The amino-acid composition, 2, 2-Diphenyl-1-picryhydrazyl (DPPH) radical-scavenging activity, and peptide patterns of tilapia protein hydrolysates produced by the enzymatic hydrolysis of Alcalase (AH), Flavourzyme (FH) and Protamex (PH) for 5h using pH-stat method were studied. The ratio of essential amino acids to non-essential amino acids increased after hydrolysis in all samples; however, no significant differences among them were observed. AH had a highest (P < 0.05) DPPH radical-scavenging activity, but no significant difference in the DPPH between FH and PH was observed. SDS-PAGE patterns for all the hydrolysates showed significant (P < 0.05) reduction in the number and the intensity of the bands with increasing time of hydrolysis. Flavourzyme showed the lowest rate of hydrolytic activity towards the tilapia mince.
This study was conducted to ascertain the cytotoxicity effect of oil palm (Elaeis guineensis) kernel protein hydrolysates (OPKHs) produced from its protein isolate. A modified microplate titer WST-1 [2-(4-iodophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium] assay was used to investigate the cytotoxicity of hydrolysates produced from protease and pepsin-pancreatin hydrolysis at various concentrations (0.1, 1, 10, 100 μg/ml and 1 mg/ml) using HepG2 cell model. Additionally, peptide stimulation test using OPKHs at 1 mg/ml was carried out to investigate whether OPKHs could serve as growth factor for HepG2 cells other than affecting its viability. As a result, oleic acid appeared to normalize the WST-1 readings of HepG2 cells treated with both hydrolysates at 1 mg/ml. The presence of amino acids in OPKHs could stimulate the growth and prolongs the viability of HepG2 cells. Both OPKHs were non-cytotoxic to HepG2 cells at all tested concentrations even at high concentrations. This study indicated that pepsin-pancreatin and protease hydrolysates produced from oil palm kernel protein were non-cytotoxic on HepG2 cells.
Introduction: Honey has potent bactericidal activity against many pathogenic organisms, including various Gram-negative and Gram-positive bacteria. This study aimed to determine the antimicrobial effect of Malaysian honey against different species of human pathogens using optimized honey broth media. Materials and Methods: The antimicrobial activity of honey against standard strains of Gram-negative and Grampositive bacteria and yeast was tested in vitro by the broth dilution method using 10%-100% w/v concentrations prepared in tryptic soy broth. Results: Streptococcus pyogenes was the most sensitive pathogen, it was completely inhibited by 30% honey broth medium. The most resistant were E. faecalis, S. aureus and MRSA, but they were all completely inhibited by 80% honey broth medium. Conclusion: Honey is shown to possess antimicrobial activity against human Gram-positive and negative medically important bacteria.
This study aimed to determine the physicochemical properties of undulated surf clam (Paphia undulata) hydrolysate as affected by the degree of hydrolysis (DH). Three levels of DH of undulated surf clam hydrolysate were prepared which were DH 36.57% (without any enzymatic hydrolysis), DH 58.25% (0.5% Alcalase®; 5 min; pH 7.5; 60ºC) and DH 91.26% (1% Alcalase®; 30 min; pH 7.5; 60ºC). After protein hydrolysis, the undulated surf clam hydrolysates were centrifuged, and their supernatants were freeze-dried. This study found that the protein hydrolysate with lower DH (DH 36.57%) gave lower protein content and higher ash and fat contents compared to other samples (DH 58.25% and DH 91.26%). However, the carbohydrate content is similar in all samples (16.56-20.04%). This study also found that foaming properties (29.43-67.50%), emulsifying capacity (11.94-110.52%) and peptide solubility (57.61-94.08%) were affected by the DH. As DH increased, the emulsifying capacity decreased, while peptide solubility increased. While the foaming capacity increased with increasing DH until it reached a maximum value and level off afterwards. For colour parameters, although there were differences between L*, a* and b* values for all three samples, a fluctuating pattern was noted with DH. DH also did not affect the water-holding and oil-holding capacity of undulated surf clam hydrolysate. This study shows that certain physicochemical properties of undulated surf clam hydrolysate can be tailored by adjusting the degree of hydrolysis.
The aim of this study was to produce a valuable protein hydrolysate from palm kernel cake (PKC) for the development of natural antioxidants. Extracted PKC protein was hydrolyzed using different proteases (alcalase, chymotrypsin, papain, pepsin, trypsin, flavourzyme, and bromelain). Subsequently, antioxidant activity and degree of hydrolysis (DH) of each hydrolysate were evaluated using DPPH• radical scavenging activity and O-phthaldialdehyde spectrophotometric assay, respectively. The results revealed a strong correlation between DH and radical scavenging activity of the hydrolysates, where among these, protein hydrolysates produced by papain after 38 h hydrolysis exhibited the highest DH (91 ± 0.1%) and DPPH• radical scavenging activity (73.5 ± 0.25%) compared to the other hydrolysates. In addition, fractionation of the most effective (potent) hydrolysate by reverse phase high performance liquid chromatography indicated a direct association between hydrophobicity and radical scavenging activity of the hydrolysates. Isoelectric focusing tests also revealed that protein hydrolysates with basic and neutral isoelectric point (pI) have the highest radical scavenging activity, although few fractions in the acidic range also exhibited good antioxidant potential.
Matched MeSH terms: Protein Hydrolysates/chemistry
The molecular mass distribution, amino acid composition and radical-scavenging activity of collagen hydrolysates prepared from collagen isolated from the sea cucumber Stichopus vastus were investigated. β and α1 chains of the collagen were successfully hydrolysed by trypsin. The molecular mass distribution of the hydrolysates ranged from 5 to 25 kDa, and they were rich in glycine, alanine, glutamate, proline and hydroxyproline residues. The hydrolysates exhibited excellent radical-scavenging activity. These results indicate that collagen hydrolysates from S. vastus can be used as a functional ingredient in food and nutraceutical products.
Matched MeSH terms: Protein Hydrolysates/chemistry*
Actinopyga lecanora, a type of sea cucumber commonly known as stone fish with relatively high protein content, was explored as raw material for bioactive peptides production. Six proteolytic enzymes, namely alcalase, papain, pepsin, trypsin, bromelain and flavourzyme were used to hydrolyze A. lecanora at different times and their respective degrees of hydrolysis (DH) were calculated. Subsequently, antibacterial activity of the A. lecanora hydrolysates, against some common pathogenic Gram positive bacteria (Bacillus subtilis and Staphylococcus aureus) and Gram negative bacteria (Escherichia coli, Pseudomonas aeruginosa, and Pseudomonas sp.) were evaluated. Papain hydrolysis showed the highest DH value (89.44%), followed by alcalase hydrolysis (83.35%). Bromelain hydrolysate after one and seven hours of hydrolysis exhibited the highest antibacterial activities against Pseudomonas sp., P. aeruginosa and E. coli at 51.85%, 30.07% and 30.45%, respectively compared to the other hydrolysates. Protein hydrolysate generated by papain after 8 h hydrolysis showed maximum antibacterial activity against S. aureus at 20.19%. The potent hydrolysates were further fractionated using RP-HPLC and antibacterial activity of the collected fractions from each hydrolysate were evaluated, wherein among them only three fractions from the bromelain hydrolysates exhibited inhibitory activities against Pseudomonas sp., P. aeruginosa and E. coli at 24%, 25.5% and 27.1%, respectively and one fraction of papain hydrolysate showed antibacterial activity of 33.1% against S. aureus. The evaluation of the relationship between DH and antibacterial activities of papain and bromelain hydrolysates revealed a meaningful correlation of four and six order functions.
Matched MeSH terms: Protein Hydrolysates/pharmacology*
The study aims to determine the optimized condition of eel protein hydrolysate (EPH)
produced using alcalase. The proximate compositions of eel flesh were determined as well.
Enzymatic hydrolysis conditions were optimized using response surface methodology (RSM)
by applying four factors, 3-levels Central Composite Design (CCD) with six centre points. The
model equation was proposed with regards to the time (60min, 120min, 180min), temperature
(40°C, 50°C, 60°C), pH (7, 8, 9) and enzyme concentration (1%, 2%, 3%). The optimum of
hydrolysis condition that be suggested to obtain the optimum yield, degree of hydrolysis (DH)
and antioxidant activity were 84.02 min, 50.18°C, pH 7.89 and 2.26% [enzyme]. The predicted
response values using quadratic model were 10.03% for yield, 83.23% for DH and 89.24%
for antioxidant activity. The chemical composition determination showed that the protein
content increased by more than 5-fold (16.88% to 98.53%) while the fat content was decreased
by 96.48% after hydrolysis. Hydrolysis process had significantly increased the amount of
both hydrophilic (serine and threonine) and hydrophobic amino acids (valine, isoleucine,
phenylalanine, methionine) which contributed to the antioxidant activity of hydrolyzed eel
protein. The enzymatic hydrolysis of eel protein had improved the protein content of EPH with
potential as new natural antioxidant.
Fish protein hydrolysate was prepared from tilapia muscle using commercial Alcalase enzyme. Optimization of enzymatic hydrolysis process for preparing tilapia muscle protein hydrolysates (TMPH) was performed by employing central composite design (CCD) method of response surface methodology (RSM). O-phtaldialdehyde (OPA) method was employed to calculate the degree of hydrolysis (DH), which is the key parameter for monitoring the reaction of protein hydrolysis. The suggested model equation was proposed based on the effects of pH, temperature, substrate concentration and enzyme concentration on the DH. Optimum enzymatic hydrolysis conditions using Alcalase enzyme were obtained at pH7.5, temperature of 50oC, substrate concentration of 2.5% and enzyme concentration of 4.0%. Under these conditions, the highest value of the DH was achieved at 25.16% after hydrolysing at 120 min. The TMPH was further assessed for their nutritional value with respect to chemical and amino acid compositions. Molecular weight distributions of TMPH were characterized by SDS-PAGE. TMPH contains moderate amount of protein (28.14%) and good nutritive value with respect to the higher total amino acid composition (267.57 mg/g). Glutamic acid, aspartic acid and lysine were the most abundant amino acids present in TMPH with values 42.68, 29.16 and 26.21 mg/g, respectively. Protein hydrolysates from tilapia muscle containing a desirable peptide with low molecular weight which may potentially to be used as functional food products.
Gelatine obtained from fish skin has become a potential source of preparing nanoparticles and
encapsulation of bioactive compounds. Within these fish skin, gelatine nanoparticles show
potent benefits for application in pharmaceutical and cosmetic industry. The encapsulated
bioactive ingredients within nanoparticles have improved bioavailability, delivery properties,
and solubility of the nutraceuticals within the human body and blood stream. Many of such
bioactive peptides (biopeptides) are potent antioxidants; and as oxidative stress is the main
cause of the onset of various chronic diseases, encapsulation of antioxidant biopeptides within
fish gelatine nanoparticles could be a potential remedy to prevent or delay the onset of such
diseases and for better health prospects. The purpose of the present work was to prepare a
simple, safe, and reproducible novel food delivery nanoparticle system encapsulating a desirable antioxidant biopeptide. An optimisation study was conducted to produce a desirable size
of gelatine nanoparticles which showed a higher encapsulation efficiency of an antioxidant
biopeptide. Sunflower biopeptide was chosen as the antioxidant biopeptide, as the activity of
this protein hydrolysate is quite high at DPPH of 89% and FRAP assay of 968 µm/L. Tilapia
fish was used as gelatine source at an average yield of the process at 10% wt/wt. Effects of
parameters such as pH, biopeptide concentration, and cross-linking agent ‘glutaraldehyde’ on
the size, stability, and encapsulation efficiency on the nanoparticles were studied. The average
diameter of the biopeptide loaded gelatine nanoparticle was between 228.3 and 1,305 nm.
Encapsulation efficiency was 76% at an optimal pH of 2, glutaraldehyde concentration of 2
mL, and biopeptide concentration of 0.1 mg/mL exhibited DPPH at 92% and FRAP assay of
978 µm/L. To understand the absorption of sunflower biopeptide in stomach, blood stream,
and biopeptide release of the gelatine nanoparticles, biopeptide loaded gelatine nanoparticles
were subjected to simulated gastrointestinal conditions mimicking human stomach and
intestine; and showed peptide release of 0.1464 and 0.277 mg/mL upon pepsin and pancreatin
digestion, respectively.
The objective of this study was to determine the possible source of predominant Bacillus licheniformis contamination in a whey protein concentrate (WPC) 80 manufacturing plant. Traditionally, microbial contaminants of WPC were believed to grow on the membrane surfaces of the ultrafiltration plant as this represents the largest surface area in the plant. Changes from hot to cold ultrafiltration have reduced the growth potential for bacteria on the membrane surfaces. Our recent studies of WPCs have shown the predominant microflora B. licheniformis would not grow in the membrane plant because of the low temperature (10 °C) and must be growing elsewhere. Contamination of dairy products is mostly due to bacteria being released from biofilm in the processing plant rather from the farm itself. Three different reconstituted WPC media at 1%, 5%, and 20% were used for biofilm growth and our results showed that B. licheniformis formed the best biofilm at 1% (low solids). Further investigations were done using 3 different media; tryptic soy broth, 1% reconstituted WPC80, and 1% reconstituted WPC80 enriched with lactose and minerals to examine biofilm growth of B. licheniformis on stainless steel. Thirty-three B. licheniformis isolates varied in their ability to form biofilm on stainless steel with stronger biofilm in the presence of minerals. The source of biofilms of thermo-resistant bacteria such as B. licheniformis is believed to be before the ultrafiltration zone represented by the 1% WPC with lactose and minerals where the whey protein concentration is about 0.6%.
Winged bean seed (WBS) is an underutilized tropical crop. The current study evaluates its potential to reduce blood pressure (BP) in spontaneously hypertensive rats and finds that it reduces BP significantly, in a dose-dependent manner. Five peptides with the sequences, RGVFPCLK, TQLDLPTQ, EPALVP, MRSVVT and DMKP, have been characterized in terms of their stability against ACE via in vitro and in silico modelling. All peptides exhibited IC50 values between 0.019 and 6.885 mM and various inhibitory modes, including substrate, prodrug and true inhibitor modes. The toxicity status of non-Current Good Manufacturing Practice (non-CGMP) peptides is evaluated and the results show that such peptides are toxic, and thus are not suitable to be tested in animals, particularly in repeated-dose studies. In short, WBS hydrolysate demonstrated in vitro ACE inhibitory properties and in vivo blood pressure lowering efficacy in rat models, fostering its potential as a functional food ingredient. Non-CGMP grade peptides are toxic and unfit for testing in animal models.
Matched MeSH terms: Protein Hydrolysates/chemistry