Whey Protein Hydrolysate Research Articles

Exploring the Nexus Between Emulsifier Characteristics and Salmonella Typhimurium Viability in Oil‐in‐Water Emulsions

ABSTRACTMolecular characteristics of emulsifiers such as their molecular weight (MW) and surface charge, not only affect the stability of the emulsion but also can have an impact on its capacity to either inhibit or promote microbial proliferation. These characteristics can affect the behavior of pathogens such as Salmonella Typhimurium in emulsion systems. The growth and thermal resistance of S. Typhimurium were monitored at different oil content levels (20%, 40%, and 60%) in emulsions stabilized by three whey protein‐based emulsifiers: whey protein isolate (WPI), whey protein hydrolysate (WPH), and a modified WPI with an alteration of charge (WPI+). Our study revealed that emulsifier itself with different MW and surface charge had no effect on bacterial growth and inactivation without oil inclusion (p > 0.05). However, it was found that higher bacterial growth rate at 60% oil content emulsion stabilized with WPI+ (0.65 ± 0.03 log CFU/h) than WPI (0.19 ± 0.04 log CFU/h), which showed the charge of emulsifiers has different effects on microbial dynamics in oil‐in‐water emulsion. Interestingly, WPI+ in emulsions also seemed to convey protection against thermal inactivation of bacteria. These data describe a complex interrelationship between the physicochemical characteristics of the emulsifier and its interacting nature with bacterial cells. They throw even more light on the insight about the importance of a strategic approach toward emulsifier selection in food formulations. This is crucial for the food safety and stability of products.

Identification of Whey Protein‐Derived Anti‐Obesity Peptides Through 3T3‐L1 Adipocyte Differentiation Assay

ABSTRACTWhey proteins are a rich source of bioactive peptides. Whey protein hydrolysate (WPH) can effectively improve metabolic syndrome and reduce the risk of obesity. Bioactive peptides isolated from various food sources exhibit anti‐obesity effects. However, few reports are available on the identification of anti‐obesity peptides from whey protein. In this study, we aimed to identify anti‐obesity peptides from whey protein. Our findings revealed that WPH suppressed the accumulation of lipid droplets in 3T3‐L1 adipocytes. Anti‐obesity peptides in WPH were identified using amino acid sequencing and LC–MS analysis. Then, the inhibitory effects of the synthetic peptides on adipogenesis were assessed through Oil Red O staining. Two peptides were identified as anti‐adipogenic: LDQW and LKPTPEGDLEIL. Subsequently, real‐time PCR analysis found that several adipogenesis‐related genes, such as peroxisome proliferator‐activated receptor γ, were downregulated in the treatment with these peptides. Furthermore, LDQW and LKPTPEGDLEIL decreased the mRNA expression levels of stearoyl‐coenzyme A desaturase 1 and increased carnitine palmitoyl transferase 1α expression in 3T3‐L1 adipocytes. These findings indicate that LDQW and LKPTPEGDLEIL have anti‐obesity properties and may be beneficial for treating metabolic diseases. This study provides a reference basis for developing new techniques to prevent obesity and related diseases.

Биологически активные гидролизаты белков молока и их комплексы включения с циклодектринами

Enzymatic hydrolysis of dairy proteins increases their nutritional and biological value while reducing their allergenic potential. The subsequent complexation of peptides with cyclodextrins (CDs) reduces the bitterness of the hydrolyzed proteins. The research objective was to obtain hydrolysates of whey proteins and their cyclodextrin inclusion complexes with peptides, as well as to describe the peptide composition of the cleaved dairy proteins, biological activity, and sensory profile of the hydrolysates and inclusion complexes. The research featured enzymatic whey protein hydrolysates with an extensive hydrolysis degree and their inclusion complexes with β- and γ-CDs. Dairy proteins were hydrolyzed with alcalase, and the hydrolysates obtained were subjected to micro- and ultrafiltration (cut-off limit – 10 kDa). The peptide composition of the hydrolyzed proteins was determined by the methods of high-performance liquid chromatography and chromatography-mass spectrometry. The antimutagenic activity was evaluated using the Ames test whereas the antibacterial effect was studied with the impedimetric method. The antioxidant activity was detected with fluorimetry and spectrophotometry. The method of competitive enzyme immunoassay was applied to reveal the antigenic properties. The bitterness of the experimental sample s was determined by a sensory evaluation. The research delivered the optimal modes for whey protein cleavage with alcalase that made it possible to achieve efficient micro- and ultrafiltration. The resulting hypoallergenic peptide fractions and their inclusion complexes with β- and γ-CDs possessed antioxidant, antibacterial, and antimutagenic properties. The whey proteolysis and subsequent filtration with/without tindalization demonstrated a 265/589-fold decrease in the residual antigenicity. The fluorimetric method showed a 1.79/1.90-fold increase in the antioxidant activity of the hydrolysate in complexes with β- and γ-CDs. Binding of β-CDs to peptides enhanced their antimicrobial activity against Escherichia coli ATCC 8739 and Staphylococcus aureus ATCC 6538. The hydrolysate samples with β-CDs showed less bitterness. Whey proteolysis with alcalase under optimized conditions and subsequent fractionation resulted in a product with high consumer qualities. Enzymatic hydrolysates of dairy proteins and their CD inclusion complexes were able to substitute native protein components. Their bioactive properties, good taste, and low allergenic potential mean good prospects for the functional food industry.

Efficient Enzymatic Hydrolysis of the Whey Protein Fraction from Bovine Milk

Studies were conducted to optimize the hydrolysis of the major whey proteins with the serine proteases Alcalase and Protozyme, and of the immunoglobulin fraction of colostrum with Alcalase. The protein-peptide composition of the enzymatic hydrolysates of whey and colostrum was determined using high-performance liquid chromatography and electrophoresis data under denaturing conditions. The hydrolysis conditions, in conjunction with the application of a heat treatment of the substrate, were designed to enhance the efficiency of whey proteolysis using Protozyme. An increase in the proteolysis degree of the native immunoglobulin fraction of colostrum with Alcalase was also achieved. The results of the experimental work are intended for the production of a hypoallergenic protein component derived from bovine milk

Characterization of Peptide Profiles and the Hypoallergenic and High Antioxidant Activity of Whey Protein Hydrolysate Prepared Using Different Hydrolysis Modes.

Food proteins and peptides are generally considered a source of dietary antioxidants. The aim of this study was to investigate the antioxidant activity, allergenicity, and peptide profiles of whey protein hydrolysates (WPHs) using different hydrolysis methods. The results demonstrated that the degrees of hydrolysis of the hydrolysates with one-step (O-AD) and two-step (T-AD) methods reached 16.25% and 17.64%, respectively. The size exclusion chromatography results showed that the O-AD had a higher content of >5 and <0.3 kDa, and the distribution of peptide profiles for the two hydrolysates was significantly different. Furthermore, 5 bioactive peptides and 15 allergenic peptides were identified using peptidomics. The peptide profiles and the composition of the master proteins of the O-AD and T-AD were different. The DPPH and ABTS radical scavenging abilities of WPHs were measured, and hydrolysates were found to exhibit a strong radical scavenging ability after being treated using different hydrolysis methods. An enzyme-linked immunosorbent assay showed that the sensitization of WPHs was significantly reduced. This study may provide useful information regarding the antioxidant properties and allergenicity of WPHs.

Camel whey protein hydrolysate diet mitigates alkaline stress–induced biochemical disorders and restores the target of rapamycin, MAPK pathway, and autophagy-related gene expression in Nile tilapia

Camel whey protein hydrolysate diet mitigates alkaline stress–induced biochemical disorders and restores the target of rapamycin, MAPK pathway, and autophagy-related gene expression in Nile tilapia

Characterization of some physicochemical, textural, and antioxidant properties of muffins fortified with hydrolyzed whey protein.

Whey protein hydrolysates, derived from enzymatic hydrolysis of whey protein isolates or concentrates, offer enhanced bioavailability and solubility compared to intact whey protein. In this study, whey protein hydrolysates (WPHs) having different hydrolysis degrees (5%, 10%, and 15%) were produced and muffin cakes were enriched with the addition of WPHs. In general, the addition of WPHs showed a significant effect on oil and protein content while the emulsion activity was improved with the increased hydrolysis degree (HD). The degree of hydrolysis increment resulted in a significant increase in both antioxidant power and antiradical activity of the WPHs. Ferric-reducing antioxidant power and ABTS radical scavenging activity ranged between 18.83-87.27 mg TE/100 g and 211.8-5063.1 mg TE/100 g, respectively. The highest FRAP and ABTS values were recorded for the 15% HD while the lowest was for the native whey protein isolate (WPI). The induction periods giving a clear information for the oxidative stability were 1593 min for the control muffins, and it was 1654for the muffin added with WPI. Rheological data revealed that all cake batter samples including WPHs showed viscoelastic behavior. WPHs could be efficiently used in muffin formulation to increase the biofunctional effects of the final products.

Effect of whey protein-derived decapeptide on mood status and blood variables in healthy adults: a randomized, double-blind, placebo-controlled cross-over trial.

The importance of maintaining good mental health with overall well-being has recently drawn attention from various fields. Functional peptides found from various protein sources reportedly reduce mental health problems. We found a new decapeptide (AJI-801) from whey proteins, which can possibly improve mood status and increase blood acetyl-L-carnitine (ALC) and fibroblast growth factor 21 (FGF21) levels. In this study, we assessed the effects of a single intake of whey protein hydrolysate containing a high amount of AJI-801 (WPH) on blood variables and mood status. A randomized, double-blind, placebo-controlled cross-over trial of two doses of WPH (100 and 500mg) was conducted. Participants, aged between 20 and 59years with fatigue were allocated to two groups based on the WPH doses received, and set first test food in each study. The blood ALC and FGF21 levels at baseline and after 60, 120, and 180min of test food intake were analyzed and the responses to the questionnaire items for mood status were obtained at baseline and after 60 and 180min of test food intake. There were no significant differences in the blood ALC and FGF21 levels between the two groups. As mood status, intake of 500-mg WPH (including 2.5-mg AJI-801) showed significant improvement in Depression/Dejection of the Profile of Mood States Questionnaire second edition and visual analog scale score for depression, as compared to the placebo. Intake of AJI-801 500-mg WPH (including 2.5-mg AJI-801) contributes to the improvement of feeling down in healthy persons with fatigue. University Hospital Medical Information Network Clinical Trial Registry (UMIN 000046829).

Characterization of lactic acid bacteria isolated from human breast milk and their bioactive metabolites with potential application as a probiotic food supplement.

The probiotic properties of twenty-five lactic acid bacteria (LAB) isolated from human breast milk were investigated considering their resistance to gastrointestinal conditions and proteolytic activity. Seven LAB were identified and assessed for auto- and co-aggregation capacity, antibiotic resistance, and behavior during in vitro gastrointestinal digestion. Three Lacticaseibacillus strains were further evaluated for antifungal activity, metabolite production (HPLC-Q-TOF-MS/MS and GC-MS/MS) and proteolytic profiles (SDS-PAGE and HPLC-DAD) in fermented milk, whey, and soy beverage. All strains resisted in vitro gastrointestinal digestion with viable counts higher than 7.9 log10 CFU mL-1 after the colonic phase. Remarkable proteolytic activity was observed for 18/25 strains. Bacterial auto- and co-aggregation of 7 selected strains reached values up to 23 and 20%, respectively. L. rhamnosus B5H2, L. rhamnosus B9H2 and L. paracasei B10L2 inhibited P. verrucosum, F. verticillioides and F. graminearum fungal growth, highlighting L. rhamnosus B5H2. Several metabolites were identified, including antifungal compounds such as phenylacetic acid and 3-phenyllactic acid, and volatile organic compounds produced in fermented milk, whey, and soy beverage. SDS-PAGE demonstrated bacterial hydrolysis of the main milk (caseins) and soy (glycines and beta-conglycines) proteins, with no apparent hydrolysis of whey proteins. However, HPLC-DAD revealed alpha-lactoglobulin reduction up to 82% and 54% in milk and whey, respectively, with L. rhamnosus B5H2 showing the highest proteolytic activity. Overall, the three selected Lacticaseibacillus strains demonstrated probiotic capacity highlighting L. rhamnosus B5H2 with remarkable potential for generating bioactive metabolites and peptides which are capable of promoting human health.

Assessment of the impact of whey protein hydrolysate on myofibrillar proteins in surimi during repeated freeze–thaw cycles: Quality enhancement and antifreeze potential

The quality of surimi, widely used in processed seafood, is compromised by freeze–thaw cycles, leading to protein denaturation and oxidative degradation. The objective of this study is to explore the effects of adding natural whey peptide hydrolysate (WPH) on the myofibrillar proteins of repeatedly freeze–thawed surimi. Results indicated surimi treated with 15% WPH exhibited only a 128% increase in surface hydrophobicity and a maximum peroxide value of 7.84 μg/kg, significantly lower than the control group. Additionally, salt-soluble protein content, emulsification activity, and stability decreased with the increase in freeze–thaw cycles. With a 15% WPH offering the most significant protective effect, evidenced by reductions of only 25.02%, 42.52% and 37.02% in salt-soluble protein content, emulsification activity, and stability, respectively. These outcomes demonstrate that WPH effectively reduces protein denaturation during repeated freeze–thaw processes. Future research should explore the molecular mechanisms underlying WPH's protective effects and evaluate their applicability in other food systems.

Whey protein hydrolysate intervention ameliorates memory deficits in APP/PS1 mice: Unveiling gut microbe–short‐chain fatty acid–brain axis

AbstractThe intricate causes of Alzheimer's disease (AD) hinder effective, lasting treatment. Although the dietary modulation of the brain–gut axis was explored for AD therapy, the exact mechanism remains unclear. This study suggested that 140 days of the whey protein hydrolysate (WPH) intake could attenuate the AD pathologic symptoms in APP/PS1 transgenic mice via a bidirectional action of the gut microbe–SCFA (short‐chain fatty acid)–brain axis. Behavioral tests demonstrated that high‐dose WPH (WPH‐H, 100 mg/kg body weight [bw]) improved passive and recognition memory in mice. Furthermore, WPH‐H significantly reduced amyloid beta 1–42 (Aβ1–42) levels in serum (p &lt; .05) and brain (p &lt; .001) while enhancing serum superoxide dismutase (SOD) activity (p &lt; .01). Brain acetylcholinesterase (p &lt; .01) activity and pro‐inflammatory factors in serum were also reduced. Notably, WPH‐H remodeled gut microbiota composition by increasing Dubosiella and decreasing Bacteroides and norank_f__Ruminococcaceae while stimulating SCFA production. Proteomics indicated that WPH enhanced neurotoxic Aβ autophagy, synaptogenesis, neurotransmitter delivery, and antioxidative stress response via regulated protein expression. Correlation analysis revealed strong links between modified gut microbiota, elevated SCFA levels, and hippocampal protein up‐regulation (Atg4b, Nsfl1c, Tcf20, Nr2f1, and Trappc9) and down‐regulation (Krt1). Overall, the amelioration of memory deficits in APP/PS1 mice through WPH‐H consumption can be attributed to the interconnected interactions among gut microbes, SCFAs, and brain. Our study illuminated the intricate interplay between nutrition, gut health, and memory function, emphasizing WPH's potential in alleviating AD symptoms.

Antihypertensive effects of whey protein hydrolysate involve reshaping the gut microbiome in spontaneously hypertension rats

Novel angiotensin-converting enzyme (ACE) inhibitory peptides were identified from whey protein hydrolysates (WPH) in vitro in our previous study and the antihypertensive abilities of WPH in vivo were further investigated in the current study. Results indicated that WPH significantly inhibited the development of high blood pressure and tissue injuries caused by hypertension. WPH inhibited ACE activity (20.81 %, P < 0.01), and reduced renin concentration (P < 0.05), thereby reducing systolic blood pressure (SBP) (12.63 %, P < 0.05) in spontaneously hypertensive rats. The increased Akkermansia, Bacteroides, and Lactobacillus abundance promoted high short chain fatty acid content in feces after WPH intervention. These changes jointly contributed to low blood pressure. The heart weight and cardiomyocyte injuries (hypertrophy and degeneration) were alleviated by WPH. The proteomic results revealed that 19 protein expressions in the heart mainly associated with the wingless/integrated (Wnt) signaling pathway and Apelin signaling pathway were altered after WPH supplementation. Notably, WPH alleviated serum oxidative stress, indicated by the decreased malondialdehyde content (P < 0.01), enhanced total antioxidant capacity (P < 0.01) and superoxide dismutase activity (P < 0.01). The current study suggests that WPH exhibit promising antihypertensive abilities in vivo and could be a potential alternative for antihypertensive dietary supplements.

Whey protein hydrolysate maintains the homeostasis of muscle metabolism in exercise mice and releases potential anti-fatigue peptides after gastrointestinal digestion

Whey protein hydrolysate (WPH) has been proven to possess anti-fatigue effects, but its regulatory mechanism on muscle metabolism in exercise mice is unclear. In the present study, the effects of WPH on muscle metabolites in mice before and after exercise were explored using metabolomics techniques. Results showed that 34 muscle metabolites were significantly altered by exercise in the WPH group, which was less than 71 in the WP group and 101 in the control group. Specifically, supplementation of WPH significantly increased the levels of amino acid and carbohydrate metabolites (i.e., 1-methylhistamine, guanidoacetic acid, melibiose, and xylulose 5-phosphate) pre-exercise, thereby delaying energy depletion and maintaining metabolic homeostasis during exercise. Furthermore, simulated gastrointestinal digestion (SGID), peptidomics and bioinformatics tools were employed to screen potential peptides in WPH. A total of 37 peptides with 2–5 residues in WPH were resistant to SGID (peak intensity > 105). Among them, YGLF showed favorable potentials in physicochemical property, bioavailability, bioactivity, SwissTargetPrediction, and molecular docking. In addition, the anti-fatigue activity of YGLF was evaluated in vivo. YGLF (100 mg/kg) significantly increased the contents of glucose, glycogens, and amino acids and decreased the levels of lactate and urea nitrogen in mice after exercise. These findings may serve as a reference for the screening of anti-fatigue peptides.

Lactobacillus brevis M2-Fermented Whey Protein Hydrolysate Increases Slow-Wave Sleep via GABAA Receptors in Rodent Models.

In this study, we investigated the effects of whey protein hydrolysate (WPH) fermented with Lactobacillus brevis on sleep behavior and GABAergic mechanisms in rodent models. Fermentation converted the glutamate in WPH to high (3.15 ± 0.21 mg/mL) levels of γ-aminobutyric acid (GABA). Fermented WPH (WP-SF) enhanced sleep duration in mice by increasing GABA content in the brain. The increase in sleep duration induced by WP-SF resulted from an increase in delta wave activity during non-rapid eye movement sleep, and its sleep-promoting effect in a caffeine-induced insomnia model was characterized by an increase in delta waves. WP-SF increased GABAergic receptors at both mRNA and protein levels. Cotreatment with GABAA receptor antagonists abolished the sleep-promoting effects of WP-SF, indicating that WP-SF shares binding sites with antagonists on GABAA receptors. Collectively, WP-SF effectively increased sleep duration by enhancing delta wave activity through GABAergic activation; thus, it is suggested as a functional food-grade ingredient for promoting sleep.

Effects of thermal treatment on the formation and properties of whey protein isolate/whey protein hydrolysate-sodium hyaluronate complexes

In dairy products, the added sodium hyaluronate may form complexes with proteins, thereby affecting product properties. In the present study, the interaction between whey protein isolate (WPI)/ whey protein hydrolysate (WPH) and sodium hyaluronate (SH) was characterized under thermal treatment at different temperatures (25 ℃, 65 ℃, 90 ℃ and 121 ℃) after studying effects of protein/SH ratio and pH on complex formation. The addition of SH reduced the particle size of WPI/WPH and increased potential value in the system, with greater variation with increasing treatment temperature. The structural properties of complexes were studied. The binding with SH decreased the contents of free amino group and free thiol group, as well as the fluorescence intensity and surface hydrophobicity. FTIR results and browning intensity measurement demonstrated the formation of Maillard reaction products. Moreover, the attachment of SH improved the thermal stability of WPI/WPH and decreased their antigenicity.

Protein-based oral rehydration solutions for patients with an ileostomy: A randomised, double-blinded crossover study

Background & AimPatients with an ileostomy are at increased risk of dehydration and sodium depletion. Treatments recommended may include oral rehydration solutions (ORS). We aimed to investigate if protein type or protein hydrolysation affects absorption from iso-osmolar ORS in patients with an ileostomy. MethodsThis was a randomised, double-blinded, active comparator-controlled 3x3 crossover intervention study. We developed three protein-based ORS with whey protein isolate, caseinate or whey protein hydrolysate. The solutions contained 40-48 g protein/L, 34-45 mmol sodium/L and had an osmolality of 248-270 mOsm/kg. The patients ingested 500 mL/d. The study consisted of three 4-week periods with a >2-week washout between each intervention. The primary outcome was wet-weight ileostomy output. Ileostomy output and urine were collected for a 24-hour period before and after each intervention. Additionally, blood sampling, dietary records, muscle-strength tests, bioimpedance analyses, questionnaires and psychometric tests were conducted. ResultsWe included 14 patients, of whom 13 completed at least one intervention. Ten patients completed all three interventions. Wet-weight ileostomy output did not change following either of the three interventions and did not differ between interventions (p=0.38). A cluster of statistically significant improvements related to absorption was observed following the intake of whey protein isolate ORS, including decreased faecal losses of energy (-365 kJ/d, 95% confidence interval (CI), -643 to -87, p=0.012), potassium (-7.8 mmol/L, 95%CI, -12.0 to -3.6, p=0.001), magnesium (-4.0 mmol/L, 95%CI, -7.4 to -0.7, p=0.020), improved plasma aldosterone (-4,674 pmol/L 95%CI, -8,536 to -812, p=0.019), estimated glomerular filtration rate (eGFR) (2.8 mL/min/1.73m2, 95%CI, 0.3 to 5.4, p=0.03) and CO2 (1.7 mmol/L 95%CI, 0.1 to 3.3, p=0.04). ConclusionIngestion of 500 mL/d of iso-osmolar solutions containing either whey protein isolate, caseinate or whey protein hydrolysate for four weeks resulted in unchanged and comparable ileostomy outputs in patients with an ileostomy. Following whey protein isolate ORS, we observed discrete improvements in a series of absorption proxies in both faeces and blood, indicating increased absorption. The protein-based ORS were safe and well-tolerated. Treatments should be tailored to each patient, and future studies are warranted to explore treatment-effect heterogeneity and whether different compositions or doses of ORS can improve absorption and nutritional status in patients with an ileostomy. ClinicalTrials.gov study identifierNCT04141826.

Ultrasonic monitoring of enzymatic hydrolysis of proteins. 2. relaxation effects

The paper investigates the occurrence of relaxation processes in enzymatic hydrolysis of whey proteins in phosphate buffer using high-resolution ultrasonic spectroscopy. The hydrolysis produces a frequency-dependent evolution of ultrasonic velocity and attenuation originated by the proton transfer between the phosphate ions and the terminal −NH2 group of protein hydrolysates. Such frequency dependence is absent in other systems, e.g., Tris buffer. Real-time profiles of ultrasonic velocity and attenuation measured during the hydrolysis of β–lactoglobulin, α–lactalbumin and bovine serum albumin by α–chymotrypsin were employed in quantitative analysis of the relaxation mechanisms, relaxation times, determination of the proton transfer rate constants and the reaction volume. The proton transfer is characterised by the rate constant 9.4 × 107 L mol−1 s−1 and the adiabatic reaction volume 24 × 10−6 m3 mol−1. The obtained reaction volume agrees well with thermodynamic data for ionisation volumes and enthalpies of the terminal amino group and phosphate. The described methodology for estimating the relaxation contribution to ultrasonic characteristics allows for precision real-time ultrasonic measurements of the concentration of peptide bonds cleaved during protein hydrolysis in a broad range of environmental conditions.

Antifungal, Antibacterial, and Antioxidant Activities of Camel Whey Protein Hydrolysates

Antifungal, Antibacterial, and Antioxidant Activities of Camel Whey Protein Hydrolysates

Novel insights into whey protein peptide-iron chelating agents: Structural characterization, in vitro stability and functional properties

In this study, whey protein iron chelating peptides were obtained by trypsin hydrolysis of whey protein, and the whey protein peptides-iron chelate (WPP-Fe) was prepared. The structural characterization of the whey protein peptides-iron chelate were determined, comprising ultraviolet-visible spectrum, fluorescence spectrum, infrared spectrum, secondary structure content, x-ray diffraction, particle size, zeta potential, microstructure and surface elemental compositions. The results showed that under the conditions of pH 5.0, the mass ratio of whey protein peptides to FeSO4 was 3:1, chelated at 35 °C for 30 min, iron chelating and chelating yield was 85.92% and 77.38% respectively. The content of aspartic acid and glutamic acid were positively correlated with iron chelating ability. The whey protein peptides-iron chelate had good pH, salt concentration and gastrointestinal digestive stability compared to FeCl2, ferrous gluconate and ferrous glycine. Besides, the DPPH eliminate ability and bacteriostatic properties of the whey protein peptides-iron chelate (WPP-Fe) were better than the whey protein peptide (WPP). These findings can be used as a theoretical basis for the development of new peptide iron supplements.

Effect of enzymatic hydrolysis with Alcalase or Protamex on technological and antioxidant properties of whey protein hydrolysates

The aim of this study was to evaluate the effect of the enzymatic hydrolysis, performed using Alcalase and Protamex enzymes, on the technological functionalities and the antioxidant capacity of whey protein hydrolysates (WPHs) to identify the conditions allowing to obtain target functionality/ies. Samples were characterized for hydrolysis degree (DH), molecular weight distribution, structural properties, and food-related functionalities. Free sulfhydryl groups and surface hydrophobicity significantly decreased with the increase in DH, regardless of the used enzyme. The foaming and antioxidant properties of Alcalase WPHs were higher as compared to those of WPI, reaching the maximum value at DH = 18–20 %, while higher DH resulted in impaired functionality. Gelling properties were guaranteed when WPI was hydrolysed by Protamex at DH < 15 % while foaming and antioxidant abilities were fostered at 15 < DH < 21 %. These results were well correlated with MW distribution and were rationalized into a road map which represents a useful tool in the selection of proper hydrolysis conditions (time, DH, enzyme type) to obtain WPHs with tailored functionalities. Research outcomes highlighted the possibility to drive protein hydrolysis to optimize the desired functionality/ies.