162
7 Agar
7.7.6 Antioxidant
When degraded into short-chain polymers (oligomers) referred to as agarooligosaccharides and neoagaro-oligosaccharides, agar demonstrates antioxidant
activities (Chen and Yan 2005). These antioxidant activities of the short-chain agar
forms are attributed to the improved chance of the short chains to cross tissue barriers
and also the presence of some sulfate groups on the chain. Most sulfated polysaccharides studied so far are attributed with some antioxidant properties. Although agar has
a relatively lower degree of sulfation (e.g., 0.14% of agar extracted from Gracilaria
caudata through enzyme extraction) (Alencar et al. 2019), more research is required
to fully understand the mechanism of its antioxidant activity. Sulfated polysaccharides with agar-like chemical structure extracted from the red algae Gracilaria caudata show antioxidant properties which suggest that agar could have some promising application beyond its rheological properties. Agar-based oligomers also show
other bioactivities such as antitumor, prebiotic, anti-inflammatory, antidiabetic and
anti-obesity activities (Kwon et al. 2019).
7.7.7 Packaging
Currently, one of the biggest global challenges of modern times is the accumulation
of non-biodegradable plastic packaging waste. These have gone on to cause serious
environmental issues as plastics from landfill clog up drainage systems and end up
in the sea where they pose fatal risk to aquatic organisms. Their floating on the
water prevents penetration of light and oxygen, and they end up inside the digestive
systems of aquatic animals where they pose potentially fatal health risks. These
fossil-based packaging materials are used for short periods; however, they take very
long time to degrade. Degradation processes such as pyrolysis and incineration either
require additional energy input (temperatures of ~450 °C for pyrolysis) or they pose
a health risk (such as release of carcinogens from incineration of plastics). Marine
microorganisms from the arctic are being studied as potential candidates to degrade
these fossil-derived plastics; however, this is yet to be actualized as it is primarily
dependent on the microbes adapting to develop enzymes and means to degrade these
plastics (Ubanek et al. 2018).
One of the factors which make these materials attractive as packaging materials
is the fact that they are not degradable by microbes and they have superior mechanical properties and water resistance; therefore, they can be used to hygienically pack
foods. Biodegradable packaging materials on the other hand are almost as biodegradable as the food they are packed in. Such that, several researches have been directed
toward developing biodegradable packaging materials, which incorporate antimicrobial properties. The fact that agar is relatively more resistant to bacterial degradation
(Kwon et al. 2019) could contribute to its applicability in packaging materials.
7 Agar
7.7.6 Antioxidant
When degraded into short-chain polymers (oligomers) referred to as agarooligosaccharides and neoagaro-oligosaccharides, agar demonstrates antioxidant
activities (Chen and Yan 2005). These antioxidant activities of the short-chain agar
forms are attributed to the improved chance of the short chains to cross tissue barriers
and also the presence of some sulfate groups on the chain. Most sulfated polysaccharides studied so far are attributed with some antioxidant properties. Although agar has
a relatively lower degree of sulfation (e.g., 0.14% of agar extracted from Gracilaria
caudata through enzyme extraction) (Alencar et al. 2019), more research is required
to fully understand the mechanism of its antioxidant activity. Sulfated polysaccharides with agar-like chemical structure extracted from the red algae Gracilaria caudata show antioxidant properties which suggest that agar could have some promising application beyond its rheological properties. Agar-based oligomers also show
other bioactivities such as antitumor, prebiotic, anti-inflammatory, antidiabetic and
anti-obesity activities (Kwon et al. 2019).
7.7.7 Packaging
Currently, one of the biggest global challenges of modern times is the accumulation
of non-biodegradable plastic packaging waste. These have gone on to cause serious
environmental issues as plastics from landfill clog up drainage systems and end up
in the sea where they pose fatal risk to aquatic organisms. Their floating on the
water prevents penetration of light and oxygen, and they end up inside the digestive
systems of aquatic animals where they pose potentially fatal health risks. These
fossil-based packaging materials are used for short periods; however, they take very
long time to degrade. Degradation processes such as pyrolysis and incineration either
require additional energy input (temperatures of ~450 °C for pyrolysis) or they pose
a health risk (such as release of carcinogens from incineration of plastics). Marine
microorganisms from the arctic are being studied as potential candidates to degrade
these fossil-derived plastics; however, this is yet to be actualized as it is primarily
dependent on the microbes adapting to develop enzymes and means to degrade these
plastics (Ubanek et al. 2018).
One of the factors which make these materials attractive as packaging materials
is the fact that they are not degradable by microbes and they have superior mechanical properties and water resistance; therefore, they can be used to hygienically pack
foods. Biodegradable packaging materials on the other hand are almost as biodegradable as the food they are packed in. Such that, several researches have been directed
toward developing biodegradable packaging materials, which incorporate antimicrobial properties. The fact that agar is relatively more resistant to bacterial degradation
(Kwon et al. 2019) could contribute to its applicability in packaging materials.