Barrier aroma

The primary appHcation for barrier polymers is food and beverage packaging. Barrier polymers protect food from environmental factors that could compromise both taste and shelf life. They also help retain desirable flavors and aroma. Barrier polymers are also used for packaging medical products, agricultural products, cosmetics, and electronic components and in moldings, pipe, and tubing. 

Providing an aroma barrier to help retain flavor in foods and to prevent the absorption of undesirable flavors or aroma. 

The most important application area of HDPE is the production of containers and injection molded articles. Bottles for detergents, gasoline cans and heating oil tanks are some examples. The most common use of HDPE for injection molded articles is for the production of storage and distribution containers, like buckets and bottle cases. However, processing into films and pipes has become increasingly more common. Films made out of HDPE possess high fat resistance (as wrappers for meat) and have better aroma barrier properties compared to lower density PE materials. 

For rigid thermoformed packaging, the stiffness of PLA enables more efficient down gauging versus existing PET materials. PLA is also an alternative to traditional plastic films such as cellophane, cellulose acetate and glassine, as well as a low temperature heat seal layer and/or flavour and aroma barrier in co-extruded structures where its combination of properties allows layer simplification or replacement of specific layers. 

NatureWorks PLA can be extruded, cast or biaxially oriented, and thermoformed using conventional processing equipment. The company claims that NatureWorks PLA performs like traditional petroleum-based plastics, and in some cases offers better performance characteristics, including gloss, clarity, strength, and flavour and aroma barrier. 

For food contact applications, EarthFirst PLA film has a good flavour and aroma barrier and air can move freely through the EarthFirst PLA film to prevent fogging on windows and promote swift adhesive drying. Also, EarthFirst PLA film in food applications extends the products freshness and results in a longer shelf-life. 

Miller, K.S. and Krochta, J.M. Oxygen and aroma barrier properties of edible films a review. Trends Food Sci. TechnoL, 8, 228, 1997. 

Wood, WE (2001). Improved aroma barrier properties in food packaging with cyclodextrins. In Polymers, Laminations and Coatings Conf, TAPPI, "ifn yil. 

Debeaufort, R, Quezada-Gallo, J.A., Voilley, A. 2002. Edible films and coatings as aroma barrier. In Protein-Based Edible Eilms and Coatings, Gennadios, A. (ed.). CRC Rress, Boca Raton, FL, Chapter 24, pp. 579-600. 

Fabra, M.J., Hambleton, A., Talens, R, Debeaufort, R, Chiralt, A., Voilley, A. 2008. Aroma barrier properties of sodium caseinate-based edible films. Biomacromolecules, 9(5) 9, 1406-1410. 

Hambleton, A., Fabra, M.J., Debeaufort, F, Brun-Dury, C., Voilley, A. 2009a. Interface and aroma barrier properties of iota-carrageenan emulsion-based films used for encapsulation of active food compounds. Journal of Food Engineering, 93 80-88. 

Nylon 6 is the least costly of the nylons and is used where an oxygen barrier is required. It has the best gas and aroma barrier and the least moisture barrier. Nylon 66 is used where temperature resistance is needed and nylon 6/66 is used where coextrusion compatibility is required. As you go down the chart, the gas barrier decreases and moisture barrier increases. Nylon 12 has the best moisture barrier and the poorest gas barrier. ... 

Orientation Orientation improves the inherent barrier and mechanical properties of unoriented nylon film. After biaxial orientation, nylon film exhibits a significant improvement in oxygen and aroma-barrier properties. ... 

Specific Gravity Melt Point (°F) HjO Absorption Max (%) Gas Aroma Barrier Relative Cost (1.0 = Least Expensive)... 

ExxonMobil Bicor films are coated, sealable OPP films with outstanding optical properties, superior machinability, excellent flavor and aroma barrier properties, broad seal ranges, excellent heat-seal and hot-tack strength, and good moisture and oxygen barrier properties. 

ExxonMobil OPPalyte films are coated, pearlescent white, opaque OPP films, with a proprietary core providing excellent opacity, good machinability, excellent flavor and aroma barrier properties, good oxygen barrier properties, excellent stiffness and flex resistance, excellent print performance, strong cold seal adhesion, and good bond strength. 

Honeywell Oxy Shield nylon/EVOH oxygen-barrier (OB) film s combination of nylon 6 and EVOH delivers a strong mix of benefits the strength, toughness, and flex-crack resistance of nylon with the extremely low oxygen transmission rates, superior fla-vor/odor/aroma-barrier properties, with the outstanding solvent and oil resistance of both nylon and EVOH. The film is microwaveable and recyclable, and does not release harmful substances upon incineration.do 3]... 

Aroma Barrier Aplastic film or its component preventing the escape of aromatic volatiles from foodstufifs or cosmetics seal-packaged in the film. 

This chapter presents an overview of properties and performance of polymer blends, focusing on these aspects that are outside the main domain of the other chapters in this handbook. Such properties as mechanical, chemical, and solvent effects and thermal, flame retardancy, electrical, and optical properties are discussed. Further, the developments in sound transmission, certain special test methods in aroma barrier, permeability test for hquids, and environment stress cracking are included in the second edition of this handbook. In addition, the data is updated and upgraded. And, finally, the relevant and useful websites for additional information are also provided towards the end of this chapter. 

Some special test methods which have illuminated the applications of polymer blends are grouped together towards the end, viz., aroma barrier test, permeation test for liquids, and environmental stress cracking, which are special in nature but not really obtained the status of ASTM or BS methods. Nevertheless, they are used in industry as they meet the special application requirements of these wonderful materials. The chapter concludes with a discussion of these aspects. 

Special Test Methods 10.10.1 Aroma Barrier Test... 

The area of flavor and aroma barrier is receiving growing attention in the field of plastics packaging. The permeation of flavors is difficult to measure quantitatively because they contain many components. Many times, only a simple component of a flavor is measured if a quantitative value must be determined. Gas chromatography and mass spectrophotometric (GC/MS) techniques have been developed that allow the analysis of complex flavors. However, in most cases, the use of organoleptic testing provides reliable and pertinent data at a greatly reduced cost. 

COC has better aroma barrier than polyethylene and is found to reduce aroma/ flavor loss from food when it is utilized as a barrier layer in food packaging. COC is also found to reduce the transmission of objectionable odors to surrounding areas and has utility in disposable food storage bags. Low extractables in COC reduce the possibility of generating an off-taste in water or susceptible foods when used as a contact layer or just under a seal layer in packaging (Jester et al. 2005). 

Eval Americas, Technical Bulletin No. 190, Flavor and Aroma Barrier Properties ofEVAL Resins (2007) www.evalca.com... 

Vibrational spectroscopy is one of the most widely used techniques for the morphological characterisation of high gas and aroma barrier materials used in food packaging. However, because of the highly hydrophobic character of ethylene-vinyl alcohol (EVOH) resins, it is usually LDPE, a high water barrier material that is put in direct contact with the packaged commodity, i.e., multi-layer EVOH-LDPE film [46]. 

The excellent properties of EVOH resins in terms of high gas, hydrocarbon and aroma barrier and transparency have allowed them to become widely implemented in many commercial applications where high barrier properties are needed to minimise product losses due to deterioration. Despite the excellent performance of these materials in high barrier food packaging applications, the materials are easily plasticised by moisture and, consequently, in most packaging applications are commonly encapsulated in multi-layer structures between hydrophobic polymers such as PP or PE. 

Body materials that have been used include polypropylene, high density-polyethylene, or low-density polyethylene mixed with the bonding agent. The barrier material generally used is nylon, which may be either on the inside of the container or on the outside. Some of the advantages claimed for the coextrusion process are excellent aroma barrier, surface gloss, surface priming, scratch resistance (with the nylon on the outside), and chemical resistance and barrier to hydrocarbons (with the nylon on the inside). 

N. Whiteman, P. DeLassus and J. Gunderson, New Flavor and Aroma Barrier Thermoplastic, Polylactide, Polyolefins 2002, International Conference on Polyolefins, Houston, TX, USA, 2(X)2. 

Oxygen and moisture are not the only substances that must be kept on the appropriate side of a package, since flavour and aroma barriers become more necessary. So packages are being developed to make sure that the good flavours are kept in and the bad flavours out. These materials can be polyester or oriented polypropylene metallised with a thin coat of aluminium. 

Barriers to aromas and flavors are very important in packaging and cannot be predicted from common gas-barrier data. Nylon has a good aroma barrier for certain snack-food packaging (74). Flavor scalping is also important in some... 

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