Stable Isotope Ratio Analysis for Assessing the Authenticity of Food of Animal Origin

The main elemental constituents (H, C, N, O, and S) of bio‐organic material have different stable isotopes (²H, ¹H; ¹³C,¹²C; ¹⁵N,¹⁴N; ¹⁸O,¹⁷O,¹⁶O; ³⁶S, ³⁴S, ³³S, and ³²S). Isotopic ratios can be measured precisely and accurately using dedicated analytical techniques such as isotope ratio mass spectrometry (IRMS). Analysis of these ratios shows potential for assessing the authenticity of food of animal origin. In this review, IRMS analysis of food of animal origin and variability factors related to stable isotope ratios in animals are described. The study also lists examples of application of stable isotope ratio analysis to meat, dairy products, fish, and shellfish and emphasizes the strengths and weaknesses of the technique. Geographical, climatic, pedological, geological, botanical, and agricultural factors affect the stable isotope ratios (SIR) of bio‐elements, and SIR variations are ultimately incorporated into animal tissue through eating, drinking, breathing, and exchange with the environment, being recorded in the resulting foods. SIR analysis was capable of determining geographical origin, animal diet, and the production system (such as organic/conventional or wild/farmed) for pork, beef, lamb, poultry, milk, butter, cheese, fish, and shellfish. In the case of the hard PDO (protected designations of origin) cheeses Grana Padano and Parmigiano Reggiano it is also used in real‐life situations to assess the authenticity of grated and shredded cheese on the market.     

Use of sourdough fermented wheat germ for enhancing the nutritional, texture and sensory characteristics of the white bread

Lactobacillus plantarum LB1 and Lactobacillus rossiae LB5, isolated from wheat germ and selected based on the kinetics of acidification, were used as starters for the manufacture of sourdough fermented wheat germ. A bread containing sourdough fermented wheat germ as an ingredient (SFWGB) was compared to breads made with (raw wheat germ bread, RWGB) or without (wheat flour bread, WFB) raw wheat germ. The higher concentration of free amino acids mainly differentiated SFWGB from WFB and RWGB. The in vitro protein digestibility of WFB was the highest, even if sourdough fermentation of wheat germ attenuated the difference. Phytase and antioxidant activities of SFWGB were highest. The specific volume and cell-total areas were also the highest for SFWGB. As determined by texture profile analysis, the values of hardness, resilience and fracturability of breads containing wheat germ were lower than those found in WFB. The crust lightness showed a decrease from WFB to SFWGB. As determined by sensory analysis, SFWGB had mainly acid taste and flavour and resulted more salty. Sourdough fermented wheat germ is an ingredient able to enhance nutritional, texture and sensory properties of bread.     

A method for evaluating personal dosemeters in workplace with neutron fields

Passive detectors, as albedo or track-etch, still dominate the field of neutron personal dosimetry, mainly due to their low-cost, high-reliability and elevated throughput. However, the recent appearance in the market of electronic personal dosemeters for neutrons presents a new option for personal dosimetry. In addition to passive detectors, electronic personal dosemeters necessitate correction factors, concerning their energy and angular response dependencies. This paper reports on the results of a method to evaluate personal dosemeters for workplace where neutrons are present. The approach here uses few instruments and does not necessitate a large mathematical workload. Qualitative information on the neutron energy spectrum is acquired using a simple spectrometer (Nprobe), reference values for H*(10) are derived from measurements with ambient detectors (Studsvik, Berthold and Harwell) and angular information is measured using personal dosemeters (electronic and bubbles dosemeters) disposed in different orientations on a slab phantom.     

Effect of high hydrostatic pressure on the quality of four edible flowers: Viola × wittrockiana,Centaurea cyanus,Borago officinalis and Camellia japonica

The aim of the study was to evaluate the effect of high hydrostatic pressure (HHP) on the appearance, bioactivity and microbial content of four edible flowers along storage. Several treatments at 75–450 MPa and holding times (1, 5 and 10 min) were applied. Borage and camellia were unacceptable after all treatments, while centaurea showed good appearance at 100/5 MPa min^?1; however, the shelf life did not increase. Pansies treated at 75/5 and 75/10 MPa min^?1 also retained the appearance of fresh flowers. Furthermore, pansies submitted at 75/5 MPa min^?1 maintained good appearance over 20 days of storage at 4 °C, while the untreated remained satisfactory only until 6 days. Even though no significant differences on microbial load were observed between untreated and HHP‐treated pansies in day 0, HHP induced the production of bioactive compounds, increasing the shelf life of pansies. So, the HHP treatment is a promising technology for Viola × wittrockiana.     

Eco-friendly Pretreatment of Oil with High Free Fatty Acid Content Using a Sulfamic Acid/Ethanol System

In recent years, sulfamic acid (SA, NH₂SO₃H) has emerged as a novel green catalyst for organic synthesis because of several advantages, including its non‐volatility, non‐hygroscopicity, non‐corrosivity, and low cost. This work reports the use of sulfamic acid as a catalyst in the pretreatment of oil with a high content of free fatty acids (10 and 20 % FFA) in ethanol or methanol. The process (esterification reaction) used in the pretreatment of the oil was carried out under a variety of conditions, initial fatty acid content, temperature, type of alcohol, and % catalyst. The experiments using an NH₂SO₃H/ethanol system resulted in a high fatty acid ethyl ester conversion, 88.53 % (±0.95) from an initial acidity of 40 mg KOH/g (20 % FFA), using 8 % NH₂SO₃H as the catalyst. According to the results, the methodology using sulfamic acid and ethanol demonstrated elevated potential for a environmentally‐friendly means of biodiesel production.     

A modeling methodology for thermal analysis of the PCB structure

A modeling methodology is proposed for the thermal analysis of the PCB structure based on integrating both the FVM-based numerical solution and the Fourier-series-based analytical solution of temperature. The heat spreading through tracks and the vertical heat transfer through vias are taken into account in a numerical way and regarded as the additional thermal boundary conditions of insulating layers, which are assumed to be homogeneous from an analytical point of view. A methodology based on the vertex-centered Cartesian-grid Finite Volume Method is also proposed for the electric analysis of PCB tracks in order to take into account the temperature-dependent Joule heating effect, thus the current carrying capacity of tracks can be estimated as well. The necessary and sufficient condition for solving electric distributions in multi-terminal tracks is discussed, described and verified through both the analysis of the equivalent resistor network in a multi-terminal track and the mathematical analysis of a matrix equation, which correlates terminal currents with terminal electric potentials. In addition, the method for analyzing the multilayer structure is also discussed. A thermal solver was developed in MATLAB based on the methodology. Several layouts were modeled in the solver and COMSOL to test the validity of the methodology and to investigate the influence factors of the solution. Based on the analysis and comparisons, mesh density and the number of eigenvalues are the main influence factors. The vertical and horizontal heat transfer contributions of vias were also investigated by modeling the footprint layout of a power mosfet in order to test the modeling assumptions. Finally, the consistency between the modeling results and the reference results was found. Both the advantages and disadvantages of the methodology are discussed throughout the analysis.     

Selective Extraction of Piceatannol from Passiflora edulis by-Products: Application of HSPs Strategy and Inhibition of Neurodegenerative Enzymes

Passiflora edulis by-products (PFBP) are a rich source of polyphenols, of which piceatannol has gained special attention recently. However, there are few studies involving environmentally safe methods for obtaining extracts rich in piceatannol. This work aimed to concentrate piceatannol from defatted PFBP (d-PFBP) by means of pressurized liquid extraction (PLE) and conventional extraction, using the bio-based solvents selected with the Hansen solubility parameters approach. The relative energy distance (Ra) between solvent and solute was: Benzyl Alcohol (BnOH) < Ethyl Acetate (EtOAc) < Ethanol (EtOH) < EtOH:H₂O. Nonetheless, EtOH presented the best selectivity for piceatannol. Multi-cycle PLE at 110 °C was able to concentrate piceatannol 2.4 times more than conventional extraction. PLE exhibited a dependence on kinetic parameters and temperature, which could be associated with hydrogen bonding forces and the dielectric constant of the solvents. The acetylcholinesterase (AChE) and lipoxygenase (LOX) IC₅₀ were 29.420 μg/mL and 27.682 μg/mL, respectively. The results reinforce the demand for processes to concentrate natural extracts from food by-products.     

Electrostatic Mechanophores in Tuneable Light‐Emitting Piezopolymer Nanowires

Electromechanical coupling through piezoelectric polymer chains allows the emission of organic molecules in active nanowires to be tuned. This effect is evidenced by highly bendable arrays of counter‐ion dye‐doped nanowires made of a poly(vinylidenefluoride) copolymer. A reversible redshift of the dye emission is found upon the application of dynamic stress during highly accurate bending experiments. By density functional theory calculations it is found that these photophysical properties are associated with mechanical stresses applied to electrostatically interacting molecular systems, namely to counterion‐mediated states that involve light‐emitting molecules as well as charged regions of piezoelectric polymer chains. These systems are an electrostatic class of supramolecular functional stress‐sensitive units, which might impart new functionalities in hybrid molecular nanosystems and anisotropic nanostructures for sensing devices and soft robotics.     

Relationship between calcium intake and body mass index in adolescents

Epidemiologic and experimental data support thee possibility that dietary calcium intake plays a role in human body weight regulation. The aim of the present study was to evaluate calcium intake and its relationship with body mass index (BMI) in adolescents. Weight, height, 3-day food record and a food frequency questionnaire were collected among all adolescents participants at the Outpatient Clinic for Adolescents at the Federal University of Sao Paulo between 2001 and 2003. The statistical analysis comprised Chi-square, Student's T-test, Pearson correlation and linear regression. One-hundred and twenty-one adolescents were studied (62.8% female), with a mean age of 14.9 +/- 2.2 years old. Mean energy and calcium intakes were 1729.9 +/- 557.8 kcal/day and 598.2 +/- 287.9 mg/day respectively, with no significant statistical differences between sex or age. Almost ninety-eight percent of adolescents presented a mean calcium intake lower than proposed values. Calcium intake adjusted for energy presented a significant negative correlation with body weight (r=-0.194, p=0.03) and BMI (r=-0.185, p=0.04). Furthermore, adolescents in the lowest quartile of calcium intake presented higher BMI (29.7 +/- 7.4 kg/m2) than adolescents in the highest calcium quartile. These results indicated a dietary calcium intake lower than recommendations for this life stage, and a contribution of this mineral in the body mass index.