Characterization and Bioactive Properties of Camel Whey Protein Hydrolysate Generated With Gastric and Pancreatic Proteases

Camel milk has been used for its nutritional and therapeutic benefits since ancient times. Previously, whole camel milk and casein proteins have been explored for their potential bioactive properties. However, studies on camel milk whey proteins and their hydrolysates are still scarce. Hence, the aim of the proposed thesis was to evaluate camel whey proteins and their hydrolysates for potential bioactivities like antioxidant, antimicrobial, antidiabetic, antihypertensive, and anti-cholesterol properties. Production of the hydrolysates was carried out using three digestive enzymes – pepsin, trypsin and chymotrypsin for 3 and 6 h of hydrolysis time. Hydrolysates were characterized by degree of hydrolysis (DH) and reversed-phase high-performance liquid chromatography (RP-HPLC). In vitro experiments were performed to evaluate the bioactive properties of different camel whey protein hydrolysates (CWPHs). Results revealed that CWPHs showed DH ranging from 11 to 47.5%, with chymotrypsin (6 h) and trypsin (3 h) exhibiting highest and lowest DH, respectively. RP-HPLC analysis revealed that α-lactalbumin underwent complete degradation and newer shorter peptides were generated. Chymotrypsin generated CWPHs demonstrated highest 2, 2-diphenyl-1-picrylhydrazy (DPPH) and 2,2\u27-azino-bis (3- ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging activities, while trypsin generated CWPHs displayed highest metal chelating activity. CWPHs showed markedly greater antimicrobial activity than un-hydrolyzed whey against all pathogenic bacteria tested. Anti-cholesterol property via inhibition of cholesterol esterase and lipase, and antihypertensive property via angiotensin-converting enzyme (ACE) inhibition were found to be highest in pepsin (6 h) and (3 h) generated CWPHs, respectively. CWPHs also displayed potential antidiabetic activity compared to intact whey proteins, where pepsin and chymotrypsin generated CWPHs showed higher inhibition of dipeptidyl peptidase-IV (DPP-IV), α-glucosidase and α-amylase (P \u3c0.05). Overall, CWPHs exhibited improved antioxidant, antimicrobial, and antidiabetic properties as well as ACE, cholesterol esterase, and lipase inhibitory effects compared to intact whey proteins in the in vitro conditions. Therefore, CWPHs could be targeted for utilization as bioactive ingredient in functional foods and nutraceuticals

Faba bean protein: a promising plant-based emulsifier for improving physical and oxidative stabilities of oil-in-water emulsions

Faba bean is a protein-rich, sustainable, but understudied legume. Faba bean protein isolates (FBPIs) can serve as promising emulsifiers. This review aims to summarize the research on FBPIs as emulsifiers and various modification methods to improve the emulsifying functionalities. The emulsifying activities of FBPIs depend on several physiochemical characteristics (e.g. solubility, surface hydrophobicity, surface charge, interfacial activity). Physical modifications, especially via linking FBPIs electrostatically to polysaccharides can effectively increase the interfacial layer thickness/compactness and maintain the interfacial protein adsorption. Chemical modifications of FBPIs (e.g. acetylation and Maillard reaction) could improve the interfacial activity and affect the droplet-size distribution. Enzymatic modifications, usually either via hydrolysis or cross-linking, help to optimize the molecular size, solubility, and surface hydrophobicity of FBPIs. It is critical to consider the lipid/protein oxidative stability and physical stability when optimizing the emulsifying functionality of FBPIs. With suitable modifications, FBPI can serve as a promising emulsifier in food production.Peer reviewe

Synergistic Interfacial Properties of Casein and Small Molecule Surfactants for Fabrication of Essential Oil Nanoemulsions

Nanoemulsions of essential oils are important for delivery of flavors and antimicrobial preservatives in food systems. The overall goal of this work was to study the formation and properties of essential oil nanoemulsions fabricated with sodium caseinate (NaCas) or its hydrolysates and small molecule surfactants (SMSs). The first group of lemon oil nanoemulsion was prepared with NaCas and Tween 20 using a phase inversion temperature (PIT) method. The combination of NaCas and Tween 20 reduced the turbidity and droplet dimension of emulsions than using them individually. Heating at 90 °C for \u3e1 h resulted in transparent nanoemulsions for samples with 1.5% lemon oil. Negative and positive effects on nanoemulsion formation were observed with 0.2-0.4 and 0.6-0.8mM NaCl, respectively. The nanoemulsion prepared with 2% NaCas, 0.4-1.2% Tween 20 and 1.5% lemon oil had a volume-area mean diameter of around 100 nm that was optically stable during 15-day storage at room temperature, while creaming occurred after longer time storage. Protein hydrolysates have a higher diffusion rate and flexibility than proteins. In order to improve the emulsification efficiency and emulsion stability, the second group of thymol nanoemulsions fabricated with combinations of casein hydrolysates (CH) and sucrose stearate (SS) was studied. For NaCas hydrolyzed by pancreatin for different durations, the product hydrolyzed for 10 min resulted in the most transparent and stable emulsions due to limited reduction of casein molecular weight. Thermal treatment further improved the emulsion stability because of the improved solubility of SS and the strengthened interactions between CH and SS during heating. Addition of 0.25-1% SS improved the emulsification capacity of 2% CH and the emulsion clarity, while excess (2%) SS significantly increased turbidity and particle dimension of emulsions. With the increased thymol concentration (0-3%), stability of emulsions improved. Emulsions prepared with 0.25% SS and 1.5-3% thymol, or 1% SS and 3% thymol, had stable droplet dimensions during ambient storage for over two months. The combination of SS and CH also enabled stable emulsions at pH 5. Therefore, combinations of SMSs with NaCas and its hydrolysate can be used as novel approaches to prepare essential oil nanoemulsions for various applications

Novel emulsions–based technological approaches for the protection of omega–3 polyunsaturated fatty acids against oxidation processes – A comprehensive review

Over recent decades, the therapeutic properties and health beneficial effects of omega-3 polyunsaturated fatty acids (omega-3 PUFAs) have been identified. These also contain a number of double bonds which make them highly reactive and, as a consequence, they are susceptible to oxidation. This is one of the main limitations when incorporating them into food matrices. This review article presents the state-of-the-art on the preparation of simple or multiple omega-3 PUFA-based lipid emulsions and other novel systems that have been developed, such as self-assembling systems or solid lipid nanoparticles. Furthermore, the main factors that impact lipid oxidation rate are comprehensively reviewed, highlighting the importance of proteins for increasing the physical stability of food emulsions. Currently, there are several works focused on simple emulsions enriched with omega-3 PUFAs that seek the definition of strategies to allow the control of lipid oxidation. Multiple emulsions and other novel systems are beginning to be considered as a possible alternative to conventional emulsions. This knowledge can be used to facilitate selection of the most appropriate system for the food industry.The Ministry of Education, Culture and Sport (MECD) is deeply grateful for supporting the grant FPU17/03005 of Mr. Vellido-Perez

Book of Abstracts of the 8th International Symposium on Delivery of Functionality in Complex Food Systems

This volume contains the abstracts presented at the 8th International Symposium on Delivery of Functionality in Complex Food Systems, held in Sheraton Porto Hotel Conference Centre, Porto, Portugal, 7-10 July, 2019.info:eu-repo/semantics/publishedVersio

Funkcionalna svojstva i primena hidrolizata proteina surutke dobijenih biotehnološkim putem

The amount of whey products on the market is negligible in relation to the amount of unused whey, which leads to the conclusion that developing and improving the process of whey processing must introduce new unconventional products, which would take a more significant place in the range of consumer products. In this sense, the aim of this doctoral dissertation was the production and characterization of bioactive whey proteins hydrolysates, which as such could be applied separately or in combination with other food products. In order to produce bioactive whey protein hydrolysates, a selection of an optimal biotechnological process for the production of hydrolysates with improved biological properties was performed. In the research, selection of optimal microorganisms and enzymes, optimization of the processes of fermentation and enzymatic hydrolysis were performed in order to produce hydrolysates of high biological activity. The produced hydrolysates are analyzed in both the bioactivity aspect and the aspect of their functional characteristics, after which the optimal production process was adopted. In the last phase of the research, a proposal for the application of the produced bioactive hydrolysate in a confectionery fat filling was made. The fat filling enriched with bioactive hydrolysate of whey proteins has been thoroughly examined in terms of sensory characteristics and texture, and the formulation by which it is possible to obtain a final product with optimal characteristics is proposed. During the selection of microorganisms and enzymes, biotechnological modification of whey proteins was carried out using Lactobacillus acidophilus ATCC 4356, Lactobacillus rhamnosus ATCC 7469 and Lactobacillus reuteri ATCC 23272 strains, as well as commercial enzymes Pepsin® and Tripsin®. Fermentation and enzymatic hydrolysis processes are optimized with the aim of producing hydrolysates with high antioxidant activity. After that, the selection of optimal bacterial strain and enzyme was performed, as well as the optimal processes conditions. During the selection, the antioxidant activity, the protein and amino acid content, the degree of hydrolysis, the foam formation ability, emulsifying properties, digestibility and bioavailability were monitored. The obtained bioactive hydrolysates were then dried, analysed and added, in powder form, to the fat filling as a model of the confectionery product. During the characterization, antioxidant, antirheumatic, anti-inflammatory and antimicrobial activity, the ability to inhibit lipid peroxidation, and the stability of the antioxidant activity of the produced hydrolysate powder were monitored. After that, an optimal amount of hydrolysate powders, which can be added to the fat filling without adversely affecting its sensory properties and texture, was tested...Količina proizvoda od surutke na tržištu je zanemarljivo mala u odnosu na količinu surutke koja se nepropisno odlaže što navodi na zaključak da bi se razvojem i unapređenjem procesa prerade surutke mogli dobiti novi nekonvencionalni proizvodi koji bi zauzeli značajnije mesto u paleti proizvoda namenjenih širokoj potrošnji. U tom smislu cilj ove doktorske disertacije je bio proizvodnja i karakterisanje bioaktivnih hidrolizata proteina surutke, koji bi kao takvi mogli biti primenjeni zasebno ili u kombinaciji sa drugim prehrambenim proizvodima. U cilju proizvodnje bioaktivnih hidrolizata proteina surutke izvršena je selekcija optimalnog biotehnološkog procesa pomoću koga se mogu proizvesti hidrolizati proteina surutke unapređenih bioloških svojstava. U okviru istraživanja izvršena je selekcija optimalnih kultura mikroorganizama i enzima, optimizacija uslova procesa fermentacije i enzimske hidrolize u cilju proizvodnje hidrolizata visoke biološke aktivnosti. Proizvedeni hidrolizati su detaljno okarakterisani kako sa stanovišta bioaktivnosti tako i sa stanovišta njihovih funkcionalnih karakteristika, nakon čega je usvojen optimalan proces proizvodnje.. U poslednjoj fazi istraživanja dat je predlog primene proizvedenog bioaktivnog hidrolizata u masnom kremu namenjenom konditorskoj industriji. Konditorski masni krem obogaćen bioaktivnim hidrolizatom proteina surutke je detaljno ispitan po pitanju senzornih karakteristika i teksture na osnovu čega je predložena receptura čijom primenom je moguće dobiti fimalni proizvod optimalnih karakteristika. Tokom selekcije kultura mikroorganizama i enzima izvršena je biotehnološka modifikacija proteina surutke primenom sojeva Lactobacillus acidophilus ATCC 4356, Lactobacillus rhamnosus ATCC 7469 and Lactobacillus reuteri ATCC 23272, kao i komercijalnih enzima Pepsin® i Tripsin®. Procesi fermentacije i enzimske hidrolize su optimizovani sa ciljem proizvodnje hidrolizata visoke antioksidativne aktivnosti. Nakon toga izvršena je selekcija optimalnog bakterijskog soja i enzima kao i uslova izvođenja ovih procesa. Tokom selekcije praćena je antioksidativna aktivnost, sadržaj proteina i aminokiselina, stepen hidrolize, svojstvo stvaranje pene, emulgujuća svojstva, svarljivost i bioraspoloživost. Dobijeni bioaktivni hidrolizati su nakon toga sušeni, detaljno okarakterisani i u praškastom obliku dodavani u masni krem kao model konditorskog proizvoda. Tokom karakterizacije praćeni su antioksidativna, antireumatska, anti-inflamatorna i antimikrobna aktivnost, sposobnost inhibicije lipidne peroksidacije kao i stabilnost antioksidativne aktivnosti proizvedenih hidrolizata u prahu. Nakon toga, ispitana je optimalna količina hidrolizata u prahu koja može biti dodata u konditorski masni krem bez negativnog uticaja na njegova senzorna svojstva i teksturu..

Characterization and Encapsulation of Natural Antioxidants: Interaction, Protection and Delivery

This book focuses on the prediction of antioxidant peptides and the improvement of the aqueous solubility, chemical stability, bioactivity, and release properties of natural antioxidants through enzymatic glycosylation and encapsulation technology. The rational design and construction of delivery systems are effective for the application of antioxidants in the industry. Special attention in this book is given to inorganic nanoparticles, biopolymer-based particulate systems, prediction in antioxidant activity of peptides, evaluation of encapsulation and delivery performance, and application in commercial products

Interfacial/foaming properties and antioxidant activity of a silkworm (Bombyx mori) pupae protein concentrate

The current consumer demand for healthier diets, the growing interest in the search for new sources of protein, and the desire to reduce the negative effects on the environment have increased interest in the study of insect proteins. The present study focused on the technofunctional characteristics (interfacial and foaming properties) and the in-vitro antioxidant activity of a protein concentrate obtained from silkworm (Bombyx mori) pupae (SPC). The isoelectric point of the SPC was close to pH 4.0–5.0 as determined by protein solubility and z potential analysis. Given that the SPC had solubilities of ~50% and z potentials of ~20 mV at pH 2.0 and 8.0, it was decided to further study SPC properties at these pH values. The supernatant obtained after adjustment of SPC to pH 8.0 showed higher (p < 0.05) antioxidant activity than that at pH 2.0 when analysed by the ferric reducing antioxidant power (FRAP) assay (168.0 ± 3.0 V. 43.5 ± 8.1 μmol Trolox Eq. ·g−1 protein). However, no significant differences in antioxidant activity were found between pH 2.0 and 8.0 when using the oxygen radical absorbance capacity (ORAC) assay (1826.0 ± 131.9 vs. 1659.2 ± 46.8 μmol Trolox Eq. g−1 protein). The interfacial properties of SPC were determined at pH 2.0 and 8.0 during protein adsorption and after reaching the pseudo equilibrium state by means of dilatational and interfacial shear rheology following by foaming capacity and stability analyses. Faster adsorption kinetic values were obtained at pH 8 ( Vs. at pH 2.0). However, lower kinetic values at pH 2.0 increased the elastic behaviour of the viscoelastic interfacial film formed (E's ⁓ 30 mN/m at pH 2.0 V. E's ⁓ 20 mN/m at pH 8.0), which can be related with the higher protein sizes found at pH 2.0. These rearrangements of the SPC components appeared to increase its foaming capacity, whereas the foaming capacity of SPC adjusted to pH 8.0 was minimal.University of Seville for the VPPI-US grant (Ref.-II.5)Ministerio de Ciencia, Innovación y Universidades (España) / FEDER RTI2018-097100-B-C2

BIOACTIVE PEPTIDES AND HEALTH EFFECTS

Bioactive peptides are organic substances formed by amino acids joined by covalent bonds known as amide or peptide bonds. Although some bioactive peptides exist free in its natural source, the vast majority of known bioactive peptides are encrypted in the structure of the parent proteins and are released mainly by enzymatic processes. Some bioactive peptides have been prepared by chemical synthesis. Bioactive peptides attributed to different health effects, including antimicrobial properties, blood pressure-lowering (ACE inhibitory) effects, cholesterol-lowering ability, antithrombotic and antioxidant activities, opioid activities, enhancement of mineral absorption and/or bioavailability, cytomodulatory and immunomodulatory effects, antiobesity, and anti-genotoxic activity. The growing interest in bioactive peptides has incentivized the scientific community and the food industry to exploring the development of new food additives and functional products based on these peptides. The present review highlights the recent findings on the identification, bioassays, and use of bioactive peptides, as well as their potential use as food additives and in the development of functional products

RELATIVE REACTIVITY OF PROTEIN AND LIPID TO OXIDANTS IN DIFFERENT BI-PHASIC SYSTEMS AND ITS IMPLICATION IN SAUSAGE QUALITY

This study investigated the progression of protein and lipid oxidation in different bi-phasic model systems: simple aqueous dispersions, liposome, and oil-in-water (O/W) emulsions. Varied concentrations of isolated pork myofibrillar protein (MFP) were mixed with free fatty acids (C18:1, C18:2, C18:3), lecithin, or vegetable oil to construct different lipid-protein dispersion systems, then subjected to hydroxyl radical stress at 4 °C. Comparison of the evolution of lipid oxidation with protein modification markers in all dispersion systems showed noteworthy attenuation of tryptophan fluorescence, protein carbonyl formation, and extensive polymerization of myosin in 2 h. This process preceded lipid oxidation which exhibited notable accumulations of thiobarbituric acid-reactive substances (TBARS) only after 2 h. The study further explored the steric role of MFP in the oxidative stability of emulsions. Oxidized MFP in the continuous phase stimulated lipid oxidation in 24 h; sharply contrasting with interface-adsorbed MFP that inhibited TBARS formation nearly 90% in 24 h. Interfacial MFP from 2 h-oxidized samples exhibited attenuated tryptophan fluorescence but more pronounced myosin polymerization than MFP in the continuous phase. Due to the site distribution, interface-adsorbed MFP in general and myosin in particular provided accentuated protection of emulsions against oxidation. Similarly, soy protein isolate (SPI) and sodium caseinate (SC) acted as antioxidant barriers in O/W emulsions. The effect of replacing pork fat by protein-stabilized soybean oil pre-emulsion on physical characteristics and oxidative stability of fresh sausages was subsequently investigated. Substitution (60%) of SC or partially denatured SPI pre-emulsified oil for fat improved sausage water-binding capacity (P \u3c 0.05). During storage at 4 °C, cooked sausage formulated with partially denatured SPI-emulsified oil displayed a slower lipid oxidation rate throughout 14 days compared with control sausage, and SC-emulsified oil sausage had the lowest TBARS produced in the first 5 days. There was no significant difference (P \u3e 0.05) in texture attributes (e.g., hardness, deformability, cohesiveness, and rupture force) between different formulations. In summary, proteins as emulsifiers at the O/W interface are kinetically preferred targets of radicals compared to unsaturated lipids and proteins in the continuous phase. Such locality effect proves to be important for the physicochemical stability of emulsion-type foods