Search results for "packaging"
showing 10 items of 256 documents
Effect of Sheep Wool Fibers on Thermal Insulation and Mechanical Properties of Cement-Based Composites
2019
The use of sheep wool as a filler of cement in order to produce mortar or plaster involves several advantages for environment and energy. Moreover, it is considered as a waste and, therefore, its use is characterized by low cost. The aim of this paper is to evaluate the influence of wool fibers on thermal conductivity and mechanical properties of cement. The samples were prepared using wool fibers, obtained from a breed of Sicilian sheep, with three different lengths (i.e., 1, 6, and 20 mm). Furthermore, in order to evaluate the influence of fiber content, the samples were prepared by varying the fiber weight fraction. The thermal conductivity of the samples was analyzed by using a heat flo…
Diffusion of Oxygen through Cork Stopper: Is It a Knudsen or a Fickian Mechanism?
2014
International audience; The aim of this work is to identify which law governs oxygen transfer through cork: Knudsen or Fickian mechanism. This is important to better understand wine oxidation during post-bottling aging. Oxygen transfer through cork wafers is measured at 298 K using a manometric permeation technique. Depending on the mechanism, we can extract the transport coefficients. Increasing the initial pressure of oxygen from 50 to 800 hPa leads to a change in the values of the transport coefficients. This implies that oxygen transport through cork does not obey the Knudsen law. From these results, we conclude that the limiting step of oxygen transport through cork occurs in the cell …
Edible Arabinoxylan-Based Films. 1. Effects of Lipid Type on Water Vapor Permeability, Film Structure, and Other Physical Characteristics
2002
Arabinoxylans (AX) are natural fibers extracted from maize bran, an industrial byproduct. To promote this polymer as a food ingredient, development of edible coatings and films had been proposed. Indeed, composite arabinoxylan-based films were prepared by emulsifying a fat: palmitic acid, oleic acid, triolein, or a hydrogenated palm oil (OK35). Lipid effects on water vapor permeability (WVP), surface hydrophobicity (contact angles), lipid particle size, and mechanical properties were investigated. Results showed that OK35-AX emulsion films had the lowest WVP. Emulsified films presented a bimodal particle size distribution; however, the smallest particle mean diameter (0.54 microm) was obser…
Methods of in vitro toxicology
2002
In vitro methods are common and widely used for screening and ranking chemicals, and have also been taken into account sporadically for risk assessment purposes in the case of food additives. However, the range of food-associated compounds amenable to in vitro toxicology is considered much broader, comprising not only natural ingredients, including those from food preparation, but also compounds formed endogenously after exposure, permissible/authorised chemicals including additives, residues, supplements, chemicals from processing and packaging and contaminants. A major promise of in vitro systems is to obtain mechanism-derived information that is considered pivotal for adequate risk asses…
Der Einfluss kondensierter Phosphate auf die Eisen-Resorption
1959
Es sollte untersucht werden, ob die kondensierten Phosphate Tetranatriumpyrophosphat, Natriumtripolyphosphat, Hexametaphosphat, Kaliummetaphosphat und Plasmal die Eisenresorption beeintrachtigen. Als Masstab fur diesselbe galten die Hamoglobin- und Erythrocytenregeneration und die Gewichtszunahme anamischer Ratten. Die Anamie wurde durch Phenylhydrazinhydrochlorid-Injektionen bzw. eine eisenarme Ernahrung (Milchdiat) hervorgerufen. Bei den herrschenden Versuchsbedingungen konnte ein nachteiliger Einflus der getesteten Substanzen auf die Eisenresorption nicht nachgewiesen werden. Auf Grund dieser Versuche und allgemeiner Uberlegungen wurde geschlossen, das dies uberhaupt unter physiologische…
Using ATR-FTIR Spectroscopy To Design Active Antimicrobial Food Packaging Structures Based on High Molecular Weight Chitosan Polysaccharide
2007
ATR-FTIR spectroscopy has been used in this study to characterize the molecular mechanisms and kinetic processes that take place when a chitosonium acetate thin coating is put in contact with water solutions, Staphylococcus aureus solutions, microbial nutrient solutions, and with a high water activity TSA hydrogel medium to simulate the effect of direct contact with high moisture foods such as fresh meats, fish, and seafood products or beverages. The results of this work suggest that the biocide carboxylate groups that form when chitosan is cast from acetic acid solutions are being continuously evaporated from the formed film in the form of acetic acid (mechanism I) in the presence of envir…
Influence of packaging on the aroma stability of strawberry syrup during shelf life
2001
Different types of packaging (glass bottle, PVC, and PET) were compared for the preservation of aroma quality of a strawberry syrup during shelf life. Esters, alcohols, and aldehydes were analyzed by solid-phase micro-extraction (SPME) and solvent extraction. During storage, hydrolysis of esters in acids and alcohols led to a modification of the aroma profile which can be explained by the replacement of “fruity” and “fresh” notes by “dairy note” in the syrup. Aroma compounds that are responsible for fruity notes, such as methyl cinnamate, methyl anthranilate, and methyl dihydrojasmonate, were strongly reduced after 90 days. This could be explained by a selective interaction of these compoun…
Factors affecting the moisture permeability of lipid-based edible films: a review.
2002
Moisture transfers inside food products could be controlled or limited by the use of edible films. These are usually based on hydrophobic substances such as lipids to improve barrier efficiency. Water permeability of films is affected by many factors, depending on both the nature of barrier components, the film structure (homogeneous, emulsion, multilayer, etc.), crystal type, shape, size and distribution of lipids, and thermodynamics such as temperature, vapor pressure, or the physical state of water in contact to the films. After a brief presentation of lipids and hydrophobic substances used as moisture barrier, cited in the scientific literature, this article reviews all of the parameter…
Shelf life assessment of industrial durum wheat bread as a function of packaging system
2017
This study compared the effect of different packaging systems on industrial durum wheat bread shelf-life, with regard to thermoformed packaging (TF) and flow-packaging (FP). Two TFs having different thickness and one FP were compared by assessing physico-chemical and sensorial properties and volatile compounds of sliced bread during 90 days of storage. Texture, aw and bread moisture varied according to a first-order kinetic model, with FP samples ageing faster than TFs. Sensorial features such as consistency, stale odor, and sour odor, increased their intensity during storage. Furans decreased, whereas hexanal increased. The Principal Component Analysis of the whole dataset pointed out that…
Nanosensors for intelligent packaging
2021
Abstract Intelligent packaging is an emerging area with a high potentials. Sensors and indicators are key elements, together with enabling technologies, for the development of a new generation of packaging able to interact with the sample and the user. Nanotechnology offers interesting opportunities for the development of active components, integration with the packaging, miniaturization, communication, and batteries. However, its use in intelligent packaging is still limited. We report herein a revision of recent examples of sensors including nanomaterials or nanostructures with potential application in packaging. The references include time temperature indicators, pH, moisture and pressur…