scholarly journals Migration of Polypropylene Oligomers into Ready-to-Eat Vegetable Soups

Foods ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1365
Author(s):  
Chiara Conchione ◽  
Paolo Lucci ◽  
Sabrina Moret
Keyword(s):  
Microwave Heating ◽  
High Performance ◽  
Heating Time ◽  
Fat Content ◽  
Polymerization Process ◽  
Flame Ionization ◽  
Time Migration ◽  
Italian Market ◽  
Wide Range ◽  
On Line

Polyolefin oligomeric hydrocarbons (POH) are non-intentionally added substances (NIAS) which mainly reside in the polymer (PE, PP) as a consequence of the polymerization process, and that under favorable conditions (high fat content, high temperature, and long contact time) may migrate at high amount from the packaging into the food. The food industry offers a wide range of ready-to-eat products, among these, vegetable soups designed to be stored at refrigeration temperature (for times around 6 weeks), and in most cases to be heated for a few minutes in a microwave oven (into the original container, mostly of PP) before consumption. The present work aimed to study for the first-time migration of POH during the shelf life of these products, including storage at refrigeration temperature and after microwave heating. On-line high-performance liquid chromatography (HPLC)-gas chromatography (GC), followed by flame ionization detection (FID), was applied for POH analysis in a number of ready-to-eat products purchased from the Italian market. Microwave heating determined a variable POH increase ranging from 0.1 to 6.2 mg/kg. Parameters possibly affecting migration such as fat content and heating time were also studied.

scholarly journals MATHEMATICAL MODELING OF MICROWAVE HEATING OF BALL-SHAPED PRODUCTS

2019 ◽  
Author(s):  
Vadim Karelin ◽  
Vladimir Salomatov
Keyword(s):  
Mathematical Modeling ◽  
Microwave Heating ◽  
High Performance ◽  
Nonlinear Models ◽  
Heating Time ◽  
Microwave Energy ◽  
Moisture Distribution ◽  
Microwave Drying ◽  
Food Industries ◽  
Analytical Approaches

Microwave heating is widely used in the energy, construction, forestry, chemical and food industries, etc. There are many publications that discuss the main mechanisms that occur during microwave heating. For a better understanding of these processes and the development of high-performance microwave installations, mathematical modeling is necessary. As a rule, nonlinear models that most adequately describe these phenomena use a numerical algorithm for calculations. The authors of this report are engaged in approximate analytical approaches for microwave heating and microwave drying of bodies, which, with a controlled decrease in accuracy, nevertheless allow you to display the main processes and evaluate such heating and drying parameters as: temperature and moisture distribution, heating time, drying speed, reaching maximum values, etc. In this work, we consider a model of microwave heating in the form of a ball with uniform irradiation of microwave energy in the conditions of radiation-convective interaction of the product with the environment. The absorption of the microwave inside the material is given by the law of the Bouguer. In this case, a number of simplifications were made: the electrophysical and thermophysical properties of the material are constant, the material is homogeneous in composition and properties.

Effect of Heating Time on Atrazine-Based MIP Materials Synthesized via the Cooling-Heating Method

2014 ◽  
Vol 896 ◽  
pp. 89-94 ◽  
Author(s):  
Idha Royani ◽  
Widayani ◽  
Abdullah Mikrajuddin ◽  
Khairurrijal
Keyword(s):  
High Performance ◽  
Chemical Properties ◽  
Reversed Phase ◽  
Heating Time ◽  
Polymerization Process ◽  
Template Molecule ◽  
Sem Images ◽  
Liquid Chromatograph ◽  
Heating Method ◽  
Equilibrium Dissociation

Molecular imprinting is a technique to produce a polymer called as molecularly imprinted polymer (MIP) that provides cavities to form a particular space generated by removing the template when the polymer has been formed. It will recognize a target that has the shape and physico-chemical properties similar or identical with those of template molecule. In this study, MIPs using atrazine as template have been made via the cooling-heating method. Initially the pre-polymer solution was cooled at a refrigerator for 1 h. Next, the polymerization was carried out at 70 °C for heating times of 90, 120, and 150 min. without nitrogen flow which is generally done for polymerization process. Characterizations were performed by employing a reversed-phase high performance liquid chromatograph (HPLC) and scanning electron microscope (SEM). From Scatchard plots, it was found that the equilibrium dissociation constantKDand the apparent maximum number of binding sitesBmax, which are written as (KD,Bmax), are (4.69 μM, 9.87 mmol/g), (4.54 μM, 9.56 mmol/g) and (3.52 μM, 7.44 mmol/g) for the heating times of 150, 120, and 90 min., respectively. This is verified by their SEM images showing that the broadest pore size distribution with the highest number of pores is in the MIP prepared under the heating time of 150 min. The MIPs therefore could be applied as an atrazine sensor and the MIP prepared under the heating time of 150 min. would give its best characteristics compared to the others.

Recent Progress and Plans in Computer-Controlled High Resolution Electron Microscopy

1990 ◽  
Vol 48 (1) ◽  
pp. 154-155
Author(s):  
W.J. de Ruijter ◽  
Peter Rez ◽  
David J. Smith
Keyword(s):  
Electron Microscopy ◽  
Digital Processing ◽  
High Resolution Electron Microscopy ◽  
Objective Lens ◽  
Linear Filter ◽  
Contrast Transfer Function ◽  
Image Displacement ◽  
Spatially Resolved ◽  
Wide Range ◽  
On Line

Digital computers are becoming widely recognized as standard accessories for electron microscopy. Due to instrumental innovations the emphasis in digital processing is shifting from off-line manipulation of electron micrographs to on-line image acquisition, analysis and microscope control. An on-line computer leads to better utilization of the instrument and, moreover, the flexibility of software control creates the possibility of a wide range of novel experiments, for example, based on temporal and spatially resolved acquisition of images or microdiffraction patterns. The instrumental resolution in electron microscopy is often restricted by a combination of specimen movement, radiation damage and improper microscope adjustment (where the settings of focus, objective lens stigmatism and especially beam alignment are most critical). We are investigating the possibility of proper microscope alignment based on computer induced tilt of the electron beam. Image details corresponding to specimen spacings larger than ∼20Å are produced mainly through amplitude contrast; an analysis based on geometric optics indicates that beam tilt causes a simple image displacement. Higher resolution detail is characterized by wave propagation through the optical system of the microscope and we find that beam tilt results in a dispersive image displacement, i.e. the displacement varies with spacing. This approach is valid for weak phase objects (such as amorphous thin films), where transfer is simply described by a linear filter (phase contrast transfer function) and for crystalline materials, where imaging is described in terms of dynamical scattering and non-linear imaging theory. In both cases beam tilt introduces image artefacts.

Validated Stability Indicating HPTLC Method for the Estimation of Amoxapine in Different Stress Conditions

2019 ◽  
Vol 15 (3) ◽  
pp. 273-279
Author(s):  
Shweta G. Rangari ◽  
Nishikant A. Raut ◽  
Pradip W. Dhore
Keyword(s):  
High Performance ◽  
Limit Of Detection ◽  
Degradation Products ◽  
Analysis Data ◽  
Peak Height ◽  
Good Resolution ◽  
Stability Indicating ◽  
Limit Of Quantitation ◽  
Wide Range ◽  
Hptlc Method

Background:The unstable and/or toxic degradation products may form due to degradation of drug which results into loss of therapeutic activity and lead to life threatening condition. Hence, it is important to establish the stability characteristics of drug in various conditions such as in temperature, light, oxidising agent and susceptibility across a wide range of pH values.Introduction:The aim of the proposed study was to develop simple, sensitive and economic stability indicating high performance thin layer chromatography (HPTLC) method for the quantification of Amoxapine in the presence of degradation products.Methods:Amoxapine and its degraded products were separated on precoated silica gel 60F254 TLC plates by using mobile phase comprising of methanol: toluene: ammonium acetate (6:3:1, v/v/v). The densitometric evaluation was carried out at 320 nm in reflectance/absorbance mode. The degradation products obtained as per ICH guidelines under acidic, basic and oxidative conditions have different Rf values 0.12, 0.26 and 0.6 indicating good resolution from each other and pure drug with Rf: 0.47. Amoxapine was found to be stable under neutral, thermal and photo conditions.Results:The method was validated as per ICH Q2 (R1) guidelines in terms of accuracy, precision, ruggedness, robustness and linearity. A good linear relationship between concentration and response (peak area and peak height) over the range of 80 ng/spot to 720 ng/spot was observed from regression analysis data showing correlation coefficient 0.991 and 0.994 for area and height, respectively. The limit of detection (LOD) and limit of quantitation (LOQ) for area were found to be 1.176 ng/mL and 3.565 ng/mL, whereas for height, 50.063 ng/mL and 151.707 ng/mL respectively.Conclusion:The statistical analysis confirmed the accuracy, precision and selectivity of the proposed method which can be effectively used for the analysis of amoxapine in the presence of degradation products.

Phytochemical, Analytical and Medicinal Studies of Holoptelea integrifolia Roxb. Planch - A Review

2019 ◽  
Vol 5 (4) ◽  
pp. 270-277 ◽  
Author(s):  
Vijay Kumar ◽  
Simranjeet Singh ◽  
Ragini Bhadouria ◽  
Ravindra Singh ◽  
Om Prakash
Keyword(s):  
Liquid Chromatography ◽  
Thin Layer ◽  
Thin Layer Chromatography ◽  
High Performance ◽  
Biologically Active ◽  
Toxicological Studies ◽  
Wide Range ◽  
Layer Chromatography

Holoptelea integrifolia Roxb. Planch (HI) has been used to treat various ailments including obesity, osteoarthritis, arthritis, inflammation, anemia, diabetes etc. To review the major phytochemicals and medicinal properties of HI, exhaustive bibliographic research was designed by means of various scientific search engines and databases. Only 12 phytochemicals have been reported including biologically active compounds like betulin, betulinic acid, epifriedlin, octacosanol, Friedlin, Holoptelin-A and Holoptelin-B. Analytical methods including the Thin Layer Chromatography (TLC), High-Performance Thin Layer Chromatography (HPTLC), High-Performance Liquid Chromatography (HPLC) and Liquid Chromatography With Mass Spectral (LC-MS) analysis have been used to analyze the HI. From medicinal potency point of view, these phytochemicals have a wide range of pharmacological activities such as antioxidant, antibacterial, anti-inflammatory, and anti-tumor. In the current review, it has been noticed that the mechanism of action of HI with biomolecules has not been fully explored. Pharmacology and toxicological studies are very few. This seems a huge literature gap to be fulfilled through the detailed in-vivo and in-vitro studies.

scholarly journals RELaTED Project: New Developments on Ultra-Low Temperature District Heating Networks

Proceedings ◽  
2020 ◽  
Vol 65 (1) ◽  
pp. 25
Author(s):  
Antonio Garrido Marijuan ◽  
Roberto Garay ◽  
Mikel Lumbreras ◽  
Víctor Sánchez ◽  
Olga Macias ◽  
...  
Keyword(s):  
Low Temperature ◽  
High Performance ◽  
Waste Heat ◽  
District Heating ◽  
Hot Water ◽  
Thermal Systems ◽  
Heating Source ◽  
Wide Range ◽  
Thermal Sources ◽  
Heating Networks

District heating networks deliver around 13% of the heating energy in the EU, being considered as a key element of the progressive decarbonization of Europe. The H2020 REnewable Low TEmperature District project (RELaTED) seeks to contribute to the energy decarbonization of these infrastructures through the development and demonstration of the following concepts: reduction in network temperature down to 50 °C, integration of renewable energies and waste heat sources with a novel substation concept, and improvement on building-integrated solar thermal systems. The coupling of renewable thermal sources with ultra-low temperature district heating (DH) allows for a bidirectional energy flow, using the DH as both thermal storage in periods of production surplus and a back-up heating source during consumption peaks. The ultra-low temperature enables the integration of a wide range of energy sources such as waste heat from industry. Furthermore, RELaTED also develops concepts concerning district heating-connected reversible heat pump systems that allow to reach adequate thermal levels for domestic hot water as well as the use of the network for district cooling with high performance. These developments will be demonstrated in four locations: Estonia, Serbia, Denmark, and Spain.

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