54
FEB 2017
FOOD FOCUSTHAILAND
STRENGTHEN THE
PACKAGING
Edible
Packaging
Theediblepackaginghasbeenused inthefoodandpharmaceutical
products to retainquality, stabilityand increase shelf-life. It provides
barrier against oxygen, humidity and volatile. There are 2 forms of
ediblepackagingnamelyediblecoatingandfilm. Theediblecoating
is a thin layer directly applied on food surface by spraying, dipping,
panning, etc. Then the edible layer adheres on food surface after
drying. Conversely, the edible film is a preformedmaterial used for
wrappingor placingbetween foodcomponents.Thefilmcanalsobe
converted intopouchandcapsule forseveral foodandpharmaceutical
applications. The terms “edible film” and “edible coating” are
interchangeably usedwhich refer to a thin layer of ediblematerials
appliedon foods toextendshelf-lifeormodify foodqualities.Theedible
film, however, generally refers toastand-alonepackagingmaterials.
In the commercial scale, the edible films can be produced by
solutioncasting (wetprocess)orextrusion (dryprocess).Thesolution
castingcomposesof thedissolutionof the ingredients,mostly inwater.
Thesolvent is further removedbystorage inacontrolled temperature
and humidity as well as drying techniques such as oven or hot-air
drying,microwaveheatingand infrareddrying.Themoisturecontent
of the films after drying strongly influences properties and strength
of thefilm.Conversely, theextrusionprocessproducesfilmswithout
solvent usingheat andshear force. Lessproduction time is required.
However, the thermoplasticpropertiesof thematerialsare important
toproduce thefilmby thismethod.Plasticizersaregenerallyused to
formulate thermoplastic materials that are not decomposed during
processing.Theextrusionprocesscan furtherdevelopedediblefilms
intobiodegradable packagingbymixingwithother polymers.
Compositionsof EdiblePackaging
Themajor componentsof ediblepackagingarebiopolymersnamely
polysaccharides,proteinand lipids,andplasticizers.Theplasticizers
are substances added to improve deformability and flexibilitywhich
modify several properties of the materials. Recently, other active
substanceshavebeenadded to improve functionalityof thematerials
andextendshelf-lifeof foods includingantioxidant,antimicrobial and
natural extract. Moreover, other ingredients such as coloring and
flavoringsubstances, surfactant andantifoaminghavebeenused to
modify properties, appearance andprocessability of the films.
Polysaccharide are biopolymer with wide varieties and
inexpensive.Theyhaveability to formfilmswithhighoxygenbarrier.
However, the high amount of hydroxyl groups facilitates hydrogen
bondingwithwater contributes toa lowwater vapor barrier property.
Proteincontainsvariousgroupsof aminoacidandhencewide range
of properties. Protein filmsmostly prevent oxygen transmission but
poor water vapor barriers. Themechanical strength of protein films
ishigher thanpolysaccharide.Themodificationofproteinsbymeans
ofmechanical force, heating, irradiation, pH, enzymes, cross-linking
agentsandetc. potentiallymodifiespropertiesof proteinpackaging.
Conversely, lipids and resins components cannot form stand-alone
films. Suchhydrophobicmaterials are rather usedas edible coating
topreventmoisture transferbetweenproductsandenvironmentsand
improve surface gloss. The emulsion systems of lipid components
withpolysaccharideandproteinstrongly improvewatervaporbarrier
of the films.
Application andUtilizationof EdiblePackaging
Thestrengthandbarrier propertiesof ediblefilmsarestill lower than
synthetic petroleum based packaging. Therefore, food products
packed in edible film still need another packaging for a sufficient
protection. Nevertheless, suchedible layers that covered foods can
preserve qualities and safety, increased shelf-life and delay food
deteriorations. It can reduce the use of additives directly added in
food formulations.
Edible packaging made from food
materials that can be safely used
in direct contact with food products.
It protects foods against extrinsic
parameters those accelerate quality
deteriorationsand increasedshelf-life
of foods. Thematerials can also be
placed to separatemulti-component
food products. The edible package
can either be eaten with food itself
or removebefore foodconsumption.
Several formsofediblepackagesare
available in themarkets such as ice
cream cone, cup, film, etc.
