99
Cs-based films (Cazón et al. 2017). In addition to improving the mechanical
strength, water vapor permeability (WVP) can also be improved by mixing of Cs
with other polysaccharides (alginate, cellulose, pectin, starch) or proteins (gelatin,
whey proteins) (Xu et al. 2005; Elsabee and Abdou, 2013; Cazón et al. 2017).
Alginate is a linear copolymer of β-(1–4) linked D-mannuronic acid and α-(1–4)
linked L-guluronic acid extracted from brown algae (Abdollahi et al. 2013; Cazón
et al. 2017). The alginate films have good mechanical strength but have a brittle
nature with high WVP. However, the crosslinking of the alginate with polyvalent
cations improve its WVP, increase its mechanical strength and improves the controlled release of incorporated functional materials (Campos et al. 2011; Cazón
et al. 2017).
Pullulan is a water-soluble exopolysaccharide which is synthesized by
Aureobasidium pullulans (Cirillo et al. 2015; Chen et al. 2017). Pullulan-based
films are biodegradable and non-toxic, as well as have good oxygen permeability,
transparency, oil and grease resistance (Tharanathan 2003; Chen et al. 2017).
Pullulan can be extruded as a film with good mechanical stability (Tharanathan
2003; Chen et al. 2017).
Kefiran, like pullulan, is also a water-soluble exopolysaccharide produced by the
microorganisms present in kefir grain flora (Motedayen et al. 2013). It has a good
film-forming capacity depending on the plasticizer used (Ghasemlou et al. 2011).
Due to their hydrophilic nature, the polysaccharide films are permeable to water
vapor (Lacroix and Le Tien 2005). Although the WVP values of kefiran films are
similar or even better than the corn starch and Cs-based films (Piermaria et al. 2009).
6.2.2 Protein Biomass
The protein biomasses used in biobased composite film formulations include whey
proteins, casein, gluten, soy protein, lentil, peanut, mung bean, quinoa, canola proteins, kafirin, zein, egg albumen, collagen, fibrin, fibroin, spidroin, gelatin (fish skin,
other animal origin), myofibrillar protein, keratin (hair), sericin (silk) (Baldwin
et al. 1995; Miller and Krochta 1997; Anyango et al. 2011; Plackett 2011; Abugoch
et al. 2016; Doblhofer et al. 2016; Cazón et al. 2017; Li et al. 2017; Garrido et al.
2018; Tomadoni et al. 2020).
Whey proteins have good gas barrier properties, good film-forming capacity,
biodegradability, elasticity, transparency and can act as a potential carrier of antioxidant and antimicrobial agents, therefore, they are the best alternative among other
protein sources (Miller and Krochta 1997; Sothornvit et al. 2009; Ramos et al. 2012;
Oymaci and Altinkaya, 2016). In addition, whey proteins have a nature compatible
with metal oxide NPs, nanocellulose, zein NPs, nanoclays and are suitable for
crosslinking or lamination with lipid matrix (Miller and Krochta 1997; Bourtoom
2009; Sothornvit et al. 2009; Zolfi et al. 2014; Oymaci and Altinkaya 2016;
Qazanfarzadeh and Kadivar 2016).
6 Functional Biobased Composite Polymers for Food Packaging Applications
Cs-based films (Cazón et al. 2017). In addition to improving the mechanical
strength, water vapor permeability (WVP) can also be improved by mixing of Cs
with other polysaccharides (alginate, cellulose, pectin, starch) or proteins (gelatin,
whey proteins) (Xu et al. 2005; Elsabee and Abdou, 2013; Cazón et al. 2017).
Alginate is a linear copolymer of β-(1–4) linked D-mannuronic acid and α-(1–4)
linked L-guluronic acid extracted from brown algae (Abdollahi et al. 2013; Cazón
et al. 2017). The alginate films have good mechanical strength but have a brittle
nature with high WVP. However, the crosslinking of the alginate with polyvalent
cations improve its WVP, increase its mechanical strength and improves the controlled release of incorporated functional materials (Campos et al. 2011; Cazón
et al. 2017).
Pullulan is a water-soluble exopolysaccharide which is synthesized by
Aureobasidium pullulans (Cirillo et al. 2015; Chen et al. 2017). Pullulan-based
films are biodegradable and non-toxic, as well as have good oxygen permeability,
transparency, oil and grease resistance (Tharanathan 2003; Chen et al. 2017).
Pullulan can be extruded as a film with good mechanical stability (Tharanathan
2003; Chen et al. 2017).
Kefiran, like pullulan, is also a water-soluble exopolysaccharide produced by the
microorganisms present in kefir grain flora (Motedayen et al. 2013). It has a good
film-forming capacity depending on the plasticizer used (Ghasemlou et al. 2011).
Due to their hydrophilic nature, the polysaccharide films are permeable to water
vapor (Lacroix and Le Tien 2005). Although the WVP values of kefiran films are
similar or even better than the corn starch and Cs-based films (Piermaria et al. 2009).
6.2.2 Protein Biomass
The protein biomasses used in biobased composite film formulations include whey
proteins, casein, gluten, soy protein, lentil, peanut, mung bean, quinoa, canola proteins, kafirin, zein, egg albumen, collagen, fibrin, fibroin, spidroin, gelatin (fish skin,
other animal origin), myofibrillar protein, keratin (hair), sericin (silk) (Baldwin
et al. 1995; Miller and Krochta 1997; Anyango et al. 2011; Plackett 2011; Abugoch
et al. 2016; Doblhofer et al. 2016; Cazón et al. 2017; Li et al. 2017; Garrido et al.
2018; Tomadoni et al. 2020).
Whey proteins have good gas barrier properties, good film-forming capacity,
biodegradability, elasticity, transparency and can act as a potential carrier of antioxidant and antimicrobial agents, therefore, they are the best alternative among other
protein sources (Miller and Krochta 1997; Sothornvit et al. 2009; Ramos et al. 2012;
Oymaci and Altinkaya, 2016). In addition, whey proteins have a nature compatible
with metal oxide NPs, nanocellulose, zein NPs, nanoclays and are suitable for
crosslinking or lamination with lipid matrix (Miller and Krochta 1997; Bourtoom
2009; Sothornvit et al. 2009; Zolfi et al. 2014; Oymaci and Altinkaya 2016;
Qazanfarzadeh and Kadivar 2016).
6 Functional Biobased Composite Polymers for Food Packaging Applications