Search results for "material"
showing 10 items of 32550 documents
Profiling Suspensions in Natural Water by a Simplified Dynamic Light Scattering Procedure and Sedimentation
2015
Abstract A coherent light scattering experiment was carried out. The samples were aqueous natural water suspensions picked from the same river. While sedimentation occurred in the samples, they were subjected to a dynamic light scattering (DLS) experiment and the time series was recorded at certain time intervals. For each recording, a program written for this purpose, performing at least square minimisation, computed the average diameter of the particles in suspension. The variation of the average diameter in time indicates the dominant type of suspensions in water.
Novel Wood Resistance Measurement Method Reducing the Initial Transient Instabilities Arising in DC Methods Due to Polarization Effects
2019
A novel method for measuring the electrical resistance in wood is presented. It is based on applying an Alternating Current (AC) to two electrodes rammed into the wood. The method reduces the transient time for value stabilization. In case of Direct Current (DC) resistance measurement methods, typically used in wood measurement, an initial transient exists, invalidating the measured value during an initial transient period. This measurement method uses an electronic circuit based on a relaxation oscillator where the wood automatically sets the oscillation frequency depending on its electrical resistance. Compared to other AC methods, this circuit greatly simplifies the measurement process, …
High-pressure processing of meat and meat products
2016
International audience; High pressure (HP) was first introduced at the end of the nineteenth century in the field of materials chemistry. The first application of high pressure in the food industry was proposed by Hite in 1899 to pasteurize milk and fruit products. The high hydrostatic pressure (HHP) treatment is considered as a nonthermal process, alternative to heat treatments, as it enables inactivation of pathogenic and spoilage microorganisms in foods. This technology is based on two principles that determine the behavior of foods under pressure. The first is an important principle that underlies the effects on reaction equilibria is known as the principle of Le Chatelier, and the seco…
Lignin Inter-Diffusion Underlying Improved Mechanical Performance of Hot-Pressed Paper Webs
2021
Broader use of bio-based fibres in packaging becomes possible when the mechanical properties of fibre materials exceed those of conventional paperboard. Hot-pressing provides an efficient method to improve both the wet and dry strength of lignin-containing paper webs. Here we study varied pressing conditions for webs formed with thermomechanical pulp (TMP). The results are compared against similar data for a wide range of other fibre types. In addition to standard strength and structural measurements, we characterise the induced structural changes with X-ray microtomography and scanning electron microscopy. The wet strength generally increases monotonously up to a very high pressing tempera…
Optimization of the enzyme power source for a nano drug delivery system fuelled by glucose in blood plasma
2019
A unique in vivo electrical pulse generator to improve membrane permeability for drugs and simultaneously facilitate self-powered nano devices for nano drug delivery systems (NDDS) was identified. The use of an unsupported biological catalyst component of the power supply was aimed at the NDDS instead of a conventional membrane electrode assembly (MEA). Self-powered carriers of drugs and prodrugs with improved controlled release capability to target areas using substrate available in biological matrices such as glucose in blood is envisaged. The experimental application implemented prototype designed chambers allowing the entry of premixed precursors and low ohm resistance due the absence o…
Interaction of Compounds
2017
Abstract Modern consumers look for functional food products to achieve well-being, preferring natural products, rather than overprocessed ones. New processing technologies have emerged as alternatives to conventional heat treatments with promising results in food development and production. They allow microbiologically safe food products to be obtained while maintaining the food products’ nutritional and sensorial properties. However, the interactions between food compounds (e.g., proteins, carbohydrates, or lipids) promoted by these technologies are still poorly known and require further research. Technologies such as high-pressure processing, pulsed electric field, high-pressure homogeniz…
Mechanical properties of natural fiber composites produced using dynamic sheet former
2018
Composites formed from wood fibers and man-made cellulosic fibers in PLA (polylactic acid) matrix, manufactured using sheet forming technique and hot pressing, are studied. The composites have very low density (due to high porosity) and rather good elastic modulus and tensile strength. As expected, these properties for the four types of wood fiber composites studied here improve with increasing weight fraction of fibers, even if porosity is also increasing. On the contrary, for man-made cellulosic fiber composites with circular fiber cross-section, the increasing fiber weight fraction (accompanied by increasing void content) has detrimental effect on stiffness and strength. The differences …
Carvacrol activated biopolymeric foam: An effective packaging system to control the development of spoilage and pathogenic bacteria on sliced pumpkin…
2021
Abstract A commercial biodegradable starch-based polymer (Mater-Bi) was activated with carvacrol to develop a biodegradable and compostable polymer to be used in food packaging. Based on previous tests, carvacrol was added at 20 % weight of foam. MB foams, with and without carvacrol, were tested for their morphological characteristics, mechanical tests and kinetics of carvacrol release under refrigerated storage conditions. Carvacrol slightly increased the porosity of the foams, induced a reduction of the compressive elastic modulus (Ecom) of foamed MB from 6 to ∼ 3.4 MPa and a decrease of the tensile elastic modulus from ∼70 MPa to ∼16.5 MPa. Carvacrol release from the foam at 4 °C was alm…
Fresh-cut storage of fruit and fresh-cuts affects the behaviour of minimally processed Big Bang nectarines ( Prunus persica L. Batsch) during shelf l…
2018
Abstract Nectarine can be minimally processed to successfully produce ready-to-eat fresh-cuts fruit. The aim of this work was to study the combined effect of the ripening stage of cold stored fruit before processing and the length of the storage period of fresh-cut slices after minimal processing, on the behaviour of minimally processed “Big Bang” nectarines during shelf life. ‘Big Bang’nectarine slices obtained from fruit stored at 1 ± 0.5 °C (RH = 90%) for 1 d, 10 d and 15 d were stored for 0, 3, 5, 7, 12 d. at 5 °C. At the end of each storage period, visual quality, color (L*, a* and b*), phenols and carothenoids content, TSS, TA were measured together with in-package CO2 and O2. Despite…
Thermoplastic starch and green tea blends with LLDPE films for active packaging of meat and oil-based products
2019
International audience; Thermoplastic starch (TPS) is an alternative biomaterial that can be used to produce bioplastics to replace petroleum-based food packaging. Active films were developed from acetylated cassava TPS and green tea using the blown extrusion process. Green tea (GT) and TPS from native starch (NS) and acetylated starch (AS) with different degrees of substitution (DS) were extruded with linear low-density polyethylene (LLDPE) at LLDPE/TPS-GT ratios of 70/30 and 60/40 prior to blown-film extrusion. Results indicated that a higher DS of AS enhanced melt flow index which altered processability and subsequently impacted film microstructures and physical and barrier properties. N…