Spoilage microbiota associated to the storage of raw meat in different conditions

The spoilage of raw meat is mainly due to undesired microbial development in meat during storage. The type of bacteria and their loads depend on the initial meat contamination and on the specific storage conditions that can influence the development of different spoilage-related microbial populations thus affecting the type and rate of the spoilage process. This review focuses on the composition of raw meat spoilage microbiota and the influence of storage conditions such as temperature, packaging atmosphere and use of different preservatives on the bacterial diversity developing in raw meat. In addition, the most recent tools used for the detection and identification of meat microbiota are also reviewed.     

Evaluation of an Improved Indirect Method for the Analysis of 3-MCPD Esters Based on Acid Transesterification

The quantification of 3-chloropropane-1,2-diol (3-MCPD) esters in fat-based matrices is currently carried out according to a number of methods that involve either the conversion of all the esters to the free form that is then quantified (indirect methods), or the separation and quantification of the individual esters (direct methods). Indirect methods of analysis show a better sensitivity, however, the series of chemical reactions that take place during sample preparation may affect the reliability of the results because of the potential ex-novo formation of 3-MCPD from precursors present in the sample. This study is focused on the evaluation of the selectivity and robustness of an indirect acid-catalysed method of 3-MCPD esters analysis. The interference of chloride ions and glycidyl esters was evaluated. 3-MCPD esters are overestimated only when high levels of chloride ions (>1.7 mmol/kg oil) were added to the samples. The interference by chloride ions can be easily eliminated by a single extraction step of the samples before analysis. In contrast, glycidyl esters did not interfere with the determination of 3-MCPD esters. Further investigation on the robustness of the method showed that the time allowed for the transesterification, a major drawback of the previous version of the method, can be reduced from 16 to 4 h without any significant reduction of the accuracy and repeatability (RSD = 0.7%).     

Thermal and mechanical properties of PES/PTFE composites and nanocomposites

Polyethersulphone/polytetrafluoroethylene (PES/PTFE) nanocomposites and composites were prepared by precipitation of PES into a PTFE latex‐containing nanoparticles. Different samples were obtained by varying the relative ratio between PES and PTFE. The complex crystallization process, discussed within the fractionated crystallization frame, allowed to identify and quantify different dispersion degree of the PTFE nanoparticles within the PES matrix. The different samples were thus divided into nanocomposite and composites. The effect of crystalline PTFE domains on the mobility of PES was investigated and discussed. The dynamic‐mechanical behavior was explained in terms of the particle aggregation state. The mechanical properties of the PES/PTFE composites were found to depend on both the dispersion and the concentration of the PTFE nanoparticles. In the glassy state the stiffness of the materials was found to increase with the dispersion degree, resulting higher for the nanocomposite with respect to composites. On the contrary, in the rubbery state the modulus was found proportional to the PTFE nanoparticles concentration, resulting higher in the composites with respect to the nanocomposite. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 3624–3633, 2013     

Non-Covalent Synthesis of Metal Oxide Nanoparticle–Heparin Hybrid Systems: A New Approach to Bioactive Nanoparticles

Heparin has been conjugated to Fe₃O₄, Co₃O₄, and NiO nanoparticles (NPs) through electrostatic interactions, producing colloidal suspensions of hybrid metal oxide heparin NPs that are stable in water. Negative zeta potentials and retention of heparin’s ability to capture toluidine blue indicate that heparin’s negative charges are exposed on the surface of the coated NPs. IR results confirmed the formation of nanohybrids as did NMR experiments, which were also interpreted on the basis of toluidine blue tests. Transmission electron microscopy results revealed that the heparin coating does not modify the shape or dimension of the NPs. Dynamic light scattering and negative zeta potential measurements confirmed that heparin surface functionalisation is an effective strategy to prevent NP aggregation.     

Recovery and concentration of phenolic compounds in blood orange juice by membrane operations

Cross-flow ultrafiltration (UF) and osmotic distillation (OD) were implemented on laboratory scale to obtain formulations of interest for food and/or pharmaceutical industry starting from the blood orange juice produced in the Calabria region. The freshly squeezed juice, after a depectinization step, was submitted to an UF process in order to recover natural antioxidants, such as hydroxycinnamic acids, hydroxybenzoic acids, flavanones, flavan-3-ols, and anthocyanins. The UF permeate, with an initial total soluble solids (TSS) content of 10.5°Brix, was concentrated by OD up to a final concentration of 61.4°Brix.     

Coating-Activation and Antimicrobial Efficacy of Different Polyethylene Films with a Nisin-Based Solution

Antimicrobial packaging can be considered an extremely challenging technology that could have a significant impact on shelf-life extension and food safety of fresh meat and meat products. In this study, different commercial polyethylene films differing in vinyl acetate ethylene, erucamide contents, and oxygen permeability were used for the coating treatment with a nisin-based antimicrobial solution (NS). Detection and measurement of the activity of the NS was determined against different food spoilage bacteria. NS was then spread manually on food contact layer of different plastic films using coating rods providing thickness of 6, 40, 60, and 100 μm. The polyethylene films before and after treatment were analysed by atomic force microscopy (AFM). NS was active against Gram-positive bacteria and the best activity was obtained against Brochothrix thermosphacta. Viable staining and epifluorescence microscopy analysis of indicator strains in contact with activated plastic films showed that the effect of the film on the various indicator strains changed very much on the basis of both type of film and indicator strain. The highest numbers of lysed cells were shown by two polyethylene films that, according to the AFM and roughness parameters analyses, were characterized by significant increase or decrease of roughness after the coating treatment. AFM analysis showed that the homogeneity of the coating was much influenced by the type of plastic films used. In order to test the efficacy in food, portions of beef chuck tender slices were prepared and covered with the antimicrobial plastic films on both sides. After 1 h and 1, 7, and 12 days of storage at 4 °C the meat samples were analyzed by standard plate counting targeting spoilage associated microbial populations. The antimicrobial plastic films after 1 h of contact with the meat caused a significant reduction of lactic acid bacteria and B. thermosphacta. The most effective antimicrobial activity of films was shown against the same populations after 24 h of storage.     

Generation of a Triadin KnockOut Syndrome Zebrafish Model

Different forms of sudden cardiac death have been described, including a recently identified form of genetic arrhythmogenic disorder, named “Triadin KnockOut Syndrome” (TKOS). TKOS is associated with recessive mutations in the TRDN gene, encoding for TRIADIN, but the pathogenic mechanism underlying the malignant phenotype has yet to be completely defined. Moreover, patients with TKOS are often refractory to conventional treatment, substantiating the need to identify new therapeutic strategies in order to prevent or treat cardiac events. The zebrafish (Danio rerio) heart is highly comparable to the human heart in terms of functions, signal pathways and ion channels, representing a good model to study cardiac disorders. In this work, we generated the first zebrafish model for trdn loss-of-function, by means of trdn morpholino injections, and characterized its phenotype. Although we did not observe any gross cardiac morphological defect between trdn loss-of-function embryos and controls, we found altered cardiac rhythm that was recovered by the administration of arrhythmic drugs. Our model will provide a suitable platform to study the effect of TRDN mutations and to perform drug screening to identify new pharmacological strategies for patients carrying TRDN mutations.     

DNA barcoding as a new tool for food traceability

Food safety and quality are nowadays a major concern. Any case of food alteration, especially when reported by the media, has a great impact on public opinion. There is an increasing demand for the improvement of quality controls, hence addressing scientific research towards the development of reliable molecular tools for food analysis. DNA barcoding is a widely used molecular-based system, which can identify biological specimens, and is used for the identification of both raw materials and processed food. In this review the results of several researches are critically analyzed, in order to exploit the effectiveness of DNA barcoding in food traceability, and to delineate some best practices in the application of DNA barcoding throughout the industrial pipeline. The use of DNA barcoding for food safety and in the identification of commercial fraud is also discussed.     

Supplementation with SCFAs Re-Establishes Microbiota Composition and Attenuates Hyperalgesia and Pain in a Mouse Model of NTG-Induced Migraine

Migraine is a common brain-disorder that affects 15% of the population. Converging evidence shows that migraine is associated with gastrointestinal disorders. However, the mechanisms underlying the interaction between the gut and brain in patients with migraine are not clear. In this study, we evaluated the role of the short-chain fatty acids (SCFAs) as sodium propionate (SP) and sodium butyrate (SB) on microbiota profile and intestinal permeability in a mouse model of migraine induced by nitroglycerine (NTG). The mice were orally administered SB and SP at the dose of 10, 30 and 100 mg/kg, 5 min after NTG intraperitoneal injections. Behavioral tests were used to evaluate migraine-like pain. Histological and molecular analyses were performed on the intestine. The composition of the intestinal microbiota was extracted from frozen fecal samples and sequenced with an Illumina MiSeq System. Our results demonstrated that the SP and SB treatments attenuated hyperalgesia and pain following NTG injection. Moreover, SP and SB reduced histological damage in the intestine and restored intestinal permeability and the intestinal microbiota profile. These results provide corroborating evidence that SB and SP exert a protective effect on central sensitization induced by NTG through a modulation of intestinal microbiota, suggesting the potential application of SCFAs as novel supportive therapies for intestinal disfunction associated with migraine.