Phthalate Sample Preparation Methods and Analysis in Food and Food Packaging: a Review

A review on phthalate esters or phthalic acid esters (PAEs), chemicals of concern since a few decades ago that are widely used as plasticizers in food processing and packaging, is presented taking into account the background of such compounds, the metabolism, human exposure to PAEs, the sources and occurrence in food as well as the toxicological aspects and human health effects. In addition, 45 novel research articles that were published between 2002 and 2017 were identified and their results were tabulated showing the PAEs analysed, food matrix of PAEs, methods of sample preparation/extraction, methods of instrumental analysis and quantitation, percentage recovery and limit of detection (LOD) of the instrument for ease of comparison and referencing. In general, it was found that in the last 15 years, the number of PAEs analysed has increased from the commonly analysed 8 PAEs, namely dimethyl phthalate (DMP), diethyl phthalate (DEP), diisobutyl phthalate (DIBP), di-n-butyl phthalate (DBP), butyl benzyl phthalate (BBP), dicyclohexyl phthalate (DCHP), di-n-octyl phthalate (DNOP) and di-(2-ethylhexyl) phthalate (DEHP) to as many as 23 PAEs. The methods of sample preparation have also progressed from the simple liquid-liquid extraction using organic solvents to solid-phase microextraction techniques to the more recent head-space or direct immersion solid-phase microextraction methods. Whereas for the analysis of PAEs, gas chromatography and liquid chromatography are still the preferred methods with improved LOD of analysis ranging from approximately 10 ppm for fatty foods to 1–60 ppt for water, juices and cooking oil samples.     

Optimization of spray drying process of Sargassum muticum color extract

ABSTRACT

Sargassum muticum is categorized as a brown seaweed species which has been used as a dye fabric colorant in certain regions of Asia. The brown extracts of S. muticum also have antioxidant properties, which could enhance the color and nutrients in food products. However, the color extract is unstable, and also limits the application. This study was performed to encapsulate the color extract with maltodextrin and stabilize the color extract by spray drying technique using combinations of various levels of inlet temperature and feed flow rate. Initially, S. muticum powder was analyzed for moisture content, water activity, solubility, and color properties for optimization purposes. This study showed that the optimum inlet temperature and feed flow rate of the spray drying process to produce good-quality, stable, and acceptable powder properties were at 140°C and 3?rpm, respectively, with 4% of maltodextrin. Then, the powder was analyzed for density, compressibility index, hygroscopicity, particle size, and antioxidant properties. This study represents an interesting food additive to be incorporated in functional food due to the attractive brown colorant and the presence of antioxidants.     

The effect of magnetic and optic field in water electrolysis

Hydrogen production via water electrolysis was studied under the effect of magnetic and optical field. A diode solid state laser at blue, green and red were utilized as optical field source. Magnetic bar was employed as external magnetic field. The green laser has shown a greatest effect in hydrogen production due to its non-absorbance properties in the water. Thus its intensity of electrical field is high enough to dissociation of hydronium and hydroxide ions during orientation toward polarization of water. The potential to break the autoprotolysis and generate the auto-ionization is the mechanism of optical field to reveal the hydrogen production in water electrolysis. The magnetic field effect is more dominant to enhance the hydrogen production. The diamagnetic property of water has repelled the present of magnetic in water. Consequently the water splitting occurs due to the repulsive force induced by the external magnetic field. The magnetic distributed more homogenous in the water to involve more density of water molecule. As a result hydrogen production due to magnetic field is higher in comparison to optical field. However the combination both fields have generated superior effect whereby the hydrogen yields nine times higher in comparison to conventional water electrolysis.     

Misalignment tolerance analysis of free-space optical interconnects via statistical methods

System-level packaging is one of the critical issues that need to be addressed for free space optical interconnections (FSOI) to become useful in desktop systems. The performance of FSOI, e.g., in terms of system bit-error rate, is greatly affected by misalignments in the optical system. Therefore tolerancing, i.e., the ability to analyze and predict the effects of misalignments in the system, is of prime importance to system designers. We introduce an approach in which we study the effects of optical misalignments and other tolerance factors using statistical methods. We use Monte Carlo simulations, design of the experiments, and regression techniques to fit a polynomial equation that expresses the relationship between the system performance and the tolerance factors. This prediction model can be used for design, cost optimization, and quality control purposes. In addition, we perform a sensitivity analysis to determine those tolerance variables that have the greatest effect on system performance.     

Productions and monomer compositions of exopolysaccharides by Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus strains isolated from traditional home-made yoghurts and raw milk

In this study, a total of forty‐five strains of lactobacilli and streptococci were determined exopolysaccharide (EPS) production in skim milk and Man Rogosa and Sharpe (MRS)/M17 medium, viscosity and proteolytic activity. The exopolysaccharide production by lactobacilli strains during growth in MRS medium was twenty‐one to 211 mg L^?1, while in skim milk was to thirty‐six to 315 mg L^?1. The EPS production by streptococci strains during growth in M17 medium was sixteen to 114 mg L^?1, while in skim milk was to twenty‐four to 140 mg L^?1. The EPS production of strains was lower in MRS/M17 medium than skim milk. Results showed that it was not clear correlation between the viscosity and EPS production of some strains. All strains were shown proteolytic activity. Positive correlations between exopolysaccharide production and proteolytic activity in skim milk were found some strains of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus. These results indicated that the high exocellular protease‐producing strains can produce high EPS in skim milk. The monomer compositions of the EPSs formed by selected five strains were analysed. Mannose dominated (99–100%) on the EPS produced by L. delbrueckii subsp. bulgaricus and S. thermophilusstrains (except L. delbrueckii subsp. bulgaricus 22) in skim milk and MRS/M17 medium. Besides, the EPSs of strains in skim milk contained small amount of lactose.     

Evaluation of counterions for electrospray ionization mass spectral analysis of a highly sulfated carbohydrate,sucrose octasulfate

A systematic approach was used to evaluate the electrospray ionization mass spectral (ESI-MS) analysis of sucrose octasulfate (SOS), an important pharmaceutical agent. SOS represents a model for other suffated carbohydrates, such as heparin and glycosaminoglycan-derived oligosaccharides that also are highly sulfated and pose difficult analytical problems. A survey of ammonium counterions showed that 1 degree, 2 degrees, and 3 degrees ammonium salts of SOS gave substantial fragmentation as a result of sulfate loss. In contrast, quaternary ammonium and phosphonium salts gave excellent ESI spectra, particularly in the positive ion mode. This represents the first report of the ESI-MS analysis of sulfated carbohydrates in the positive ion mode.     

A methodology for verification of digital items in fair exchange protocols with active trustee

Fair exchange constitutes a fundamental mechanism for electronic commerce. Fair exchange assumes that it is possible to verify the correctness of the digital items to be exchanged. However, when an item is indescribable , i.e., it cannot be formally specified, its verification becomes difficult, if not impossible. This hinders a practical deployment of fair exchange. We propose a methodology for the verification of indescribable digital items. The methodology allows a participant in a fair exchange protocol to personally verify the indescribable item without giving him any practical advantage over the other participant, and therefore without violating the fairness imposed by the protocol.     

Applied Genetic Algorithm for Solving Rich VRP

In this article, we present a study of the effectiveness of a genetic algorithm (GA) to solve a combinatorial problem, that is, a vehicle routing problem (VRP). We propose a new selection method, called “rank and select,” based on selection rate, and we compare it with roulette wheel selection. In this article, we use two types of crossover method and two types of mutation method. These are applied for comparing the best fitness at the end of a generation. The problem solved in this study is how to generate feasible route combinations for a rich VRP and meet all the requirements with an optimum solution. Initial test results show that the route produced by the GA was effectively used for solving rich VRP and especially for a large number of customers, depots, and vehicles. Fuel consumption by proposed routes was lower by about 20.38% compared to that of an existing route.     

Cell Culture on MEMS Platforms: A Review

Microfabricated systems provide an excellent platform for the culture of cells, and are an extremely useful tool for the investigation of cellular responses to various stimuli. Advantages offered over traditional methods include cost-effectiveness, controllability, low volume, high resolution, and sensitivity. Both biocompatible and bio-incompatible materials have been developed for use in these applications. Biocompatible materials such as PMMA or PLGA can be used directly for cell culture. However, for bio-incompatible materials such as silicon or PDMS, additional steps need to be taken to render these materials more suitable for cell adhesion and maintenance. This review describes multiple surface modification strategies to improve the biocompatibility of MEMS materials. Basic concepts of cell-biomaterial interactions, such as protein adsorption and cell adhesion are covered. Finally, the applications of these MEMS materials in Tissue Engineering are presented.     

On the location of different titanium sites in Ti–OMS-2 and their catalytic role in oxidation of styrene

Octahedral manganese oxide molecular sieves (OMS-2) modified by impregnation of TiO₂ exhibit a higher catalytic activity for oxidation of styrene with tert-butylhydroperoxide in comparison to titanium-incorporated OMS-2, where the styrene conversions were ca. 70% and 45–50%, respectively. The framework of titanium species has no effect on the enhancement of catalytic activity, while the non-framework of titanium species induces a synergetic effect that enhances the oxidation of styrene with tert-butylhydroperoxide.