Formulation of garlic oil‐in‐water nanoemulsion: antimicrobial and physicochemical aspects

Despite the unique properties, application of garlic essential oil (GEO) is too limited in food and drugs, due to its low water solubility, very high volatility and unpleasant odour. In this work, a nanoemulsion containing GEO was formulated to cover and protect the volatile compounds of GEO. The encapsulation efficiency of formulated nanoemulsions was measured by gas chromatography and obtained encapsulation efficiency ranged from 91 to 77% for nanoemulsions containing 5–25% GEO, respectively. The 2,2‐diphenyl‐1‐picrylhydrazyl method for antioxidant activity measurement showed that free radical scavenging capacity of nanoemulsions intensified during storage time. The electrical conductivity of the samples was constant over storage time while linearly increased by raising the temperature. Thermogravimetric analysis was used to determine the thermal resistance of nanoemulsions and their ingredients. Interestingly, microbial tests cleared that the control nanoemulsion with a particle size below 100 nm (nanoemulsion without GEO) also showed antimicrobial activity. Disk diffusion method showed that pure GEO and also formulated nanoemulsions had a stronger effect against Gram‐positive bacterium (Staphylococcus aureus) than Gram‐negative bacterium (Escherichia coli).Inspec keywords: emulsions, nanostructured materials, antibacterial activity, microorganisms, electrical conductivity, thermal analysis, thermal resistance, oils, nanobiotechnology, food safety, cellular biophysicsOther keywords: garlic oil‐in‐water nanoemulsion, antimicrobial aspects, physicochemical aspects, garlic essential oil, GEO, volatile compounds, encapsulation efficiency, gas chromatography, 2,2‐diphenyl‐1‐picrylhydrazyl method, antioxidant activity measurement, free radical scavenging capacity, storage time, electrical conductivity, thermogravimetric analysis, thermal resistance, antimicrobial activity, disk diffusion method, Gram‐positive bacterium, Staphylococcus aureus, Gram‐negative bacterium, Escherichia coli     

How nano‐wollastonite can change the fundamental properties of a wood fibre and rice straw composites?

The potential of using rice straw (RS) in combination with wood fibre in the production of medium density fibreboard was investigated. Nano‐wollastonite (NW) was added to some of the panels to determine if it would enhance the physical and mechanical properties. It was found that satisfactory composite boards could be made with the addition of 10% RS to the wood fibre. Furthermore, the mechanical and physical properties of the composite were enhanced when NW was added.Inspec keywords: wood products, ecocomposites, fibresOther keywords: RS, composite boards, mechanical properties, physical properties, NW, medium density fibreboard, rice straw composites, wood fibre, fundamental properties, nanowollastonite     

Web-Vacuum: Web-Based Environment for Automated Assessment of Civil Infrastructure Data

Data quality is extremely important where information dramatically influences the decisions being made. In the context of civil infrastructure systems, planning and management activities are critically dependent on data to support the efficient allocation of resources, detailed cost-benefit analysis, and informed decision-making. A Web-based tool, called Web-Vacuum, which employs data-mining (DM) techniques and partially implements a two-level data-quality assessment procedure, was developed to support the general purpose of data-quality assessment. The algorithms, workflow, and interfaces used in Web-Vacuum are presented. A data-quality assessment case study using a bridge management system data set is used to demonstrate that the application of Web-Vacuum can be used to assist in determining the quality of a data set.     

Survival of Escherichia coli O157:H7, Salmonella enteritidis, Staphylococcus aureus, and Listeria monocytogenes in Kimchi

The survival of gram-positive and gram-negative foodborne pathogens in both commercial and laboratory-prepared kimchi (a traditional fermented food widely consumed in Japan) was investigated. It was found that Escherichia coli O157:H7, Salmonella Enteritidis, Staphylococcus aureus, and Listeria monocytogenes could survive in both commercial and laboratory-prepared kimchi inoculated with these pathogens and incubated at 10 degrees C for 7 days. However, when incubation was prolonged, the S. aureus level decreased rapidly from the initial inoculum level to the minimum detectable level within 12 days, whereas Salmonella Enteritidis and L. monocytogenes took 16 days to reach similar levels in commercial kimchi. On the other hand, E. coli O157:H7 remained at high levels throughout the incubation period. For laboratory-prepared kimchi, the S. aureus level decreased rapidly from the initial inoculum level to the minimum detectable level within 12 days, and L. monocytogenes took 20 days to reach a similar level. E. coli O157:H7 and Salmonella Enteritidis remained at high levels throughout the incubation period. The results of this study suggest that the contamination of kimchi with E. coli O157:H7, Salmonella Enteritidis, S. aureus, or L. monocytogenes at any stage of production or marketing could pose a potential risk.     

Irradiation inactivation of Listeria monocytogenes in low-fat ground pork at freezing and refrigeration temperatures

Gamma radiation effectively controls Listeria monocytogenes in uncooked and in ready-to-eat foods. This study was conducted to determine if gamma radiation could be used to control L. monocytogenes in ground pork. Ground pork was contaminated with L. monocytogenes, kept at refrigeration (4 degrees C), chilling (0 degrees C), and freezing (-18 degrees C) temperatures overnight, exposed to gamma radiation and stored at 4 degrees C for 7 days, and at 0 and -18 degrees C for 60 days. Following irradiation, the meat was assayed for L. monocytogenes viable counts and lipid oxidation. A triangle test was performed to determine if sausage made from the irradiated and nonirradiated ground pork differed in sensory quality. It was observed that a 5-log reduction of L. monocytogenes viable counts would require a 3.0-kGy radiation dose. The results of a 60-day storage study of ground pork inoculated with 10(5) to 10(6) CFU of L. monocytogenes per gram indicated that counts for nonirradiated meat remained fairly constant at refrigeration, chilling, and freezing temperatures. However, irradiation of ground pork at 3.0 kGy could inactivate L. monocytogenes totally in ground pork subsequently held at all the temperatures used in this study. Lipid oxidation measurements, as determined by the thiobarbituric acid-reactive substance assay, ranged from 0.16 nmol/g for nonirradiated ground pork and 0.20 nmol/g for meat irradiated at 3.0 kGy. Sensory panelists could distinguish between irradiated and nonirradiated sausage but were divided on whether irradiation adversely affected the sausage quality. Our results suggest that gamma radiation could be useful to control L. monocytogenes in ground pork and improve the safety of ground pork products.     

Chitosan Protects Cooked Ground Beef and Turkey Against Clostridium perfringens Spores During Chilling

ABSTRACT:  We investigated the inhibition of Clostridium perfringens spore germination and outgrowth by the biopolymer chitosan during abusive chilling of cooked ground beef (25% fat) and turkey (7% fat) obtained from a retail store. Chitosan was mixed into the thawed beef or turkey at concentrations of 0.5%, 1.0%, 2.0%, or 3.0% (w/w) along with a heat-activated 3-strain spore cocktail to obtain a final spore concentration of 2 to 3 log₁₀ CFU/g. Samples (5 g) of the ground beef or turkey mixtures were then vacuum-packaged and cooked to 60 °C in 1 h in a temperature-controlled water bath. Thereafter, the products were cooled from 54.4 to 7.2 °C in 12, 15, 18, or 21 h, resulting in 4.21, 4.51, 5.03, and 4.70 log₁₀ CFU/g increases, respectively, in C. perfringens populations in the ground beef control samples without chitosan. The corresponding increases for ground turkey were 5.27, 4.52, 5.11, and 5.38 log₁₀ CFU/g. Addition of chitosan to beef or turkey resulted in concentration- and time-dependent inhibition in the C. perfringens spore germination and outgrowth. At 3%, chitosan reduced by 4 to 5 log₁₀ CFU/g C. perfringens spore germination and outgrowth ( P ≤ 0.05) during exponential cooling of the cooked beef or turkey in 12, 15, or 18 h. The reduction was significantly lower ( P < 0.05) at a chilling time of 21 h, about 2 log₁₀ CFU/g, that is, 7.56 log₁₀ CFU/g (unsupplemented) compared with 5.59 log₁₀ CFU/g (3% chitosan). The results suggest that incorporation of 3% chitosan into ground beef or turkey may reduce the potential risk of C. perfringens spore germination and outgrowth during abusive cooling from 54.4 to 7.2 °C in 12, 15, or 18 h.     

A New Human Platelet Lysate for Mesenchymal Stem Cell Production Compliant with Good Manufacturing Practice Conditions Preserves the Chemical Characteristics and Biological Activity of Lyo-Secretome Isolated by Ultrafiltration

Recently, we proposed a Good Manufacturing Practice (GMP)-compliant production process for freeze-dried mesenchymal stem cell (MSC)-secretome (lyo-secretome): after serum starvation, the cell supernatant was collected, and the secretome was concentrated by ultrafiltration and freeze-dried, obtaining a standardized ready-to-use and stable powder. In this work, we modified the type of human platelet lysate (HPL) used as an MSC culture supplement during the lyo-secretome production process: the aim was to verify whether this change had an impact on product quality and also whether this new procedure could be validated according to GMP, proving the process robustness. MSCs were cultured with two HPLs: the standard previously validated one (HPL-E) and the new one (HPL-S). From the same pool of platelets, two batches of HPL were obtained: HPL-E (by repeated freezing and thawing cycles) and HPL-S (by adding Ca-gluconate to form a clot and its subsequent mechanical wringing). Bone marrow MSCs from three donors were separately cultured with the two HPLs until the third passage and then employed to produce lyo-secretome. The following indicators were selected to evaluate the process performance: (i) the lyo-secretome quantitative composition (in lipids and proteins), (ii) the EVs size distribution, and (iii) anti-elastase and (iv) immunomodulant activity as potency tests. The new HPL supplementation for MSCs culture induced only a few minimal changes in protein/lipid content and EVs size distribution; despite this, it did not significantly influence biological activity. The donor intrinsic MSCs variability in secretome secretion instead strongly affected the quality of the finished product and could be mitigated by concentrating the final product to reach a determined protein (and lipid) concentration. In conclusion, the modification of the type of HPL in the MSCs culture during lyo-secretome production induces only minimal changes in the composition but not in the potency, and therefore, the new procedure can be validated according to GMP.     

Electrical properties of chemically prepared nonstoichiometric CuIn(S,Se)2 thin films

Polycrystalline thin films of copper indium sulphoselenide [CuIn(S,Se)₂] were deposited on glass substrate by chemical bath deposition technique. The deposition parameters such as pH, temperature and time were optimized. A set of films having different elemental compositions was prepared by varying Cu/In ratio from 1·87–12·15. The films were characterized by X-ray diffraction (XRD) and energy dispersive X-ray analysis (EDAX). The chemical composition of the CuIn(S,Se)₂ was found to be nonstoichiometric. The d.c. conductivities of the films were studied below and near room temperature. The thermo-electric power of the films was also measured and type of semiconductivity was ascertained.     

Stability of C60 chains: molecular dynamics simulations

A linearly aligned structure of three C60 fullerene, interconnected by two benzorods of same size, have been investigated under heat treatment. The overall structure resembles a section of a beaded string. Nine different lengths of benzorods have been considered, and the effect on the thermal stability have been investigated by means of molecular dynamics method. It has been found that the structure is thermally stable up to elevated temperatures, and the linear alignment of the structure is persistent, up to the temperature of decomposition.     

Graft copolymerization of vinyl monomers on modified cottons,part XVII. Continuous and semi continuous methods for grafting of partially carboxymethylated cotton with acrylamide

Semi continuous and continuous methods were described for grafting of acrylamide to partially carboxymethylated cotton (PCMC). In essence, PCMC previously treated with ferrous sulphate was padded in a solution containing acrylamide and H₂O₂ followed by drying and baking. Incorporation of N-methylol finishing agent to the polymerization solution brought about easy care cotton with improved strength properties and good fabric performancy as measured by crease recovery.