340
legumes, fish, microorganisms, algae, and plant leaves (Joshi et al. 2012; Zeng et al.
2013). Proteins have also been added into various food products in order to improve
the flavor, texture, and other sensory attributes of the processed foods.
Embarking upon a society that is increasingly aware about food and health, the
science behind food and its constituents is an area that has inspired several scientists
toward the bioactive nature of food proteins. Additionally, using as a source of
energy and providing amino acids for the synthesis of body proteins, food proteins
are essential biological entities that not only help sustain the overall growth, metabolism, and functioning of cellular metabolisms but also provide health attributes. It
has been analyzed that increasing the dietary protein intake can modulate anabolic
response (Tieland et al. 2012), improve muscle strength and physical function, cardiovascular health and weight management, fat and glucose metabolism, and modulate the immune system (Hartmann and Meisel 2007; Wolfe 2015). In this context,
this chapter outlines proteins as hydrolysates, edible films and coatings and wall
material for encapsulation and nano delivery systems for bioactive compounds. In
addition, protein engineering and immobilization is also discussed.
Protein Hydrolysates
Protein hydrolysates are defined as the products obtained from cleavage of protein’s
peptide bonds, producing peptides with varying sizes and free amino acids. This
type of protein structure modification has an effect on its physicochemical and
functional properties (Severin and Xia 2006). The most notable modifications that
affect functionality include a decrease in molecular weight of the peptide chain, an
increase in polar groups (–NH 4
+
, –CO 2
−
), which increase hydrophilicity, and a
change in molecular configuration. The cleavage of peptide bonds can be carried
out via enzymatic or chemical methods. Hydrolysis using a chemical, alkaline or
acidic process is more difficult to control and reduces the nutritional quality of
products (Celus et al. 2007), destroying L-form of amino acids and producing toxic
substances such as lysino-alanine (Lahl and Grindstaff 1989). Enzymatic hydrolysis works without destructing amino acids and therefore, the nutritional properties
of the protein hydrolysates remain largely unaffected by avoiding the extreme temperatures and pH levels needed for chemical hydrolysis (Celus et al. 2007).
Although more expensive than chemical hydrolysis, enzymatic hydrolysis is the
preferred method.
Protein hydrolysates derived from food possess various physicochemical properties such as solubility, lipid binding, foaming, and emulsification properties depending on their composition, sequence, and length (Cho et al. 2014; Pokora et al. 2013).
Hence, food derived protein hydrolysates are promising ingredients for developing
functional foods (Chalamaiah et al. 2012). Several works in the past few decades
have demonstrated that protein hydrolysates from various food sources exhibited
various beneficial pharmacological properties namely, antioxidant (Udenigwe and
Aluko 2012), hypotensive (He et al. 2013), anticancererous (Kannan et al. 2010),
F. Jhan et al.
legumes, fish, microorganisms, algae, and plant leaves (Joshi et al. 2012; Zeng et al.
2013). Proteins have also been added into various food products in order to improve
the flavor, texture, and other sensory attributes of the processed foods.
Embarking upon a society that is increasingly aware about food and health, the
science behind food and its constituents is an area that has inspired several scientists
toward the bioactive nature of food proteins. Additionally, using as a source of
energy and providing amino acids for the synthesis of body proteins, food proteins
are essential biological entities that not only help sustain the overall growth, metabolism, and functioning of cellular metabolisms but also provide health attributes. It
has been analyzed that increasing the dietary protein intake can modulate anabolic
response (Tieland et al. 2012), improve muscle strength and physical function, cardiovascular health and weight management, fat and glucose metabolism, and modulate the immune system (Hartmann and Meisel 2007; Wolfe 2015). In this context,
this chapter outlines proteins as hydrolysates, edible films and coatings and wall
material for encapsulation and nano delivery systems for bioactive compounds. In
addition, protein engineering and immobilization is also discussed.
Protein Hydrolysates
Protein hydrolysates are defined as the products obtained from cleavage of protein’s
peptide bonds, producing peptides with varying sizes and free amino acids. This
type of protein structure modification has an effect on its physicochemical and
functional properties (Severin and Xia 2006). The most notable modifications that
affect functionality include a decrease in molecular weight of the peptide chain, an
increase in polar groups (–NH 4
+
, –CO 2
−
), which increase hydrophilicity, and a
change in molecular configuration. The cleavage of peptide bonds can be carried
out via enzymatic or chemical methods. Hydrolysis using a chemical, alkaline or
acidic process is more difficult to control and reduces the nutritional quality of
products (Celus et al. 2007), destroying L-form of amino acids and producing toxic
substances such as lysino-alanine (Lahl and Grindstaff 1989). Enzymatic hydrolysis works without destructing amino acids and therefore, the nutritional properties
of the protein hydrolysates remain largely unaffected by avoiding the extreme temperatures and pH levels needed for chemical hydrolysis (Celus et al. 2007).
Although more expensive than chemical hydrolysis, enzymatic hydrolysis is the
preferred method.
Protein hydrolysates derived from food possess various physicochemical properties such as solubility, lipid binding, foaming, and emulsification properties depending on their composition, sequence, and length (Cho et al. 2014; Pokora et al. 2013).
Hence, food derived protein hydrolysates are promising ingredients for developing
functional foods (Chalamaiah et al. 2012). Several works in the past few decades
have demonstrated that protein hydrolysates from various food sources exhibited
various beneficial pharmacological properties namely, antioxidant (Udenigwe and
Aluko 2012), hypotensive (He et al. 2013), anticancererous (Kannan et al. 2010),
F. Jhan et al.