[ PACKAGING ]

by Claire Koelsch Sand

Packaging Strategies to Stall Lipid Oxidation

O
ff-flavors and odors that decrease
shelf life can result from the lipid down into secondary reaction byprod- bags, can be used to gas flush
oxidation of unsaturated fats and ucts that produce off-flavors and odors. packaging and reduce and eliminate O2
oils in foods, including beef jerky, crack- Antioxidants have been in use for many inside the package. For example, BW
ers, chips, nuts, and bakery goods. years, but the use of naturally Flexible Systems’ ISB family of vertical
Recent trends in using more unsaturated derived antioxidants is increasing. form-fill- seal machines reduces O2 to
than saturated lipids mean more foods levels ranging from 1% to 2% for foods
are now prone to lipid oxidation. Packaging Machinery Strategies prone to oxidation.
Packaging, however, can help combat Employing packaging machinery to “The packaging environment we cre-
these issues by stalling the origination reduce initial O2 and using high-barrier ate is a function of the product
and propagation of oxidation. Inhibiting packaging to impede permeation of O2 needs,” says Jim Kolmus, mechanical
oxidation origination can be accom- into the package can inhibit or stall engineer- ing lead at BW Flexible
oxida- tion. This is a specific area of Systems. “For example, our horizontal
modified flow wrapper machines use CO2 to
flush packaging, enrobing a 1-pound
cheese chunk. After
the cheese absorbs the CO2, a low O2
package is similar to a vacuum package in
appearance. This creates a 0% 02 pack-
age inhibiting oxidation. In contrast, the
BW Flexible Systems vertical form-
fill-seal machines for shredded
cheese replace some O2 with N2, and
this creates an inflated bag which also
serves to protect the product during
distribution.”
Although gas flushing technology is a
critical part of achieving low or no
O2 within the packaging, BW Flexible
Systems says other factors also come
into play to ensure the machines enable
safe and consistent low or no O2.
“[Food and Drug Administration]-
compliant gas flushing mechanisms,
intuitive human machine interfaces
(HMI), and flexibility are critical,” says
Kolmus. “Advanced HMIs and associated
The BW Flexible Systems ISB family of vertical form-fill machines reduces O2 to levels ranging from 1% to ease of use help to compensate for
2% for foods prone to oxidation, such as cheese and chips. Photo courtesy of BW Flexible Systems
high employee turnover experienced in
food packaging operations, operator
error, and
plished by removing the O2 within the atmosphere packaging (MAP) within the the need for rapid changeovers. For
package headspace and using superior field of active packaging. An abundance example, our machines have recipes—
O2 barriers, machinery, and oxygen scav- of packaging machines can be used to including seal pressure, seal jaw
engers. The propagation of the oxidation reduce or remove oxygen within temperature, line speeds—stored so that
reaction can be stalled by using packaging. line operators may rapidly select the
antioxi- dants that prevent free radicals Bags formed via vertical and horizon- product and package size to dictate
produced from the initiation phase tal form-fill-seal machinery, or premade proper settings. These recipes ensure
from breaking

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that proper settings are always used, and low and no O2 packaging, sealing
seal integrity is consistently at peak gaskets that connect two package
performance.” components are very critical. We fine-
Proper machine settings are espe- tune our wide array of sealing gasket
cially critical because these designs, including parabolic-shape for
parameters define the elastomers’ some wetter foods, double bead for
behavior that must flow to caulk other applications, to make sure the
potential channels within the seal area seal is robust.”
to maintain a low O2 envi- ronment Although reducing or eliminating O2
within the package. Many within the package headspace is the pri-
shelf-life issues with low O2 packaging mary goal of MAP machinery, food safety
can be traced back to production- is also center stage. The unique head-
induced inconsistent seals. space evacuation system allows for
“Brands also increasingly desire flex- enhanced food safety, McCann explains.
ibility in achieving low O2 packaging,” “We have separate pins for evacuation
Kolmus continues. “For example, BW’s and gassing. O2 is evacuated through one
machines now have 50% higher seal set of pins while the proper gas mixture is
pressure capability. This allows the same added through a second set of pins to
seal integrity and production line speeds ensure that the gas entering the system
when using alternative or more sustain- remains uncontaminated,” he says.
able packaging, including recyclable,
recycled content, and thinner gauge Oxygen Scavengers
package materials. This gives brands Evacuating O2 from foods such as bakery
much needed flexibility to convert to products, with an inherent amount of air
more sustainable low and no O2 packag- channels, and foods with intercellular
ing operations.” oxygen presents a particular challenge.
Reiser also supplies a range of pack- O2 levels remain higher than desired
aging machinery to remove or reduce when air is not quickly released from
oxygen from the package headspace, these channels and intercellular regions

Many shelf-life issues with low O2 packaging can be

traced back to production-induced inconsistent
The Reiser horizontal form-fill-seal packaging
seals. machine produces vacuum, MAP, and VSP
packages to reduce
including Ross tray sealing lines, in the degassing and gassing operations oxidation in foods such as pizza. Photo courtesy of Reiser
Repak and Variovac horizontal and before sealing.
form- fill-seal packaging machinery, Often oxygen scavengers are used in iron powder and enzymes, ascorbic acid,
and Supervac vacuum chamber combination with barrier packaging unsaturated fatty acids, photosensitive
packaging machines. “The pulsing and packaging machinery that creates a dyes, immobilized yeast, or palladium.
evacuation sequence allows the vac- uum and low O2 environment.
product to equili- brate and release Oxygen absorbers and scavengers are Introducing Antioxidants
the O2 in stages for incorpo- rated into the package structure Synthetic and edible packaging imparts
much reduced O2 levels in bakery and or added as sachets within the package antioxidants, which stall oxidation.
wet foods,” says Mike McCann, head- space. For example, beef jerky Butylated hydroxyanisole (BHA) and
packaging specialist at Reiser. brands Jack Link’s, Great Value, Wild butylated hydroxytoluene (BHT) and tert-
Ensuring the proper seal also West, and Cattleman’s Cut contain butylhydroquinone (TBHQ) are commonly
demands machinery finesse. “Reiser oxygen scaven- gers within their high- used synthetic antioxidants that are
packaging specialists fine-tune machin- barrier packaging to inhibit oxidation incorporated into packaging. These anti-
ery specifications such as seal area and microbial growth. Sachet oxidants diffuse from the package
design and gaskets,” says McCann. “For components commonly include
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 [ PA C K A G I N G ]

Packaging Strategies to Stall Lipid Oxidation continued...

material into the package headspace and
foods, inhibiting further oxidation by
impeding the formation of secondary
reaction byproducts.
The use of natural antioxidants within
bioderived and edible packaging
(packag- ing that humans can consume),
however, is rapidly replacing or
complementing the use of these
synthetic antioxidants. This conversion
is the result of interest in clean labels,
cost reduction, and more focused
solutions with intimate food con- tact.
Common bioderived and edible
packaging substrates include polysac-
charides and proteins such as
hydroxypropyl methylcellulose, chitosan,
sodium alginate, and whey and soy
pro- teins. Antioxidants incorporated
into edible packaging include alpha-
tocopher- ols, phenolics, ginger,
rosemary, oregano, and thyme essential Yanyun Zhao (left) and Jooyeoun Jung (former assistant professor and senior researcher in Zhao’s
oils; green, oolong, and black tea; and lab) hold hamburger patties covered by edible film. Photo courtesy of Chris Branam, Oregon State University
cypress and grape seed extracts.
Yanyun Zhao, professor in the lone pairs of electrons from positively Zhao says several of her research
Department of Food Science and charged amino groups and hydroxyl areas have implications relating to bio-
Technology at Oregon State University groups in chitosan for scavenging free derived and edible packaging that inhibits
and an IFT Fellow, has researched bio- radicals and chelating metal ions. We oxidation. “One area is how the proper-
derived and edible packaging for more have interest in chitosan because of its ties of food waste can be harnessed to
than 20 years. “When I began research in unique antioxidant and antimicrobial extend the shelf life of food. For example,
bioderived and edible packaging, I con- functions.” we have employed the natural antioxi-
sidered edible packaging substrates as The Zhao laboratory has also pro- dant capability of phenolics extracted
an excellent carrier for nutrients such as duced beta-chitosan from squid pens from upcycled fruit and wine grape pom-
vitamin E and calcium onto carrots, with fewer extraction steps than shrimp ace in edible film formulations to reduce
strawberries, and other fruit that lack and crab shells. “We also have advanced lipid oxidation,” she explains. “A second
these nutrients,” she says. “Since edible packaging production and can area is laminating our bioderived packag-
then, we have expanded this capability produce monolayer films and multilayer ing onto synthetic films such as
to carry not only nutrients but also coatings and laminates. This last area, Saranex to significantly decrease lipid
antioxidant and antimicrobial agents. laminates, has much promise,” she says. oxidation. The third area defines the use
Specifically, to stall lipid oxidation in the “The ability to create laminations has of cellulose microfibrils and cellulose
packaging used for high-fat food items, allowed my laboratory to refine edible microcrystals within edible packaging,
such as fish fil- lets, meat, tree nuts, packaging to have mechanical—tensile and our recent patents—US10334863B2,
and cheese, we have enabled the use strength, elongation, seal strength—and US9826750B2, US10400128B2—on this
of antioxidants such as vitamin E and barrier and chemical—permeability and area are a glimpse into how fast this area
phenolics.” water and oil resistance—properties is developing. The incorporation of alpha-
Vitamin E (alpha-tocopherol) is a nat- that closely match the capabilities of tocopherol into nanoparticle-loaded films
ural, free radical scavenger that stops nonedible films to release antioxidants for the controlled release of antioxidants
oxidation reactions specifically within and antimicrobials. is of particular interest.” FT
cell membranes by donating a hydrogen “For example, to create edible pack-
atom to a peroxyl radical. Phenolics are aging effective against gram+ and The contributions of Rachel Rosenbloom,
free radical acceptors and prevent the gram- bacteria, suitable for cheese former research assistant in Yanyun
formation of other radicals. and other food items, we combine Zhao’s laboratory, are appreciated.
In addition, “we have advanced the layers composed of chitosan and
use of other substrates such as chitosan lysozyme with other layers with higher Claire Koelsch Sand, PhD, Contributing Editor
as a film-forming (matrix) material,” says mechanical and chemical strength. This • Owner, Packaging Technology
Zhao. “Chitosan has great antioxidant same approach is used to create a and Research, LLC
• Adjunct Professor
activity due to several mechanisms, combination antioxidant and • claire@packagingtechnologya
including the donation of hydrogen or antimicrobial film,” she says.
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