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Characterization and Analysis of Bioactive Peptides
To identify food-derived peptides in food matrices, blood and other biological samples, potential methods are being evolved. The sequence of peptides is conventionally identified by Edman degradation or enzyme-linked immunoassay (ELISA).
However, these techniques require significant fractionation work before the peptides can be identified, rendering the methodology quite complex. To isolate specific
peptides from hydrolysates is difficult because of hundreds of peptides present in
any given hydrolysate. Also, some peptides are very much alike to each other in
terms of physiochemical properties like mass, charge, solubility etc., which makes
the separation even more challenging (Capriotti et al. 2016). Additionally, food
matrices are intricate too, which combined with the protein hydrolysate makes the
identification, characterization and quantification a difficult task (RutherfurdMarkwick 2012). Nevertheless, advanced analytical techniques such as mass spectrometry (MS), Nuclear Magnetic Resonance (NMR), High Performance Liquid
Chromatography (HPLC), Capillary Electrophoresis (CE) are available to carry out
complex food matrices studies. Sometimes, a combination of these techniques is
used when analyzing multiple components (Bernal et al. 2011). Also, the type of
technique employed will differ according to the target compound in the said matrix.
For instance, physico-chemical properties like size, polarity, volatility etc. will
strongly affect the sample preparation, separation mechanism and technique (HPLC,
CE, GC) as well as the type of detector used (UV, Fluorescence Detector, MS, etc.).
Advanced analytical techniques also help in the better understanding of bioactivity
and bioavailability of the food derived peptides (Bernal et al. 2011). Table 1 provides examples of the types of techniques used to analyze bioactive peptides.
Identification of Sequence by Edman Degradation
Edman degradation is of one of the first and frequent methods used for peptide
identification before high-throughput proteomics technologies were introduced.
The process required an extensive purification before sequencing, thus the process
was laborious and time consuming. The automated instrumentation process was
also limited to identification of 50 residues only (Rizzello et al. 2016). Although the
Edman degradation process is an outdated approach, however, in recent studies the
use of this method has been reported (Jamdar et al. 2017; Furuta et al. 2016).
Capillary Electrophoresis (CE)
For the quantitative determination of peptides, CE is an attractive method that is
being used due to its low consumption of sample, reagent and time as well as its
ability to separate small to large sized peptides (Herrero et al. 2008; Acunha et al.
S. Maqsood et al.
Characterization and Analysis of Bioactive Peptides
To identify food-derived peptides in food matrices, blood and other biological samples, potential methods are being evolved. The sequence of peptides is conventionally identified by Edman degradation or enzyme-linked immunoassay (ELISA).
However, these techniques require significant fractionation work before the peptides can be identified, rendering the methodology quite complex. To isolate specific
peptides from hydrolysates is difficult because of hundreds of peptides present in
any given hydrolysate. Also, some peptides are very much alike to each other in
terms of physiochemical properties like mass, charge, solubility etc., which makes
the separation even more challenging (Capriotti et al. 2016). Additionally, food
matrices are intricate too, which combined with the protein hydrolysate makes the
identification, characterization and quantification a difficult task (RutherfurdMarkwick 2012). Nevertheless, advanced analytical techniques such as mass spectrometry (MS), Nuclear Magnetic Resonance (NMR), High Performance Liquid
Chromatography (HPLC), Capillary Electrophoresis (CE) are available to carry out
complex food matrices studies. Sometimes, a combination of these techniques is
used when analyzing multiple components (Bernal et al. 2011). Also, the type of
technique employed will differ according to the target compound in the said matrix.
For instance, physico-chemical properties like size, polarity, volatility etc. will
strongly affect the sample preparation, separation mechanism and technique (HPLC,
CE, GC) as well as the type of detector used (UV, Fluorescence Detector, MS, etc.).
Advanced analytical techniques also help in the better understanding of bioactivity
and bioavailability of the food derived peptides (Bernal et al. 2011). Table 1 provides examples of the types of techniques used to analyze bioactive peptides.
Identification of Sequence by Edman Degradation
Edman degradation is of one of the first and frequent methods used for peptide
identification before high-throughput proteomics technologies were introduced.
The process required an extensive purification before sequencing, thus the process
was laborious and time consuming. The automated instrumentation process was
also limited to identification of 50 residues only (Rizzello et al. 2016). Although the
Edman degradation process is an outdated approach, however, in recent studies the
use of this method has been reported (Jamdar et al. 2017; Furuta et al. 2016).
Capillary Electrophoresis (CE)
For the quantitative determination of peptides, CE is an attractive method that is
being used due to its low consumption of sample, reagent and time as well as its
ability to separate small to large sized peptides (Herrero et al. 2008; Acunha et al.
S. Maqsood et al.