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protection against serious diseases, it is important to inhibit lipid oxidation and free
radicals formation occurring in the foodstuff and living body.
Many food proteins, upon hydrolysis, have been shown to possess antioxidant
activities. Antioxidant peptides from protein hydrolysates contain certain amino
acid residues that help in preventing lipid-oxidation, as well as chelating oxidant
metal ions. Yee et al. (1980) reported tha tsoy protein hydrolysates upon proteolysis
exhibited antioxidant potential, as measured by the thiobarbituric (TBA) assay,
which is a measure of lipid peroxidation. It was proposed that the liberation of
bound antioxidant phenolics or copper chelating agents was responsible for the
observed antioxidant activity. Similarly, soy protein hydrolysates manufactured
with Flavourzyme or chymotrypsin had antioxidant potential greater than unhydrolysed soy protein isolate. However, it was observed that using enzymes such as
papain, large-scale degradation unfavourably altered the antioxidant activity (PenaRamos and Xiong 2002). In addition, protein hydrolysates derived from wheat germ
also possess radical scavenging abilities, with an antioxidant activity close to that of
the well known, antioxidant α-tocopherol. Interestingly, these hydrolysates had low
molecular weight <1500 Da (Zhu et al. 2006). Memarpoor-Yazdia et al. (2013)
revealed that protein hydrolysates and purified peptides from fruits of Zizyphus
jujuba could be included as antioxidant constituents in the food industry due to their
role in food quality preservation and human health promotion. Furthermore, in rats
fed a high-cholesterol diet, oral administration of boops boops protein hydrolysates
has been reported to enhance antioxidant activity by strengthening antioxidant
enzymes (Lassoued et al. 2014). Recently, Kumar et al. (2016a, b) reported that
using enzymes such as Alcalase, α-chymotrypsin, and Papain, camel milk casein
could be used to produce different protein hydrolysates with high antioxidant and
antimicrobial activities.
Anti-Hypertensive Activity
High blood pressure is a precursor of the pathological condition called hypertension, which affects 30% of the adult population in the world and has been regarded
as one of the major independent risk factors for cardiovascular diseases (CVDs)
(Harris et al. 1985). Angiotensin-converting enzyme (ACE) inhibitors are an example of a drug treatment in regulating blood pressure. ACE reduces the conversion of
angiotensin-1 (vasodilatory) to angiotensin-2 (vasoconstrictory) leading in a
reduced blood pressure. Hence, there is great interest in novel compounds that can
inhibit ACE. Among bioactive food protein hydrolysates, those that are ACE inhibitors are of particular interest for the prevention and treatment of hypertension.
Indeed, the ACE-inhibitory peptides that modulate the renin–angiotensin system
(RAS) are the most studied bioactive peptides.
Most of the recognized ACE-inhibitory peptides are short peptides with 2–20
amino acid residues and exhibiting different activities. This finding was supported
by a study of Wu and Ding (2001) who reported that ACE-inhibitory activity
F. Jhan et al.
protection against serious diseases, it is important to inhibit lipid oxidation and free
radicals formation occurring in the foodstuff and living body.
Many food proteins, upon hydrolysis, have been shown to possess antioxidant
activities. Antioxidant peptides from protein hydrolysates contain certain amino
acid residues that help in preventing lipid-oxidation, as well as chelating oxidant
metal ions. Yee et al. (1980) reported tha tsoy protein hydrolysates upon proteolysis
exhibited antioxidant potential, as measured by the thiobarbituric (TBA) assay,
which is a measure of lipid peroxidation. It was proposed that the liberation of
bound antioxidant phenolics or copper chelating agents was responsible for the
observed antioxidant activity. Similarly, soy protein hydrolysates manufactured
with Flavourzyme or chymotrypsin had antioxidant potential greater than unhydrolysed soy protein isolate. However, it was observed that using enzymes such as
papain, large-scale degradation unfavourably altered the antioxidant activity (PenaRamos and Xiong 2002). In addition, protein hydrolysates derived from wheat germ
also possess radical scavenging abilities, with an antioxidant activity close to that of
the well known, antioxidant α-tocopherol. Interestingly, these hydrolysates had low
molecular weight <1500 Da (Zhu et al. 2006). Memarpoor-Yazdia et al. (2013)
revealed that protein hydrolysates and purified peptides from fruits of Zizyphus
jujuba could be included as antioxidant constituents in the food industry due to their
role in food quality preservation and human health promotion. Furthermore, in rats
fed a high-cholesterol diet, oral administration of boops boops protein hydrolysates
has been reported to enhance antioxidant activity by strengthening antioxidant
enzymes (Lassoued et al. 2014). Recently, Kumar et al. (2016a, b) reported that
using enzymes such as Alcalase, α-chymotrypsin, and Papain, camel milk casein
could be used to produce different protein hydrolysates with high antioxidant and
antimicrobial activities.
Anti-Hypertensive Activity
High blood pressure is a precursor of the pathological condition called hypertension, which affects 30% of the adult population in the world and has been regarded
as one of the major independent risk factors for cardiovascular diseases (CVDs)
(Harris et al. 1985). Angiotensin-converting enzyme (ACE) inhibitors are an example of a drug treatment in regulating blood pressure. ACE reduces the conversion of
angiotensin-1 (vasodilatory) to angiotensin-2 (vasoconstrictory) leading in a
reduced blood pressure. Hence, there is great interest in novel compounds that can
inhibit ACE. Among bioactive food protein hydrolysates, those that are ACE inhibitors are of particular interest for the prevention and treatment of hypertension.
Indeed, the ACE-inhibitory peptides that modulate the renin–angiotensin system
(RAS) are the most studied bioactive peptides.
Most of the recognized ACE-inhibitory peptides are short peptides with 2–20
amino acid residues and exhibiting different activities. This finding was supported
by a study of Wu and Ding (2001) who reported that ACE-inhibitory activity
F. Jhan et al.