness and the growing demand for food safety, sustainable and environmentally friendly cellulose-based materials have become a promising alternative to petroleum-based plastics. However, in practice, packaging materials prepared from cellulose-based materials still have some unsatisfactory properties, such as monofunctionality, low transparency, and lack of UV shielding, antibacterial or antioxidant properties. Herein, a novel synthetic strategy is proposed in this paper, specifically, tannic acid (TA), a green natural extract with antibacterial and antioxidant properties, is used as a plasticizer and cross-linker, and oxidized cellulose nanocellulose (TOCN) modified with folic acid (FA) grafting is blended with TA, and cellulose-based biomass thin films with ultraviolet (UV) shielding, antibacterial, and antioxidant properties have been successfully prepared by using a simple vacuum-assisted filtration. The experimental results showed that the films could completely block ultraviolet light at wavelengths of 200–400 nm while providing 81.47 % transparency in the visible spectrum, while the introduction of TA conferred excellent antibacterial and antioxidant capabilities with antioxidant activity of up to 95 %, and also resulted in films with excellent mechanical properties. Therefore, this work provides ideas for the design and manufacture of competitive biomass green packaging materials, laying the foundation for future applications in food packaging.

Optimising Technological Treatments with the Taguchi Approach to Reduce Acrylamide and Improve Colour Properties in Potato Chips

Today, consumer demand for food safety, especially in fried foods, is increasing. In the first place, it is demanded to reduce the amount of food toxins, in particular toxins resulting from the thermal process such as acrylamide. This study aimed to examine the effect of different technological treatments on the optimisation of minimum acrylamide and maximum colour properties by applying the Taguchi approach in the production of chips. In this study, design of experiments, signal-to-noise (S/N) ratio, analysis of variance, and regression analysis methods were used to optimise the minimum acrylamide and redness (a*), maximum brightness (L*), and yellowness (b*) values. The optimal parameters for acrylamide were found to be 90 °C slice washing temperature, 175 °C frying temperature, and 175 s frying time. The optimal parameters for colour analysis were determined as 30 °C slice washing temperature, 175 °C frying temperature, and 175 s frying time. Analysis of variance showed that frying temperature and time had a significant (p < 0.05) effect on the results. It was determined that a decrease in frying temperature and time led to a decrease in the amount of acrylamide and redness and an increase in brightness and yellowness. According to the results of the analysis of variance, the most effective technological treatments were frying temperature with effect rates of 37.45% and 60.26% for acrylamide and L* values, respectively, and frying time with effect rates of 40.50% and 44.19% for a* and b* values, respectively. As a result of the study, through the Taguchi method, while quality features in chips were preserved, the amount of acrylamide was reduced.

Gardenia yellow pigment: Extraction methods, biological activities, current trends, and future prospects

Food coloring plays a vital role in influencing consumers' food choices, imparting vibrant and appealing colors to various food and beverage products. Synthetic food colorants have been the most commonly used coloring agents in the food industry. However, concerns about potential health issues related to synthetic colorants, coupled with increasing consumer demands for food safety and health, have led food manufacturers to explore natural alternatives. Natural pigments not only offer a wide range of colors to food products but also exhibit beneficial bioactive properties. Gardenia yellow pigment is a water-soluble natural pigment with various biological activities, widely present in gardenia fruits. Therefore, this paper aims to delve into Gardenia Yellow Pigment, highlighting its significance as a food colorant. Firstly, a thorough understanding and exploration of various methods for obtaining gardenia yellow pigment. Subsequently, the potential functionality of gardenia yellow pigment was elaborated, especially its excellent antioxidant and neuroprotective properties. Finally, the widespread application trend of gardenia yellow pigment in the food industry was explored, as well as the challenges faced by the future development of gardenia yellow pigment in the field of food and health. Some feasible solutions were proposed, providing valuable references and insights for researchers, food industry professionals, and policy makers.

Review on functionalized pectin films for active food packaging

AbstractOwing to environmental distresses and growing demands for food safety, biopolymers have found noble applications in food packaging films as they are biodegradable, biocompatible and non‐toxic. Pectin, polysaccharide based biomass was considered a promising substrate in fabricating polymeric films because of its advantages concerning film‐forming ability, low cost, bioactivity, compatibility with other polymers with a distinctive oxygen barrier capacity, which helps in improving shelf life of commodities. Introducing active agents into the packaging films focus to prolong the shelf life and preserve the sensorial quality and safety of packaged foods devoid of contamination. Antimicrobial agents or secondary metabolites derived from plants and fungi are perceived as promising natural bio‐active agents integrated into films to prevent microbial deterioration. Pectin has been greatly utilized in active packaging films incorporated with natural additives such as essential oils, nanoparticles, free fatty acids and phenolic compounds that inhibit/retard the growth of major foodborne pathogens. The above‐mentioned functionalization of pectin films with bio‐active compounds enhanced microbial resistance and contemporarily influenced the mechanical strength and barrier properties of the film. This review is intended to focus on the background of pectin, its source and the utilization of pectin in active packaging films, and the types and method of incorporation of natural compounds. Specific emphasis has been given to the types of bioactive compounds incorporated into pectin films and their impact on the functional properties of the films. This review will benefit researchers in exploring innovative methods of incorporating bioactive compounds into pectin‐based films.

Consumer Food Safety Awareness and Demand for Fluid Milk: A Case Study from India

ABSTRACT: Despite significant improvements in consumers’ food safety awareness, the literature provides little or no evidence of the impact of food safety awareness on the quantity of fluid milk consumers purchased. This is especially true for India’s consumers, where the economy is changing rapidly regarding food marketing, incomes, urbanization, and increased demand for food safety.The study is based on primary data from a survey of consumers from urban and peri-urban districts in India. The survey collected information on socioeconomic characteristics, dairy consumption, purchasing patterns, and food safety awareness. This study first creates a food safety awareness (FSA) index to measure consumers’ awareness of food safety attitudes and perceptions. It investigates the factors affecting consumers’ food safety awareness and FSA’s impact on fluid milk demand. The study uses a newly developed impact evaluation method, continuous treatment matching estimation, and dose-response functions (DRFs) to assess the impact of FSA on consumers’ fluid milk purchases. Findings show that educational attainment, sources of information on food safety, age, and gender of the head of the household significantly influenced consumers’ food safety awareness. Further, the study finds that food safety awareness positively impacts the demand for fluid milk. After controlling for milk prices and family income, Indian consumers aware of and adopt seven or more food safety habits or practices are likely to demand more fluid milk. Results are robust to specifications, income levels, and the location of households. The link between food safety awareness and the quantity of milk purchased implies a latent consumer demand for food safety. Any consumer awareness programs and policies supporting milk and its products’ hygienic production will likely increase demand for milk and dairy products. At a policy level, credible systems can be put in place for food certification and labeling, which enhance the availability of safe and hygienic food.

Improvement of meat product traceability system using digital technologies

This research work addresses the issue of enhancing the effectiveness of the meat product traceability system using modern digital technologies. In the context of increasing demand for food safety and minimizing risks to consumer health, ensuring accurate and reliable traceability of the origin, production conditions, and storage of meat products has become a crucial aspect. The aim of the study is to create an integration between the meat product traceability system and contemporary digital technologies. During the work, an analysis of existing problems and shortcomings in the current traceability system is planned, as well as an exploration of experiences from other industries where digital technologies have been successfully implemented to ensure transparency and data authenticity. In analyzing technological risks, all possible types of threats were considered. The sources of danger include incoming raw materials, the technological line of semi-smoked sausages, and their storage. The use of digital technologies allows for continuous data monitoring using Wi-Fi, combined thermometers, and quality logs. It is anticipated that the implementation of such a system will significantly reduce risks, improve product tracking, and enhance consumer trust in the quality and safety of meat products. The outcomes of this research will be valuable for food industry enterprises, regulatory bodies, and the scientific community that are striving to improve the control and traceability system of food products, utilizing cutting-edge digital innovations.

Protein nanoscaffold enables programmable nanobody-luciferase immunoassembly for sensitive and simultaneous detection of aflatoxin B1 and ochratoxin A

Mycotoxins produced by fungi can contaminate various foods and pose significant health risks. Ensuring food safety demands rapid, highly sensitive analytical techniques. One-step Bioluminescent Enzyme Immunoassays (BLEIAs) employing nanobody-nanoluciferase fusion proteins have recently garnered attention for operational simplicity and heightened sensitivity. Nevertheless, fixed nanobody:nanoluciferase ratios in fusion proteins restrict the customization and sensitivity of traditional BLEIAs. In this study, we present a Scaffold Assembly-based BLEIA (SA-BLEIA) that overcomes these limitations through the programmable conjugation of nanobodies and luciferases onto 60-meric protein nanoscaffolds using SpyTag/SpyCatcher linkages. These nanoscaffolds facilitate the adjustable coupling of anti-aflatoxin B1 and anti-ochratoxin A nanobodies with luciferases, optimizing nanobody/luciferase ratios and diversifying specificities. Compared to conventional methods, SA-BLEIA demonstrates considerably elevated sensitivity for detecting both toxins. The elevated local concentration of luciferase significantly amplifies bioluminescence intensity, permitting reduced substrate consumption and cost-effective detection. The usage of dual-nanobody conjugates facilitates the quantification or simultaneous detection of both mycotoxins in a single test with shared reagents. The assay exhibits exceptional recovery rates in spiked cereal samples, strongly correlating with outcomes from commercial ELISA kits. Overall, this adaptable, highly sensitive, cost-effective, and multiplexed immunoassay underscores the potential of tunable scaffold assembly as a promising avenue for advancing bioanalytical diagnostic tools.

A Blockchain-Based Framework to Make the Rice Crop Supply Chain Transparent and Reliable in Agriculture

Rice is one of the major food crops across the globe, and its quality and safety highly influence human health. It is the basis of many different products, including rice flour, rice bread, noodles, rice vinegar, and others. Therefore, the rice supply chain has garnered increasing attention due to the high demand for food safety. Furthermore, malpractices in the rice supply chain can impact farmers by generating low revenues despite their great efforts in rice cultivation. In addition, they would cause governments to suffer significant economic losses due to the high cost of importing rice crops from other countries during the off-season. These issues derive from the lack of reliability, trust, transparency, traceability, and security in the rice supply chain. In this research, we propose a secure, trusted, reliable, and transparent framework based on a Blockchain for rice crop supply chain’s traceability from farm to fork. A new crypto token, the Rice Coin (RC), is introduced to keep a record of all transactions between the stakeholders of the rice supply chain. Moreover, the proposed framework includes an economic model and a crypto wallet and introduces an Initial Coin Offering (ICO) for the RC. Based on smart contracts, a transaction processing system was developed for the transparency and traceability of rice crops, including the conversion of the RC to fiat currency. Furthermore, the InterPlanetary File System (IPFS) is proposed in this research to store encrypted data of companies, retailers, and farmers, so to increase data security, transparency, and availability. In the end, the experimental results showed a better performance of the proposed framework compared to already available supply chain solutions in terms of transaction verification time, transaction average gas cost, and new block latency.

Au@4-MBA@Ag NPs labeled SERS lateral flow immunoassay for ultrasensitive and quantitative detection of Salmonella enteritidis

Salmonella enteritidis (S. enteritidis) is a common zoonotic pathogen which can cause acute gastroenteritis characterized with fever, diarrhea and vomiting, posing a serious threat to public health. Rapid and accurate detection of S. enteritidis is in great demand for food safety and timely diseases treatment. In the present study, a surface-enhanced Raman scattering lateral flow immunoassay sensor (SERS-LFIA) was developed for the rapid, ultrasensitive and quantitative detection of S. enteritidis using Au-core Ag-shell nanoparticles sandwiched with Raman molecules. S. enteritidis could be quantitatively detected by SERS-LFIA at concentrations ranging from 1 × 103 to 1 × 107 CFU mL−1, with limits of detection (LOD) of 1 × 105 CFU mL−1 and 1.36 × 102 CFU mL−1 based on naked eye observation and SERS signal analysis, respectively. No cross-reaction was observed from other serotypes of Salmonella and other common pathogens. The coefficient of variation for both the intra- and inter-batch repetitive tests were less than 10%. The recovery rates of spiking feces and eggshells were between 94.8% and 104.7%. Thus, this SERS-LFIA is able to quantitatively detect S. enteritidis in 20 min with high sensitivity, specificity, repeatability, and could be a promising method for the early detection of S. enteritidis in various clinical samples.

The food industry supply chain in the light of COVID-19: the constraint and development of measures to ensure food safety and quality control

The international borders opening led to goods and people migration with a significant change of consumer behavior, this favored new food-borne diseases uprising and outbreaks worldwide. Recently, the resurgence of COVID-19 has highlighted the limitations of the world-health surveillance measures and caused unprecedented effects on the food supply chain and the food industry. Amid this recent crisis, aroused population and scientific concerns and the demand for food safety and quality control improvement trough-out the food supply chain. To solve this constraint, it is primordial to understand food supply chain contamination stem and develop new, more sensitive, specific effective, and efficient point-of-care detection methods to segregate food items at an early pathogen contamination stage. 3D printing technology positioned itself as the solution because it enables the synergistic action of new molecular detection methods combined with the new 3D printing techniques for the production of high end-point biosensors capable of direct testing of food along the production line and the food supply chain. Because 3D printed biosensors are user and eco-friendly, convenient, fast, and take away the laboratory analysis constraints, 3D printed molecular biosensor devices are the new trend to enhance the food safety screening performances and guarantee food quality. We aimed to present how impactful COVID-19 was in the food industry and food supply chain across the globe and the adaptive measures that have been put in place to ensure consumer were provided with safe food with the usage of biosensors and 3D printed technology.

Synergetic effect of ZnS: SnS2/reduced graphene oxide heterostructures for electrochemical detection of carcinogenic pollutant Maleic hydrazide

To ensure agricultural productivity, food security, and an ever-increasing demand for food safety, herbicides are employed to maintain unrestrained weed growth during crop production. Maleic hydrazide (MD) has become an important commonly consumed herbicide due to its various uses which include inhibition of sprouting in vegetables and stored root crops. But unfortunately, MD has genotoxic and carcinogenic effects, thus monitoring the presence of MD in food samples is of prime importance. Therefore, an electrochemical sensing platform based on heterojunctions of ZnS/SnS2/RGO was used for the electrochemical detection of MD. The composite ZnS:SnS2@RGO was synthesized via the hydrothermal method providing a large specific surface area, superior electrical conductivity, rich electrocatalytic sites, and a fast charge transfer rate. A good synergetic effect between the ZnS:SnS2 and RGO results in a wide linear range of 0.01–2359 µM, low LOD of 0.02 µM, and a good anti-interfering capability towards the detection of MD. In addition, good recovery results were obtained for the potato and water samples. Hence, the detection of MD was successfully demonstrated using ZnS:SnS2@RGO composite with superior stability and can be recommended for food monitoring applications.

Recent Advances in Halal Bioactive Materials for Intelligent Food Packaging Indicator.

Food safety and security are top priorities for consumers and the food industry alike. Despite strict standards and criteria for food production processes, the potential for food-borne diseases due to improper handling and processing is always present. This has led to an urgent need for solutions that can ensure the safety of packaged foods. Therefore, this paper reviews intelligent packaging, which employs non-toxic and environmentally friendly packaging with superior bioactive materials that has emerged as a promising solution. This review was prepared based on several online libraries and databases from 2008 to 2022. By incorporating halal bioactive materials into the packaging system, it becomes possible to interact with the contents and surrounding environment of halal food products, helping preserve them for longer periods. One particularly promising avenue of research is the use of natural colourants as halal bioactive materials. These colourants possess excellent chemical, thermal, and physical stabilities, along with antioxidant and antimicrobial properties, making them ideal candidates for use in intelligent indicators that can detect food blemishes and prevent pathogenic spoilage. However, despite the potential of this technology, further research and development are needed to promote commercial applications and market development. With continued efforts to explore the full potential of natural colourants as halal bioactive materials, we can meet the increasing demand for food safety and security, helping to ensure that consumers have access to high-quality, safe, and nutritious foods.

DEVELOPMENT OF BIODEGRADABLE FILMS USING NANOCELLULOSE FOR FOOD PACKAGING APPLICATION – REVIEW

Due to the development of nanotechnology and changing customer demands for food safety and hygiene, the food packaging industry is growing significantly. In today's worldwide market, active packaging offers a number of advantages over traditional wrapping because of its capacity to absorb or release substances to improve the shelf life of food. Traditional food packaging materials are difficult to recycle and are made from nonrenewable fossil fuels. Development of Biodegradable films using Nano cellulose can be a good replacement for synthetic plastic packaging materials and can be a good solution for this problem. Other than that it has multiple advantages regarding tensile and physical properties, also in reducing health hazards. Tensile and physical characteristics are improved and water vapor permeability is decreased with the addition of cellulose nanoparticles to the biodegradable films/biodegradable composite films. The production of biodegradable materials employing Nano cellulose has been covered in this review study in four different ways, including extracts from agricultural waste, rice husk, various plant extracts, and biopolymer composite material in food packaging. The reason for using Nano cellulose based Biodegradable films in food packaging are also reviewed in this article. The key points for the future research in overcoming the problems related to Nano cellulose, biodegradable films are also predicted in the paper

Metabolic engineering and optimization of Escherichia coli co-culture for the de novo synthesis of genkwanin.

Genkwanin has various significant roles in nutrition, biomedicine, and pharmaceutical biology. Previously, this compound has been chiefly produced by plant-originated extraction or chemical synthesis. However, due to increasing concern and demand for safe food and environmental issues, the biotechnological production of genkwanin and other bioactive compounds based on safe, cheap, and renewable substrates has gained much interest. This paper described recombinant Escherichia coli-based co-culture engineering that was reconstructed for the de novo production of genkwanin from D-glucose. The artificial genkwanin biosynthetic chain was divided into two modules in which the upstream strain contained the genes for synthesizing p-coumaric acid from D-glucose. And, the downstream module contained a gene cluster that produced the precursor apigenin and the final product, genkwanin. The Box-Behnken design, a response surface methodology, was used to empirically model the production of genkwanin and optimize its productivity. As a result, the application of the designed co-culture improved the genkwanin production by 48.8±1.3mg/L or 1.7-fold compared to the mono-culture. In addition, the scale-up of genkwanin bioproduction by bioreactor resulted in 68.5±1.9mg/L at a 48h time point. The combination of metabolic engineering and fermentation technology was therefore a very efficient and applicable approach to enhance the production of other bioactive compounds.

Review Article: Development of biodegradable films using nanocellulose for food packaging application

Due to the development of nanotechnology and changing customer demands for food safety and hygiene, the food packaging industry is growing significantly. In today's worldwide market, active packaging offers a number of advantages over traditional wrapping because of its capacity to absorb or release substances to improve the shelf life of food. Traditional food packaging materials are difficult to recycle and are made from nonrenewable fossil fuels. The development of biodegradable films using Nano cellulose can be a good replacement for synthetic plastic packaging materials and can be a good solution for this problem. Other than that it has multiple advantages regarding tensile and physical properties, also as reducing health hazards. Tensile and physical characteristics are improved and water vapor permeability is decreased with the addition of cellulose nanoparticles to the biodegradable films/biodegradable composite films. The production of biodegradable materials employing Nano cellulose has been covered in this review study in four different ways, including extracts from agricultural waste, rice husk, various plant extracts, and biopolymer composite material in food packaging. The reason for using Nano cellulose-based biodegradable films in food packaging is also reviewed in this article. The key points for future research related to Nanocellulose and biodegradable films.

Predictions of multiple food quality parameters using near-infrared spectroscopy with a novel multi-task genetic programming approach

In order to meet the increasing demand for food safety and quality, new methods for simultaneous and rapid determination of multiple food quality parameters (FQPs) are urgently needed in the food industry. Incorporating near-infrared (NIR) spectroscopy and spectral prediction model for rapid, repeatable, non-destructive, and low running costs quantitative analysis of FQPs is enjoying increasing popularity in the food industry. However, most existing spectrum-based prediction models are trained under a single-task learning framework, that is, a prediction model for each quality parameter and spectrum is constructed separately. This paradigm ignores possible connections among prediction tasks of different FPQs, which may result in the performance degradation of a single FPQ prediction model. This study proposes a novel multi-task genetic programming-based approach named EM4GPO for building multiple FQPs predictions simultaneously. In EM4GPO, the multi-dimensional trees are used to encode the raw NIR spectrum to shared features of multiple FQPs; for each FQP, a least square support vector regression (LS-SVR) modeling is performed on the shared features to obtain private features and prediction model; during the optimization process, a new algorithm is developed to optimize the previously obtained shared and private features, and LS-SVR prediction models through population evolution by combining the multidimensional multiclass genetic programming with multidimensional populations optimization method with nondominated sorting method. The proposed EM4GPO model is evaluated and compared with nine popular NIR prediction models using 10 NIR spectral datasets. The experimental results showed that EM4GPO outperformed other commonly used methods in all datasets which indicates that EM4GPO is competitive and effective in solving the problem of multiple FQPs predictions using the NIR spectrum.

Applications of Bacteriocins of Lactic Acid Bacteria in Biotechnology and Food Preservation: A Bibliometric Review

Introduction: Due to the growing prevalence of antibiotic resistance in microorganisms and the demand for safe food, there is increasing interest in using natural bioproducts such as the antimicrobial peptides bacteriocins to extend the shelf-life of foods. This is because of their spectrum of activity, ease of synthesis and applicability. This study reports on the global trends in lactic acid bacteria (LAB) bacteriocins based research publications in the Web of Science core collections within the last 20 years (2000-2019), with specific focus to their applications in biotechnology and food science. Methods: Data analysis was undertaken using VOSviewer and HistCite software to evaluate relationships between articles and visualise research linkages amongst authors, institutions and countries. Results: In the 20 years under review, a total of 1741 bacteriocin related articles were published, with the most cited publication examining the anti-infective activity of Lactobacillus salivarius. The highest research output was recorded by the United States, followed by Spain and China. However, Europe as a continent had the highest research output with a higher inter-institution collaboration network and stronger food safety legislations. Discussion: The bibliometric analysis gave insights into the research areas, cooperation network of authors, co-citation maps and co-occurrence of keywords utilized in the research field and indicates that bacteriocin-based research is highly multidisciplinary with a global reach. Conclusion: Key focus is on the control of foodborne disease pathogens, search for new producer organisms and approaches to improve bacteriocin yield and application. This class of antimicrobial peptides has the potential to replace chemical food preservatives in the future.

Effects of Rubus fruticosus and Juniperus oxycedrus derivatives on culturability and viability of Listeria monocytogenes

The consumers’ demand for safe foods without chemical additives increased the research for green solutions, based on natural antimicrobials. Plants can be an important source of bioactive compounds able to prevent the development of foodborne pathogens and spoilage microflora. This paper aimed to characterize phenolic extracts (PEs) and essential oils (EOs) obtained from Mediterranean Rubus fruticosus leaves and Juniperus oxycedrus needles and to evaluate their antimicrobial effects against Listeria monocytogenes Scott A. The growth dynamics with sub-lethal concentrations of plant derivatives were modeled and flow cytometry was used to better evidence the effect on cell viability and culturability. The results showed that these plant derivatives affected the growth of L. monocytogenes, increasing lag phase (about 40 h in the presence of PEs vs. 8 h in the control) and decreasing the final cell load of at least 1 log cycle with respect to the control. R. fruticosus EO was the most effective, determining an initial decrease of cell counts of about 6 log cycles, followed by a restart of growth after 10 h, with rate similar to the control (0.08 with R. fruticosus EO vs. 0.09 ((log CFU/ml)/h in the control) but significantly lower final cell load (7.33 vs. 8.92 log CFU/ml). According to flow cytometry, only R. fruticosus EO induced a relevant increase of dead cells, while the other plant derivatives determined different extent of sub-lethal cell injury. The discrepancy observed in some cases between viability and culturability could indicate the presence of cells not able to grow in culture media, whose fate needs to be further investigated to assess their potential recovery, thus bringing to an overestimation of the antimicrobial effect of these substances. This research contributed to increase the knowledge of these underused raw materials such as blackberry leaves and juniper needles that can be exploited in food and other industries.