Recovery of value-added glycopeptides from edible bird's nest (EBN) co-products: enzymatic hydrolysis, physicochemical characteristics and bioactivity

Gellan gum-sialoglycan conjugates: a mucin mimic for alleviating inflammation in Caco-2 cells and modulating gut microbiota in the elderly

The sialylation of intestinal mucins plays a crucial role in maintaining intestinal homeostasis and shaping the gut microbiota. This study aims to develop a mucin-like polymer to modulate the intestinal microbiota in the elderly individuals. We synthesized functionalized conjugates using sialic acid monomer, 3'-sialyllactose, and Gellan gum, resulting in a series of GG-sialoglycan conjugates with diverse glycan chain lengths and terminal structures. The sialic acid contents of GG-EDA-Sia, GG-EDA-SL, GG-HAD-Sia, and GG-HAD-SL were 28.48 %, 29.78 %, 23.45 and 41.58 %, respectively. These conjugates exhibited anti-digestion effects. In addition, they demonstrated favorable biocompatibility and exhibited notable anti-inflammatory properties. In vitro fermentation experiments using fecal bacteria from elderly individuals revealed that GG-sialoglycan conjugates enhanced the proliferation of beneficial bacteria such as Lactobacillus, Bifidobacterium, and Blautia, while simultaneously suppressing pathogens like Escherichia-Shigella. It is worth noting that GG-sialoglycan conjugates containing 3'-sialyllactose exhibited superior prebiotic activity compared to those with sialic acid monomer. In summary, our findings strongly support the promising potential of functional sialic acid-based macromolecular glycan conjugates as a novel strategy to improve aging-related intestinal health.

Combining Sensory Analysis and Flavoromics to Determine How the Maillard Reaction Affects the Flavors of Golden Pomfret Hydrolysates

Enzymatic hydrolysis can enhance the flavor of aquatic products. Nevertheless, the strong fishy odor restricts its utilization in culinary applications. This study is centered on enhancing the flavor of golden pomfret samples by promoting the Maillard reaction (MR) between golden pomfret hydrolysate (GHES) and reducing sugars. The research results demonstrate that the Maillard reaction significantly improves the sensory characteristics of GHES. It prompts the formation of diverse volatile compounds, such as aldehydes, esters, and furans. Simultaneously, it reduces the relative amounts of substances associated with fishy odor, such as 1-Octen-3-ol and Hexanal. Moreover, the Maillard reaction increases the contents of amino acids contributing to umami and sweetness, as well as 5'-nucleotides in the samples, thus enriching their umami flavor profiles. After undergoing the Maillard reaction treatment, the antioxidant capacity of the samples is also significantly enhanced (p < 0.05). This research highlights the potential of the Maillard reaction in improving both the flavor and antioxidant properties of GHES, establishing a theoretical basis for elevating the quality of golden pomfret products.

Development and evaluation of an immunoassay for the quantification of N-acetylneuraminic acid (Neu5Ac) in foods and biosamples

N-acetylneuraminic acid is an active ingredient in tonic foods and an important additive in foods and biopharmaceuticals. To address the limitations of existing methods of N-acetylneuraminic acid quantification, we developed an immunoassay based on antibodies induced in hens using artificial antigen, showing high sensitivity and specificity with no cross-reactivity with eight N-acetylneuraminic acid analogues. An IgY-based indirect competitive enzyme-linked immunosorbent assay showed a detection range of 1.14 to 70.08 ng/mL and a limit of detection of 0.57 ng/mL. In spiked samples, recoveries by the indirect competitive enzyme-linked immunosorbent assay ranged from 74.05% to 110.87% compared with HPLC (73.01% to 108.8%). Consistency between the indirect competitive enzyme-linked immunosorbent assay and HPLC was satisfactory (R2 = 0.9736), demonstrating this established immunoassay as a rapid and reliable approach for N-acetylneuraminic acid analysis. The assay described in this study provides an important method for the screening of N-acetylneuraminic acid in biological samples and foodstuffs.

Extraction, structural characteristics and antioxidant activity of hemp seeds glycoprotein

The extraction process of hemp seeds glycoprotein (HGP) was optimized by using response surface methodology based on the single-factor experiments, and the structure characteristic and antioxidant activity of HGP were evaluated. The optimum conditions were extracting temperature of 58.54 °C, material-liquid ratio of 1:22.21 and ultrasonic power of 344.53 W. The molecular weight of HGP was identified by SDS-PAGE to be about 35 kDa. The FT-IR results demonstrated the presence of uronic acid and pyranose in the HGP structure. UV spectral scanning results confirmed the presence of a polypeptide skeleton structure and aromatic amino acids in HGP. TGA analysis revealed two weight loss intervals for HGP, with a thermal degradation temperature of 341.6 °C. Moreover, HGP demonstrated good antioxidant activity in vitro, with IC50 values of all antioxidant indexes below 0.5 mg/mL. These findings provide a basis for in-depth exploration of functional characteristics of hemp seeds glycoprotein.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-024-01583-3.

Fractionation and characterisation of sialylated-mucin glycoprotein from edible birds' nest hydrolysates through anion exchange chromatography

Edible bird's nest (EBN) is made up of sialylated-mucin glycoprotein with various health benefits due to its high antioxidative activity. However, as a macromolecule with distinct charged sialic acid and amino acids, fractions with different charges would have varied physicochemical properties and antioxidant activity, which have not been studied. Therefore, this study aimed to fractionate and purify the enzymatic hydrolysed of cleaned EBN (EBNhc) and EBN by-product (EBNhbyp) through anion exchange chromatography (AEC), and determine their molecular weights, physicochemical properties, and antioxidative activities. Overall, 26 fractionates were collected from enzymatic hydrolysate by AEC, which were classified into 5 fractions. It was found that the positively charged fraction of EBNhc (CF 1) and EBNhbyp (DF 1) showed the significantly highest (p < 0.05) soluble protein contents (22.86 and 18.40 mg/g), total peptide contents (511.13 and 800.47 mg/g) and ferric reducing antioxidant power (17.44 and 6.96 mg/g) among the fractionates. In conclusion, a positively charged fraction (CF 1 and DF 1) showed more desired physicochemical properties and antioxidative activities. This research suggests the potential of AEC fractionation as a technology to purify EBN and produce positively charged EBN fractionates with antioxidative potential that could be applied as food components to provide health benefits.

Insights into the Structure, Metabolism, Biological Functions and Molecular Mechanisms of Sialic Acid: A Review

Sialic acid (SA) is a kind of functional monosaccharide which exists widely in edible bird's nest (EBN), milk, meat, mucous membrane surface, etc. SA is an important functional component in promoting brain development, anti-oxidation, anti-inflammation, anti-virus, anti-tumor and immune regulation. The intestinal mucosa covers the microbial community that has a significant impact on health. In the gut, SA can also regulate gut microbiota and metabolites, participating in different biological functions. The structure, source and physiological functions of SA were reviewed in this paper. The biological functions of SA through regulating key signaling pathways and target genes were discussed. In summary, SA can modulate gut microbiota and metabolites, which affect gene expressions and exert its biological activities. It is helpful to provide scientific reference for the further investigation of SA in the functional foods.

Marine glycoproteins: a mine of their structures, functions and potential applications

Many bioactive compounds are reported from marine organisms, which are significantly different from those found in terrestrial organisms regarding their chemical structures and pharmacological activities. Marine glycoproteins (MGs) have aroused increasing attention as a good nutrient source owing to their potential applications in medicine, cosmetics and food. However, there is a lack of a comprehensive study on MGs to help readers understand the current state of research on marine-derived glycoproteins. The current review compiles the recent progress made on the structures and functions of MGs with future perspectives to maximize their value and applications via bibliometric analysis methods for the first time. The current research on MGs appears mostly limited to the laboratory, with no large-scale production of marine glycoproteins developed. The sugar chains are bound to proteins through covalent bonds that can readily be cleaved leading to difficultly in their separation and purification. Health effects attributed to MGs include treatment of inflammatory diseases, as well as anti-oxidant, immune modulation, anti-tumor, hypolipidemic, hypoglycemic, anti-bacterial and anti-freeze activities. This review can not only deepen the understanding of the functions of MGs, but also lay an important foundation for the further development and utilization of marine resources.

Effect of ultrasound-assisted pretreatment in combination with heating on characteristics and antioxidant activities of protein hydrolysate from edible bird's nest co-product

Protein hydrolysates (P-HS) from edible bird's nest co-product prepared without and with ultrasound (US) pretreatment in combination with heating before hydrolysis using alcalase at different concentrations were characterized. US treatment of co-product in water at 60% amplitude for 20 min, followed by heating at 95 °C for 3 h was done before enzymatic hydrolysis. The degree of hydrolysis (DH), yield and sialic acid (SL) content of P-HS samples were not different (p > 0.05) when 1 or 2% alcalase was used for hydrolysis. The highest protein content and lightness (L * ) were observed in P-HS prepared from co-product subjected to US treatment (60% amplitude for 20 min) using 1% alcalase for hydrolysis. When antioxidant activities of dried P-HS were determined, P-HS from co-product subjected to US treatment had higher DPPH and ABTS radical scavenging activities, ferrous reducing antioxidant power and oxygen radical absorbance capacity, compared to those prepared from non-US treated co-product. P-HS with higher DH contained greater amount of small peptides having MW lower than 1,883 Da. The P-HS produced under optimum condition had major essential amino acids (EA-A) including leucine, threonine, lysine and valine of 4.28, 3.53, 3.30 and 3.08%, respectively. Therefore, P-HS from co-product could serve as both nutrients and functional ingredients.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-022-05420-5.

Effects of Continuous Care Combined with Evidence-Based Nursing on Mental Status and Quality of Life and Self-Care Ability in Patients with Liver from Breast Cancer: A Single-Center Randomized Controlled Study

Objective

To explore the multidisciplinary collaborative extended care combined with EBN to improve breast cancer liver metastasis patients' psychological status and self-care ability.

Background

In the past ten years, the number of breast cancer patients with liver metastases has increased year by year, becoming a global public health problem. Studies have shown that 30% of breast cancer patients with liver metastases show varying degrees of anxiety and depression, and their quality of life is significantly lower than that of the normal population. Multidisciplinary collaborative continuous care can improve the prognosis of breast cancer treatment to a certain extent and is the key to meeting the needs of cancer patients.

Materials and Methods

The clinical data of 96 patients with liver metastases from breast cancer were selected as the study subjects and divided into a comparison group and an observation group of 48 cases each according to a random number table. Among them, the comparison group implemented evidence-based nursing (EBN) and the observation group implemented multidisciplinary collaborative extended care based on the comparison group. The effects of psychological status, quality of life, self-care ability, and sleep quality were compared between the two groups before and after nursing care.

Results

After nursing, the sleep quality scores, increased awakening scores, sleep quality that shows weakness because important things are not steady or strong scores, and night terrors scores of the two groups of breast cancer patients with liver the spread of diseases through the body were very much improved, and the sleep quality scores of the instance of watching, noticing, or making a statement group were much lower than those of the comparison group (P < 0.05). After nursing, the fear and stress-related score, depression score, tiredness and distress score, and anger score of the two groups of breast cancer patients with liver (the spread of diseases through the body) were very much improved, and the mental state score of the instance of watching, noticing, or making a statement group was much lower than that of the comparison group (P < 0.05). The scores of self-care skills, self-responsibility, health knowledge, and self-idea of patients in the instance of watching, noticing, or making a statement group after nursing were higher than those in the comparison group (P < 0.05). After nursing, the scores of mental energy, social interaction, emotional restriction, and mental status of patients in (instance of watching, noticing, or making a statement) were much higher than those in the comparison group (P < 0.05).

Conclusion

Multidisciplinary collaborative continuous nursing combined with EBN can effectively improve the sleep quality and psychological state of patients with breast cancer and liver metastases and improve self-care ability.

Using RSM for Optimum of Optimum Production of Peptides from Edible Bird’s Nest By-Product and Characterization of Its Antioxidant’s Properties

In this research, the neutrase hydrolysis conditions of edible bird’s nest (EBN) by-products were optimized by response surface methodology (RSM). Antioxidant peptides were then isolated from the EBN by-products by ultrafiltration and chromatography taking the DPPH radical scavenging ability as an indicator. The antioxidant activity of the purified peptides was estimated by radical scavenging ability and sodium nitroprusside (SNP)-induced damage model in PC12 cells. When the enzyme concentration was10 kU/g-hydrolysis temperature was 45 °C, and hydrolysis time was 10.30 h, the degree of hydrolysis (DH) of EBN by-product hydrolysate (EBNH) was the highest. The purified peptide exerted strong scavenging ability with EC₅₀ values of 0.51, 1.31, and 0.65 mg/mL for DDPH, ABTS, and O₂⁻ radicals, respectively. In addition, the purified peptides could significantly reduce the SNP-induced oxidative damage of PC12 cells, and twelve peptides that were rich in leucine (Leu), valine (Val), and lysine (Lys) were identified by LC-MS/MS. These results suggested that EBN by-products have potential as new materials for natural antioxidant peptides.

Edible Bird's Nest: Recent Updates and Industry Insights Based On Laboratory Findings

Edible bird’s nest (EBN) is a traditional Chinese delicacy made of the saliva of swiftlets found in Southeast Asia. With increasing demands for EBN, quality control of EBN products is important for safe consumption. The processing steps are particularly important for efficient extraction of bioactive compounds. Geographical location, collection place, and harvesting season contribute to differences in nutritional contents in EBN. Concerns regarding presence of adulterant, chemical, and microbial contaminants in EBN as well as authentication and chemical composition measuring methods are discussed in this review. Recent discoveries of beneficial health functions of EBN in antimicrobial and antiviral actions, immunomodulation, cancer prevention and treatment, tissue regeneration, cardiometabolic maintenance, antioxidant action and neuroprotection are also reviewed. Our review provides an update on the recent research on EBN.

Review of sialic acid's biochemistry, sources, extraction and functions with special reference to edible bird's nest

Sialic acids are a group of nine-carbon α-keto acids. Sialic acid exists in more than 50 forms, with the natural types discovered as N-acetylneuraminic acid (Neu5Ac), deaminoneuraminic acid (2-keto-3-deoxy-nonulononic acid or Kdn), and N-glycolylneuraminic acid (Neu5Gc). Sialic acid level varies depending on the source, where edible bird's nest (EBN), predominantly Neu5Ac, is among the major sources of sialic acid. Due to its high nutritive value and complexity, sialic acid has been studied extensively through acid, aqueous, and enzymatic extraction. Although detection by chromatographic methods or mass spectrometry is common, the isolation and recovery work remained limited. Sialic acid is well-recognised for its bioactivities, including brain and cognition development, immune-enhancing, anti-hypertensive, anticancer, and skin whitening properties. Therefore, sialic acid can be used as a functional ingredient in the various industries. This paper reviews the current trend in the biochemistry, sources, extraction, and functions of sialic acids with special reference to EBN.

The Anti-Viral and Anti-Inflammatory Properties of Edible Bird's Nest in Influenza and Coronavirus Infections: From Pre-Clinical to Potential Clinical Application

Edible bird's nest (BN) is a Chinese traditional medicine with innumerable health benefits, including anti-viral, anti-inflammatory, neuroprotective, and immunomodulatory effects. A small number of studies have reported the anti-viral effects of EBN against influenza infections using in vitro and in vivo models, highlighting the importance of sialic acid and thymol derivatives in their therapeutic effects. At present, studies have reported that EBN suppresses the replicated virus from exiting the host cells, reduces the viral replication, endosomal trafficking of the virus, intracellular viral autophagy process, secretion of pro-inflammatory cytokines, reorient the actin cytoskeleton of the infected cells, and increase the lysosomal degradation of viral materials. In other models of disease, EBN attenuates oxidative stress-induced cellular apoptosis, enhances proliferation and activation of B-cells and their antibody secretion. Given the sum of its therapeutic actions, EBN appears to be a candidate that is worth further exploring for its protective effects against diseases transmitted through air droplets. At present, anti-viral drugs are employed as the first-line defense against respiratory viral infections, unless vaccines are available for the specific pathogens. In patients with severe symptoms due to exacerbated cytokine secretion, anti-inflammatory agents are applied. Treatment efficacy varies across the patients, and in times of a pandemic like COVID-19, many of the drugs are still at the experimental stage. In this review, we present a comprehensive overview of anti-viral and anti-inflammatory effects of EBN, chemical constituents from various EBN preparation techniques, and drugs currently used to treat influenza and novel coronavirus infections. We also aim to review the pathogenesis of influenza A and coronavirus, and the potential of EBN in their clinical application. We also describe the current literature in human consumption of EBN, known allergenic or contaminant presence, and the focus of future direction on how these can be addressed to further improve EBN for potential clinical application.

Functional polysaccharides of fucoidan, laminaran and alginate from Malaysian brown seaweeds (Sargassum polycystum, Turbinaria ornata and Padina boryana)

Brown seaweeds are rich source of functional polysaccharides that exhibit various bioactivities. However, Malaysian seaweeds are under-utilised, leading to low revenue throughout the supply chain of the seaweed industry. The aims of this study were to extract the functional polysaccharides, namely fucoidan (F), laminaran (L) and alginate (A) from Malaysian brown seaweeds (Sargassum polycystum, Turbinaria ornata and Padina boryana) and subsequently evaluate the properties of the extracted polysaccharides. P. boryana recorded the significantly (p ≤ 0.05) highest carbohydrate content (74.78 ± 1.63%) with highest fucoidan yield (Fpad = 1.59 ± 0.16%) while T. ornata contained significantly (p ≤ 0.05) highest alginate yield (Atur = 105.19 ± 3.45%). Water activities of these extracted polysaccharides varied from 0.63-0.71 with average score of browning indexes (~40). Fourier transform infrared (FTIR) spectroscopy analysis demonstrated that the extracted polysaccharides exhibited similar spectral pattern of spectra with the respective standards. Meanwhile, laminaran extracts showed the significantly highest (p ≤ 0.05) total phenolic contents (Lsar = 43.29 ± 0.43 mgGAE/g) and superoxide anion scavenging activity (Lsig = 21.7 ± 3.6%). On the other hand, the significantly highest (p ≤ 0.05) DPPH scavenging activity was recorded in alginate with Asar at 85.3 ± 0.8%. These findings reported the properties and bioactivities of natural polysaccharides from Malaysian brown seaweeds that revealed the potential to develop high-value functional ingredients from Malaysian brown seaweeds.