Investigating the Effect of Protease Enzyme Type and Hydrolysis Time on the Antioxidant Properties of Flaxseed Meal (Linum usitatissimum) Protein Hydrolysates (original) (raw)
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Antioxidant Activity of Hydrolysates Prepared from Flaxseed Cake Proteins Using Pancreatin
Polish Journal of Food and Nutrition Sciences, 2014
Proteins were isolated from defatted flaxseed cake and hydrolysed with pancreatin. The hydrolysis process was conducted at a stable temperature of 50°C and pH 7.5, and monitored with the pH-stat method. The obtained hydrolysates with a degree of hydrolysis (DH) of 5, 10, 15, 20, 25% were investigated in terms of antioxidant properties. The radical scavenging activity was assayed against DPPH• and ABTS•+, the reducing ability – with FRAP assay, and the capability to bind Fe(II) – by reaction with ferrozine. SE-HPLC analysis was used to determine molecular weight distribution of hydrolysis products. The antiradical activity of pancreatin hydrolysates of flaxseed proteins was increasing along with an increasing DH and for the hydrolysate with DH 25% the EC50 value determined with the DPPH assay accounted for 0.083 mg/assay, and the ABTS•+ scavenging activity – for 0.218 mmol Trolox/g. This hydrolysate was constituted mainly by peptides with low molecular weights (MW) of 0.238-0.556 kDa. In turn, the Fe(II) binding capability increased from 44.5% to 64.9% in the case of hydrolysates with DH 5-20% and decreased in the case of the hydrolysate with DH 25%. A similar dependency was observed in the ability of pancreatin hydrolysates of flaxseed proteins to reduce Fe(III). The maximum value of reducing ability reached 0.25 mmol Fe(II)/g for the hydrolysate with DH 20% that was predominated by polypeptides and peptides with MW of 0.238-1.046 Da.
Journal of Agricultural and Food Chemistry, 2017
The impact of the naturally-present phenolic compounds and/or proteins on the antioxidant capacity of flaxseed products-phenolic fraction, protein concentrates and hydrolysates-before and after simulated gastrointestinal digestion was studied. For that, whole and phenolic reduced products were assessed. Four glycosylated phenolic compoundssecoisolariciresinol and ferulic, p-coumaric and caffeic acids-were identified in flaxseed products. Phenolic fraction exerts the highest antioxidant capacity that increased by alkaline hydrolysis and by simulated gastrointestinal digestion. The action of Alcalase ® and digestive enzymes resulted in an increase of the antioxidant capacity of whole and phenolic reduced products. Principal component analysis showed that proteinaceous samples act as antioxidant is by H+ transfer, while those samples containing phenolic compounds exert their effects by both electron donation and H+ transfer mechanisms. Protein/peptide-phenolic complexation, confirmed by fluorescence spectra, exerted a positive effect on the antioxidant capacity, mainly in protein concentrates.
Antioxidants
Flaxseed proteins exhibit functionalities interesting for the food industry, including antioxidant capacity. Antioxidant activity depends on the protein composition and the presence of phenolic compounds extracted with them from the matrix. The research focused on the effect of subsequent protein extractions (water, salt and alkaline) of flaxseed meals (of three cultivars) on the protein fraction composition and its relations to antioxidant capacity. The protein and phenolic profiles and antioxidant functionalities (in antiradical ORAC and emulsion assays) were analysed. Spectroscopic characteristics of the fractions (fluorometric and FT-IR analysis) were also included. Our study has shown the effect of fractionation on the share of proteins at MW from 56–38 kDa (globulin-like) and <15 kDa (albumin-like) in the protein profiles. The highest globulin share was in the alkaline-extracted fractions (AEF) and albumin in the salt-extracted (SEF) ones. SDG (secoisolariciresinol diglucos...
Antioxidant activity of flaxseed meal components
Canadian Journal of Plant Science, 2014
Barthet, V. J., Klensporf-Pawlik, D. and Przybylski, R. 2014. Antioxidant activity of flaxseed meal components. Can. J. Plant Sci. 94: 593–602. The meals of borage, hemp, Solin, golden, and brown flaxseed, including the meals of dehulled flaxseed and their corresponding hulls, were reconstituted with 40% of standard flaxseed oil and stored for 2 wk to assess if these meals had any antioxidant activity to protect in situ oil from oxidation. Weekly measured peroxide and aldehyde values showed that Solin, golden and brown flaxseed meals had more effective antioxidant activity than hemp and borage meals. Flaxseed hull showed very weak antioxidant potential, whereas dehulled meals maintained their antioxidant activity. This suggested that secoisolariciresinol diglucoside was not acting as the primary antioxidant of flaxseed meal. The seed antioxidant activity was greatly affected by water extraction, suggesting that the system contains water-soluble components. When flaxseed oil was reco...
Antioxidant Activity of Oat Bran Hydrolyzed Proteins in Vitro and in Vivo
Oats contain molecules with well-known health benefits. Its fibers are used in different preparations to improve gastro-intestinal health and to reduce blood cholesterol. Avenanthramides, a group of phenolic antioxidants only present in oats have been demonstrated to be bioavailable in animals and humans. In recent years, proteins from foods have been viewed as not just sources of essential amino acids but also as sources of biologically active peptides (e.g. antioxidant, antihypertensive, antitumor). Antioxidant activities have been reported for hydrolyzed proteins from wheat, rice and corn byproducts but not for those from oats. The objective of this thesis was to investigate the antioxidant properties of hydrolyzed oat proteins in three different conditions (in vitro and in vivo). The first part of this thesis focusses on the activity of proteins extracted in the presence of salt and digested with trypsin (TPH) and alcalase (APH). The digests TPH and APH were ultra-filtered using 2kDa, and 10kDa molecular cutoff membranes. The radical scavenging properties were determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and oxygen radical absorbance assay (ORAC). It was found that APH 2kDa was the strongest inhibitor (35%) of DPPH radicals and also TPH had a better peroxyl radical scavenging activity (ORAC) 434 ±16 µmol trolox equivalents (TE)/g) compared to APH (269±4 µmol TE/g) and TPH>2kDa (345±15 µmol TE/g). In the metal chelating assay, trypsin digest (TPH) better chelated Fe 2+ ions compared to APH and other fractions. The inhibition of linoleic acid autoxidation, showed that both trypsin and alcalase digests equally lowered the formation of lipid peroxides after five days of incubation. It appeared that trypsin hydrolysate and its ≤2kDa fraction possessed the strongest activities and may have application in food products.
Food & Function, 2013
During this study, the effect of germination in combination with in vitro pepsin and pancreatin digestion of protein flours extracted from black soybean on the production of bioactive peptides was investigated. Black soybean (Glycine max L.) were germinated for 3 days (at 24, 48 and 72 h, respectively germination periods) and harvested. Protein hydrolysates from germinated black soybean were prepared from protein isolate by in vitro digestion using pepsin and pancreatin and then evaluated for antioxidant activity. Soy protein hydrolysate from 48 h of germination exhibited the highest scavenging activity against 2, 2-Diphenyl-1-Picrylhydrazyl (DPPH) free radicals (76.56 % at 2.5 mg/mL) followed by 24 and 72 h (66.62 and 60.55% at 2.5 mg/mL, respectively). Protein hydrolysate from germinated black soybean also exhibited noticeable scavenging activity for hydroxyl. Soy protein hydrolysate from 48 h of germination (97.475% at 2 mg/mL) significantly was the most effective in neutralizing •OH (p<0.05) than that from 24 and 72 h (88.56 and 92.5%, respectively at 2 mg/mL), compared to the nongerminated which was 34.42% also at the same concentration. In addition, soyprotein hydrolysate from 24 h of germination significantly showed the highest reducing power (0.32 at 2.0 mg/mL) compared to that from 48 and 72 h germination period (0.25 and 0.23 at 2.0 mg/mL, respectively). Molecular Weights distribution of protein hydrolysates from germinated black soybean was believed to have correlation with their antioxidant activities. Results showed that germination with in vitro digestion (pepsin and pancreatin) of protein hydrolysate from germinated black soybean was successful in production of natural antioxidant compounds which established obvious antioxidant potency than non-germinated. As conclusion, soy protein hydrolysate from 48 h of germination had the best antioxidant potency and could be used as natural antioxidant in food systems.
Antioxidant Potentials of Flaxseed by in Vivo Model
Journal of Agricultural and Food Chemistry, 2006
The present study reports the antioxidant activity of flaxseed as measured by feeding weanling albino rats with 5.0% and 10.0% of flaxseed (constituting approximately 0.75 and 1.5 g kg-1) for 14 days followed by challenging animals with 2.0 g kg-1 b.w. CCl 4 as toxin. Activity was assessed by measuring hepatic marker enzymes like catalase, superoxide dismutase (SOD), and peroxidase and comparing with those from the normal group and from a group receiving toxin without flaxseed. Treatment of CCl 4 at dose of 2.0 g kg-1 b.w. decreased the activities of various antioxidant enzymes such as catalase, superoxide dismutase (SOD), and peroxidase by 35.6%, 47.76%, and 53.0%, respectively, compared to the control group, and the lipid peroxidation value increased nearly 1.2-fold compared to that of the group treated with toxin without flaxseed. Pretreatment of rats with 5.0% flaxseed followed by CCl 4 treatment caused restoration of catalase, SOD, and peroxidase by 39.7%, 181.42%, and 123.7%, respectively, as compared to control. The group treated with 10.0% flaxseed has shown the restoration of 95.02%, 182.31%, and 136.0% of catalase, SOD, and peroxidase. In the case of the group treated with toxin without flaxseed, the level of superoxide dismutase and the catalse value decreased 91.4% and 55.33%, respectively, in comparison with the control group. These results clearly indicate the beneficial effect of flaxseed components as an antioxidant as seen by restoration of hepatic enzymes, which were varied from normal to one due to toxicity induced by toxin (CCl 4). Owing to this property, the flaxseed known for its functional properties can be further extended to exploit its possible application for various health benefits as nutraceuticals and food ingredient.
Journal of The American Oil Chemists Society, 2008
A study was conducted to determine bioactivities of flaxseed (Linum usitatissimum L.; variety: Valour) proteins and their hydrolysates. Isolated flaxseed proteins were treated with Flavourzyme® at different levels of enzyme to substrate ratio (E/S) and hydrolysis time. The unhydrolysed proteins and hydrolysates were studied for angiotensin I-converting enzyme inhibiting (ACEI) activity, hydroxyl radical (OH·) scavenging activity and bile acid binding ability. Flavourzyme catalysed hydrolysis generated hydrolysates with a 11.94–70.62% degree of hydrolysis (DH). The hydrolysates (0.67 mg/ml) had strong ACEI activity (71.59–88.29%). The maximum ACEI activity containing hydrolysate exhibited an IC50 of 0.07 mg/ml (E/S: 1.5; Time: 12 h; DH: 11.94%). The OH· scavenging activity of the hydrolysates (0.5 mg/ml) was 12.48–22.08% with an IC50 of 1.56 mg/ml in the sample possessing maximum activity (E/S: 47.5; Time 0.7 h; DH: 24.63%). Both these activities were greater in hydrolysates with lower DH and higher peptide chain length (PCL) than those with higher DH and lower PCL. Hydrolysed flaxseed proteins (0.67 mg/ml) had no bile acid binding ability. The unhydrolysed proteins had no ACEI or OH· scavenging activity but demonstrated bile acid binding ability.
Flaxseed proteins: food uses and health benefits
… Journal of Food …, 2011
Flaxseed proteins are potent multi-functional ingredients for food formulation owing to their technofunctionalities, food preservation capacity, and health benefits. A possible synergistic effect with mucilage on their functionalities could be valuable even though this co-product in flaxseed may limit the protein yield during their production processes. Their techno-functional properties could also be considered in mixture with other flax bioactive components such as lignans and fibre to enhance the value of the flaxseed meal. The present paper reviews flaxseed protein uses in food and their health benefits. New perspectives according to consumers' demand for products with health promoting bioactive components are also suggested.