Antioxidant Activity of Hydrolysates Prepared from Flaxseed Cake Proteins Using Pancreatin

Abstract

Key words: flaxseed protein hydrolysates, pancreatin, degree of hydrolysis, antioxidant activity 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 EC 50 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.

Influence of the degree of hydrolysis and type of enzyme on antioxidant activity of okara protein hydrolysates

“…Several authors have reported the positive effect of DH on antioxidant activity. For instance, Jamdar et al (2010) and Karamać et al (2014) verified that, as the DH increased, so the ferrous ion chelating activity and DPPH radical scavenging activity of peanut and flaxseed cake proteins hydrolysates increased. According to Elias et al (2008), the antioxidant activity of proteins can be related to their amino acid compositions.…”

Erythrina Edulis (Pajuro) Seed Protein: A New Source of Antioxidant Peptides

“…The release of antioxidant peptides has been demonstrated from animal sources like milk, egg, fish, and meat proteins [9][10][11][12]. Recently, studies have focused on the antioxidant properties of hydrolyzates from plant-derived proteins, including soybean, canola, flaxseed, and amaranth, among others [13][14][15][16]. The activity of those hydrolyzates has been evaluated using several in vitro antioxidant systems such as 2,2'-azinobis(3-ethylbenzothiazoline-6sulfonic acid) (ABTS), diphenyl-1-picryhydradzyl (DPPH) radicals scavenging activity, oxygen radical antioxidant capacity (ORAC), metal chelating, and linoleic acid oxidation inhibition.…”

Rheological properties of flaxseed meal and soybean protein isolate blend by extrusion

“…Traditionally, flaxseed is mainly used in industrial applications for flaxseed oil. Flaxseed meal (FM) is just the by-product of flaxseed after oil solvent extraction from seeds or seeds squeezing [3] . Although as a residue of flaxseed, it still has relatively high protein concentration [4] .…”

“…Although as a residue of flaxseed, it still has relatively high protein concentration [4] . In most cases, FM is mainly applied to a limited extent as animal feed as a cheaper material, particularly for ruminants [3,5] . Therefore, the nutrition of FM, especially the protein component, was not utilized well in a large scale.…”