UHPLC-MS/MS and GC-MS Metabolic Profiling of a Medicinal Flourensia Fiebrigii Chemotype.

The comparative metabolic profiling and their biological properties of eight extracts obtained from diverse parts (leaves, flowers, roots) of the medicinal plant Flourensia fiebrigii S.F. Blake, a chemotype growing in highland areas (2750 m a.s.l.) of northwest Argentina, were investigated. The extracts were analysed by GC-MS and UHPLC-MS/MS. GC-MS analysis revealed the presence of encecalin (relative content: 24.86 %) in ethereal flower extract (EF) and this benzopyran (5.93 %) together sitosterol (11.35 %) in the bioactive ethereal leaf exudate (ELE). By UHPLC-MS/MS the main compounds identified in both samples were: limocitrin, (22.31 %), (2Z)-4,6-dihydroxy-2-[(4-hydroxy-3,5-dimethoxyphenyl)methylidene]-1-benzofuran-3-one (21.31 %), isobavachin (14.47 %), naringenin (13.50 %), and sternbin, (12.49 %). Phytocomplexes derived from aerial parts exhibited significant activity against biofilm production of Pseudomonas aeruginosa and Staphylococcus aureus, reaching inhibitions of 74.7-99.9 % with ELE (50 µg/mL). Notably, the extracts did not affect nutraceutical and environmental bacteria, suggesting a selective activity. ELE also showed the highest reactive species scavenging ability. This study provides valuable insights into the potential applications of this chemotype.

Green synthesis of zinc oxide nanoparticles using novel bacterium strain (Bacillus subtilis NH1-8) and their in vitro antibacterial and antibiofilm activities against Salmonellatyphimurium.

Zinc oxide nanoparticles (ZnO NPs) are used in a range of applications, including food packaging, preservation, and storage. In the current investigation, extracellular green synthesis of ZnO NPs through an simple, eco-friendly, and rapid approach using a novel bacterial strain (Bacillus subtilis NH1-8) was studied. To assess the morphological, optical, and structural properties of ZnO NPs, transmission electron microscopy (TEM), energy-dispersive X-ray (EDX), scanning electron microscopy (SEM), fourier transform infrared (FTIR) spectroscopy, ultraviolet-visible (UV-vis) spectroscopy, and X-ray diffraction (XRD) techniques were carried out. In addition, disk diffusion, minimum bactericidal concentration (MBC), and minimum inhibitory concentration (MIC) methods were performed to determine the antibacterial activity of ZnO NPs. The average size of biosynthesized ZnO NPs was 39 nm, exhibiting semi-spherical, which was confirmed by TEM analyses. The UV-vis spectroscopy exhibited the absorption peak at 200-800nm. The ZnO NPs have shown effective antimicrobial and antibiofilm activities against S. typhimurium. Thus, biosynthesized ZnO NPs could be exploited as a breakthrough technology in the surface coating of food containers and cans to minimize contamination by S. typhimurium.

Antimicrobial food packaging integrating polysaccharide-based substrates with green antimicrobial agents: A sustainable path.

Food spoilage and waste, human and animal poisoning, and even death caused by foodborne microorganisms remain extensive concerns in food safety. The global demand for functional, eco-friendly, and efficient antimicrobial food packaging is increasing. However, the bacteriostatic or bactericidal effects of most conventional food packaging display limited action, and their major components are petrochemical materials (non-renewable, non-biodegradable, and not environmentally friendly), and the current target microorganisms easily acquire drug-resistant. Therefore, the development of more effective, sustainable and safe antimicrobial materials has become a research hotspot in food packaging. This paper systematically reviews the latest research on antimicrobial active packaging materials combining renewable and biodegradable polysaccharide-based substrates with green organic guanidine-based polymers, inorganic chlorine dioxide, or natural antimicrobial agents (such as essential oils, other plant extracts, chitosan, propolis, protein, bacteriocin, probiotics, and bacteriophages). The compositions, characteristics, antimicrobial mechanisms, and food applications of the various types of sustainable antimicrobial materials are updated, and future trends are explored. Although they show impressive properties, further studies are required to confirm the safety and efficacy of these materials as a majority of the studies have been conducted under laboratory conditions. This review provides theoretical and technical support for the development of new antimicrobial food packaging and extending the shelf-life of foods.

Plant Extract and Essential Oil Application against Food-Borne Pathogens in Raw Pork Meat.

Herbal and plant extracts are being applied for a wide range of foods against different types of food-borne pathogens. In the present study, ethanolic and aqueous extracts (2% w/v) from cranberry (Vaccinium macrocarpon) and pomegranate (Punica granatum L.) plants were applied alone or in combination with two essential oils (thyme and oregano in a concentration of 0.150 µg/g) in pork meatballs and their antimicrobial activity was estimated. The extracts exhibited promising results (aqueous and ethanolic extracts of pomegranate and cranberry in a food-compatible concentration of 2% w/v) were applied to raw pork meatball production and their antimicrobial activity was recorded versus Enterobacteriaceae, total mesophilic bacteria, yeasts/molds, Staphylococcus spp., Pseudomonas spp. and lactic acid bacteria (LAB). The outcome demonstrated that meatballs containing aqueous extracts of pomegranate were more resistant to spoilage compared to all the other samples since they were preserved for more days. The chemical profiles of plant extracts were determined through LC-QTOF/MS and the chemical composition of the essential oils applied was determined with the use of GC/MS in order to identify the substances involved in the observed antimicrobial activity. Phenolic acids (quinic acid, chlorogenic acid), monoterpenes (p-cymene, carvacrol, thymol, limonene), organic acids (citric acid) and phenols were the main constituents found in the plant extracts and essential oils applied. These extracts of plant origin could be used as natural preservatives in meat products, even in low concentrations.

Bio-fabrication of Selenium Nanoparticles Using Baker's Yeast Extract and Its Antimicrobial Efficacy on Food Borne Pathogens.

In the current study, selenium nanoparticles (SeNPs) were biosynthesized via extract of baker's yeast (Saccharomyces cerevisiae) for a green, economic, and eco-friendly strategy. The biosynthesized SeNPs were characterized using UV-vis, XRD, FTIR, DLS, and TEM. The particulates showed a spherical morphology with diameters between 4 and 51 nm; FTIR studies on NPs show functional groups corresponding to metabolites (proteins), which reduces and stabilizes the nanoparticle. Antimicrobial efficacy of biosynthesized SeNPs against food borne pathogens was assessed. SeNPs showed promising antimicrobial action against food borne pathogens (Escherichia coli, Staphylococcus aureus, Aspergillus fumigatus, and Aspergillus niger) with a minimal inhibitory concentration (MIC) of 62.5, 125, 250, and 500 µg/mL against Staphylococcus aureus, Escherichia coli, Aspergillus fumigatus, and Aspergillus niger, respectively. In conclusion, the biosynthesized SeNPs using extract of baker's yeast are promising as a safe antimicrobial agent against food pathogens. Hence, the biosynthesized SeNPs using baker's yeast extract exhibit antimicrobial activities and could be a useful efficacious antimicrobial agent in the preservation of food and medical field.

Effects of Green Tea Powder, Pomegranate Peel Powder, Epicatechin and Punicalagin Additives on Antimicrobial, Antioxidant Potential and Quality Properties of Raw Meatballs.

Alternative technologies, which have been developed in order to meet the consumers' demand for nourishing and healthy meat and meat products, are followed by the food industry. In the present study, it was determined, using the HPLC method, that green tea contains a high level of epicatechin (EP) under optimal conditions and that pomegranate peel contains a high level of punicalagin (PN). Green tea, pomegranate peel, EP and PN were added to meatballs at different concentrations in eight groups. The antioxidant capacities of extracts were measured. The antimicrobial activity was examined for 72 h using three different food pathogens. The highest level of antimicrobial activity was achieved in the 1% punicalagin group, whereas the minimum inhibition concentration (L. monocytogenes, S. typhimurium) was found to be 1.87 mg/mL. A statistically significant decrease was found in FFA, POV and TBARS levels of meatballs on different days of storage (p < 0.05). When compared to the control group, the bioactive compounds preserved the microbiological and chemical properties of meatballs during storage at +4 °C (14 days). It was concluded that the extracts with high EP and PN concentrations can be used as bio-preservative agents for meat and meat products.

MacConkey broth purple provides an efficient MPN estimation method for Shigatoxigenic Escherichia coli.

MacConkey broth purple provides a more efficient method for Most Probable Number estimation for Shigatoxigenic Escherichia coli (E.coli) than the process of bacterial enrichment in buffered peptone water followed by detection on MacConkey agar, since it is a single-step process that gives comparable results in plant extracts.

Inactivation effect of marination liquids prepared with koruk juice and dried koruk pomace on Salmonella Typhimurium, Escherichia coli O157:H7 and Listeria monocytogenes inoculated on meat.

The aim of this study was to determine the effects of marination liquids prepared with koruk juice and dried koruk pomace in terms of meat safety. In the study, marination liquids containing two different concentrations of koruk juice (25% and 50%) or dried koruk pomace (1% and 2%) were prepared separately with or without ingredients (1% salt and 0.1% thyme). Meat samples inoculated with two different levels (≅3 log and ≅6 log) of food-borne pathogens (S. Typhimurium, E. coli O157:H7 and L. monocytogenes) were marinated at 4 °C for different times (2, 24 and 48 h) and the effects of the treatment on target pathogens were determined. As a result of marinating process, the counts of S. Typhimurium, E. coli O157:H7 and L. monocytogenes inoculated at high levels (≅6 log) on meat samples were reduced in the range of 0.109-2.648 log CFU/g, 0.264-3.373 log CFU/g and 0.023-2.781 log CFU/g, respectively. The most effective treatment in reducing the counts of S. Typhimurium and E. coli O157:H7 was achieved by marination with ML1 (50% koruk juice + 50% water) for 48 h, while marination with ML2 (50% koruk juice + 50% water + 1% salt + 0.1% thyme) for 24 h was the most effective treatment for L. monocytogenes. When low inoculum levels were used (≅3 log), the counts of pathogens on meat samples were determined under detection limits after marination even for 2 h application. The results of sensory evaluation showed that the sample marinated with ML2 for 48 h was the most favored sample in terms of appearance, color, texture, taste and overall appreciation.

Efficacy of plant-derived antimicrobials for controlling Salmonella Schwarzengrund on dry pet food.

Salmonella enterica is a major human pathogen that is responsible for 23,000 hospitalizations annually in the United States. Contact with contaminated pet food and infected companion animals can transmit salmonellosis to humans. Recent multistate human outbreaks of salmonellosis linked to commercial contaminated dry dog foods underscore the need for controlling the pathogen in pet foods for protecting pet and public health. In this study, the efficacy of five Generally Recognized as Safe (GRAS) status, plant-derived antimicrobials (PDAs), namely trans-cinnamaldehyde (TC), carvacrol (CR), thymol (TY), eugenol (EG), and caprylic acid (CA) applied as a vegetable oil or chitosan based antimicrobial spray on dry pet food for reducing Salmonella Schwarzengrund was investigated. Three hundred gram portions of a commercial dry dog food were inoculated with a two-strain mixture of nalidixic acid (NA) resistant S. Schwarzengrund (~6 log CFU/g), followed by a spray treatment with 0%, 0.5%, 1% or 2% of TC, CR, TY, EG or CA in combination with 5% vegetable oil or 1% chitosan as a carrier. The control and treated dog food samples were stored at 25 °C for 28 days. On days 0, 1, 3, 5, 7, 14, 21, and 28, Salmonella on pet food was enumerated by serial dilution and plating on xylose lysine desoxycholate (XLD) agar. All PDAs at 1% and 2% applied in vegetable oil or chitosan reduced S. Schwarzengrund by at least ~2 log CFU/g on day 3 of storage when compared to control (P < 0.05). No significant reductions in Salmonella were observed on feed sprayed with only vegetable oil or chitosan (P > 0.05). Overall, 2% TC in vegetable oil or chitosan was the most effective treatment, where at least 3 to 3.5 log CFU/g reduction in bacterial populations was observed during storage (P < 0.05). Results suggest that the aforementioned PDAs could potentially be used as an antimicrobial spray to reduce S. Schwarzengrund on dry dog food. However, further studies on the acceptance of PDA-treated dry food by dogs are needed.

Role of Natural Volatiles and Essential Oils in Extending Shelf Life and Controlling Postharvest Microorganisms of Small Fruits.

Small fruits are a multi-billion dollar industry in the US, and are economically important in many other countries. However, they are perishable and susceptible to physiological disorders and biological damage. Food safety and fruit quality are the major concerns of the food chain from farm to consumer, especially with increasing regulations in recent years. At present, the industry depends on pesticides and fungicides to control food spoilage organisms. However, due to consumer concerns and increasing demand for safer produce, efforts are being made to identify eco-friendly compounds that can extend the shelf life of small fruits. Most volatiles and essential oils produced by plants are safe for humans and the environment, and lots of research has been conducted to test the in vitro efficacy of single-compound volatiles or multi-compound essential oils on various microorganisms. However, there are not many reports on their in vivo (in storage) and In situ (in the field) applications. In this review, we discuss the efficacy, minimum inhibitory concentrations, and mechanisms of action of volatiles and essential oils that control microorganisms (bacteria and fungi) on small fruits such as strawberries, raspberries, blueberries, blackberries, and grapes under the three conditions.

Biosynthesis of Silver Nanoparticles from Protium serratum and Investigation of their Potential Impacts on Food Safety and Control.

Silver nanoparticles play an integral part in the evolution of new antimicrobials against the broad ranges of pathogenic microorganisms. Recently, biological synthesis of metal nanoparticles using plant extracts has been successfully consummated. In the present study, the biosynthesis of silver nanoparticles (AgNPs) was conducted using the leaf extract of plant Protium serratum, having novel ethnomedicinal. The synthesized AgNPs were characterized using UV-Visible spectroscopy, dynamic light scattering spectroscopy (DLS), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy. The DLS study revealed the surface charge of the resulted nanoparticles that was highly negative, i.e., -25.0 ± 7.84 mV and the size was 74.56 ± 0.46 nm. The phytochemical and FTIR analysis confirmed the role of water-soluble phyto-compounds for the reduction of silver ions to silver nanoparticles. The potential antibacterial activity of AgNPs was studied against the food borne pathogens viz. Pseudomonas aeruginosa (IC50 = 74.26 ± 0.14 µg/ml), Escherichia coli (IC50 = 84.28 ± 0.36 µg/ml), Bacillus subtilis (IC50 = 94.43 ± 0.4236 µg/ml). The in vitro antioxidant potential of AgNPs was evaluated using 1, 1-diphenyl-2-picryl-hydrazil (IC50 = 6.78 ± 0.15 µg/ml) and hydroxyl radical assay (IC50 = 89.58 ± 1.15 µg/ml). In addition, the cytotoxicity of AgNPs was performed against fibroblast cell line L-929 to evaluate their biocompatibility. The overall results of the present investigation displayed the potential use of P. serratum leaf extract as a good bio-resource for the biosynthesis of AgNPs and their implementation in diverse applications, specifically as antibacterial agent in food packaging and preservation to combat against various food borne pathogenic bacteria along with its pharmaceutical and biomedical applications.

Antimicrobial activity of eugenol and essential oils containing eugenol: A mechanistic viewpoint.

Eugenol is a hydroxyphenyl propene, naturally occurring in the essential oils of several plants belonging to the Lamiaceae, Lauraceae, Myrtaceae, and Myristicaceae families. It is one of the major constituents of clove (Syzygium aromaticum (L.) Merr. & L.M. Perry, Myrtaceae) oil and is largely used in both foods and cosmetics as a flavoring agent. A large body of recent scientific evidence supports claims from traditional medicine that eugenol exerts beneficial effects on human health. These effects are mainly associated with antioxidant and anti-inflammatory activities. Eugenol has also shown excellent antimicrobial activity in studies, being active against fungi and a wide range of gram-negative and gram-positive bacteria. The aim of this review is to analyze scientific data from the main published studies describing the antibacterial and antifungal activities of eugenol targeting different kind of microorganisms, such as those responsible for human infectious diseases, diseases of the oral cavity, and food-borne pathogens. This article also reports the effects of eugenol on multi-drug resistant microorganisms. On the basis of this collected data, eugenol represents a very interesting bioactive compound with broad spectrum antimicrobial activity against both planktonic and sessile cells belonging to food-decaying microorganisms and human pathogens.

The antibiotic activity and mechanisms of sugarcane (Saccharum officinarum L.) bagasse extract against food-borne pathogens.

Sugarcane bagasse contains natural compositions that can significantly inhibit food-borne pathogens growth. In the present study, the phenolic content in sugarcane bagasse was detected as higher than 4 mg/g dry bagasse, with 470 mg quercetin/g polyphenol. The sugarcane bagasse extract showed bacteriostatic activity against the growth of Staphylococcus aureus, Listeria monocytogenes, Escherichia coli and Salomonella typhimurium. Additionally, the sugarcane bagasse extract can increase the electric conductivity of bacterial cell suspensions causing cellular leaking of electrolytes. Results of sodium dodecyl sulfate polyacrylamide gel electrophoresis suggested the antibacterial mechanism was probably due to the damaged cellular proteins by sugarcane bagasse extract. The results of scanning electron microscopy and transmission electron microscopy showed that the sugarcane bagasse extract might change cell morphology and internal structure.

Swarm motility of Salmonella enterica serovar Typhimurium is inhibited by compounds from fruit peel extracts.

UNLABELLED: Controlling spread of human pathogens on fresh produce is a top priority for public health reasons. Isolation of compounds from agricultural waste that would control spread of human pathogens was explored using Salmonella enterica serovar Typhimurium as a model organism. In the environment, micro-organisms migrate as a 'community' especially when they move on moist surfaces. This type of motility is characterized as swarming motility. We examined extracts from agricultural waste such as soya bean husk, peels of orange, pineapple, avocado and pomegranate for antiswarming activity. Avocado and pineapple peels showed moderate (~40%) inhibition of swarming motility while pomegranate peel extract had high antiswarming activity (~85% inhibition) and was examined in further detail. Although the pomegranate peel extract was acidic, swarm-inhibitory activity was not due to low pH and the peel extract did not inhibit growth of Salmonella. Among the key swarm motility regulatory genes, class II (fliF, fliA, fliT and fliZ) and class III (fliC and fliM) regulators were downregulated upon exposure to pomegranate peel extract. Pomegranate peels offer great potential as a bioactive repellent for pathogenic micro-organisms on moist surfaces. SIGNIFICANCE AND IMPACT OF THE STUDY: Controlling the spread of food-borne pathogens in moist environments is an important microbial food safety issue. Isolation of compounds from agricultural waste (such as fruit peels) that would control spread of human pathogens was explored using Salmonella enterica serovar Typhimurium as a model organism. Pomegranate peels offer great potential as a bioactive repellent for pathogenic micro-organisms.

Effect of Agrimonia Pilosa Ledeb. Extract on the Growth of Food-Borne Pathogens

This study was performed to investigate the antimicrobial effect of the Agrimonia pilosa Ledeb. extracts against food-borne pathogens. First, the Agrimonia pilosa Ledeb. was extracted with methanol at room temperatures, and fractionation of the methanol extracts from Agrimonia pilosa Ledeb. was carried out by using petroleum ether, chloroform, and ethyl acetate, and methanol respectively. The antimicrobial activity of the Agrimonia pilosa Ledeb. extracts was determined using a paper disc method against food-borne pathogens and food spoilage bacteria. The petroleum ether extracts of Agrimonia pilosa Ledeb. showed the highest antimicrobial activity against Pseudomonas aeruginosa. The synergistic effect has been found in combined extracts of Agrimonia pilosa Ledeb. and Perillae folium as compared to each extracts alone. Finally, the growth inhibition curve was determined using ethyl acetate extracts of Agrimonia pilosa Ledeb. against Bacillus Cereus and Salmonella Enteritidis. The petroleum ether extract of Agrimonia pilosa Ledeb. showed strong antimicrobial activity against Bacillus Cereus at the concentration of 4,000 ppm. The 4,000 ppm of petroleum ether extract from Agrimonia pilosa Ledeb. retarded the growth of Bacillus Cereus more than 24 hours and Salmonella Enteritidis up to 36 hours. The petroleum ether extracts of Agrimonia pilosa Ledeb. has been shown the antimicrobial effect against Bacillus Cereus and Salmonella Enteritidis.

Antimicrobial Effect of Pulsatilla Koreana Extracts on Food-Borne Pathogens

This study was performed to investigate the antimicrobial effect of the Pulsatilla koreana extracts against food-borne pathogens. First, the Pulsatilla koreana was extracted with methanol at room temperatures, and fractionation of the methanol extracts from Pulsatilla koreana was carried out by using petroleum ether, chloroform, and ethyl acetate, and methanol respectively. The antimicrobial activity of the Pulsatilla koreana extracts was determined using a paper disc method against food-borne pathogens and food spoilage bacteria. The ethyl acetate extracts of Pulsatilla koreana showed the highest antimicrobial activity against Staphylococcus aureus, Salmonella enteritidis and Shigella dysenteriae. The Staphylococcus aureus and Shigella dysenteriae were inhibited by petroleum ether and chloroform extracts of Pulsatilla koreana as well as ethyl acetate extracts of Pulsatilla koreana. The synergistic effect has been found in combined extracts of Pulsatilla koreana and Portulaca oleracea as compared to each extracts alone. Finally, the growth inhibition curve was determined using ethyl acetate extracts of Pulsatilla koreana against Staphylococcus aureus and Shigella dysenteriae. The ethyl acetate extract of Pulsatilla koreana showed strong antimicrobial activity against Staphylococcus aureus at the concentration of 2,000 ppm. The 2,000 ppm of ethyl acetate extract from Pulsatilla koreana retarded the growth of S. aureus more than 12 hours and Shigella dysenteriae up to 9 hours.

Effect of Artemisia Capillaris Extract on the Growth of Food-Borne Pathogens

In this study, Artemisia capillaries, which has been used as a folk remedy, was investigated for its antimicrobial activity. First, the Aremisia capillaris was extracted with methanol at room temperature, and fractionation of the methanol extracts from Artemisia capillaris was carried out using petroleum ether, chloroform, and ethyl acetate. Second, the antimicrobial activity of the Artemisia capillaris extracts was determined using a paper disc method and minimum inhibitory concentration of ethyl acetate extracts from Artemisia capillaris against food-borne pathogens and food spoilage bacteria was measured. Finally, the growth inhibition curve was determined using ethyl acetate extracts of Artemisia capillaris against Staphylococcus aureus and Salmonella typhimurium. The ethyl acetate extract of Artemisia capillaris showed strong antimicrobial activity against S. typhimurium at a concentration of 1,000 ppm. The 3,000 ppm of ethyl acetate extract from Artemisia capillaris retarded the growth of S. aureus and S. typhimurium for up to 6 hours.