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Cereal Proteins
Zein, the major storage protein of corn, is one of the few hydrophobic, waterinsoluble materials approved for food use by the FDA (Patel and Velikov 2014). In
food applications, zein has become an extremely attractive delivery system for functional ingredients, not only because of its fully natural, biodegradable and foodgrade origin, but also because of its ability to physically entrap a large number of
hydrophobic compounds (Davidov-Pardo et al. 2015). Additionally, zein has been
used to design functional organic-inorganic composite particles (Baars et al. 2015)
and for the stabilization of foams and emulsions (Blanco et al. 2016). Moreover,
zein particles are characterized by slower digestibility in the gastrointestinal tract in
comparison with other proteins due to its resistance to digestive enzymes and therefore, enhanced capability of controlled release of the payload molecules (Patel and
Velikov 2014). Therefore, zein is considered as a good candidate for the encapsulation of functional compounds and development of the delivery system in food and
pharmaceutical industries (Yang et al. 2017). Phenolic phytochemical such as procyanidin with antioxidant activity was encapsulated into the zein NPs using an
aqueous medium and it was found that the solubility of procyanidin enhanced when
it was encapsulated (Zou et al. 2012). Tocopherol encapsulated in Zein-Gum Arabic
biopolymer nanoparticles was investigated and found that the presence of GA not
only prevented the precipitation of zein nanoparticles but also controlled the release
of TOC from zein-GA nanoparticles during in vitro gastrointestinal digestion (Li
et al. 2018a, b). More recently, it has been studied that zein/SSPS (soluble soybean
polysaccharide) nanoparticles successfully used to encapsulate hydrophobic quercetin. The results disclosed that the encapsulation efficiency was greatly enhanced
to 82.5% after SSPS coating, compared to 59.2% for the zein without coating,
which suggests that zein/SSPS nanoparticles have great potential to be used as
nano-delivery systems for bioactive compounds (Li et al. 2018a, b).
Wheat protein has successful application in encapsulation with alone or in combination with polysaccharides (Andreani et al. 2009; Liao et al. 2012). However,
wheat gluten is allergenic and susceptible to celiac disease. Therefore, modification
of wheat gluten could improve its properties. It has been reported that wheat gluten
can be modified by acid heating deamidation which reduces its cytotoxicity and
improves the overall functionalities (Berti et al. 2007). In subsequent, Liao et al.
(2012) developed succinic acid deamidated wheat gluten microspheres for encapsulation of fish oil through double emulsion technique. The study revealed that the
deamidated wheat gluten microspheres were suitable for the encapsulation, controlled release, and stability maintenance of fish oil.
Barley is a very adaptable crop. Barley grains and by-products are abundant and
affordable protein sources which contain 8–13% and 20–30% (w/w) protein, respectively (Yalcin et al. 2008). The two major endosperm storage proteins of barley are
hordein and glutelin which ranges from 35–55% and 35–40%, respectably, whereas
albumin and globulin proteins are enriched in the bran and germ (Finnie and
Svensson 2009). Barley proteins have excellent emulsification and film formation
features as they are highly hydrophobic (Wang et al. 2010). Wang and coworkers
F. Jhan et al.
Cereal Proteins
Zein, the major storage protein of corn, is one of the few hydrophobic, waterinsoluble materials approved for food use by the FDA (Patel and Velikov 2014). In
food applications, zein has become an extremely attractive delivery system for functional ingredients, not only because of its fully natural, biodegradable and foodgrade origin, but also because of its ability to physically entrap a large number of
hydrophobic compounds (Davidov-Pardo et al. 2015). Additionally, zein has been
used to design functional organic-inorganic composite particles (Baars et al. 2015)
and for the stabilization of foams and emulsions (Blanco et al. 2016). Moreover,
zein particles are characterized by slower digestibility in the gastrointestinal tract in
comparison with other proteins due to its resistance to digestive enzymes and therefore, enhanced capability of controlled release of the payload molecules (Patel and
Velikov 2014). Therefore, zein is considered as a good candidate for the encapsulation of functional compounds and development of the delivery system in food and
pharmaceutical industries (Yang et al. 2017). Phenolic phytochemical such as procyanidin with antioxidant activity was encapsulated into the zein NPs using an
aqueous medium and it was found that the solubility of procyanidin enhanced when
it was encapsulated (Zou et al. 2012). Tocopherol encapsulated in Zein-Gum Arabic
biopolymer nanoparticles was investigated and found that the presence of GA not
only prevented the precipitation of zein nanoparticles but also controlled the release
of TOC from zein-GA nanoparticles during in vitro gastrointestinal digestion (Li
et al. 2018a, b). More recently, it has been studied that zein/SSPS (soluble soybean
polysaccharide) nanoparticles successfully used to encapsulate hydrophobic quercetin. The results disclosed that the encapsulation efficiency was greatly enhanced
to 82.5% after SSPS coating, compared to 59.2% for the zein without coating,
which suggests that zein/SSPS nanoparticles have great potential to be used as
nano-delivery systems for bioactive compounds (Li et al. 2018a, b).
Wheat protein has successful application in encapsulation with alone or in combination with polysaccharides (Andreani et al. 2009; Liao et al. 2012). However,
wheat gluten is allergenic and susceptible to celiac disease. Therefore, modification
of wheat gluten could improve its properties. It has been reported that wheat gluten
can be modified by acid heating deamidation which reduces its cytotoxicity and
improves the overall functionalities (Berti et al. 2007). In subsequent, Liao et al.
(2012) developed succinic acid deamidated wheat gluten microspheres for encapsulation of fish oil through double emulsion technique. The study revealed that the
deamidated wheat gluten microspheres were suitable for the encapsulation, controlled release, and stability maintenance of fish oil.
Barley is a very adaptable crop. Barley grains and by-products are abundant and
affordable protein sources which contain 8–13% and 20–30% (w/w) protein, respectively (Yalcin et al. 2008). The two major endosperm storage proteins of barley are
hordein and glutelin which ranges from 35–55% and 35–40%, respectably, whereas
albumin and globulin proteins are enriched in the bran and germ (Finnie and
Svensson 2009). Barley proteins have excellent emulsification and film formation
features as they are highly hydrophobic (Wang et al. 2010). Wang and coworkers
F. Jhan et al.