The mechanism of pulsed electric field (PEF) targeting location on the spatial conformation of pine nut peptide

Production of bioactive peptides by high-voltage pulsed electric field: Protein extraction, mechanism, research status and collaborative application

Bioactive peptides exhibit a variety of potential applications in the fields of medicine, food and cosmetics. However, studies have shown that the traditional preparation is characterized by low efficiency, substantial pollution, limited activities and poor purity, which constrains their further application. High-voltage pulsed electric field (HPEF) technology, as a physical non-thermal processing method, shows unique advantages in bioactive peptide preparation. Through comprehensive analysis, this paper reveals the main principle of HPEF technology, the extraction of proteins (break up cellular tissue), the structural changes of proteins, enzymes and bioactive peptides after treatment, the improvement of bioactive peptides' functional properties and the potential in promoting bioactive peptides' large-scale production. Besides, this paper introduces the application of other non-thermal processing technologies, artificial intelligence and nanotechnology, providing new ways of thinking for the efficient preparation and application of bioactive peptides and establishes a theoretical foundation for the application and promotion of HPEF technology.

Bioactive peptides with potential anticancer properties from various food protein sources: status of recent research, production technologies, and developments

Recently, bioactive peptides, from natural resources, have attracted remarkable attention as nutraceutical treasures and the health benefits of their consumption have extensively been studied. Therapies based on bioactive peptides have been recognized as an innovative and promising alternative method for dangerous diseases such as cancer. Indeed, there has been enormous interest in nutraceuticals and bioactive-based chemopreventive molecules as a potential opportunity to manage chronic diseases, including cancer at different stages, rather than the traditionally used therapies. The relative safety and efficacy of these peptides in targeting only the tumor cells without affecting the normal cells make them attractive alternatives to existing pharmaceuticals for the treatment, management, and prevention of cancer, being able to act as potential physiological modulators of metabolism during their intestinal digestion. Novel bioactive peptides derived from food sources can be beneficial as anticancer nutraceuticals and provide a basis for the pharmaceutical development of food-derived bioactive peptides. Bioactive peptides can be generated through different protein hydrolysis methods and purified using advanced chromatographic techniques. Moreover, establishing bioactive peptides' efficacy and mechanism of action can provide alternative methods for cancer prevention and management. Most of the research on anticancer peptides is carried out on cell lines with very limited research being investigated in animal models or human clinical models. In this context, this review article comprehensively discusses anticancer peptides': production, isolation, therapeutic strategies, mechanism of action, and application in cancer therapy.

Regulation of ovalbumin allergenicity and structure-activity relationship analysis based on pulsed electric field technology

The study focused on the regulation of ovalbumin (OVA) allergenicity using pulsed electric field (PEF) technology and examined the structure-activity link. Following PEF treatment, the ability of OVA to bind to IgE and IgG1 at 6 kHz was inhibited by 30.41 %. According to the microstructure, PEF caused cracks on the OVA surface. Spectral analysis revealed a blue shift in the amide I band and a decrease in α-helix and β-sheet content indicating that the structure of OVA was unfolded. The disulfide bond conformation was transformed and the structure tended to be disordered. The increased fluorescence intensity indicated that tryptophan and tyrosine were exposed which led an increase in hydrophobicity. In addition, the results of molecular dynamics (MD) simulations confirmed that the stability of OVA was reduced after PEF, which was related to the reduction of hydrogen bonding and the sharp fluctuation of aspartic acid. Therefore, PEF treatment induced the exposure of hydrophobic amino acids and the transformation of disulfide bond configuration which in turn masked or destroyed allergenic epitopes, and ultimately inhibited OVA allergenicity. This study provided insightful information for the production of hypoallergenic eggs and promoted the use of PEF techniques in the food field.

Impact of Pulsed Electric Fields and pH on Enzyme Inactivation and Bioactivities of Peptic Hydrolysates Produced from Bovine and Porcine Hemoglobin

The production of bioactive peptides from hemoglobin via peptic hydrolysis is a promising alternative to valorizing slaughterhouse blood proteins. Nevertheless, it has some limitations such as low yield, high cost of enzymes, and the use of chemical reagents. The latter is aggravated by the pH increase to inactivate the enzyme, which can affect the bioactivity of the peptides. Thus, this study aimed to evaluate the effect of pulsed electric fields (PEF) on the pepsin inactivation and biological activities (antimicrobial and antioxidant) of hemoglobin hydrolysates. Bovine (Hb-B) and porcine (Hb-P) hemoglobin were hydrolyzed with pepsin for 3 h and treated with PEFs to inactivate the enzyme. The degree of hydrolysis (DH) did not show significant changes after PEF inactivation, whereas peptide population analysis showed some changes in PEF-treated hydrolysates over time, suggesting residual pepsin activity. PEF treatments showed no significant positive or negative impact on antimicrobial and antioxidant activities. Additionally, the impact of pH (3, 7, and 10) on bioactivity was studied. Higher pH fostered stronger anti-yeast activity and DPPH-scavenging capacity, whereas pH 7 fostered antifungal activity. Thus, the use of hemoglobin from the meat industry combined with PEF treatments could fit the circular economy concept since bioactive peptides can be produced more eco-efficiently and recycled to reduce the spoilage of meat products. Nevertheless, further studies on PEF conditions must be carried out to achieve complete inactivation of pepsin and the potential enhancement of peptides’ bioactivity.

Tryptophan targeted pulsed electric field treatment for enhanced immune activity in pine nut peptides

To investigate immune activity of pine nut peptides treated by PEF technology and mechanism of targeting immunoactive sitesits, immune regulatory active was evaluated by RAW 264.7 cells model and the structures of pine nut peptides were researched by fluorescence, CD, and 1D/2D NMR spectrum. These consequences showed the ability of macrophages to phagocytosis neutral red and the production of nitric oxide (NO) were improved after PEF treatment. KWFCT treated by PEF treatment with 40 kV/cm obtained the best immunocompetence. The CD spectroscopy showed that PEF could transform the secondary structures of pine nut peptides. The short-range correlation between C_γ H (1.65 ppm) and C_α H (3.35 ppm), and long-range correlation between C_α H (3.37 ppm) and N_α H (8.07 ppm) were enhanced by PEF treatment. PEF treatment of tryptophan in the pine nut peptides enhanced the immunological activity of the pine nut peptides. PRACTICAL APPLICATIONS: Bioactive peptides derived from food proteins have been extensively studied in recent years. However, little research has been done on the immunoactive peptide of pine nut source. PEF treatment is promising for improving certain properties of foods while maintaining the flavor, color, taste, and nutritional value of the food. This research demonstrated that PEF treatment increased the immunological activity of KWFCT and KWFM. The primary structure of KWFCT and KWFM did not change after PEF treatment, but the secondary structure was transformed into each other. A new perspective on the PEF action site is proposed, which is beneficial to the application of PEF technology.