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healing properties (Gomez-Estaca et al. 2012; Rao and Khanum 2016). However,
curcumin is difficult to incorporate in to some food products because it is a fat soluble compound and therefore has poor water solubility (Pinheiro et al. 2016). It is
also susceptible to degradation under neutral and alkaline pH, high temperature, and
exposition to light, metallic ions, enzymes, and oxygen (Kumar et al. 2016a, b). To
overcome these drawbacks, encapsulation of curcumin might be the solution to this
problem.
Encapsulation within or complexation with proteins has been regarded as most
effective way for increasing the solubility of curcumin in aqueous solutions and
enhancing its bioavailability. In this context, different food proteins including soy
proteins (Chen et al. 2015), whey proteins (Liu et al. 2017), zein (Gomez-Estaca
et al. 2012), and gelatin (Gomez-Estaca et al. 2015) have been used as carriers for
improving the aqueous solubility and antioxidant activity of curcumin. Tapal and
Tiku (2012) reported that the complexation with soy protein isolate, curcumin aqueous solubility drastically increased by 812-fold. Similarly, aqueous solubility of
curcumin increased by about 1200-fold through the complexation with WPN,
whereas its solubility is increased by approximately 180-fold through the complexation with WPI (Mohammadian et al. 2018). Isuru et al. (2016) investigated that
curcumin encapsulated in a chickpea (Cicer arietinum) protein matrix improved the
stability and bioavailability in the gut.
Flavan-3-Ols
Flavan-3-ols, also known as catechin monomers, occur naturally as aglycons of
catechin and epicatechin without glycosylation in plant foods (Pappas and Schaich
2009). Flavan-3-ols are abundant in tea. In unfermented tea, the concentration of
flavan-3-ols ranges from 35 to 115 mg/g of tea leaves, with (−)-epigallocatechin
gallate (EGCG) being the most abundant (Socha et al. 2013). EGCG possesses several pharmacological properties such as antioxidant, anti-proliferative, antiangiogenic and anti-carcinogenic effects (Singh et al. 2011).
The EGCG stability is affected by the pH, oxygen, and the temperature
(Shpigelman et al. 2010). EGCG is easily oxidized at neutral and basic pH and
forms a dimer, which is irreversible (Shpigelman et al. 2012) and it undergoes
epimerization at high temperatures (Li et al. 2012). Due to the low pH in the stomach, EGCG is stable after ingestion while degradation of EGCG occurs in the intestine as the pH rises to a neutral pH (Haratifar et al. 2014). Therefore, EGCG
bioavailability is very low. One effective way to prevent catechin degradation in an
aqueous environment is microencapsulation
Among the catechins, epigallocatechin-3-gallate (EGCG) has been widely studied in microencapsulation. Catechins have been encapsulated in β-lactoglobulin
(β-Lg) matrices by gelation and it was reported that the nanoparticles showed activities against oxidation and degradation. Moreover, these particles had good encapsulation efficiency (60–70%) for EGCG (Shpigelman et al. 2010). In another study
EGCG encapsulating in native, heated, and desolvated β-Lg matrix respectively and
Advances in the Application of Food Proteins and Enzymes
healing properties (Gomez-Estaca et al. 2012; Rao and Khanum 2016). However,
curcumin is difficult to incorporate in to some food products because it is a fat soluble compound and therefore has poor water solubility (Pinheiro et al. 2016). It is
also susceptible to degradation under neutral and alkaline pH, high temperature, and
exposition to light, metallic ions, enzymes, and oxygen (Kumar et al. 2016a, b). To
overcome these drawbacks, encapsulation of curcumin might be the solution to this
problem.
Encapsulation within or complexation with proteins has been regarded as most
effective way for increasing the solubility of curcumin in aqueous solutions and
enhancing its bioavailability. In this context, different food proteins including soy
proteins (Chen et al. 2015), whey proteins (Liu et al. 2017), zein (Gomez-Estaca
et al. 2012), and gelatin (Gomez-Estaca et al. 2015) have been used as carriers for
improving the aqueous solubility and antioxidant activity of curcumin. Tapal and
Tiku (2012) reported that the complexation with soy protein isolate, curcumin aqueous solubility drastically increased by 812-fold. Similarly, aqueous solubility of
curcumin increased by about 1200-fold through the complexation with WPN,
whereas its solubility is increased by approximately 180-fold through the complexation with WPI (Mohammadian et al. 2018). Isuru et al. (2016) investigated that
curcumin encapsulated in a chickpea (Cicer arietinum) protein matrix improved the
stability and bioavailability in the gut.
Flavan-3-Ols
Flavan-3-ols, also known as catechin monomers, occur naturally as aglycons of
catechin and epicatechin without glycosylation in plant foods (Pappas and Schaich
2009). Flavan-3-ols are abundant in tea. In unfermented tea, the concentration of
flavan-3-ols ranges from 35 to 115 mg/g of tea leaves, with (−)-epigallocatechin
gallate (EGCG) being the most abundant (Socha et al. 2013). EGCG possesses several pharmacological properties such as antioxidant, anti-proliferative, antiangiogenic and anti-carcinogenic effects (Singh et al. 2011).
The EGCG stability is affected by the pH, oxygen, and the temperature
(Shpigelman et al. 2010). EGCG is easily oxidized at neutral and basic pH and
forms a dimer, which is irreversible (Shpigelman et al. 2012) and it undergoes
epimerization at high temperatures (Li et al. 2012). Due to the low pH in the stomach, EGCG is stable after ingestion while degradation of EGCG occurs in the intestine as the pH rises to a neutral pH (Haratifar et al. 2014). Therefore, EGCG
bioavailability is very low. One effective way to prevent catechin degradation in an
aqueous environment is microencapsulation
Among the catechins, epigallocatechin-3-gallate (EGCG) has been widely studied in microencapsulation. Catechins have been encapsulated in β-lactoglobulin
(β-Lg) matrices by gelation and it was reported that the nanoparticles showed activities against oxidation and degradation. Moreover, these particles had good encapsulation efficiency (60–70%) for EGCG (Shpigelman et al. 2010). In another study
EGCG encapsulating in native, heated, and desolvated β-Lg matrix respectively and
Advances in the Application of Food Proteins and Enzymes