Production of ACE Inhibitory Peptides from Whey Proteins Modified by High Intensity Ultrasound Using Bromelain

Abstract

High Intensity Ultrasound (HIUS) can induce modification of the protein structure. The combination of enzymatic hydrolysis and ultrasound is an interesting strategy to improve the release of the Angiotensin-Converting Enzyme (ACE) inhibitory peptides. In this study, whey proteins were pretreated with HIUS at two levels of amplitude (30 and 50%) for 10 min, followed by hydrolysis using the vegetable protease bromelain. The hydrolysates obtained were ultrafiltrated and their fractions were submitted to a simulated gastrointestinal digestion. The conformational changes induced by HIUS on whey proteins were analyzed using Fourier-transform infrared spectroscopy by attenuated total reflectance (FTIR-ATR) and intrinsic spectroscopy. It was found that both levels of ultrasound pretreatment significantly decreased the IC50 value (50% Inhibitory Concentration) of the hydrolysates in comparison with the control (α = 0.05). After this treatment, HIUS-treated fractions were shown as smaller in size and fractions between 1 and 3 kDa displayed the highest ACE inhibition activity. HIUS promoted significant changes in whey protein structure, inducing, unfolding, and aggregation, decreasing the content of α-helix, and increasing β-sheets structures. These findings prove that ultrasound treatment before enzymatic hydrolysis is an innovative and useful strategy that modifies the peptide profile of whey protein hydrolysates and enhances the production of ACE inhibitory peptides.

Characterization of a Novel Aspartic Protease from Rhizomucor miehei Expressed in Aspergillus niger and Its Application in Production of ACE-Inhibitory Peptides

“…Recently, studies have discovered antioxidant peptides from duck blood [ 51 , 52 ]. Food-derived ACE-inhibitory peptides are promising components for the prevention and treatment of hypertension [ 53 ]. Turtle meat was hydrolyzed by RmproA to prepare ACE-inhibitory peptides with ACE-inhibitory activity of 88% at concentration of 1 mg/mL [ 24 ].…”

Extraction of Bioactive Peptides from Whey Proteins by Conventional and Novel Technologies

“…The novel/ conventional technologies UAE-EH Change of peptide profile [48] Shortening of hydrolysis time [48,49] Low molecular weight peptide extraction [48,49] Increase in bioactivity [48] Reducing the amount of enzymes required [48] Increasing substrate sensitivity [39,41] HHP-EH Increased number of bioactive peptides [50] Enhancement of physiological properties [51] Enzyme to improve substrate accessibility [41] After HPP pretreatment, protein/peptide interaction may occur again [3] MAE-EH Obtaining low molecular weight peptides [41] Enables rapid and efficient hydrolysis [2,52] OH-EH Enhancing bioactive properties [48] Table 1.…”

Conventional and Novel Technologies in the Production of Dairy Bioactive Peptides

“…As presented in Table 3 , recently UAP has been employed as pretreatment for various milk proteins hydrolysis, including whey proteins ( 98 ), caprine milk protein ( 99 ), fresh milk ( 100 ), cheddar cheese ( 101 ), whey protein isolate ( 102 ), whey protein ( 103 ), and milk protein concentrate ( 104 , 105 ). UAP in combination with enzymatic hydrolysis has been employed for various proteins, i.e., eggshell membrane ( 106 ), egg white ( 107 ), and isolated oat protein ( 108 ).…”