Aroma compound and water vapor permeability of edible films and polymeric packagings (original) (raw)
Related papers
Measuring Aroma Transport in Polymer Films
Transactions of the ASAE, 1998
F ood quality is reduced by the loss of characteristic volatile flavor and aroma. While measurements of moisture, oxygen, and carbon dioxide transport through films are relatively easy to obtain, quantitative evaluation of aroma transport can be a difficult process. As such, the literature is lacking in work examining flavor and aroma transport in edible polymers (Miller and Krochta, In Press). This article presents a brief review of existing techniques for measuring aroma transport in polymer films and then describes a new technique used to measure aroma transport through edible and other polymer films.
Water vapor permeability and diffusivity through methylcellulose edible films
Journal of Membrane Science, 1994
A model edible film made with methylcellulose was studied for its water vapor barrier properties. The steadystate water vapor transmission rate (WVTR) increased with both the water vapor pressure gradient and the initial water content before permeation. A decrease in water diffusion with increasing moisture content was due to a clustering phenomenon of water molecules within the film. Water concentration profiles within the film were estimated from the sorption isotherm, and differed from the theoretical linear profile based on Fick's first law. The WVTR and the diffusivity depended strongly on the water concentration because of interactions between water molecules and the polymer matrix. Thus water vapor permeability (WVP) calculations used for synthetic polymeric packaging and based on Fick's and Henry's laws do not apply for methylcellulose edible films.
Journal of Agricultural and Food Chemistry, 2005
The ethylene-vinyl alcohol copolymers (EVOHs) are well-known high oxygen barrier materials that are being used successfully in the design of packaging structures for oxygen-sensitive food or pharmaceutical products. Recently, there has been increasing interest in using EVOH materials to provide a high barrier to organic compounds as a means to reduce food aroma scalping. However, the barrier function of this family of materials diminishes significantly in humid environments, and it is supposed that so does the organic vapor barrier. In this work, a new sorption-based method to characterize the interaction between food aroma and polymer films for packaging as a function of relative humidity is presented and is used to determine the barrier to ethyl butyrate and R-pinene of EVOH at 23°C. The results show that although EVOH is an excellent barrier to food aroma when dry, a property that even improves at low relative humidity (RH), the solubility and diffusivity of the compounds tested increase dramatically with humidity at medium to high water activities. However, even in the worst case (100% RH), EVOH outperforms low-density polyethylene (LDPE) as a barrier to organic vapors at least 500 000-fold.
Flavor and Aroma Permeation Concepts and Applications
2006
In this paper, permeation of aromas and flavors through plastic packaging materials is discussed. The importance of understanding aroma and flavor transmission is explained by examples. Aroma and flavor barrier measurement is contrasted with the measurement of O2, water vapor and CO2 barriers. Criteria for a measurement system are outlined. Permeation measurement is divided into the actual techniques for accomplishing the permeation and detecting the level of permeation. The isostatic, quasi-isostatic and sorption / gravimetric permeation methods are compared. Detection methods described and compared are FID, GC/FID, weight, MS, GC/MS, TIR, manometry and PID. Combined detection methods are also discussed. To effectively meet the criteria, it is concluded that a diffusion cell permeation method with a combined detector is probably the best current option.
Journal of Food Science, 1993
The ASTM E96 Standard Method for determining water vapor permeability (WVP) was modified for hydrophilic edible films. Accurate measurement of relative humidity conditions and maintenance of 152 m/min air speeds were essential outside the test cups. The WVP Correction Method was developed to account for the water vapor partial pressure gradient in stagnant air layer of the test cup. Errors were as high as 35% without this correction. Applying these guidelines explained commonly observed thickness effects on WVP values of hydrophilic films. Relative humidity was the cause of observed thickness effects.
Biomacromolecules, 2008
Edible films made of ι-carrageenans display interesting advantages: good mechanical properties, stabilization of emulsions, and reduction of oxygen transfers. Moreover, the addition of lipids to ι-carrageenan-based films to form emulsified films decreases the transfer of water vapor and can be considered to encapsulate active molecules as flavors. The aim of this study was to better understand the influence of the composition and the structure of the carrageenan-based film matrices on its barrier properties and thus on its capacity to encapsulate and to protect active substances encapsulated. Granulometry, differential scanning calorimetry, and Fourier transform infrared spectroscopy characterizations of films with or without flavor and/or fat showed that the flavor compound modifies the film structure because of interactions with the ι-carrageenan chains. The study of the water vapor permeability (WVP), realized at 25 and 35°C and for three relative humidity differentials (30-100%, 30-84%, 30-75%), showed that the flavor compound increases significantly the WVP, especially for the weaker gradients, but has no effect on the oxygen permeability. This study brings new understanding of the role of carrageenan as a film matrix and on its capacity to protect encapsulated flavors.