against a broad spectrum of gram-positive and gram-negative bacteria, including
Listeria monocytogenes. The researchers proposed the possibility of incorporating
AMPs derived from whey proteins directly into pharmaceuticals and dietary food
therapies [114].
Proteolytic fragments derived from whey proteins, lactoferrin, and lysozyme
were widely studied concerning the search for their antimicrobial activity. Fragments TPEVDDEALEK f(125–135), KVAGT f(14–18), VRT f(123–125), PEGDI
f(50–54), and LPMH f(143–146) were released from b-LG with trypsin or pepsin
[115, 116]. For example, proteolytic digestion of b-LG by trypsin released four
antimicrobial fragment peptides against gram-positive bacteria corresponding to
VAGTWY f (15–20), AASDISLLDAQSAPLR f(25–40), IPAVFK f(78–83), and
VLVLDTDYK f(92–100) [117].
Mohanty et al. [118] reviewed the antimicrobial bioactive peptides derived from
milk and whey proteins and their mechanism of action.
5.5 Antioxidant Peptides
In recent years, special attention focused on the search for whey-derived peptides
with free-radical quenching activities (scavenging) and lipid peroxidation. Free
radicals can modify nucleic acid molecules, in particular DNA, proteins, lipids, and
cell small molecules. Several authors report that they play a significant role in the
occurrence of some diseases, such as cardiovascular diseases, diabetes, and neurological disorders such as Alzheimer´s disease. Also, lipid peroxidation in food
products can cause deterioration in food quality, shorten its shelf life, and reduce
consumer's acceptability of processed foods. Drug regulatory agencies restricted the
use of synthetic antioxidants such as butylated hydroxytoluene (BHT), butylated
hydroxyanisole (BHA), propyl gallate (PG), and tert-butylhydroquinone (TBHO)
due to their potential toxic effect on humans [119].
Conway et al. [120] suggested that peptides derived from enzymatic hydrolysis
of a-LA and b-LG present in WPC were probably responsible for antioxidant
activity in comparison with caseins present in skimmed milk. These authors also
found that the primary mode of action is related to the peptide chain of amino acid
sequence and composition.
The antioxidant fragments INYW f(101–104) and LDQW f(115–118) were
released from a-LA, while FNPTO f(151–155), LQKW f(58–61), and LDTDYKK
f(95–101) were released from b-LG using thermolysin [121, 122]. The fragments
WYSLAMAASDI f(19–29) and YVEEL f(42–46) result from the digestion of
b-LG with Corolase PP [123].
Peptides with sequences of 5–11 amino acids, including hydrophobic residues
such as Tyr, Trp, Phe, Pro, His, and Val or Leu in the N-terminal, were associated
with the most significant antioxidant activity [124]. Other hydrophobic amino acids,
such as Pro and His, are also described as essential for antioxidant activity as this
activity is related to a high number of ionizable groups and the exposure of
hydrophobic groups [125]. There are inexpensive and straightforward methods to
496
A. F. A. Salvado et al.
Listeria monocytogenes. The researchers proposed the possibility of incorporating
AMPs derived from whey proteins directly into pharmaceuticals and dietary food
therapies [114].
Proteolytic fragments derived from whey proteins, lactoferrin, and lysozyme
were widely studied concerning the search for their antimicrobial activity. Fragments TPEVDDEALEK f(125–135), KVAGT f(14–18), VRT f(123–125), PEGDI
f(50–54), and LPMH f(143–146) were released from b-LG with trypsin or pepsin
[115, 116]. For example, proteolytic digestion of b-LG by trypsin released four
antimicrobial fragment peptides against gram-positive bacteria corresponding to
VAGTWY f (15–20), AASDISLLDAQSAPLR f(25–40), IPAVFK f(78–83), and
VLVLDTDYK f(92–100) [117].
Mohanty et al. [118] reviewed the antimicrobial bioactive peptides derived from
milk and whey proteins and their mechanism of action.
5.5 Antioxidant Peptides
In recent years, special attention focused on the search for whey-derived peptides
with free-radical quenching activities (scavenging) and lipid peroxidation. Free
radicals can modify nucleic acid molecules, in particular DNA, proteins, lipids, and
cell small molecules. Several authors report that they play a significant role in the
occurrence of some diseases, such as cardiovascular diseases, diabetes, and neurological disorders such as Alzheimer´s disease. Also, lipid peroxidation in food
products can cause deterioration in food quality, shorten its shelf life, and reduce
consumer's acceptability of processed foods. Drug regulatory agencies restricted the
use of synthetic antioxidants such as butylated hydroxytoluene (BHT), butylated
hydroxyanisole (BHA), propyl gallate (PG), and tert-butylhydroquinone (TBHO)
due to their potential toxic effect on humans [119].
Conway et al. [120] suggested that peptides derived from enzymatic hydrolysis
of a-LA and b-LG present in WPC were probably responsible for antioxidant
activity in comparison with caseins present in skimmed milk. These authors also
found that the primary mode of action is related to the peptide chain of amino acid
sequence and composition.
The antioxidant fragments INYW f(101–104) and LDQW f(115–118) were
released from a-LA, while FNPTO f(151–155), LQKW f(58–61), and LDTDYKK
f(95–101) were released from b-LG using thermolysin [121, 122]. The fragments
WYSLAMAASDI f(19–29) and YVEEL f(42–46) result from the digestion of
b-LG with Corolase PP [123].
Peptides with sequences of 5–11 amino acids, including hydrophobic residues
such as Tyr, Trp, Phe, Pro, His, and Val or Leu in the N-terminal, were associated
with the most significant antioxidant activity [124]. Other hydrophobic amino acids,
such as Pro and His, are also described as essential for antioxidant activity as this
activity is related to a high number of ionizable groups and the exposure of
hydrophobic groups [125]. There are inexpensive and straightforward methods to
496
A. F. A. Salvado et al.