Edible Bird's Nest Research Articles

Development of Method for Evaluation of Edible Bird's Nest Content in Ready-to-Eat Beverages.

Edible bird's nest (EBN) is one of the most valuable tonic Chinese foods, made from glutinous salivary secretion with highly concentrated mucin glycoprotein. For ease of consumption, manufacturers have marketed different ready-to-eat EBN products, in which the EBN content varies. This is the first study to analyze the EBN content in ready-to-eat beverages. To determine the EBN content in ready-to-eat beverages by its active ingredient, N-acetylneuraminic acid (sialic acid). Sialic acid in ready-to-eat beverages and raw EBN was extracted in sodium hydrogen sulfate solution, followed by derivatization using o-phenylenediamine dihydrochloride and determination using high-performance liquid chromatography (HPLC). Method precision, recovery of extraction, degradation of sialic acid due to cooking, and measurement uncertainty were evaluated. The mean concentrations of raw EBN in different origins and colors ranged from 5.77 to 10.92%. Ten different brands of traditional ready-to-eat EBN beverages from the market were analyzed, in which estimated concentrations of EBN were diversified, ranging from 0.014 ± 0.010 to 0.66 ± 0.069% (w/w) (95% confidence level). The concentration of sialic acid was found to range from 11.4 to 527 mg/kg. Based on the results, sialic acid content can provide a better estimation of the EBN content in traditional ready-to-eat beverages. Neither the selling price nor dried matter could be used as an indicator of the quality of the ready-to-eat EBN beverage among the samples obtained. Sialic acid can be used as an indicator to estimate EBN content, where the sialic acid and EBN content in ready-to-eat beverages from the market were found to vary significantly.

Influence of level and oxidation state of iron on colors of edible bird’s nest

Edible bird's nests (EBNs) are known as a medical food with abundant mineral and nutrition. Their colors vary from white, yellow and red according to their production sites. White EBNs are produced by swiftlets living in both natural caves and man-made bird's houses. Red EBNs, on the other hand, can be only found in a certain cave. Due to the higher price of red EBNs in comparison with white EBNs, artificial red EBNs are made by exposing white EBNs with nitrous acid vapor generated from a solution of sodium nitrite and hydrochloric acid. According to ICP-OES, red cave EBNs displayed 3–35-fold higher amount of iron (4.18 ± 1.00 mg/100g), compared to white EBNs (0.57 ± 0.40 - 0.66 ± 0.13 mg/100g) and artificial red EBNs (0.12 ± 0.06 - 1.45 ± 0.03 mg/100g). Fe K-edge XAS demonstrated the presence of iron (II) and iron (III) species in all EBNs. Both red cave EBNs and artificial red EBNs from both cave and house showed significantly higher amount of iron (III) (96.69–99.08%) than white EBNs from both cave and house (68.81–74.19%). This study suggests that the red color in EBNs of both authentic red cave and artificial red EBNs are associated with their iron (III) content.

Tissue-engineered edible bird's nests (TeeBN).

Edible bird's nests (EBN)-the nests of swiftlet birds harvested from the wild- are high-end healthcare food in East Asia, while their excessive harvesting poses increasing ecological, environmental, and food safety concerns. Here, we report for the first time a tissue-engineering (TE) approach for fabricating EBNs substitutes by integrating the technologies of three-dimensional (3D) printing and live cell culture. The engineered products, tissue-engineered edible bird's nests (TeeBN), comprise two layers. The first is a feeding layer that encapsulates epithelial cells in 3D-printed biocompatible gelation scaffolds. These cells secrete bioactive ingredients, e.g., sialic acid and epidermal growth factors (EGF), recapitulating the natural production of these substances by birds. The second is a receiving layer, consisting of foodgrade natural polymers, e.g., polysaccharides, which mimics the building blocks of natural EBNs while biologically stabilizing the factors released from the feeding layer. In vitro characterizations demonstrate that the feeding layer facilitates 3D cell growth and functions, and the receiving layer (as the end product) contains the necessary nutrients expected from natural EBNs-while without harmful substances commonly detected in natural EBNs. Further, in vivo metabolomics studies in mice indicate that TeeBN showed a similar profile of serum metabolites as natural EBN, reflecting comparable nutritional effects. In summary, we innovatively developed a tissue engineering-based substitute for EBNs with comparable metabolic functions and minimized safety risks, opening a new avenue for producing delicacy food from laboratorial cell culture with 3D printing technology.

Investigation of Structural Characteristics and Solubility Mechanism of Edible Bird Nest: A Mucin Glycoprotein

In this study, the possible solubility properties and water-holding capacity mechanism of edible bird nest (EBN) were investigated through a structural analysis of soluble and insoluble fractions. The protein solubility and the water-holding swelling multiple increased from 2.55% to 31.52% and 3.83 to 14.00, respectively, with the heat temperature increase from 40 °C to 100 °C. It was observed that the solubility of high-Mw protein increased through heat treatment; meanwhile, part of the low-Mw fragments was estimated to aggregate to high-Mw protein with the hydrophobic interactions and disulfide bonds. The increased crystallinity of the insoluble fraction from 39.50% to 47.81% also contributed to the higher solubility and stronger water-holding capacity. Furthermore, the hydrophobic interactions, hydrogen bonds, and disulfide bonds in EBN were analyzed and the results showed that hydrogen bonds with burial polar group made a favorable contribution to the protein solubility. Therefore, the crystallization area degradation under high temperature with hydrogen bonds and disulfide bonds may be the main reasons underlying the solubility properties and water-holding capacity of EBN.

Photodynamic antitumor activity of halogenated gallium(III) and phosphorus(V) corroles

Four new phosphorus(V) and gallium(III) corrole complexes were prepared and evaluated as antitumor agents in photodynamic therapy (PDT) in vivo and vitro. All complexes showed low dark toxicity and good photocytotoxicity under light illumination (625 ± 2 nm, 3 W/m2). Especially, phosphorus(V) corrole (1-P) exhibited quite excellent photocytotoxicity with IC50 of 0.03 (±0.003) μM with phototoxic indices (p.i.) of >3333.33 against MDA-MB-231 tumor cells. Under light irradiation, 1-P could produce reactive oxygen species (ROS) in cells and destroy mitochondrial membrane potential, leading to apoptosis. The PDT treatment with 1-P arrested the cell at sub-G1 phase. Animal test showed 1-P could effectively inhibit the growth of MDA-MB-231 tumor cell grafted BALB/c nude mice. The PDT generated ROS might boost the anti-tumor immune response (e.g., CD3+, CD4+ and CD8+). It is well known that edible bird's nest (EBN) helps to improve the immune system and thus is beneficial to health. Photodynamic therapy combined with EBN (100 mg/kg) treatment was conducted for the first time to evaluate the possible antitumor synergistic effect in mice. It turned that EBN may do significant positive help in eliminating the tumors in PDT-treated mice by enhancing T cell expression as indicated by the detection of remarkable higher CD3+ expression in tumor and spleen tissue.

Effect of edible bird's nest and N-acetylneuraminic acid on gut microbiota in different stages of pregnant rats fed with zinc deficient diet

Zinc deficiency diet during pregnancy and lactation have become an important hidden danger to the healthy development of offspring. Therefore, natural supplements are urgently needed to treat gut microbiota disorder induced by zinc deficiency diet. The study aims to investigate the effects of edible bird's nest (EBN) and N-acetylneuraminic acid (NANA) on gut microbiota in different stages of pregnant rats fed with zinc deficient diet. Zinc deficiency diet was used to induce gut microbiota disorder in pregnant rats. High-throughput 16S rRNA gene sequencing and bioinformatics analysis technology were also conducted. And the relationship between body weight, food intake and organ index of pregnant rats and differential microbiota was analyzed. It was found that dietary zinc deficiency can lead to gut microbiota disturbance in pregnant rats, which can be improved by EBN and NANA to increase beneficial bacteria such as Bacteroides, Bifidobacterium and Lactobacillus, and reduce the harmful ones such as Enterococcus, Turicibacter and Parabacteroides. These results can not only deepen the understanding of the effects of EBN and NANA on gut microbiota in pregnant rats, but also lay an important foundation for the further utilization of them in the pregnant population.

Utilization of Ultrasonic Waves to Reduce Nitrite Levels in Edible Bird Nest

Utilization of Ultrasonic Waves to Reduce Nitrite Levels in Edible Bird Nest

An oligosaccharide marker for rapid authentication of edible bird’s nest

Edible bird’s nest (EBN) is a popular and expensive food material. The limited supply and great demand result in the use of adulterants. The authenticity concern is raised due to the lack of appropriate quality markers. Herein, this study aims to provide a specific oligosaccharide marker for rapid EBN authentication. Comparing the benzocaine (ABEE)-labeled saccharide profiles of multiple batches of EBN and adulterants indicates seven unique EBN oligosaccharides. The most abundant one, named BNM001, was selected as a marker and characterized to be Neu5Ac (2–3) Gal by MS and NMR spectra. This new oligosaccharide marker enables a rapid authentication of EBN within 10 min. ABEE labelling of this marker further upgraded the accuracy and sensitivity of the LC-qTOF-MS quantitative analysis. The relative marker content was associated with the quality of EBN products. These results suggest a specific and efficient quality marker for rapid authentication of EBN and related products.

COMPARISON BETWEEN PREFERENCE OF SWIFTLET HOUSING DESIGN AND CHARACTERISTICS BY RANCHERS IN SABAH AND SARAWAK

For the past few years, demand for health and beauty products has been high, including bird nests, which has led to the thriving of Malaysia’s swiftlet ranching industry. Hence, the macro parameters related to swiftlet housing characteristics and designs owned by swiftlet ranchers in Sabah and Sarawak were identified. The size of the house, placement of the bird entrance, house orientation, flooring, and location were observed. The descriptive data were analyzed by using ANOVA (p<0.05) and the interaction between variables was determined by using Chi-square regression via SPSS 25.0. The number of swiftlet houses in Sabah was identified as higher than in Sarawak. 57% of the swiftlet houses are in the agricultural area, and 41% of the swiftlet houses are in the forest area. 37% of the chosen orientation by a rancher in Sabah was in the directions of east to west and north to south. This data was significantly different compared to Sarawak as 25% of the houses in Sarawak were constructed from southeast to northwest by the ranchers. The two-floor design was most preferred by the ranchers in Sabah and Sarawak with a total of 43% respectively, followed by a three-floor design at 27% in Sabah and 34% in Sarawak. The size of the swiftlet buildings preferred by ranchers in Sabah and Sarawak was small, with a length and width below 10 feet. Meanwhile, there is no significant difference (p>0.05) in terms of bird entrance, placement, and measurement of the swiftlet houses. Several improvements are needed to reduce the limitation, such as widening the distribution of survey locations or in quantitative aspects, such as edible bird nest production among farmers.

Fabricating Ceramic Scaffolding Nest through the addition of Calcium Carbonate (CaCO₃) in Ceramic Stoneware Body

Edible bird nest (EBN) is based from swiftlet's saliva and it is widely consumed as a health food due to its high beneficial effects to human health and has been considered to be one of the most precious food items by the Chinese for thousands of years. The role of a scaffolding nest is to guide the young swiftlet to build a typical form of the edible bird nest that will increase its commercial values. However, the price of edible bird nests decreased due to various shapes and sizes of EBN in the market. This study will design standard scaffolding nests followed by MS 2334:2011 and introduce the Calcium Carbonate as the main material and associate it with the stoneware body as the binder to create a natural environment to swiftlets.

Evaluation on the Antibacterial Activity and Biocompatibility Natural Soap Formulated with Edible Bird Nest

Edible bird’s nest (EBN) derived from saliva of swiftlet is often consumed for its nutritional benefit. In this study, EBN natural soap was studied based on their morphology, antibacterial activity and cytotoxicity. The surface morphology and the presence of heavy metal in the soaps were investigated through scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). The antibacterial activity of EBN natural soap against Escherichia coli ATCC 25922 was investigated using disc diffusion and bacterial colony count method while the biocompatibility property was determined with human skin fibroblast cells through MTT assay and morphology observation under an inverted microscope. A consistent surface morphology pattern and no heavy metal were recorded on the soaps. The results of antibacterial activity indicated that the EBN natural soap did not have any antibacterial property but able to retain high cell viability percentage of 91.88±3.04% with normal cell morphology. Therefore, the EBN natural soap is biocompatible and appropriate to be incorporated in skin products.

Enzymatic hydrolysis improves digestibility of edible bird’s nest (EBN): combined effect of pretreatment and enzyme

Enzymatic hydrolysis improves digestibility of edible bird’s nest (EBN): combined effect of pretreatment and enzyme

The scavenging activity of encapsulated EBN hydrolysates using different combinations of polysaccharides as wall material by spray drying

Encapsulation process has been widely applied in food industry to improve the properties and stability of bioactive ingredients. However, a suitable type of wall material needs to be studied as different wall formulation will produce powders with different characteristics. This research aims to evaluate the influences using different combination of polysaccharides as the wall material on the encapsulation process of edible bird's nest (EBN) hydrolysates. 3% w/v of EBN hydrolysate was encapsulated with 10% w/v maltodextrin (MD), a combination of 9% MD and 1% carboxymethyl cellulose (MD-CMC) and a combination of 9.95% MD and 0.05% xanthan gum (MD-XG). The recovery yield, encapsulation efficiency, moisture content, water activity, solubility, hygroscopicity, morphology, structure and scavenging activity of the spray dried powders were evaluated. Although the recovery yield of MD (24.86 ± 0.13%), MD-CMC (8.57 ± 0.23%) and MD-XG (16.02 ± 0.18%) were significantly different, the encapsulation efficiency of MD (85.97 ± 0.01%), MD-CMC (81.15 ± 0.01%) and MD-XG (86.58 ± 0.01%) were not, proving all the formulations possess high efficiency to encapsulate EBN hydrolysates. MD-XG also showed the lowest moisture content (6.18 ± 1.01%), lowest water activity (0.25 ± 0.01), highest solubility (90.48 ± 0.23%) and lowest hygroscopicity (7.20 ± 0.01%). The highest scavenging activity was observed when EBN was encapsulated with MD-XG (55.89 ± 0.01%), followed by MD-CMC (50.88 ± 0.01%) and the lowest when encapsulated with MD (27.77 ± 0.01%). The morphology of encapsulated EBN hydrolysates depended on the type of wall material and all of them showed an amorphous structure. Thus, different concentration of MD and combination with other polysaccharides can affect the physicochemical properties and scavenging activity of encapsulated EBN hydrolysates.

Edible Bird’s Nest, a Valuable Glycoprotein Source: Current Research Prospects and Challenges in Malaysia

Edible bird's nest (EBN) is a salivary secretion of swiftlets which consist of protein and carbohydrate rich glycoproteins. This natural ingredient is very valuable, nutritional and medically valuable. The EBN industry have grown rapidly and benefited the Malaysian economy, hence, it is viewed seriously and it is actively supported by the government. This review discusses the progress and development of EBN industry as well as the R&D activities and endeavours especially that which involves deriving peptides with biological activities from EBN and its by-product sources. Many studies have documented the therapeutic properties of EBN such as antiaging, antiviral, antioxidant, and antihypertensive. Studies have also been conducted to produce glycoprotein hydrolysates from EBN through enzymatic hydrolysis, and findings showed that these bioactive peptides increase solubility as well as antioxidant and antihypertensive activities. Enzymatic hydrolysis breaks long protein chains at specific sites and releases amino acids and small peptides with lower molecular weights. The EBN hydrolysates produced can improve bioactivity and overcome insolubility and low absorption of EBN prepared and consumed through traditional means. Further studies need to be carried out to optimise EBN glycoprotein hydrolysates production as well as maximising their bioavailability and efficacy in the human gastrointestinal system. In addition, EBN by-products produced during EBN cleaning process should be fully utilised to recover the high-value glycoproteins, while reducing pollution and wastage. By enhancing R&D activities of EBN, bioactive glycopeptides produced from EBN may become an important functional food ingredient for various uses and innovative value-added products in the future.

Edible bird's nest, an Asian health food supplement, possesses anti-inflammatory responses in restoring the symptoms of atopic dermatitis: An analysis of signaling cascades.

Edible bird’s nest (EBN) is a Chinese delicacy possessing skin rejuvenating functions. To verify skin anti-inflammatory function of EBN, water extract and enzymatic digest of EBN, as well as the major sialic acid, N-acetyl neuraminic acid (NANA), were probed in TNF-α-treated HaCaT keratinocytes. The mRNA expressions of pro-inflammatory cytokines, e.g., IL-1β, IL-6, TNF-α, and an enzyme responsible for inflammatory response, i.e., Cox-2, as well as filaggrin and filaggrin-2, were markedly altered after treating with different preparations of EBN. The EBN-mediated responses could be accounted by its robust reduction of reactive oxygen species (ROS), NF-κB signaling and phosphorylation of p38 MAPK and JNK, as triggered by TNF-α-induced inflammation. The anti-inflammatory response of EBN was further supported in animal model. In 2,4-dinitrochlorobenzene (DNCB)-induced dermatitic mice, the effects on skin thickness, severity level of damage and scratching behavior, exerted by DNCB, were reversed after EBN treatments, in dose-dependent manners. In parallel, the levels of immune cells and pro-inflammatory cytokines in dermatitic skin were markedly reduced by treatment of EBN preparations. In general, NANA and enzymatic digest of EBN showed better anti-inflammatory responses in both models of in vitro and in vivo. These lines of evidence therefore suggest the possible application of EBN in treating atopic dermatitis.

Microbial diversity and microbiological quality of edible-birdnest (EBN) during processing and storage

Microbial diversity and microbiological quality of edible-birdnest (EBN) during processing and storage

Enzymatic recovery of glycopeptides from different industrial grades edible bird’s nest and its by-products: nutrient, probiotic and antioxidant activities, and physicochemical characteristics

This study was conducted to recover edible bird’s nest (EBN) hydrolysates from different grades of EBN, including the industrial by-products, using enzymatic treatment. The nutrient, physicochemical properties and antioxidant activities of the recovered hydrolysates at different hydrolysis times were evaluated. Results showed that the recovery yield of enzymatic hydrolysis was above 89 % for all grades of EBN and the degree of hydrolysis increased over time. Nitrite content (0.321–0.433 mg/L) was below the permissible tolerance level for all samples. Interestingly, the antioxidant activities (DPPH and ABTS scavenging activities and ferric reducing antioxidant powder (FRAP) activity) were significantly higher (P ≤ 0.05) in hydrolysates recovered from EBN by-products (EBNhC and EBNhD) as compared to the high grade EBN hydrolysates (EBNhA and EBNhB). The in-vitro probiotic activity of EBN and its hydrolysates were examined using the probiotic bacterium Lactobacillus plantarum. Evidently, EBN by-products hydrolysate (EBNhD) recorded the highest number of L. plantarum (1.1 × 1011 CFU/mL), indicating that low grade EBN has the potential as prebiotic material that promotes probiotic activity. This study demonstrated the concept of using EBN by-products hydrolysates for various applications, such as functional ingredients with enhanced bioactivities, to improve its economic value.

Revealing the species-specific genotype of the edible bird’s nest-producing swiftlet, Aerodramus fuciphagus and the proteome of edible bird’s nest

Only a few species of swiftlets in the Aerodramus and Collocalia genera can produce edible bird's nests (EBN). These saliva-cemented nests have been consumed as delicacies for centuries in Asia. Many researches have reported the aqueous extract of EBN has epidermal growth factor-like (EGF-like) activity. However, no standalone EGF has been identified in EBN. Moreover, proteome of EBN remained unclear due to lack of genomic data base of an EBN-producing swiftlet to support proteomic analysis of EBN. To address this, the first genome of the EBN-producing swiftlet, Aerodramus fuciphagus, was constructed. Orthology comparison of A. fuciphagus with 10 other avian species were conducted. The results revealed that the number of predicted paralogous coiled-coil domain-containing protein 63 (CCDC63) coding sequences (CDSs) in A. fuciphagus was found to be significantly expanded in comparison to Gallus gallus. There were 3 paralogous CCDC63 genes in the genome of A.fuciphagus. The CDSs predicted from the genome of A. fuciphagus were used to construct a database for proteomic analysis of EBN. In total, 398 proteins have been identified in EBN. The proteome of EBN was significant enriched with extracellular proteins as well as proteins related to extracellular matrix (ECM) organization and immune response. A few proteins with Ca2+-binding EGF-like domains were found in the proteome of EBN, like fibrillin-1, protocadherin fat 4 and coagulation factor X. No standalone EGF protein was identified. This indicated that the proteins with EGF-like domains might be responsible for the EGF-like activity of EBN. In addition, acidic mammalian chitinase and lysyl oxidase in EBN were found to be active when extracting with distilled water at room temperature. The current study has not just revealed the species-specific genotype of the EBN-producing swiftlet, A. fuciphagus, but also revealed the proteome of EBN. This established an important foundation for subsequently studies on efficacies of EBN.

A preliminary metagenomics study of bacteria present in the dirt of Swiftlet farmhouses based on nitrite levels in edible bird's nest on Sumatera Island, Indonesia.

Background and Aim:Since the past decade, metagenomics has been used to evaluate sequenced deoxyribonucleic acid of all microorganisms in several types of research. Nitrite contamination originates from the natural environment in Swiftlet farmhouses (SFHs) and can influence nitrite levels in edible bird’s nest (EBN). It is strongly speculated that the conversion process into nitrite is influenced by the bacteria present in SFHs. Nitrite can cause adverse effects on human health. The previous research has focused on the characteristics of bacteria that may influence the nitrite conversion process in SFHs. This study aimed to a metagenomics analysis of bacteria present in the dirt of SFHs and evaluated nitrite levels in EBN on Sumatera Island.Materials and Methods:In total, 18 SFHs on Sumatera Island were selected, and EBN and dirt samples were collected from each SFH, resulting in 18 EBN and 18 dirt SFH samples. Raw uncleaned white EBN and dirt from three areas of SFH were collected. The samples were analyzed for nitrite levels using a spectrophotometer, and the metagenomics sequencing of SFH dirt samples was performed using the MinIon nanopore method. The sequenced data were analyzed using the EPI2ME software.Results:Of the 18 raw uncleaned white EBN samples, 9 (50%) had <30 ppm nitrite levels. The top five bacterial genera in SFH dirt samples in Group A (nitrite levels >30 ppm) were Aeromonas, Escherichia, Acinetobacter, Arcobacter, and Acetoanaerobium. Those in Group B (nitrite levels <30 ppm) were Aeromonas, Pseudomonas, Shewanella, Escherichia, and Acinetobacter. There were 12 genera of nitrifying bacteria in Group A and 8 in Group B. The total cumulative read of nitrifying bacteria in Groups A and B were 87 and 38 reads, respectively.Conclusion:This is the first study to show that characteristic bacteria present in the dirt of SFHs might significantly influence the conversion from nitrogen to nitrite. Approximately 50% of raw uncleaned EBN samples had <30 ppm nitrite levels. Aeromonas was the most dominant bacterial genus found in Groups A and B. The variations in genus and cumulative reads nitrifying bacteria in group A were greater than those in Group B. This study provides information on the characteristics of bacteria that may influence the nitrite conversion process in SFHs. Metagenomics data were obtained from the reading using the software EPI2ME. Further research is needed on the bacterial target species that can convert nitrite in SFHs.

IN SILICO ANALYSIS OF EDIBLE BIRD’S NEST PROTEINS AS POTENTIAL PRECURSORS FOR BIOACTIVE PEPTIDES

The present study aimed to perform an in silico evaluation of edible bird’s nest protein as potential precursors of bioactive peptides, as well as to determine whether such peptides can be released by selected proteolytic enzymes. Six edible bird’s nest (EBN) protein sequences from a previous study were chosen as potential precursors to produce bioactive peptides via in silico method using the BIOPEP database. AMCase protein sequences gave the highest number of bioactivities (16 to 18) and nucleobindin-2 protein gave the lowest number of bioactivities (9) among the other protein sequences. It was found that the most potential bioactive peptides from EBN proteins are angiotensin-converting enzyme (ACE) inhibitors and dipeptidyl peptidase-IV (DPPIV) inhibitors. Furthermore, in silico proteolysis using six selected enzymes was employed to release both dominant bioactivities in EBN proteins, which were ACE and DPP-IV inhibitors. This study shows that a combination of enzymes, chymotrypsin, and papain, produced the highest number of activities for both ACE and DPP-IV inhibitor peptides with the frequency of occurrence of bioactive peptides of 0.0968 and 0.1104, respectively. The toxic prediction tool, ToxinPred, found that all EBN peptides derived by in silico analysis were non-toxic. The current study proposed that EBN can serve as a potential source of bioactive peptides.