Combined Neutrase–Alcalase Protein Hydrolysates from Hazelnut Meal, a Potential Functional Food Ingredient

Abstract

Consumers' interest in functional foods has significantly increased in the past few years. Hazelnut meal, the main valuable byproduct of the hazelnut oil industry, is a rich source of proteins and bioactive peptides and thus has great potential to become a valuable functional ingredient. In this study, hazelnut protein hydrolysates obtained by a single or combined hydrolysis by Alcalase and Neutrase were mainly characterized for their physicochemical properties (SDS-PAGE, particle size distribution, Fourier-transform infrared (FTIR) spectroscopy, molecular weight distribution, etc.) and potential antiobesity effect (Free fatty acid (FFA) release inhibition), antioxidant activity (DPPH and ABTS methods), and emulsifying properties. The impact of a microfluidization pretreatment was also investigated. The combination of Alcalase with Neutrase permitted the highest degree of hydrolysis (DH; 15.57 ± 0.0%) of hazelnut protein isolate, which resulted in hydrolysates with the highest amount of low-molecularweight peptides, as indicated by size exclusion chromatography (SEC) and SDS-PAGE. There was a positive correlation between the DH and the inhibition of FFA release by pancreatic lipase (PL), with a significant positive effect of microfluidization when followed by Alcalase hydrolysis. Microfluidization enhanced the emulsifying activity index (EAI) of protein isolates and hydrolysates. Low hydrolysis by Neutrase had the best effect on the EAI (84.32 ± 1.43 (NH) and 88.04 ± 2.22 m 2 /g (MFNH)), while a negative correlation between the emulsifying stability index (ESI) and the DH was observed. Again, the combined Alcalase−Neutrase hydrolysates displayed the highest radical scavenging activities (96.63 ± 1.06% DPPH and 98.31 ± 0.46% ABTS). FTIR results showed that the application of microfluidization caused the unfolding of the protein structure. The individual or combined application of the Alcalase and Neutrase enzymes caused a switch from the β-sheet organization of the proteins to α-helix structures. In conclusion, hazelnut meal may be a good source of bioactive and functional peptides. The control of its enzymatic hydrolysis, together with an appropriate pretreatment such as microfluidization, may be crucial to achieve the best suitable activity.

Conformation-Activity Mechanism of Alcalase Hydrolysis for Reducing In Vitro Allergenicity of Instant Soy Milk Powder

“…The conformational structures of ISMP and alcalase-hydrolyzed ISMPH were characterized by spectroscopy techniques in Figure . FTIR spectroscopy is one of the widely applied and well-established methods for the structural characterization of proteins and peptides. , As shown in Figure A, ISMP and ISMPH had similar functional groups with absorption peaks of O–H and N–H (3409.01 and 3392.2 cm –1 ), −CH 2 – (2927.23 and 2927.12 cm –1 ), amide I band/CO (1655.22 and 1659.11 cm –1 ), −COOH (1402.86 and 1403.27 cm –1 ), amide III/C–O (1241.95 and 1244.25 cm –1 ), and C–O/C–C–C/C–N (1033.99 and 1034.95 cm –1 ), respectively . And it was observed that ISMP had an absorption peak of the amide II band at 1546.14 cm –1 , which was higher than that of ISMPH ( P < 0.05).…”

Impact of Time and Enzyme Concentration on Sangyod Rice Bran Hydrolysate: Phytochemicals, Antioxidants, Amino Acids, and Cytotoxicity

“…Likewise, the study conducted by Fathi et al ( 2021 ) indicates that prolonging the incubation time allows for a more extensive action of alcalase on the protein, resulting in heightened extraction efficiency and increased cleavage of peptide bonds (Gong et al 2021 ). Consequently, these factors significantly enhance extraction efficiency (Ceylan et al 2023 ). Furthermore, the relationship between the degree of hydrolysate and protein extraction efficiency is evident.…”

Employing fruit juices to hydrolyze edible bird's nest and enhance the antioxidant, anti-tyrosinase, and wound-healing activities of the hydrolysates

“…As proteolytic enzymes can differ in cleavage sites, the combination of proteolytic enzymes can sometimes be applied to generate protein hydrolysates with more diverse peptides and ultimately more attractive properties than individual enzymes. For instance, hazelnut protein isolate treated with both Alcalase and Neutrase displayed a higher antioxidant capacity than that treated with individual Alcalase and Neutrase [ 16 ]. The utility of two enzymes (pepsin-papain, papain-trypsin and papain-pancreatin) has been reported for EBN hydrolysis.…”