Page 391 - Natural Antioxidants, Applications in Foods of Animal Origin

370 Natural Antioxidants: Applications in Foods of Animal Origin
VetBooks.ir desiccants such as silica gel, calcium oxide and activated clays, and minerals

are typically tear-resistant permeable plastic sachets. In addition to mois-
ture-absorber sachets for humidity control in packaged dried foods, several
companies manufacture moisture-drip absorbent pads, sheets, and blankets
for liquid water control in high activity water foods such as meats, fish, fruit,
and vegetables (Dobrucka & Cierpiszewski, 2014).
Regarding the antioxidant releasing packaging materials, one of the main
benefits, as compared to the direct addition of antioxidants to food, is that
active materials may act as a source of antioxidants that are released to the
food at controlled rates, so that a predetermined concentration of the active
compound is maintained in the food, compensating the continuous using
up of antioxidants during storage (Mastromatteo et al., 2010). There are
basically two methodologies for producing antioxidant-packaging systems
(Gómez-Estaca et al., 2014):

a) Independent devices: An independent device such as a sachet, pad
or label containing the agent separately from the food product is
added to a conventional “passive” package.
b) Antioxidant packaging materials: Antioxidant packaging mate-
rials are used in the manufacture of the package, that is, the active
agent is incorporated in the walls of the package exerting its action
by absorbing undesirable compounds from the headspace or by
releasing antioxidant compounds to the food or the headspace
surrounding it.

Many different active packaging structures can be built with active mate-
rials prepared by extrusion processes, including coextruded, and laminated
multilayers. The design is dependent on the type of agent and the type of
polymer matrix, but primarily on the packaging requirements of the food
product. Due to environmental motivation there is increasing interest in the
use of biodegradable/compostable packaging and/or edible materials. This
tendency increases when materials come from industrial waste or renew-
able resources (Gómez-Guillén et al., 2007). Four types of plastics mate-
rials could be used for food packaging (Mecking, 2004; Reddy et al., 2012;
Peelman et al., 2013; Reddy et al., 2013):

a) Non-bio-based non-biodegradable conventional plastic mate-
rials, for instance: polyethylene (PE), polypropylene (PP), poly
(ethyleneterephthalate) (PET), and polystyrene (PS).