Production Of Protein Hydrolysates Research Articles

Fish protein hydrolysate production from sardine solid waste by crude pepsin enzymatic hydrolysis in a bioreactor coupled to an ultrafiltration unit

The aims of the study were to optimize the production a fish protein hydrolysate (FPH) by enzymatic hydrolysis of sardine solid waste using crude pepsin, and to scale up the process in a bioreactor coupled to an ultrafiltration unit for product recovery. Results showed that the crude pepsin prepared by autolysis of the mucous membranes of a sheep stomach at optimal conditions (i. e. pH=1.5–2 and incubation time of 6h) could be satisfactory used for the enzymatic hydrolysis of fish solid waste. The optimal conditions for enzymatic reaction were: temperature 48°C, and pH 1.5. The scale up of the enzymatic hydrolysis and the coupling of the reactor an ultrafiltration unit to concentrate the hydrolysate gave good results with a rejection coefficient for the protein hydrolysate product in the range of 90%. The volumetric concentration factor was 2.5, with a permeate flux of 200Lm−2bar−1. However, the results also suggest that the ultrafiltration product concentration process may be operating beyond the critical flux at which point irreversible membrane fouling occurs.

Lima Bean (<i>Phaseolus lunatus</i>) Protein Hydrolysates with ACE-I Inhibitory Activity

Several protein sources can be used to produce bioactive peptides with angiotensin I-converting enzyme (ACE) inhibittory activity. Protein concentrates from ungerminated and germinated lima bean Phaseolus lunatus seed flours were hydrolyzed with Alcalase 2.4 L or pepsin-pancreatin sequential hydrolysis, and ACE inhibitory activity measured in the different hydrolysis treatments. Protein hydrolysate production was analyzed with a 23 factorial design with four replicates of the central treatment. Evaluated factors were protein concentrate source (ungerminated seeds, PC1; germinated seeds, PC2), enzyme/substrate ratio E/S (1/50 or 1/10) and hydrolysis time (0.5 or 2.0 h for Alcalase; 1 or 3 h for pepsin-pancreatin). Degree of hydrolysis (DH) was high for the Alcalase hydrolysates (24.12% 58.94%), but the pepsin-pancreatin hydrolysates exhibited the highest ACE inhibitory activity (IC50 = 0.250 0.692 mg/mL). Under the tested conditions, the hydrolysates with the highest ACE inhibitory activity were produced with sequential pepsin-pancreatin using either PC1 at 1 h hydrolysis time and a 1/10 E/S ratio or PC2 at 1 h hydrolysis time and a 1/50 E/S ratio. Lima bean protein hydrolysates prepared with Alcalase or pepsin-pancreatin are a potential ingredient in the production of physiologically functional foods with antihypertensive activity.

GROWTH INHIBITION AND DIFFERENTIATING EFFECTS OF PROTEIN HYDROLYSATES FROM BOVINE COLOSTRUMS ON HUMAN LEUKEMIC U937 CELLS

ABSTRACT This research investigates the effects of bovine colostrums and their protein hydrolysates on human mononuclear cell (MNC) growth, on the secretion of cytokines (interleukin-1β, interferon-γ and tumor necrosis factor-α) as well as nitric oxide, and on the growth inhibition of human leukemic U937 cells. The results indicate that the colostrum hydrolysates obtained by porcine small-intestinal enzymes (PIS) exhibit more significant inhibitory effect on U937 cell growth than do the caseins (PIC) and the whey (PIW) hydrolysates (PIS 57.45%, PIC 42.58% and PIW 48.47% at 1,000 µg/mL). The greatest growth index of MNC, up to 1.43, was achieved by a treatment of PIS at 300 µg/mL for 3 days. The cytokines (IL-1β, TNF-α and IFN-γ) secretion of MNC by a treatment of PIS for 3 days (at 800 µg/mL) was 4,443.35, 325.04 and 4,649.67 pg/mL, respectively. The results suggest that bovine colostrum protein hydrolysates may be utilized in functional food. PRACTICAL APPLICATIONS Large quantities of protein-rich bovine colostrums are used for feeding calves or discarded as waste because this glutinous, yellowish fluid is also bitter tasting and coagulates easily upon heating. Such waste is a good source for the extraction of bioactive molecules such as proteins, growth factors, antimicrobial compounds and immunological components. The results of this research shed light on the effects of bovine colostrums and their protein hydrolysates on the immunomodulatory activities and the growth inhibition of U937 cells. They may help in the discovery of new applications while reducing the considerable problem caused by waste disposal. The use of food protein hydrolysates is widely accepted in the field of cosmetics and healthcare products. Bovine colostrum protein hydrolysate products can be useful to enhance human health. Our results point to the possibility that colostrums may be processed into an antileukemic drug or may be used as an immunomodulatory activity ingredient in health foods.

Brewer's spent grain: Characterization and standardization procedure for the enzymatic hydrolysis by Bacillus cereus strain

An important way to reuse agroindustrial by-products and to produce added-value products consists of the production of protein hydrolysates. In the current study, we used Brewer's spent grain (BSG), mainly because of its availability and cost, as a substrate for the enzymatic hydrolysis by Bacillus cereus. First, the physicochemical and microbiological characterization of BSG batches from three varieties was carried out. Furthermore, the optimal fermentation upstream processes for enzymatic hydrolysis by B. cereus were defined. Finally, the ability of B. cereus to hydrolyze different fractions of BSG was analyzed and possible synergistic effects of this bacterium along with other proteolytic bacteria were also investigated. Results showed that the naturally associated microflora was predominantly thermophilic aerobic bacteria and the drying process was the better alternative for BSG preservation. Water, lipids, and ash content differed significantly among the three varieties; however, no statistically significant differences were found in the protein content among them. After BSG characterization studies, the following protocol was set to obtain the fermentation substrate (FS): drying at 60°C for 24-48 H; sieving, grinding, and polyphenol extraction with an alcohol-water solution; and finally autoclaving. A synergistic effect was observed when B. cereus was inoculated with Pseudomonas strains in FS.

Poultry By-Products and Enzymatic Hydrolysis: Optimization by Response Surface Methodology Using Alcalase® 2.4L

The objective of this study was to determine the optimum conditions for production of a poultry by-product hydrolysate by Alcalase® 2.4L. Response surface methodology was conducted to ascertain this aim. The effects of enzyme/substrate ratio (Anson unit/g protein), time (minute) and temperature (°C) were determined. The responses included the degree of hydrolysis (%) and nitrogen recovery (%) at pH 8.5. The model showed a good fit, since the R2 = 0.981 for DH and the R2 = 0.968 for nitrogen recovery indicated that 98.1% and 96.8% of the variability within the range of values studied could be explained by the models. Furthermore, lack of fit of the models was not significant (p<0.05). Optimum conditions were an enzyme/substrate ratio of 0.05 Anson unit/g protein, a time of 85.64 minutes and a temperature of 45.52°C. The predicted responses were 26.14% DH and 81.38% nitrogen recovery. Histidine and methionine were the limiting amino acids in the hydrolysate. These results showed that this optimized assay is suitable to screen for protein hydrolysate production from poultry by-products. This work suggests that the protein hydrolysate could be a good protein source in fish diets and a functional additive in the food industry.

Optimization of the production of shrimp waste protein hydrolysate using microbial proteases adopting response surface methodology

Protein hydrolysates were produced from shrimp waste mainly comprising head and shell of Penaeus monodon by enzymatic hydrolysis for 90min using four microbial proteases (Alcalase, Neutrase, Protamex, Flavourzyme) where PR(%) and DH (%) of respective enzymes were compared to select best of the lot. Alcalase, which showed the best result, was used to optimize hydrolysis conditions for shrimp waste hydrolysis by response surface methodology using a central composite design. A model equation was proposed to determine effects of temperature, pH, enzyme/substrate ratio and time on DH where optimum values found to be 59.37°C, 8.25, 1.84% and 84.42min. for maximum degree of hydrolysis 33.13% respectively. The model showed a good fit in experimental data because 92.13% of the variability within the range of values studied could be explained by it. The protein hydrolysate obtained contained high protein content (72.3%) and amino acid (529.93mg/gm) of which essential amino acid and flavour amino acid were was 54.67-55.93% and 39.27-38.32% respectively. Protein efficiency ratio (PER) (2.99) and chemical score (1.05) of hydrolysate was suitable enough to recommend as a functional food additive.

Total solubilisation of the chicken feathers by fermentation with a keratinolytic bacterium, Bacillus pumilus A1, and the production of protein hydrolysate with high antioxidative activity

A feather protein hydrolysate was effectively produced using the keratinolytic bacterium Bacillus pumilus strain A1. In fact, complete feather degradation was achieved in medium containing up to 50g/l of raw feathers. Cultivation of 50g/l of feathers for two days, at 45°C and at initial pH of 10.0, resulted in maximum production of amino acids and peptides (42.4g/l). The feather protein hydrolysate (FPH) presents a very high in vitro digestibility (98%) compared with that of the untreated feathers (2%). Furthermore, the antioxidant activities of FPH were evaluated using in vitro antioxidant assays, such as 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity and reducing power. Interestingly, FPH presents an important antioxidant potential with an IC50 value of 0.3±0.01mg/ml. These results indicate that FPH may be useful as supplementary protein and antioxidants in animal feed formulations.

Enzymatic Hydrolysis of Fish Frames Using Pilot Plant Scale Systems

Papain was used to hydrolyse fish frames under controlled conditions at a batch-pilot plant scale- process, for the production of fish protein hydrolysates (FPH). Mass balance calculations were carried out so that the rate of hydrolysis, rate of protein solubilisation and yields could be estimated. Almost complete hydrolysis could be achieved in 1 hour, at 40oC, with no pH adjustment, at 0.5% (5 g.kg-1) enzyme to substrate ratio (E/S, were S is Kjeldahl protein) using whole fish frames (including heads and flaps). This was achieved both with the addition of water (1/1 to 2/1 frames/water) but more importantly from commercial considerations without the initial addition of water (after mincing of the fish material). The degree of protein solubilisation ranged between 71% - 86% w/w. Four different processes are described, namely: 1) a soluble spray-dried FPH powder 2) a liquid FPH 3) a partly soluble, spray dried FPH powder and 4) a crude, drum-dried protein for animal consumption. The amino acid profile of the FPH was identical to that of the parent substrate (fish frames).

Endogenous Proteases in Pacific Whiting (Merluccius productus) Muscle as A Processing Aid in Functional Fish Protein Hydrolysate Production

A fish protein hydrolysate (FPH) from Pacific whiting (Merluccius productus) muscle was produced by autolysis of a minced homogenate (8% protein) at pH 7.0 and 60°C, where maximum endogenous proteolytic activity was detected. FPH production was controlled by the pH stat method, yielding a 4.43% degree of hydrolysis after 1 h of autolysis. Upon autolytic processing, 28.9 ± 0.7% of the total protein was found in the soluble fraction. FPH was 100% soluble at pH 7.0 and 10.0 and was less soluble at pH 4 (82.5%, P ≤ 0.05). FPH showed better emulsifying properties than sodium caseinate (SCA) at pH 4.0 (P ≤ 0.05), but had a lower foaming capacity (P ≤ 0.05) than bovine albumin (BSA) at all evaluated pHs. FPH foaming capacity was not affected by pH, however, foam stability was equal or better than that of BSA, especially at pH 4.0 (P ≤ 0.05). These results suggest the possibility of producing FPH with similar or better functional properties than those of functional ingredients, such as SCA and BSA. Furthermore, the data presented support our hypothesis that the high proteolytic activity in Pacific whiting could be used as an advantage in fish protein hydrolysate production or as a processing aid where protein hydrolysis is required.

CATIONIC TRYPSIN: A PREDOMINANT PROTEINASE IN PACIFIC SAURY (COLOLABIS SAIRA) PYLORIC CECA

ABSTRACT Cationic trypsin was purified from Pacific saury (Cololabis saira) pyloric ceca by the successive steps of ammonium sulfate precipitation, anion exchange chromatography and gel filtration chromatography. The purification and yield were 90-fold and 8.9%, respectively. The molecular weight was determined to be 24 kDa using Sephacryl S-200 and SDS-PAGE. Cationic trypsin was stable at pH 7–11 for 30 min at 30C, and its maximal activity against L-arginine methyl ester hydrochloride (TAME) was at pH 8.5. Thermostability for cationic trypsin was up to 50C for 15 min and its temperature optimum was 60C. Cationic trypsin was stabilized by calcium ion. Activity decreased as NaCl concentration (0–30%) increased. Inhibitor susceptibility analysis revealed that the enzyme was inhibited effectively by soybean trypsin inhibitor and N-p-tosyl-L-lysine chloromethyl ketone. The Km and Kcat of the enzyme were 0.17 mM and 200 s−1, respectively. The N-terminal amino acid sequence of cationic trypsin was partially determined as IVGGYECQPH- and was very homologous to other trypsins. PRACTICAL APPLICATIONS Trypsin is a major member of the serine proteases, which constitute a large family of biologically important enzymes. Trypsins from various sources catalyze the hydrolysis of peptide bonds on the carboxyl sides of arginine and lysine. Hence, it is expected that like other trypsins, Pacific saury trypsin would also be used for processing aids in industry applications. Most trypsins are used for a variety of products in the food industry including baked foods, beer, wine, cereal, meat and fish products, and for production of protein hydrolysates and flavor extract. Trypsins are also used in mammalian cell culture to disaggregate adherent cells for research and the production of recombinant proteins, in diabetes diagnosis and therapy, in detergents and bating of leather.

Enzymatic production of bioactive protein hydrolysates from tuna liver: effects of enzymes and molecular weight on bioactivity

SummaryTuna liver is fish by‐product, which is normally discarded and/or used as fish meal and animal feed because of poor functionality. In this study, we attempt to recover functional peptides from tuna liver protein by enzymatic hydrolysis using various proteases, and further hydrolysates were fractionated into four categories base on their molecular weight (MW) by ultrafiltration membranes. All fractionated hydrolysates produced by Alcalase, Neutrase and Protamex following Flavourzyme hydrolysis showed excellent antioxidant activities against DPPH, hydrogen peroxide and hydroxyl radical scavenging, and reducing power. Their bioactivity was dependent on treated enzymes, and antioxidant activities of fractions dependent on employing bioassay. Moreover, they confirmed antioxidant ability toward the protection effects on hydroxyl radical‐induced DNA damage by the measuring the conversion of supercoiled pBR322 plasmid DNA to the open circular form. In addition, all fractionated hydrolysates inhibited acetylcholinesterase activity, which is involved in Alzheimer’s diseases, and high MW fractions showed high AChE inhibition activity than those of low MW fractions.

Characterisation of leucyl aminopeptidase from Solanum tuberosum tuber

Potato juice (a waste product from the starch industry) is a potential source of novel enzymes for food applications. For use in the production and improvement of food protein hydrolysates, commercially available exopeptidases, predominantly aminopeptidases, are recommended. The present study was performed to explore possible biotechnological interest of leucyl aminopeptidase (LAP) activity in the potato tuber. The LAP from potato tuber was purified and characterised. Specific LAP activity was increased 200-fold by purification of the crude extract. The purified enzyme had a pH optimum of 9.0 and temperature optimum of 45 °C. LAP hydrolysed leucine-, alanine- and lysine- p-nitroanilide to a similar degree. The most efficient inhibitor was 1,10-phenanthroline. Almost all divalent cations tested inhibited the enzyme activity, while Co 2+ stimulated LAP activity by over 100%. The purified LAP had a molecular weight of 90 kDa with an isoelectric point of 5.45. Sodium dodecylsulfate–polyacrylamide gel electrophoresis revealed one band of 48 kDa.

Milk clotting and proteolytic activity of an enzyme preparation from Bromelia hieronymi fruits

A new enzyme preparation (hieronymain), obtained from unripe fruits of Bromelia hieronymi Mez (Bromeliaceae), was assayed for its ability to clot milk and hydrolyze bovine casein and milk whey proteins. Caseinolytic activity at 30 °C and pH 6.5 (milk clotting conditions) was 3.3 Ucas/mL and milk clotting activity was 40 ± 0.2 IMCU/mL. The κ-casein fraction, involved in the clotting formation, began to be degraded after 10 min of reaction, while the degradation of the other casein fractions proceeded slowly enough as to guarantee the production of a firm curd, with no evidence of extensive hydrolysis, a necessary condition for cheese making. In the case of whey proteins, bovine serum albumin and α-lactalbumin were quickly degraded after 30 min, while β-lactoglobulin was considerably degraded only after 60 min at 50 °C. Miniature cheeses were manufactured both with chymosine and hieronymain and analyzed by a taste panel, who found acceptable both cheeses. Hieronymain might be appropriate for cheese making, as well as for the production of milk protein hydrolysates.

In situ immobilization of acid protease on mesoporous activated carbon packed column for the production of protein hydrolysates

The mesoporous activated carbon (MAC) was used as a support material for in situ immobilization of acid protease (AP). The optimum temperature for the activities of both free and immobilized AP was found to be 50 °C. The catalytic efficiency of AP–MAC system has significantly been maintained for more than ten consecutive reaction cycles. The functional groups and surface morphology of the AP, MAC and AP–MAC were observed by Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). The production of protein hydrolysates was carried out from bovine serum albumin (BSA) using AP–MAC packed column and its properties were studied.

The effect of enzyme systems and processing on the hydrolysis of peanut (Arachis hypogaea L.) protein

Abstract In vitro protein digestion studies were carried out on raw and roasted peanut flour as the starting material in the production of peanut protein hydrolysate. Peanut flour was hydrolyzed with alcalase and alternately in a sequential digestion with pepsin-pancreatin, both for up to 24 h. The degree of hydrolysis (DH) at different times of hydrolysis was determined using the trinitrobenzenesulfonic acid (TNBS) method. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) was used to indicate destruction of native protein units in the enzymatic digests. Hydrolysis with alcalase was very rapid for the first 6 h after which a plateau was reached, whereas that with pepsin–pancreatin was more gradual reaching a plateau after 12 h of hydrolysis. Raw peanut hydrolyzed with alcalase and pepsin–pancreatin had 23% and 21% DH after 24 h respectively, whilst roasted peanut hydrolyzed with alcalase had 21% DH, with the pepsin–pancreatin hydrolysate recording the highest value of 25% after 24 h of hydrolysis. SDS-PAGE results showed that raw peanut samples behaved differently from the roasted samples; increasing hydrolysis time reduced larger peanut protein subunits, with only peptides of

Functional properties of hydrolysates from Phaseolus lunatus seeds

SummaryUse of low degree of hydrolysis (DH < 10%) with enzymatic treatment can produce protein hydrolysates with functional properties superior to the raw material. Suspensions of Phaseolus lunatus protein isolate (PPI) were treated with one of two commercial enzymes (Alcalase or Flavourzyme) at 50 °C and pH 8.0. DH with Alcalase was greater than Flavourzyme at 5 or 15 min of reaction. Alcalase‐prepared hydrolysates had more peptides than those prepared with Flavourzyme. All the hydrolysates had higher solubility than the PPI, the highest being for the Alcalase‐prepared hydrolysate at 15 min reaction time. Overall, the Alcalase‐prepared hydrolysates had better solubility characteristics, whereas the Flavourzyme‐prepared hydrolysates had better film properties (maximum emulsifying capacity and the highest foam formation values). This is probably because of the greater ease of movement toward the interface as shown by their high surface hydrophobicity values. The Alcalase‐prepared hydrolysates had generally low or nonexistent film properties.

Utilisation of Chlorellavulgaris cell biomass for the production of enzymatic protein hydrolysates

Studies on enzymatic hydrolysis of cell proteins in green microalgae Chlorellavulgaris 87/1 are described. Different proteases can be used for production of hydrolysates from ethanol extracted algae. The influence of reaction parameters on hydrolysis of extracted biomass with pancreatin was considered, and the composition of hydrolysates (Cv-PH) was investigated in relation to the starting materials. Significant changes in the degree of hydrolysis were observed only during the first 2h and it remained constant throughout the process. An enzyme-substrate ratio of 30–45units/g algae, an algae concentration of 10–15% and pH values of 7.5–8.0 could be recommended. Differences in the chromatographic patterns of Cv-PH and a hot-extract from Chlorella biomass were observed. Adequate amounts of essential amino acids (44.7%) in relation to the reference pattern of FAO for human nutrition were found, except for sulfur amino acids. Cv-PH could be considered as a potential ingredient in the food industry.

PURIFICATION AND CHARACTERIZATION OF TRYPSIN FROM THE PYLORIC CECA OF THE NEW ZEALAND HOKI FISH (MACRURONUS NOVAEZEALANDIAE)

Trypsin was purified from the pyloric ceca of hoki fish by (NH4)2SO4 fractionation, acetone precipitation and affinity chromatography. The purified trypsin migrated as a single band in sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and the isoelectric point was determined as 6.5. The molecular weight was determined as 26,000 Da by SDS-PAGE and as 23,791 Da by matrix-assisted laser desorption/ionization time-of-flight mass spectroscopy. The enzyme was stable within the pH range of 6.0–11.0, and exhibited optimum activity for the hydrolysis of N-α-benzoyl-dl-arginine-p-nitroanilide (dl-BAPNA) at pH 9.0. The enzyme was stable up to 40C, and its optimum temperature fordl-BAPNA hydrolysis was 60C, and was inhibited by soybean trypsin inhibitor, aprotinin, phenyl methyl sulfonyl fluoride and benzamidine. The apparent Michaelis–Menten constant (Km′) and substrate turnover number (kcat) for thedl-BAPNA hydrolase reaction was 0.06 mM and 0.33 s−1, respectively, while the corresponding values for tosyl arginine methyl ester hydrolysis were 2.08 mM and 19.0 s−1, respectively. The N-terminal 20 amino acid residues of hoki trypsin, IVGGQECVPNSQPFMASLNY, displayed considerable homology with other fish trypsins. PRACTICAL APPLICATIONS Trypsins from various sources catalyze the hydrolysis of peptide bonds on the carboxyl sides of arginine and lysine. Thus, it is expected that like other trypsins, hoki trypsin would also be useful in biomedical, food and beverage industry applications. Examples of the practical applications of trypsins include their use in mammalian cell culture to disaggregate adherent cells for research and the production of recombinant proteins; in cancer therapy to break down tumors and cancer cells; and in wound care, for treatment of acne and other skin disorders. Other uses are as a digestive aid, for treating pain, inflammations, arthritis, tendonitis, ulcers, hemorrhoids and navel infections in newborns. Trypsins are also used in diabetes diagnosis and therapy; in detergents and bating of leather; and in the food industry for the production of protein hydrolysates, as meat tenderizer and as an aid to improve yields in oil extractions.

Production of protein hydrolysates in an enzymatic membrane reactor

The hydrolysis of casein in the presence of proteolytic enzymes: thermolysin and subtilisin, is discussed. For both biocatalysts an appropriate process temperature was chosen and the kind and values of constants in the kinetic equation were determined. Thermolysin was selected for further studies as the more appropriate catalyst because of a strong inhibition of subtilisin. A model of the process was proposed for enzymatic reaction which takes place in a membrane bioreactor with a complete retention of the enzyme and a partial retention of the substrate in the reaction zone. Having selected a proper membrane, the model was successfully verified using the data from the considered casein hydrolysis. It was proved that at a relatively high substrate retention (i.e. ca. 50%), the substrate conversion degree could increase by ca. 50%. Owing to a high cost of biocatalysts such process intensification is significant. It is all the more promising, as separation of the enzyme on a membrane allows us to use the biocatalyst many times without applying any surface immobilisation techniques.

Physicochemical and bitterness properties of enzymatic pea protein hydrolysates.

The effects of different proteolytic treatments on the physiochemical and bitterness properties of pea protein hydrolysates were investigated. A commercial pea protein isolate was digested using each of 5 different proteases to produce protein hydrolysates with varying properties. After 4 h of enzyme digestion, samples were clarified by centrifugation followed by desalting of the supernatant with a 1000 Da membrane; the retentates were then freeze-dried. Alcalase and Flavourzymetrade mark produced protein hydrolysates with significantly higher (P < 0.05) degree of hydrolysis when compared to the other proteases. Flavourzyme, papain, and alcalase produced hydrolysates that contained the highest levels of aromatic amino acids, while trypsin hydrolysate had the highest levels of lysine and arginine. Papain hydrolysate contained high molecular weight peptides (10 to 178 kDa) while hydrolysates from the other 4 proteases contained predominantly low molecular weight peptides (</= 23 kDa). DPPH (1,1-diphenyl-2-picrylhydrazyl) free radical scavenging activity of the Flavourzyme hydrolysate was significantly (P < 0.05) the highest while alcalase and trypsin hydrolysates were the lowest. Inhibition of angiotensin converting enzyme (ACE) activity was significantly higher (P < 0.05) for papain hydrolysate while Flavourzyme hydrolysate had the least inhibitory activity. Sensory analysis showed that the alcalase hydrolysate was the most bitter while papain and alpha-chymotrypsin hydrolysates were the least. Among the 5 enzymes used in this study, papain and alpha-chymotrypsin appear to be the most desirable for producing high quality pea protein hydrolysates because of the low bitterness scores combined with a high level of angiotensin converting enzyme inhibition and moderate free radical scavenging activity.