Antioxidant Activities Of Peptide Fractions Research Articles

Antioxidant Activity of Peptide Fractions from Chickpea Globulin Obtained by Pulsed Ultrasound Pretreatment

Protein hydrolysates and peptides can show biological activities, and pulsed ultrasound improves bioactivities. Among matrices from which protein hydrolysates can be obtain, chickpea is an excellent source. The objective of this research was to evaluate the effect of pulsed ultrasound on globulin concentrate to obtain chickpea hydrolysate (HGb) and peptide fractions and their bioactivity. Antioxidant activity by ABTS (2,2′-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt), FRAP (Ferric Reducing Antioxidant Power) and human erythrocyte assays was determined. The electrophoretic profile, amino acid profile, and antimicrobial activity of hydrolysates were also determined. Two hydrolysates had the highest antioxidant activity: HGb (91.44% ABTS inhibition, 73.04% hemolysis inhibition and 5185.57 µmol TE/g dried sample in FRAP assay) and HGb-20 (48.25% ABTS inhibition, 100% hemolysis inhibition and 2188.53 µmol TE/g dried sample in FRAP assay). Peptide fractions inhibited 100% of the hemolysis on human erythrocytes. The hydrolysates from chickpea proteins obtained with savinase have antioxidant activity through the SET and HAT mechanisms. The application of the obtained compounds for the development of functional foods or for food preservation should be considered.

Anti-proliferative Effect of a Novel Anti-oxidative Peptide in Hanwoo Beef on Human Colorectal Carcinoma Cells.

The present study aimed to characterise anti-oxidant peptides from water-soluble protein extracts of Hanwoo beef and evaluate their anti-proliferative effect on human colorectal carcinoma cells (HCT116). Antioxidant peptides were purified from the low-molecular-weight fraction (<3 kDa) of Hanwoo beef extract. Antioxidant activity of peptide fractions was determined using the oxygen radical absorbance capacity (ORAC) assay. Purified peptide (P3) displayed higher ORAC activity than the low-molecular-weight fraction (202.66 μM TE/g vs 167.38 μM TE/g of dry matter, respectively) (p<0.05). The peptide sequence of P3 was Cys-Cys-Cys-Cys-Ser-Val-Gln-Lys (888.30 Da). The novel peptide P3, at 250 μg/mL, also significantly inhibited HCT116 cell proliferation up to 25.24% through phosphorylation of ERK, JNK, and p38 kinase (p<0.05). Hence, antioxidant peptide P3 from Hanwoo beef extract can be used as an antioxidative and anti-cancer agent in the functional food industry.

Antioxidant activities of peptide fractions derived from freshwater mussel protein using ultrasound-assisted enzymatic hydrolysis

The freshwater mussel protein was hydrolysed using ultrasound-assisted enzymolysis. Ultrasound-assisted freshwater mussel protein hydrolysates (UPH) were divided into four fractions (&amp;gt; 10, 6–10, 3–6, and &amp;lt; 3 kDa) using ultrafiltration, and the fraction with the highest antioxidant activity was further subdivided into four fractions (F&lt;sub&gt;1&lt;/sub&gt;–F&lt;sub&gt;4&lt;/sub&gt;) using gel chromatography. The amino acid compositions and antioxidant activities (DPPH, hydroxyl and superoxide radical scavenging activities, reducing power, ferrous ion chelating activity, and inhibition of linoleic acid oxidation) of peptide fractions were investigated. The results showed that the antioxidant activity of the &amp;lt; 3 kDa fraction was significantly higher than that of UPH, &amp;gt; 10, 6–10, and 3–6 kDa fractions. The antioxidant activity of F&lt;sub&gt;2&lt;/sub&gt; was again higher compared with the &amp;lt; 3 kDa fraction and higher than that of F&lt;sub&gt;1&lt;/sub&gt;, F&lt;sub&gt;3&lt;/sub&gt;, and F&lt;sub&gt;4&lt;/sub&gt;. Amino acid analysis showed that the antioxidant activities (except for chelating activity) of peptides increased with increasing hydrophobic amino acid content. The &amp;lt; 3 kDa and F&lt;sub&gt;2&lt;/sub&gt; fractions exhibited strong inhibition of linoleic acid oxidation, their effects being even better than that of ascorbic acid (Vc) and l-glutathione (GSH). Therefore, these peptide fractions from freshwater mussel may be a potential natural antioxidant that could be added to various foods.

Antioxidant activities of chicken bone peptide fractions and their Maillard reaction products: Effects of different molecular weight distributions

ABSTRACTChicken bone protein hydrolysate (CBPH) and its peptide fractions (CBPH-I, molecular weight < 3 kDa; CBPH-II, molecular weight 3–10 kDa) were heated with galactose in aqueous solution at 100°C for 90 min. Antioxidant activities of CBPH, CBPH-I, CBPH-II, and their derived Maillard reaction products (MRPs) were evaluated. CBPH, peptide fractions, and their MRP exerted strong DPPH radical scavenging activity and reducing power, but low scavenging activity toward the hydroxyl radicals. All the tested antioxidant activities of CBPH and its peptide fractions were significantly increased after the Maillard reaction with galactose. The increment in the antioxidant activity of CBPH-II MRP was higher than that of CBPH-I MRP, although more glycation was found in CBPH-I MRP. The results indicated that the improvement of the antioxidant activity of peptide fraction via the Maillard reaction should be closely related to its molecular size.

Survival and bioactivities of selected probiotic lactobacilli in yogurt fermentation and cold storage: New insights for developing a bi-functional dairy food

In previous work, we demonstrated that two probiotic strains, namely Lactobacillus casei PRA205 and Lactobacillus rhamnosus PRA331, produce fermented milks with potent angiotensin-converting enzyme (ACE)-inhibitory and antioxidant activities. Here, we tested these strains for the survivability and the release of antihypertensive and antioxidant peptides in yogurt fermentation and cold storage. For these purposes three yogurt batches were compared: one prepared using yogurt starters alone (Lactobacillus delbrueckii subspecies bulgaricus 1932 and Streptococcus thermophilus 99), and the remaining two containing either PRA205 or PRA331 in addition to yogurt starters. Despite the lower viable counts at the fermentation end compared to PRA331, PRA205 overcame PRA331 in survivability during refrigerated storage for 28 days, leading to viable counts (>108 CFU/g) higher than the minimum therapeutic threshold (106 CFU/g). Analyses of in vitro ACE-inhibitory and antioxidant activities of peptide fractions revealed that yogurt supplemented with PRA205 displays higher amounts of antihypertensive and antioxidant peptides than that produced with PRA331 at the end of fermentation and over storage. Two ACE-inhibitory peptides, Valine-Proline-Proline (VPP) and Isoleucine-Proline-Proline (IPP), were identified and quantified. This study demonstrated that L. casei PRA205 could be used as adjunct culture for producing bi-functional yogurt enriched in bioactive peptides and in viable cells, which bring health benefits to the host as probiotics.

The comparative assessment of ACE-inhibitory and antioxidant activities of peptide fractions obtained from fermented camel and bovine milk by Lactobacillus rhamnosus PTCC 1637

The aim of this study was to compare angiotensin-converting enzyme (ACE)-inhibitory and antioxidant activities of peptide fractions obtained from fermented bovine and camel milk by Lactobacillus rhamnosus PTCC 1637 during 21 days of cold storage. The proteolytic activity was determined using the o-phthaldialdehyde method, antihypertensive effect was performed based on inhibition of ACE activity, and antioxidant activity was measured using the 2,2'-azino-bis-(3-ethyl-benzthiazoline-6-sulfonic acid) scavenging assay. In most cases, higher ACE-inhibitory and antioxidant activity was observed from cultured camel milk than bovine milk. This may be explained by structural differences and the presence of higher proline content in the primary structure of camel milk caseins compared with bovine milk. In both milk types, increased proteolytic activity during storage resulted in increased antioxidant activity. The results suggest the potential use of fermented camel milk with Lb. rhamnosus PTCC 1637 for production of dairy product with ACE-inhibitory and antioxidant properties.

Antihypertensive effect and antioxidant activity of peptide fractions extracted from Spanish dry-cured ham

This study examined the antihypertensive and antioxidant activities of water soluble fractions of a Spanish dry-cured ham extract. Antihypertensive activity of a fractionated peptide extract, by size-exclusion chromatography was determined by measuring changes in systolic blood pressure of spontaneously hypertensive rats after oral administration. Every sample exhibited antihypertensive activity, pooled fractions corresponding to 1700Da or lower were the most antihypertensive with a decrease of 38.38mm Hg in systolic blood pressure. In vitro experiments revealed marked in vitro angiotensin I-converting enzyme inhibitory activity in fractions corresponding to these elution volumes. Some of the fractions exhibited great 1,1-diphenyl-2-picrylhydrazyl radical-scavenging activity, ranging from 39% to 92% as well as superoxide ion extinguishing ability with values ranging from 41.67% to 50.27% of the antioxidant activity, suggesting the presence of peptides with antioxidant activity. These findings suggest that Spanish dry-cured ham contains peptides with antioxidant and antihypertensive activities.

Antioxidant Activity of Protein Hydrolysates from Aqueous Extract of Velvet Antler (Cervus elaphus) as Influenced by Molecular Weight and Enzymes

The crude protein hydrolysates from aqueous extract of velvet antler (AEVA) were prepared by simulated gastrointestinal digestion (SGI, pepsin-pancreatin) using pancreatin-pepsin, alcalase and neutrase. The resulting hydrolysates were separated by sequential ultrafiltration into four fractions. The antioxidant activities of peptide fractions were evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, ferric reducing antioxidant power (FRAP), 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging and Fe(2+)-chelating assays. Results showed that the hydrolysate prepared by SGI had a low degree of hydrolysis, which was significantly improved with altered proteases, such as pancreatin-pepsin and alcalase. Antioxidant activities of peptide fractions varied with molecular weight (MW) and the enzyme used. Generally, low-MW peptide fractions had higher ABTS radical scavenging activity and Fe(2+)-chelating ability, and high-MW peptide fractions were more effective in DPPH radical scavenging activity and reducing power.

Comparative composition and antioxidant activity of Peptide fractions obtained by ultrafiltration of egg yolk protein enzymatic hydrolysates.

The objective of the study was to compare the antioxidant activity of two distinct hydrolysates and their peptide fractions prepared by ultrafiltration (UF) using membranes with molecular weight cut-off of 5 and 1 kDa. The hydrolysates were a delipidated egg yolk protein concentrate (EYP) intensively hydrolyzed with a combination of two bacterial proteases, and a phosphoproteins (PPP) extract partially hydrolyzed with trypsin. Antioxidant activity, as determined by the oxygen radical absorbance capacity (ORAC) assay, was low for EYP and PPP hydrolysates with values of 613.1 and 489.2 μM TE·g−1 protein, respectively. UF-fractionation of EYP hydrolysate increased slightly the antioxidant activity in permeate fractions (720.5–867.8 μM TE·g−1 protein). However, ORAC values were increased by more than 3-fold in UF-fractions prepared from PPP hydrolysate, which were enriched in peptides with molecular weight lower than 5 kDa. These UF-fractions were characterized by their lower N/P atomic ratio and higher phosphorus content compared to the same UF-fractions obtained from EYP-TH. They also contained high amounts of His, Met, Leu, and Phe, which are recognized as antioxidant amino acids, but also high content in Lys and Arg which both represent target amino acids of trypsin used for the hydrolysis of PPP.

Sensory Characteristics and Antioxidant Activities of Maillard Reaction Products from Soy Protein Hydrolysates with Different Molecular Weight Distribution

Soy protein was hydrolyzed using two enzymes to obtain soy protein hydrolysate (SPH), the SPH was fractionated with ultrafiltration membranes to obtain peptide fractions below 1,000 Da (SP1) and 1,000–5,000 Da (SP2), and for the meantime, SPH was further completely hydrolyzed to get compound amino acids (CAA). Maillard reaction products (MRPs) were prepared from aqueous xylose–SPH/SP1/SP2/CAA model systems by heating at 120°C for 2.0 h. Compared with the original hydrolysates and other MRPs, the MRPs from SP2 exhibited a distinctly enhanced effect on flavor, including the caramel-like, soy sauce-like odors, umami and mouthful tastes and a greatly reduced bitterness in consomme´ soup. Antioxidant activities of SPH, SP1, SP2, CAA, and their MRPs were investigated through reducing power, DPPH radical-scavenging activity, and Fe2+ chelating activity. Before Maillard reaction, the antioxidant activities of peptide fractions with different molecular weights were quite different, and SP2 showed the highest activity; however, CAA exhibited very poor antioxidant activity. The antioxidant activities of SPH, SP1, SP2, and CAA were greatly enhanced by Maillard reaction, and the MRPs prepared from xylose–CAA model system exhibited a higher antioxidant activity than those from other model systems. Pyrazines, pyrroles, furans, and thiazoles were significantly correlated with reducing power and Fe2+ chelating activity by principal component analysis.

Angiotensin‐I converting enzyme inhibitory and antioxidant activities of peptide fractions extracted by ultrafiltration of cowpea Vigna unguiculata hydrolysates

Enzymatic proteolysis of food proteins is used to produce peptide fractions with the potential to act as physiological modulators. Fractionation of these proteins by ultrafiltration results in fractions rich in small peptides with the potential to act as functional food ingredients. The present study investigated the angiotensin-I converting enzyme (ACE-I) inhibitory and antioxidant activities for hydrolysates produced by hydrolyzing Vigna unguiculata protein extract as well as ultrafiltered peptide fractions from these hydrolysates. Alcalase(®), Flavourzyme(®) and pepsin-pancreatin were used to produce extensively hydrolyzed V. unguiculata protein extract. Degree of hydrolysis (DH) differed between the enzymatic systems and ranged from 35.7% to 58.8%. Fractionation increased in vitro biological activities in the peptide fractions, with IC(50) (hydrolysate concentration in µg protein mL(-1) required to produce 50% ACE inhibition) value ranges of 24.3-123 (Alcalase hydrolysate, AH), 0.04-170.6 (Flavourzyme hydrolysate; FH) and 44.7-112 (pepsin-pancreatin hydrolysate, PPH) µg mL(-1), and TEAC (Trolox equivalent antioxidant coefficient) value ranges of 303.2-1457 (AH), 357.4-10 211 (FH) and 267.1-2830.4 (PPH) mmol L(-1) mg(-1) protein. The results indicate the possibility of obtaining bioactive peptides from V. unguiculata proteins by means of a controlled protein hydrolysis using Alcalase(®), Flavourzyme(®) and pepsin-pancreatin. The V. unguiculata protein hydrolysates and their corresponding ultrafiltered peptide fractions might be utilized for physiologically functional foods with antihypertensive and antioxidant activities.

Antioxidant activity of peptide fractions derived from cottonseed protein hydrolysate

Cottonseed protein is widely regarded as a potential source of nutrients for humans and animals, but it is mainly used as forage in China. In the present study, Neutrase was employed to hydrolyse cottonseed protein to produce a hydrolysate with antioxidant activity suitable for conversion to high-value products. The antioxidant potential of the cottonseed protein hydrolysate (CPH) and its fractions was investigated using different in vitro methods. Furthermore, the amino acid composition of the CPH fractions was determined to evaluate the relationship between antioxidant activity and amino acid composition. The CPH prepared using Neutrase was separated into four fractions (I, II, III and IV) by gel filtration on Sephadex G-25. All fractions were effective antioxidants, with fraction III (0.8-1.2 kDa) showing the strongest activity. The amino acid analysis showed that fraction III also had the highest total amino acid content (616.8 g kg(-1) protein) and was rich in Phe, His, Pro, Met, Ile and Cys compared with the other fractions. The results showed that the hydrolysate derived from cottonseed protein, particularly fraction III, could be a natural antioxidant source suitable for use as a food additive.

Amino acid composition and antioxidant properties of pea seed ( Pisum sativum L.) enzymatic protein hydrolysate fractions.

The amino acid composition and antioxidant activities of peptide fractions obtained from HPLC separation of a pea protein hydrolysate (PPH) were studied. Thermolysin hydrolysis of pea protein isolate and ultrafiltration (3 kDa molecular weight cutoff membrane) yielded a PPH that was separated into five fractions (F1-F5) on a C(18) reverse phase HPLC column. The fractions that eluted later from the column (F3-F5) contained higher contents hydrophobic and aromatic amino acids when compared to fractions that eluted early or the original PPH. Fractions F3-F5 also exhibited the strongest radical scavenging and metal chelating activities; however, hydrophobic character did not seem to contribute to reducing power of the peptides. In comparison to glutathione, the peptide fractions had significantly higher (p < 0.05) ability to inhibit linoleic acid oxidation and chelate metals. In contrast, glutathione had significantly higher (p < 0.05) free radical scavenging properties than the peptide fractions.

Antioxidant activity of peptide fractions from whey protein hydrolysates as measured by electron spin resonance

Whey protein isolate (WPI) was hydrolysed for 0.5–8 h using Alcalase, and the 5-h hydrolysate, identified to possess the strongest reducing ability, was subjected to column fractionation and antioxidant activity assays. Sephadex G-10 gel filtration chromatography of the 5-h hydrolysate yielded four fractions (I, II, III and IV) that were composed of peptides of >40 k, 2.8–40 k, 0.1–2.8 k, and <0.1 k, respectively. Fraction III exhibited the strongest free radical scavenging effects, which was evidenced by the electron spin resonance (ESR) of 1,1-diphenyl-2-picrylhydrazyl radicals (DPPH ) and of trapped hydroxyl ( OH) and superoxide ( O 2 - ) radicals. The results indicated that antioxidant activity of whey protein hydrolysates depended on peptide molecular weight, with peptides of 0.1–2.8 k possessing the strongest radical scavenging activity.

Antioxidant activity of peptide fractions of capelin protein hydrolysates

Four peptide fractions were separated from protein hydrolysates of capelin ( Mallotus villosus) using Sephadex G-10 gel filtration column chromatography. Antioxidant activity of each fraction was determined in a β-carotene-linoleate model system. One isolated fraction possessed a notable antioxidant activity, another two had a weak efficacy while the fourth exerted a prooxidant effect. Two-dimensional thin layer chromatography (TLC) of isolated fractions gave spots with both antioxidant and prooxidant activities. Two prooxidant compounds were separated from the hydrolysate by preparative TLC using silica gel plates. One compound exhibited a maximum absorption at 254 nm while the other absorbed at 260 nm.