Food Preservative Agent Research Articles

Preliminary Evaluation of Anti-Listerial Bacteriocin-like Peptide Produced by Enterococcus lactis PMD74 Isolated from Ezine Cheese

Enterococcus lactis PMD74 is a novel strain with a notably high antimicrobial activity. The present study evaluated the anti-listerial effect of a bacteriocin-like peptide (BLIP) produced by E. lactis PMD74 isolated from Ezine cheese (PDO). The strain was screened for its antimicrobial activity against 22 indicator strains using both agar spot and well diffusion methods. We observed that the neutralized cell-free supernatant (CFS) of E. lactis PMD74 exhibited varying levels of antimicrobial activity against both closely and distantly related pathogenic strains, with the highest activity displayed against Listeria monocytogenes strains. Although thermostable and resistant to lysozyme treatment, BLIP could be completely inactivated by trypsin, proteinase K, and α-chymotrypsin treatments. BLIP production starts in the early exponential growth phase of E. lactis PMD74 (3 h incubation, 400 AU mL–1) and reaches its maximal production (6400 AU mL–1) at the end of the exponential growth phase. Moreover, it is stable in the pH range of 2.0 to 7.0. The treatment of cultures of L. monocytogenes ATCC 7644 and Escherichia coli ATCC 26922 with sterilized CFS exhibited bactericidal and bacteriostatic effects, respectively. Furthermore, co-inoculation of L. monocytogenes ATCC 7644 and E. lactis PMD74 in skim milk led to complete loss of viability of L. monocytogenes ATCC 7644. These findings suggest that BLIP produced by E. lactis PMD74 could serve as a promising food preservative agent owing to its bactericidal and bacteriostatic properties.

Chemical Composition of Essential Oil from Rhanterium suaveolens Desf. and its Antimicrobial Activity Against Foodborne Spoilage Pathogens and Mycotoxigenic Fungi

The intention of this study was to explore the antibacterial and antifungal properties of essential oil from the flowers of Rhanterium suaveolens Desf. growing in Tunisia and determine its chemical composition which leads to the Tunisian chemotype. The GC and GC-MS analyses of essential oil conducted to the identification of twenty-seven compounds representing 99.08 % of the total oil. The main constituents were α-pinene (25.84 %), β-pinene (17.57 %), 1-octen-3-ol (16.23 %), camphene (12.28 %), limonene (8.03 %), β-myrcene (5.13 %), pinocarvone (2.98 %) and p-cymene (2.51 %). The antibacterial and antifungal activities of the volatile oil were screened in vitro using microdilution and disc diffusion methods. Considerable antibacterial effect was recorded against both Gram-positive and Gram-negative bacteria with MIC values ranging from 23 to 230 μg/mL. A powerful antifungal activity was also observed against five human pathogenic fungi. The highest antifungal effect was revealed against Candida albicans and Fusarium phylophylum with less MIC values of 11.5 μg/mL. On the basis of these results, the major eight chemical constituents of Rhanterium suaveolens essential oil could be used for constructing regression models to predict antibacterial and antifungal activities. These results suggest the possibility to use of Rh. suaveolens essential oil as a promising antimicrobial agent in drug and food preservation.

The Preservative Efficacy of Antimicrobial Proteins and Metabolites from Microorganisms, Animals and Plants as Potential Alternative to Chemical Food Preservation: A Review

Food is a source of nutrients and energy for humans and animals. Though food is assumed to be safe for consumption, it is highly susceptible for microbial contamination responsible for health risks and economic loss. This requires the mechanism that keep food fresh and safe for extended period of time. So far, in human history various physical and chemical methods have been employed to extend shelf life. Unfortunately, these methods are found to have a lot of drawbacks that pose problem on the quality and safety of the product beyond consumer need. Biological preservation using microbial, plant and animal derived metabolites and antimicrobial peptides has recently got considerable attention as the safest way of extending shelf life of food with no adverse effects on product quality. The antimicrobial efficiency of antimicrobial peptides and metabolites have been found to significantly inhibit the growth of potent food borne pathogens and spoilage microorganisms. However, the efficacy of biological antimicrobial agents for food preservation is potentiated by combined application with fewer chemical preservatives with smart formulation of a series of hurdle called hurdle technology. In this review, reports on the efficacy of antimicrobial peptides and metabolites of microbes, plants and animals in preserving various food stuffs are well reviewed during independent application and as part of hurdle system. Keywords: Biological preservation, Food, Food quality, Hurdle technology, Microbial/plant/animal metabolites DOI : 10.7176/FSQM/87-05 Publication date :May 31 st 2019

Antioxidant and antimicrobial activities of water-soluble polysaccharide isolated from Balangu seed (Lallemantia royleana) gum

BackgroundBalangu (Lallemantia royleana) belongs to Lamiaceae and is a medicine used in Iranian traditional and folklore medicine in the treatment of various nervous, hepatic, and renal diseases.MethodsIn this study, the influence of molecular weight (MW) was measured on antioxidant and antimicrobial activities of Balangu seed gum fractions. Firstly, Balangu seed gum was fractionated by precipitation method using ethanol on the basis of MW. Two fractions called precipitate (PER) Balangu and supernatant (SUPER) Balangu were obtained as the highest and lowest MW fractions, respectively. Monosaccharide composition was measured by GC-MS. The antioxidant activity was measured by two methods, DPPH and FRAP assay. The antibacterial activities were screened against two Gram-positive bacteria (Staphylococcus aureus and Bacillus cereus) and two Gram-negative bacteria (Salmonella enterica and Escherichia coli) by minimum inhibitory and bactericidal concentration (MIC and MBC), disc, and well diffusion method.ResultsThe results showed that the total phenol contents of Balangu, PER-Balangu, and SUPER-Balangu were 76.28 ± 1.41, 43.56 ± 1.72, and 89.46 ± 1.38 μg gallic acid equivalent/mg sample, respectively. Balangu and its fractions were composed of galactose, glucose, arabinose, rhamnose, and xylose. The IC50 values of Balangu, PER-Balangu, SUPER-Balangu, and BHT in DPPH assay were 0.46, 0.65, 0.38 and 0.31 mg/ml, respectively. In addition, the reducing power of Balangu, PER-Balangu, SUPER-Balangu, and BHT were 534.92, 431.80, 636.36, and 772.72 (mM Fe+2/g), respectively. Antibacterial test results showed, that for SUPER-Balangu, the minimum inhibitory concentration and the minimum bactericidal concentration against Staphylococcus were 3.125 mg/mL and 6.25 mg/mL.ConclusionsSUPER-Balangu has a great potential as a natural food preservative, antibacterial, and antioxidant agent.

Piper Species: A Comprehensive Review on Their Phytochemistry, Biological Activities and Applications.

Piper species are aromatic plants used as spices in the kitchen, but their secondary metabolites have also shown biological effects on human health. These plants are rich in essential oils, which can be found in their fruits, seeds, leaves, branches, roots and stems. Some Piper species have simple chemical profiles, while others, such as Piper nigrum, Piper betle, and Piper auritum, contain very diverse suites of secondary metabolites. In traditional medicine, Piper species have been used worldwide to treat several diseases such as urological problems, skin, liver and stomach ailments, for wound healing, and as antipyretic and anti-inflammatory agents. In addition, Piper species could be used as natural antioxidants and antimicrobial agents in food preservation. The phytochemicals and essential oils of Piper species have shown strong antioxidant activity, in comparison with synthetic antioxidants, and demonstrated antibacterial and antifungal activities against human pathogens. Moreover, Piper species possess therapeutic and preventive potential against several chronic disorders. Among the functional properties of Piper plants/extracts/active components the antiproliferative, anti-inflammatory, and neuropharmacological activities of the extracts and extract-derived bioactive constituents are thought to be key effects for the protection against chronic conditions, based on preclinical in vitro and in vivo studies, besides clinical studies. Habitats and cultivation of Piper species are also covered in this review. In this current work, available literature of chemical constituents of the essential oils Piper plants, their use in traditional medicine, their applications as a food preservative, their antiparasitic activities and other important biological activities are reviewed.

Bioactivities of phytochemicals in Callistemon citrinus against multi-resistant foodborne pathogens, alpha glucosidase inhibition and MCF-7 cancer cell line

This study investigates in-vitro activities of phytochemicals in Callistemon citrinus against multi-resistant foodborne pathogens, alpha-glucosidase enzyme and MCF-7 cancer cell line. Assays were prepared with lyophilized extracts to determine antioxidant capacity, inhibition of α-glucosidase enzyme and growth of foodborne bacteria. Annexin-V detection kit was used for apoptosis detection and FT-IR spectroscopy to confirm structural and functional groups of phytochemicals. Cytotoxicity of the extracts against MCF-7 cells was monitored with xCELLigence Real-Time Cell Analyser. The result from FT-IR analysis gave a peak at 3295 cm−1 wavenumber, confirming the presence of O–H alcohol functional group. FT-IR analysis also showed the presence of different functional groups such as carboxylic acids, aromatics, alkanes, alcohols, aliphatic amines, alkenes and amine groups in the extracts. Callistemon exhibited strong antioxidant capacities with EC50 values of 0.474 ± 0.03 and 0.787 ± 0.15 mL sample/g of 2,2-diphenyl-1-picrylhydeazyl (DPPH) from leaf and flower extracts, respectively. Growth inhibition of most gram-positive foodborne bacteria by phytochemicals from flower extract appeared more promising as an alternative antimicrobial agent for food preservation. IC50 value of 3.69 ± 0.61 μg/mL obtained from leaf extract showed its inhibitory potential against α-glucosidase enzyme for managing diabetes type-2. A dose response obtained from real-time monitoring with xCELLigence system indicated higher cytotoxicity of the extracts against MCF-7 cell line at ≥200 μg/mL concentrations within 24 h of incubation. The versatility of phytochemicals in Callistemon observed in this study signifies its potential for enhancing feed or food functionality, moderating blood glucose level and inhibiting the growth of foodborne pathogens or invasive carcinoma in man.

Antioxidant and anti-Salmonella activities of eggplant peel compounds obtained by solvent-free calcium-based extraction

ABSTRACTFresh products demand natural preservatives without solvent traces. Calcium-based extraction of bioactive compounds from eggplant peels (EP), could be used as an alternative solvent-free natural antimicrobial food preservative agent. In this study, we extracted bioactive compounds from EP using different calcium salts (CaSO4, CaCO3, and CaCl2) and evaluated the total phenolic and flavonoid contents, antioxidant activity, and bactericidal activity against Salmonella Typhimurium. The EP extracts obtained using 1% CaCO3 exhibited the highest total phenolic content and pronounced antioxidant activity. All EP extracts decreased Salmonella concentration after 10 and 12 h. In infected-lettuce leaves, the 1% CaCO3 EP extract inhibited bacterial growth at similar levels as a commercial disinfectant. The main compound identified in this EP extract was the chlorogenic acid. The extracts from EP obtained using calcium salts, represent a natural novel alternative preservative agent for the food industry, with antioxidant properties and potentially positive effects on human health.

Anti-biofilm effect of crude bacteriocin derived from Lactobacillus brevis DF01 on Escherichia coli and Salmonella Typhimurium

Biofilm is a community of microorganisms that adhere to abiotic or biotic surfaces, and is problematic in a wide range of food industries, as well as to human health. Although bacteriocin from lactic acid bacteria is well known as a natural antimicrobial agent in food preservation, it has been poorly investigated that bacteriocin inhibits the biofilm formation of foodborne pathogens. In this study, we demonstrated that bacteriocin produced by Lactobacillus brevis DF01 was partially purified and investigated whether the bacteriocin inhibited the biofilm formation of Escherichia coli and Salmonella Typhimurium. Assessment by the microtiter plate method, as well as by fluorescence and scanning electron microscopy, showed that the biofilm formation of E. coli and S. Typhimurium was reduced when the bacteria was co-incubated with crude bacteriocin of L. brevis DF01 (DF01 bacteriocin). Although pre-treated DF01 bacteriocin also significantly inhibited the biofilm formation of E. coli and S. Typhimurium (P = 0.0035 and P = 0.0003, respectively) post-treatment with DF01 bacteriocin did not significantly inhibit the biofilm formation (P = 0.1314 for E. coli and P = 0.2939 for S. Typhimurium), suggesting that DF01 bacteriocin interfered with biofilm formation, but did not disrupt the established biofilm of E. coli and S. Typhimurium. In addition, biofilms of both E. coli and S. Typhimuriun on the surface of stainless steel coupons were decreased in the presence of DF01 bacteriocin. Taken together, these results suggest that DF01 bacteriocin may be applied to control the biofilm formation of E. coli and S. Typhimurium.

Generation of antibacterial peptides from crude cheese whey using pepsin and rennet enzymes at various pH conditions.

The current study aimed to prepare antimicrobial agents for food preservation from crude cheese whey. Crude cheese whey was digested with porcine pepsin, and calf and fungal rennets at various pHs. The digests were assessed for antibacterial activities against Escherichia coli and Bacillus subtilis. The calf rennet digest at pH 3.0 showed the highest antibacterial activity. Three antibacterial peptides that acted against B. subtilis lactoferrin f(20-30), and β-lactoglobulin f(14-22) and f(92-103) were identified in the calf rennet digest. Only lactoferrin f(20-30) also exerted bactericidal activity against E. coli. LC-MS/MS analysis revealed that the three peptides were generated by the porcine pepsin at pH 2.5, whereas the calf rennet generated them at a wider pH (pH 2.5-3.5). Fungal rennet generated only β-lactoglobulin f14-22 at pH 3.5. The pepsin and calf rennet digests at pH 2.5 and 3.0, respectively, reduced the E. coli and B. subtilis populations by approximately 2 log at 6000 µg mL-1 in milk at 4 °C. The calf rennet and porcine pepsin digests of cheese whey, at a specific acidic pH, which can be prepared from food-grade materials, have the potential to be used as natural food preservatives due to the presence of the three antibacterial peptides. © 2018 Society of Chemical Industry.

A Comparative Study on the Effects of Quinic Acid and Shikimic Acid on Cellular Functions of Staphylococcus aureus

Quinic acid (QA) and shikimic acid (SA), two kinds of natural organic acids, have been reported to exhibit potent antibacterial activity against Staphylococcus aureus. In this study, the effects of QA and SA on the cellular functions of S. aureus were investigated by measuring the intracellular pH, intracellular and extracellular ATP concentrations, succinate dehydrogenase activity, DNA content, and interactions between SA and QA with S. aureus DNA. Studies of the cellular functions demonstrated that QA could significantly decrease the intracellular pH, whereas SA had no effect on intracellular pH. QA and SA reduced succinate dehydrogenase activity and caused a significant decrease in intracellular ATP concentration but no proportional increase in extracellular ATP. Moreover, QA and SA both could remarkably reduce the DNA content of S. aureus and directly interact with genomic DNA. The results suggested that the effects of QA and SA on cellular functions were distinguishable, although the chemical structures of these two compounds were similar. In conclusion, the results of the present research suggested that SA and QA could be used as antibacterial agents in food preservation.

Chemical composition and antimicrobial activity of Gannan navel orange (Citrus sinensis Osbeck cv. Newhall) peel essential oils.

The present investigation reported the chemical composition of cold pressed Gannan navel orange peel essential oil (EO) and its molecular distillation fraction (light phase EO), and examined their antimicrobial activity against spoiling and pathogenic microorganisms. Gas chromatography‐mass spectrometry analysis identified 27 and 20 different chemical constituents in cold pressed EO and light phase EO, respectively. Limonene was the major constituent, accounting for 85.32% of cold pressed EO and 60.44% of light phase EO. Both EOs and some of their constituents showed good antimicrobial activity. Compared to cold pressed EO, light phase EO exhibited the better antimicrobial activity under weak acidic and neutral conditions. The light phase EO presented a higher antimicrobial activity after thermo‐treatment at 60–100°C for 20 min than cold pressed EO. These results demonstrated that light phase EO had a potential to be used as a novel antimicrobial agent for food preservation and food processing.

Nerol-induced apoptosis associated with the generation of ROS and Ca2+ overload in saprotrophic fungus Aspergillus flavus.

The contamination of food with Aspergillus flavus and subsequent aflatoxins is one of the most serious safety problems in the world. In this study of nerol (NEL)'s antifungal mechanism of action, we observed morphological and physiological changes in Aspergillus flavus. We found that NEL resulted in elevated levels of reactive oxygen species (ROS) and calcium ions (Ca2+). On ROS assays, compared with the controls, the proportion of fluorescent cells treated with concentrations of 0.25, 0.5, 1, and 2μL/mL NEL increased to 8.4 ± 1.07%, 10.2 ± 1.72%, 13.4 ± 0.50%, and 26.2 ± 4.21%, respectively. Increased mitochondrial dysfunction and oxidative stress induced by the interactions between Ca2+ and ROS subsequently activate the release of cytochrome c and caspase activity. Characteristic changes of apoptosis were also observed via various detection methods, including phosphatidylserine externalization, nuclear condensation, and DNA fragmentation. Meanwhile, we found that the expression of CaMKs increased significantly in NEL-treated cells. In conclusion, our findings indicate that NEL has great potential as an eco-friendly antifungal agent for food preservation.

Validation of a Novel Cost Effective Easy to Produce and Durable In Vitro Model for Kidney-Puncture and Percutaneous Nephrolitholapaxy-Simulation.

Nephrolithiasis is one of the most common diseases in urology. According to the EAU Guidelines, a percutaneous nephrolitholapaxy (PNL) is recommended when treating a kidney stone >2 cm. Nowadays, PNL is performed even for smaller stones (<1 cm) using miniaturized instruments. The most challenging part of any PNL is the puncture of the planned site. PNL-novice surgeons need to practice this step in a safe environment with an ideal training model. We developed and evaluated a new, easy to produce, in vitro model for the training of the freehand puncture of the kidney. Porcine kidneys with ureters were embedded in ballistic gel. Food coloring and preservative agent were added. We used the standard imaging modalities of X-ray and ultrasound to validate the training model. An additional new technique, the iPAD-guided puncture, was evaluated. Five novices and three experts conducted 12 punctures for each imaging technique. Puncture time, radiation dose, and number of attempts to a successful puncture were measured. Mann-Whitney-U, Kruskal-Wallis, and U-Tests were used for statistical analyses. The sonography-guided puncture is slightly but not significantly faster than the fluoroscopy-guided puncture and the iPAD-assisted puncture. Similarly, the most experienced surgeon's time for a successful puncture was slightly less than that of the residents, and the experienced surgeons needed the least attempts to perform a successful puncture. In terms of radiation exposure, the residents had a significant reduction of radiation exposure compared to the experienced surgeons. The newly developed ballistic gel kidney-puncture model is a good training tool for a variety of kidney-puncture techniques, with good content, construct, and face validity.

Antibacterial activity of a novel characterized and purified bacteriocin extracted from Bifidobacterium adolescentis

Lactic acid bacteria and their own bacteriocin are great promising in health and industry; hence, too many lactic acid bacteria species and metabolites are involve in health maintenance and treatment of infectious disease as well as food preservation and dairy production. Current study sought to produce, isolate, purify and characterize novel bacteriocin from oral Bifidobacterium adolescentis and studying its effect on antibiotic-resistant pathogenic bacteria. Saliva of 18 volunteers postmenopausal women with their age ranging from 49 to 58 years was included. Bifidobacterium spp. cultivates in anaerobic conditions and identified by API50. Bifidobacterium bacteriocin prepared in De Man, Rogosa and Sharpe broth (MRS) broth as a crude preparation then concentrated by ammonium sulphate precipitation and purified by ion exchange and gel filtration chromatography. The molecular weight of B. adolescentis bacteriocin was estimated by gel filtration chromatography. The effect of temperature and pH value on purified bacteriocin activity was estimated using Escherichia coli American Type Culture Collection (ATCC) and Staphylococcus aureus ATCC. To determine the nature of produced bacteriocin and whether or not the bacteriocin contain lipid or carbohydrate moiety, it was treated with some enzymes (pepsin, lipase, α-amylase, papain and chemotrypsin). Challenged pathogenic bacteria were surveyed for occurrence of antibiotic resistance genes by PCR and to verify the inhibitory effect of B. adolescentis bacteriocin on challenged pathogenic bacteria, disc diffusion method was used. The result of anaerobic culture showed that, 35 Bifidobacterium isolates were obtained, the predominant species was B. adolescentis other species was lesser, namely Bifidobacterium dentium, Bifidobacterium longum and Bifidobacterium urinalis. The purified B. adolescentis bacteriocin was 14 600-Da protein and was active at wide range of pH value (3–8), thermostable and has no lipid or carbohydrate moiety. Almost all of pathogenic bacteria, whether or not they carry antibiotic resistance genes, appeared to be sensitive to crude and purified bacteriocin but purified bacteriocin was more effective as antimicrobial agent. The results suggest that Bifidobacterium spp. was dominant in oral cavities of postmenopausal women who have no caries it may prevent dental caries via antimicrobial activities of their own bacteriocin. Bifidobacterium bacteriocin is protein in nature, without lipid or carbohydrate moiety, heat-stable and active at wide range of pH values and can be classified as type II bacteriocin and so-called bifidoadocin. The antimicrobial activity of bifidoadocin makes it probable food preservative and antagonistic agent against pathogens of oral cavity and causative agents of dental caries as well as other pathogens.

Characterization and evaluation of antimicrobial activity of actinonin against foodborne pathogens.

This study revealed the antimicrobial properties of actinonin against major foodborne pathogens, Escherichia coli O157:H7, Listeria monocytogenes, Salmonella Typhimurium, Staphylococcus aureus, and Vibrio vulnificus. Among them, actinonin caused growth defect in S. Typhimurium and V. vulnificus. Minimal inhibitory concentration (MIC) values of actinonin were determined by broth microdilution methods. The MICs of actinonin were ≤0.768μg/ml for S. Typhimurium and ≤0.192μg/ml for V. vulnificus. Susceptibility to actinonin in both pathogens was measured by colony-forming ability and disc diffusion test. The results showed actinonin had antimicrobial activity against S. Typhimurium and V. vulnificus in a dose-dependent manner. The inhibitory effects on swarming motility were determined, and cytotoxicity of each pathogen against HeLa cells was decreased significantly by actinonin treatment. Furthermore, actinonin showed an antimicrobial efficacy in food models infected with these pathogens. These results demonstrate that actinonin is potentially an effective agent for food sanitization or preservation.

Purification and characterization of macrolactins and amicoumacins from Bacillus licheniformis BFP011: a new source of food antimicrobial substances

ABSTRACTIn this study, Bacillus licheniformis BFP011 has been cultivated for producing antimicrobial compounds, which were concentrated from the crude supernatant and purified using thin-layer chromatography. The antimicrobial activity was investigated in the presence of several organic solvents and detergents, and inhibiting effects to various Gram-negative and Gram-positive human pathogenic and food spoilage bacteria were observed. Three bands (F4, F5 and F6) showing antimicrobial activity against Salmonella typhi ATCC 5784 were subjected to reversed-phase high-performance liquid chromatography purification. Two peaks of fraction F5, F5-P3 and F5-P4, showed 100% inhibition against S. typhi ATCC 5784. The contained mixture of antimicrobial compounds consists of macrolactins and amicoumacins, which induced the collapse and breaking of S. typhi ATCC 5784 cell membranes in a time-dependent manner. Taken collectively, the results indicate that these compounds may represent promising candidates for the development of food preservative agents of natural origin, as well as novel antimicrobial drug candidates against multiresistant bacterial strains.

Assessment of Antioxidant and Antibacterial Properties on Meat Homogenates of Essential Oils Obtained from Four Thymus Species Achieved from Organic Growth.

In the organic food industry, no chemical additives can be used to prevent microbial spoilage. As a consequence, the essential oils (EOs) obtained from organic aromatic herbs and spices are gaining interest for their potential as preservatives. The organic Thymus zygis, Thymus mastichina, Thymus capitatus and Thymus vulgaris EOs, which are common in Spain and widely used in the meat industry, could be used as antibacterial agents in food preservation. The aims of this study were to determine (i) the antibacterial activity using, as culture medium, extracts from meat homogenates (minced beef, cooked ham or dry-cured sausage); and (ii) the antioxidant properties of organic EOs obtained from T. zygis, T. mastichina, T. capitatus and T. vulgaris. The antioxidant activity was determined using different methodologies, such as Ferrous ion-chelating ability assay, Ferric reducing antioxidant power, ABTS radical cation (ABTS•+) scavenging activity assay and 2,2′-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging method; while the antibacterial activity was determined against 10 bacteria using the agar diffusion method in different meat model media. All EOs analyzed, at all concentrations, showed antioxidant activity. T. capitatus and T. zygis EOs were the most active. The IC50 values, for DPPH, ABTS and FIC assays were 0.60, 1.41 and 4.44 mg/mL, respectively, for T. capitatus whilst for T. zygis were 0.90, 2.07 and 4.95 mg/mL, respectively. Regarding antibacterial activity, T. zygis and T. capitatus EOs, in all culture media, had the highest inhibition halos against all tested bacteria. In general terms, the antibacterial activity of all EOs assayed was higher in the medium made with minced beef than with the medium elaborated with cooked ham or dry-cured sausage.

Benzoate and Sorbate Salts: A Systematic Review of the Potential Hazards of These Invaluable Preservatives and the Expanding Spectrum of Clinical Uses for Sodium Benzoate.

Sodium benzoate and potassium sorbate are extremely useful agents for food and beverage preservation, yet concerns remain over their complete safety. Benzoate can react with the ascorbic acid in drinks to produce the carcinogen benzene. A few children develop allergy to this additive while, as a competitive inhibitor of D-amino acid oxidase, benzoate can also influence neurotransmission and cognitive functioning. Model organism and cell culture studies have raised some issues. Benzoate has been found to exert teratogenic and neurotoxic effects on zebrafish embryos. In addition, benzoate and sorbate are reported to cause chromosome aberrations in cultured human lymphocytes; also to be potently mutagenic toward the mitochondrial DNA in aerobic yeast cells. Whether the substantial human consumption of these compounds could significantly increase levels of such damages in man is still unclear. There is no firm evidence that it is a risk factor in type 2 diabetes. The clinical administration of sodium benzoate is of proven benefit for many patients with urea cycle disorders, while recent studies indicate it may also be advantageous in the treatment of multiple sclerosis, schizophrenia, early-stage Alzheimer's disease and Parkinson's disease. Nevertheless, exposure to high amounts of this agent should be approached with caution, especially since it has the potential to generate a shortage of glycine which, in turn, can negatively influence brain neurochemistry. We discuss here how a small fraction of the population might be rendered-either through their genes or a chronic medical condition-particularly susceptible to any adverse effects of sodium benzoate.

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.

Adverse Effects of Two Kinds of Food Additive Mixtures (Flavor Enhancer, Food Preservative or Food Coloring Agent) on Physiological Parameters in Young Male Albino Rats

Background: food additives are substances used in food industry in order to improve the food’s taste, appearance by preserving its flavor and preventing it from souring. Food additives are added to the most junk and fast foods, especially food for kids. Aim of the work: this work was aimed to investigate the adverse effects of some food additives on the biochemical parameters in addition to study the side effects of these food additives in male albino rats. Materials and Methods: this study was performed on twenty four young male albino rats with an average 120-145 g body weight. Animals were divided into four groups (6 /cage); Group I (Control untreated group), Group II (administered orally with sodium nitrite (0.1 mg/kg b.wt./day) and annatto (0.065 mg/kg b.wt./day)), Group III (administered orally with sodium nitrite (0.1 mg/kg b.wt./day) and monosodium glutamate (MSG) (15 mg/kg b.wt./day)) and Group IV (administered orally with annatto (0.065 mg/kg b.wt./day) and monosodium glutamate (15 mg/kg b.wt./day)). Blood samples were collected on the last day of experiment, for biochemical estimations which included levels of serum glucose, total protein (TP), albumin, creatinine, urea, testosterone , thyroid hormones (T3 and T4), activities of AST and ALT in addition to lipid profile. Results: showed marked elevation in levels of fasting glucose, activities of AST, ALT, urea, creatinine, total cholesterol (TC), triglycerides (TG) and high density lipoprotein cholesterol (HDL-C), VLDL and ratios of TC/HDL-C and LDL-C/HDL-C (risk factors) as well as albumin / globulin ratio and serum thyroid hormones (T3 & T4) accompanied with marked decline in levels of serum total proteins, albumin, globulin, albumin/ creatinine ratio, testosterone and HDL-C in all treated groups in comparison to the control group. There was a significant reduction in the body weight in groups that received (NaNO2 with annatto) and (MSG with NaNO2) while treated rats with (MSG and annatto) showed a significant increase in body weight as compared to control rats. Conclusion:Due to the harmful effects of food additives, the use of these compounds must be limited as it resulted in a vehement disturbance in the biochemical and physiological parameters that was grievously pronounced on many hormones.