Anti-biofilm effect of enzymatic hydrolysates of ovomucin in Listeria monocytogenes and Staphylococcus aureus.

Despite modern advances in food hygiene, food poisoning due to microbial contamination remains a global problem, and poses a great threat to human health. Especially, Listeria monocytogenes and Staphylococcus aureus are gram-positive bacteria found on food-contact surfaces with biofilms. These foodborne pathogens cause a considerable number of food poisoning and infections annually. Ovomucin (OM) is a water-insoluble gel-type glycoprotein in egg whites. Enzymatic hydrolysis can be used to improve the bioactive properties of OM. This study aimed to investigate whether ovomucin hydrolysates (OMHs) produced using five commercial enzymes (Alcalase®, Bromelain, α-Chymotrypsin, Papain, and Pancreatin) can inhibit the biofilm formation of L. monocytogenes ATCC 15313, L. monocytogenes H7962, S. aureus KCCM 11593, and S. aureus 7. Particularly, OMH prepared with papain (OMPP; 500 µg/mL) significantly inhibited biofilm formation in L. monocytogenes ATCC 15313, L. monocytogenes H7962, S. aureus KCCM 11593, and S. aureus 7 by 85.56 %, 80.28 %, 91.70 %, and 79.00 %, respectively. In addition, OMPP reduced the metabolic activity, exopolysaccharide production (EPS), adhesion ability, and gene expression associated with the biofilm formation of these bacterial strains. These results suggest that OMH, especially OMPP, exerts anti-biofilm effects against L. monocytogenes and S. aureus. Therefore, OMPP can be used as a natural anti-biofilm agent to control food poisoning in the food industry.

The inhibitory effect of ovomucoid from egg white on biofilm formation by Streptococcus mutans.

BACKGROUND: Streptococcus mutans, the main pathogen associated with tooth decay, forms cariogenic biofilms on tooth surfaces. Therefore, controlling oral biofilm helps prevent dental caries. Hen's egg is a nutrient-dense food, and egg white is a good source of protein. Ovomucoid is one of the major proteins in egg white, with a 28 kDa molecular weight. The present study aimed to investigate the inhibitory effects of ovomucoid on the biofilm formation of S. mutans by suppressing virulence factors, including bacterial adherence, cellular aggregation and exopolysaccharide (EPS) production. RESULTS: Crystal violet staining showed that biofilm formation by S. mutans was inhibited by ovomucoid at 0.25-1 mg mL-1 levels. Field emission scanning electron microscopy also confirmed this inhibition. In addition, ovomucoid reduced mature biofilm, water-insoluble EPS synthesis and the metabolic activity of bacterial cells in the biofilm. The bacterial adhesion and aggregation abilities of S. mutans were also decreased in the presence of ovomucoid. Ovomucoid downregulated the expression of comDE and vicR genes involved in the two-component signal transduction system and gtfA and ftf genes involved in EPS production. CONCLUSION: Ovomucoid has the potential for use as an anti-biofilm agent for dental caries treatment because of its inhibitory effects on the virulence factors of S. mutans. © 2023 Society of Chemical Industry.

Antioxidant and anticancer effects of functional peptides from ovotransferrin hydrolysates.

BACKGROUND: Egg white is a good source for making functional peptides that can be used in the food industry. Ovotransferrin (OTF) is one of the major egg white proteins, with many functional properties, including antioxidant, antimicrobial and antiviral activities. However, enzymatic hydrolysis of ovotransferrin is known to further improve the functional activities of OTF. The aim of this study was to investigate the antioxidant and anticancer activities of functional peptides produced by two-step enzyme hydrolysis of OTF. RESULTS: OTF hydrolysates were prepared using promod 278P, thermolysin and a combination of the two enzymes. OTF and OTF hydrolysates showed strong antioxidant activities when analyzed using the DPPH assay. However, only OTF hydrolysates showed a strong free radical scavenging activity when NO- or ABTS-scavenging activity was measured. OTF hydrolysates showed stronger cytotoxic activities than the natural OTF against human cancer cell lines. Furthermore, OTF hydrolysates prepared with promod 278P + thermolysin combination showed the strongest cytotoxic activity, and their IC50 values were 0.79, 0.78, 0.92 and 0.78 mg mL-1 against AGS, LoVo, HT-29 and HeLa, respectively. CONCLUSION: These results indicated that the two-step enzyme hydrolysates of OTF have great potential for use as a food ingredient with antioxidant and anticancer activities. © 2017 Society of Chemical Industry.

Effect of Dietary Beta-Glucan on the Performance of Broilers and the Quality of Broiler Breast Meat.

A total of 400, one day-old commercial broiler chicks were divided into five diet groups (negative control, positive control group with 55 ppm Zn-bacitracin, 15 ppm ß-glucan, 30 ppm ß-glucan, and 60 ppm ß-glucan) and fed for six weeks. Ten broilers were allotted to each of 40 floor pens. Eight floor pens were randomly assigned to one of the 5 diets. Each diet was fed to the broilers for 6 weeks with free access to water and diet. The survival rate, growth rate, feed efficiency, and feed conversion rate of the broilers were calculated. At the end of the feeding trial, the birds were slaughtered, breast muscles deboned, and quality parameters of the breast meat during storage were determined. The high level of dietary ß-glucan (60 ppm) showed better feed conversion ratio and survival rate than the negative control. The survival rate of 60 ppm ß-glucan-treated group was the same as that of the antibiotic-treated group, which showed the highest survival rate among the treatments. There was no significant difference in carcass yield, water holding capacity, pH, color, and 2-thiobarbituric acid reactive substances values of chicken breast meat among the 5 treatment groups. Supplementation of 60 ppm ß-glucan to broiler diet improved the survival rate and feed conversion rate of broilers to the same level as 55 ppm Zn-bacitracin group. The result indicated that use of ß-glucan (60 ppm) can be a potential alternative to antibiotics to improve the survival and performance of broilers. However, dietary ß-glucan showed no effects on the quality parameters of chicken breast meat.

In vitro antioxidant and mineral-chelating properties of natural and autocleaved ovotransferrin.

BACKGROUND: Egg white proteins can be excellent substrates for the development of functional foods and nutraceuticals. In this study, several in vitro antioxidant methods, namely the ß-carotene linoleate model system, the ferric thiocyanate method, the 2-thiobarbituric acid-reactive substances (TBARS) method and copper/calcium ion chelation, were used to determine the antioxidant capacity of natural and autocleaved ovotransferrin. RESULTS: Autocleaved ovotransferrin was prepared by reducing natural ovotransferrin with tris(2-carboxyethyl)phosphine (TCEP) for 6 h at 37 °C. Autocleaved ovotransferrin suppressed the discoloration of ß-carotene effectively and prevented the oxidation of linoleic acid during 5 days of storage at 4 °C. However, the concentration of autocleaved ovotransferrin had no influence on its antioxidant effect. Similarly, the highest TBARS values were obtained from autocleaved ovotransferrin (>90%) and the lowest value in natural ovotransferrin (24%) during incubation at 37 °C for 48 h. The hydrolysates obtained from autocleaved ovotranferrin showed better copper/calcium-solublilizing activity than those from natural ovotransferrin. CONCLUSION: The results indicated that autocleaved ovotransferrin has the potential to be used as a natural antioxidant in foods.

Sequential separation of immunoglobulin Y and phosvitin from chicken egg yolk without using organic solvents.

A study was conducted to develop a simple sequential separation protocol to separate phosvitin and IgY from egg yolk without using organic solvents. Egg yolk was diluted with 2 volumes of distilled water (DW), homogenized, and centrifuged. The precipitant was collected and homogenized with 4 volumes of 10% NaCl (wt/vol) in 0.05 N NaOH solution to extract phosvitin. The pH of the homogenate was adjusted to 4.0 and the precipitate was removed by centrifugation. The supernatant was collected and then heat-treated at 70°C for 30 min and centrifuged to remove impurities. The supernatant containing phosvitin was collected, had salts removed, and was concentrated and then freeze-dried. The supernatant from the centrifugation of diluted egg yolk was diluted again with 3 volumes of DW, and the precipitate was removed by centrifugation. The resulting supernatant was concentrated using ultrafiltration and then IgY was precipitated using 20% saturated (NH4)2SO4+ 15% NaCl (wt/vol). The precipitant was collected after centrifugation at 3,400 × g for 30 min at 4°C and dissolved with DW, had salts removed, and then was freeze-dried. The purity of separated phosvitin and IgY was checked using SDS-PAGE and the proteins were verified using Western blotting. The purity of phosvitin and IgY was 97.2 and 98.7%, and the yield was 98.7 and 80.9%, respectively. The ELISA results indicated that the activities of separated IgY and phosvitin were 96.3 and 98.3%, respectively. This study proved that both phosvitin and IgY can be separated in sequence from egg yolk without using an organic solvent. Also, the method is very simple and has a high potential for scale-up processing.

Cytotoxic and antigenotoxic activities of phosvitin from egg yolk.

Egg yolk phosvitin is one of the most phosphorylated proteins in nature, and thus has a strong metal-binding ability. The objective of this study was to evaluate the cytotoxic and antigenotoxic activities of phosvitin in vitro. Using the 3-[4,5-dimethythiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay, the cytotoxicity of phosvitin was evaluated in human cancer cell lines of various tissue origins, including the cervix (HeLa), breast (MCF-7), stomach (AGS), lung (A549 and SK-MES-1), liver (HepG2), and larynx (Hep-2). The growth of all cancer cell lines was inhibited in a dose-dependent manner by phosvitin. Among the cancer cell lines tested, MCF-7 and SK-MES-1 were the least sensitive and HeLa, AGS, and HepG2 were the most sensitive to phosvitin. The 50% inhibition of cell viability values of phosvitin were 5.38, 11.57, 4.78, 6.98, 11.82, 3.93, and 9.97 mg/mL for HeLa, MCF-7, AGS, A549, SK-MES-1, HepG2, and Hep-2, respectively. The protective effects of phosvitin against DNA damage in human leukocytes indicated that phosvitin showed protective effects against the oxidative stress-induced DNA damages in human leukocytes. These results suggested that phosvitin has a high potential to be used as an anticancer agent for humans.

Effect of packaging method and storage time on physicochemical characteristics of dry-cured pork neck products at 10°c.

Dry-cured pork neck samples were stored at 10°C for 90 days under vacuum packaging (VP) or modified atmosphere packaging (MAP; 25% CO2+75% N2) conditions. The pH, moisture, water activity, total aerobic bacteria, and Enterobacteriaceae counts of dry-cured pork neck products with MAP were significantly lower than those with VP (p<0.05) after 90 days of storage. However, CIE b* and 2-thiobarbituric acid reacted substance (TBARS) values of the pork product with MAP were significantly higher (p<0.05) than those with VP. Total aerobic bacterial counts and Enterobacteriaceae counts of samples with MAP were lower than those with VP after 30 days of storage. Sensory results indicated that aroma, flavor and tenderness scores of the samples with both VP and MAP decreased during storage and the scores after >60 days of storage were lower than those at Day 1. In conclusion, despite presenting higher lipid oxidation, the samples stored in packages containing 25% CO2 for 90 days at 10°C have lower bacterial counts than vacuum-packed samples. Therefore, further studies should be performed on the packaging of dry-cured meat at adjusted concentrations of CO2.

Effect of Bioactive Peptides on Gut Microbiota and Their Relations to Human Health.

Bioactive peptides derived from both exogenous and endogenous origins have been studied extensively to use their beneficial effects in humans and animals. Bioactive peptides exhibit beneficial bodily functions and contribute to a healthy gastrointestinal system by influencing barrier functions, immune responses, and gut microbiota. Gut microbiota is a diverse microbial community that significantly influences the overall well-being and homeostasis of the body. Factors such as diet, age, lifestyle, medication, and environmental circumstances can affect the composition and diversity of the gut microbiota. The disturbances or imbalances in the gut microbiota have been associated with various health problems. The interplays between bioactive peptides and gut microbiota are not fully understood, but bioactive peptides hold promise as modulators of the gut microbiota to promote gut health. Almost all the bioactive research on human health, including the development of therapeutics and nutritional interventions, uses cell culture, even though their direct biofunctional activities can only occur when absorbed in the intestine and into the blood system. This review focuses on the current understanding of bioactive peptides in gut microbiota and their impact and mechanisms on gut and human health. The novelty of this review lies in its comprehensive analysis of the multifaceted interactions between bioactive peptides and gut microbiota, integrating knowledge from diverse disciplines between microbiology and nutrition. By elucidating the underlying mechanisms and identifying current research gaps, this review offers an outlook on the potential of bioactive peptides in promoting gut health and shaping future therapeutic and nutritional interventions.

Immunostimulatory Effect of Ovomucin Hydrolysates by Pancreatin in RAW 264.7 Macrophages via Mitogen-Activated Protein Kinase (MAPK) Signaling Pathway.

Ovomucin (OM), which has insoluble fractions is a viscous glycoprotein, found in egg albumin. Enzymatic hydrolysates of OM have water solubility and bioactive properties. This study investigated that the immunostimulatory effects of OM hydrolysates (OMHs) obtained by using various proteolytic enzymes (Alcalase®, bromelain, α-chymotrypsin, Neutrase®, pancreatin, papain, Protamax®, and trypsin) in RAW 264.7 cells. The results showed that OMH prepared with pancreatin (OMPA) produced the highest levels of nitrite oxide in RAW 264.7 cells, through upregulation of inducible nitric oxide synthase mRNA expression. The production of pro-inflammatory cytokines such as tumor necrosis factor-α and interleukin-6 were increased with the cytokines mRNA expression. The effect of OMPA on mitogen-activated protein kinase signaling pathway was increased the phosphorylation of p38, c-Jun NH2-terminal kinase, and extracellular signal-regulated kinase in a concentration-dependent manner. Therefore, OMPA could be used as a potential immune-stimulating agent in the functional food industry.

Identification and Molecular Mechanism of Novel Two-Way Immunomodulatory Peptides from Ovalbumin: In Vitro Cell Experiments, De Novo Sequencing, and Molecular Docking.

The purpose of this study was to identify ovalbumin-derived immunomodulatory peptides by in vitro cell experiments, de novo sequencing, and molecular docking. Ovalbumin hydrolysates were prepared by two enzymes (alkaline protease and papain) individually, sequentially, or simultaneously, respectively. The simultaneous enzymatic hydrolysate (OVAH) had a high degree of hydrolysis (38.12 ± 0.48%) and exhibited immune-enhancing and anti-inflammatory activities. A total of 160 peptides were identified by LC-MS/MS in OVAH. Three novel peptides NVMEERKIK, ADQARELINS, and WEKAFKDE bound to TLR4-MD2 through hydrogen bonds and hydrophobic interactions with high binding affinity and binding energies of -181.40, -178.03, and -168.12 kcal/mol, respectively. These three peptides were synthesized and validated for two-way immunomodulatory activity. NVMEERKIK exhibiting the strongest immunomodulatory activity, increased NO and TNF-α levels by 128.69 and 38.01%, respectively, in normal RAW264.7 cells and reduced NO and TNF-α levels by 27.31 and 39.13%, respectively, in lipopolysaccharide-induced inflammatory RAW264.7 cells. Overall, this study first revealed that ovalbumin could be used as an immunomodulatory source for controlling inflammatory factor secretion.

Promoting effect of phosvitin in the mineralization of eggshell inner membrane with the application in osteogenic induction scaffold.

Exploring affordable and easily prepared inorganic-organic hybrid membrane materials has attracted a great interest in the bone repair field. This study is based on biomimetic mineralization technique to study the role of phosvitin (PV) in the mineralized process of eggshell inner membrane. Results showed that PV promoted the formation of hydroxyapatite on the eggshell inner membrane surface, and the phosvitin content in the simulated body fluid was decreased during the mineralization process. Besides, in vitro preosteoblast experiments indicated that mineralized membrane with PV exhibited more conducive to cell proliferation and differentiation than that mineralized membrane without PV. Interestingly, with the increase of mineralization time, the stimulating ability of mineralized membranes with PV on adhesion, proliferation, alkaline phosphatase activity and collagen type I content gradually improved. In summary, the eggshell inner membrane composites mineralized with PV obtained by biomimetic mineralization might be potential scaffold materials for bone repair.

Effect of dietary cholesterol and cholesterol oxides on blood cholesterol, lipids, and the development of atherosclerosis in rabbits.

Two studies were conducted to determine the effects of dietary cholesterol (CHO) and cholesterol oxides (COPs) on the development of atherosclerosis and the changes in fatty acid and blood characteristics in rabbits. In the first study, forty male New Zealand white rabbits were divided into 5 groups and fed commercial rabbit chow with no added CHO or COPs, 1 g CHO, 0.9 g CHO + 0.1 g COPs, 0.8 g CHO + 0.2 g COPs, or 0.5 g CHO + 0.5 g COPs per kg diet. In the second study, 24 male New Zealand White rabbits were divided into 3 groups and fed a diet containing 2 g CHO, 1.6 g CHO + 0.4 g COPs, or 1.2 g CHO + 0.8 g COPs per kg diet. All diets induced atherosclerotic lesions in the rabbits' ascending thoracic aorta. The serum CHO and triglyceride levels (p < 0.05) increased significantly with the increased levels of CHO in the diets. Dietary CHO or COPs did not influence high-density lipoprotein CHO levels. The ratio of saturated fatty acid to unsaturated fatty acid increased as the level of dietary CHO and COPs increased.

Flavour chemistry of chicken meat: a review.

Flavour comprises mainly of taste and aroma and is involved in consumers' meat-buying behavior and preferences. Chicken meat flavour is supposed to be affected by a number of ante- and post-mortem factors, including breed, diet, post-mortem ageing, method of cooking, etc. Additionally, chicken meat is more susceptible to quality deterioration mainly due to lipid oxidation with resulting off-flavours. Therefore, the intent of this paper is to highlight the mechanisms and chemical compounds responsible for chicken meat flavour and off-flavour development to help producers in producing the most flavourful and consistent product possible. Chicken meat flavour is thermally derived and the Maillard reaction, thermal degradation of lipids, and interaction between these 2 reactions are mainly responsible for the generation of flavour and aroma compounds. The reaction of cysteine and sugar can lead to characteristic meat flavour specially for chicken and pork. Volatile compounds including 2-methyl-3-furanthiol, 2-furfurylthiol, methionol, 2,4,5-trimethyl-thiazole, nonanol, 2-trans-nonenal, and other compounds have been identified as important for the flavour of chicken. However 2-methyl-3-furanthiol is considered as the most vital chemical compound for chicken flavour development. In addition, a large number of heterocyclic compounds are formed when higher temperature and low moisture conditions are used during certain cooking methods of chicken meat such as roasting, grilling, frying or pressure cooking compared to boiled chicken meat. Major volatile compounds responsible for fried chicken are 3,5-dimethyl-1,2,4-trithiolanes, 2,4,6-trimethylperhydro-1,3,5-dithiazines, 3,5-diisobutyl-1,2,4-trithiolane, 3-methyl-5-butyl-1,2,4-trithiolane, 3-methyl-5-pentyl-1,2,4-trithiolane, 2,4-decadienal and trans-4,5-epoxy-trans-2-decenal. Alkylpyrazines were reported in the flavours of fried chicken and roasted chicken but not in chicken broth. The main reason for flavour deterioration and formation of undesirable "warmed over flavour" in chicken meat products are supposed to be the lack of α-tocopherol in chicken meat.

Separation of Phosvitin from Egg Yolk without Using Organic Solvents.

The objective of this study was to develop a new method to separate phosvitin from egg yolk without using organic solvents. Phosvitin was extracted from yolk granules using 10% NaCl or 10% (NH4)2SO4 (final concentration) and then treated with heat to precipitate the lipoproteins from the extracted solution. The optimal pH for the phosvitin extraction from yolk granules was determined, and the iron-binding ability of the extracted phosvitin (final product) was tested. Adding 10% (NH4)2SO4 disrupted the granules, and the subsequent thermal treatment at 90°C for 1 h precipitated low density and high density lipoproteins, which enabled separation of phosvitin by centrifugation. The phosvitin concentration in the extract was significantly higher when the pH of the solution was adjusted to pH ≥9. The purity and recovery rate of phosvitin at the end of the separation process were approximately 78% and 56%, respectively. The separated phosvitin was confirmed to have ferrous and ferric iron binding ability. The advantages of this new method compared with the traditional methods include no organic solvents and high-priced equipment are needed for the separation. Also, this method is more environment and consumer friendly than that of the traditional methods.

Co-encapsulation of fish oil with essential oils and lutein/curcumin to increase the oxidative stability of fish oil powder.

The oxidation-resistant and multi-functional fish oil powders were produced by co-encapsulating fish oil with essential oils, lutein, and curcumin. The ovalbumin/alginate complex was used as the wall, and the wall-to-oil ratio was fixed at 1:1 based on yield, oil recovery, and internalization efficiency (IE). Surface oil was removed to better understand the characteristics of the fish oil powders. Scanning electron microscopy (SEM) results indicated that the freeze-dried fish oil powders had irregular shapes with visible pores on the surface. Covalent bonds and electrostatic interactions within the ovalbumin/alginate complex were detected through FTIR. The garlic essential oil-added sample showed the strongest oxidative stability throughout the storage period (30 days). This work showed that fish oil had been encapsulated successfully and multi-functional fish oil powders could be produced by dissolving lipophilic bioactive compounds in fish oil before encapsulation.

The elastase and melanogenesis inhibitory and anti-inflammatory activities of phosvitin phosphopeptides produced using high-temperature and mild-pressure (HTMP) pretreatment and enzyme hydrolysis combinations.

This study aimed to determine the skin protective effect of egg yolk phosvitin phosphopeptides (PPPs). Phosvitin was separated from the egg yolk, and PPPs were produced using high-temperature and mild-pressure (HTMP) pretreatment and enzyme-sterilization hydrolysis combinations. The elastase and melanogenesis inhibitory activities and anti-inflammatory effects of egg yolk PPPs were determined. All PPPs significantly inhibited elastase activity, but the PPPs prepared with HTMP pretreatment and trypsin-sterilization (HTMP-T-S) combination suppressed the tyrosinase activity the most. PPPs (3 mg/mL) inhibited the α-melanocyte-stimulating hormone-induced melanin production in B16F10 melanoma cells by 31.18 to 38.58%. In addition, PPPs effectively inhibited nitric oxide (NO) production in the LPS (lipopolysaccharide)-stimulated RAW 264.7 macrophages, and the PPPs from HTMP-T-S exhibited the highest inhibitory activity. The protein expressions of pro-inflammatory enzymes, inducible nitric oxide synthase, and cyclooxygenase-2 were down-regulated by the PPPs from the HTMP-T-S. Therefore, PPPs could be used as an anti-melanogenic, anti-elastase, and anti-inflammatory agent for humans and skin care products.

Comparison of Functional Properties of Blood Plasma Collected from Black Goat and Hanwoo Cattle.

Slaughterhouse blood is a by-product of animal slaughter that can be a good source of animal protein. This research purposed to examine the functional qualities of the blood plasma from Hanwoo cattle, black goat, and their hydrolysates. Part of the plasma was hydrolyzed with proteolytic enzymes (Bacillus protease, papain, thermolysin, elastase, and α-chymotrypsin) to yield bioactive peptides under optimum conditions. The levels of hydrolysates were evaluated by 15% sodium dodecyl sulfate polyacrylamide gel electrophoresis. The antioxidant, metal-chelating, and angiotensin I-converting enzyme (ACE) inhibitory properties of intact blood plasma and selected hydrolysates were investigated. Accordingly, two plasma hydrolysates by protease (pH 6.5/55°C/3 h) and thermolysin (pH 7.5/37°C/3-6 h) were selected for analysis of their functional properties. In the oil model system, only goat blood plasma had lower levels of thiobarbituric acid reactive substances than the control. The diphenyl picrylhydrazyl radical scavenging activity was higher in cattle and goat plasma than in proteolytic hydrolysates. Ironchelating activities increased after proteolytic degradation except for protease-treated cattle blood. Copper-chelating activity was excellent in all test samples except for the original bovine plasma. As for ACE inhibition, only non-hydrolyzed goat plasma and its hydrolysates by thermolysin showed ACE inhibitory activity (9.86±5.03% and 21.77±3.74%). In conclusion, goat plasma without hydrolyzation and its hydrolysates can be a good source of bioactive compounds with functional characteristics, whereas cattle plasma has a relatively low value. Further studies on the molecular structure of these compounds are needed with more suitable enzyme combinations.

Radical scavenging-linked antioxidant activities of commonly used herbs and spices in Korea.

Herbs and spices not only variety and racy flavour to Korean foods, they also are the richest source for antioxidant power. The present study evaluates the radical scavenging-linked antioxidant activities of hot water extracts from commonly used herbs and spices in Korea. 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical and superoxide anion scavenging activities of bay extract were 39.5% and 22.1%, respectively. The hydroxyl radical scavenging activity was in order of dill (50.0%) > bay (31.3%) > garlic (27.9%) > white pepper and black pepper (15.1-15.3%) > onion (10.1%) extracts. Bay extract had the highest total phenolic content (17.86 µg CE/g). High correlation coefficients were found between the total phenol content and DPPH radical scavenging activity (R = 0.9162). These results indicate that herbs and spices had high antioxidant activity that is partly due to the phenolic compounds and provide basic data for further development of processed food products.

A basis for IgY-themed functional foods: Digestion profile of oral yolk immunoglobulin (IgY) by INFOGEST static digestion model.

Although yolk immunoglobulin (IgY) has been reported its functions of antiviral, antibacterial, energy balancing, and gut microbiota regulating, its gastrointestinal digestion process and the digestion products have not been studied, which is of great significance for the development of IgY-themed functional foods. This work investigated the digestion behaviors of oral IgY by static digestion simulation in vitro. IgY showed low digestibility (23.97%) in the gastric phase but was highly digestible (89.49% digestibility) in the initial intestinal phase. The entire digestion involved IgY aggregation, degradation, re-aggregation, and gradual decomposition into small pieces (by dynamic light scattering). These results indicated that IgY was impressionable, unstable and changeful in gastrointestinal environment, which might impair the bioactive function of IgY. Over 6 peptides (such as RGFK, TVPSGASTK, VPAATASPR) and 21 amino acids were detected, including 6 essential amino acids (methionine, isoleucine, leucine, histidine, tryptophan, and lysine), suggesting that IgY could be involved in human health regulation as active peptides or as rich sources of amino acids in addition to its own bioactive functions. The digestion kinetic curve confirmed that IgY did not reach its maximum digestion at the end of simulation of intestinal phase, implying the incomplete utilization of IgY. This study provides valuable details of oral IgY for development as active ingredients of a functional food, contributing to boosting the egg industry and improving human health.