Antioxidant potential and protective effect of modified sea cucumber peptides against H2O2-induced oxidative damage in vitro HepG2 cells and in vivo zebrafish model.

In this study, modified sea Cucumber Peptides (SCP) were prepared by reacting with xylooligosaccharide (XOS) and alginate oligosaccharides (AOS) via glycation. Free radical inhibitory and inhibition of oxidative stress of modified SCP was evaluated using human hepatocellular carcinoma (HepG2) cells and zebrafish embryos. LC-MS analysis revealed that SCPs mainly consist of 40 active peptides, with an average molecular weight of 1122.168 Da and an average length of 11 amino acid residues. For amino acid composition, L-Asparagine, L-Methionine, and L-Aspartic Acid were dominant amino acids in SCP. The result showed that the antioxidant ability of SCP against 2,2-Diphenyl-1-picrylhydrazyl (DPPH), superoxide anion radical (O-2), and Hydroxyl Radical (OH) was significantly improved after modification. In HepG2 cells, the modified SCP showed stronger protection than native SCP native against H2O2-induced oxidative stress by enhancing cell viability and reducing radical oxygen species (ROS) generation. The inhibition effect of SCP was increased after modification with XOS and AOS by 13 % and 19 % respectively. Further studies displayed that the activity of antioxidative enzymes, including Superoxide dismutase (SOD), Glutathione Peroxidase (GPx), and catalase (CAT), was remarkably enhanced, whereas malondialdehyde (MDA) level was reduced compared with native SCP and H2O2-treated groups, thus, improving the intracellular antioxidant defenses. The gene expression analysis showed that the mechanism underlying the modified SCP protective effect may be linked with the capability to regulate Nuclear factor-erythroid factor 2-related factor 2 (NRF2) gene expression. The protective effect of modified SCP against H2O2 in vitro was confirmed in vivo by reduced toxicity in zebrafish embryos via improvement of mortality rate, hatching rate, heart beating rate, and deformities of the zebrafish model. However, SCPAOS conjugate displayed greater antioxidant potentials compared to the SCPXOS, the different effects between SCPAOS and SCPXOS could be due to their different antioxidant activity. Thus, modified SCP could be potentially used as a novel nutraceutical in the preparation of anti-aging food and medicine.

Exploration of hypoglycemic peptides from porcine collagen based on network pharmacology and molecular docking.

In recent years, the extraction of hypoglycemic peptides from food proteins has gained increasing attention. Neuropeptides, hormone peptides, antimicrobial peptides, immune peptides, antioxidant peptides, hypoglycemic peptides and antihypertensive peptides have become research hotspots. In this study, bioinformatic methods were used to screen and predict the properties of pig collagen-derived hypoglycemic peptides, and their inhibitory effects on α-glucosidase were determined in vitro. Two peptides (RL and NWYR) were found to exhibit good water solubility, adequate ADMET (absorption, distribution, metabolism, elimination, and toxicity) properties, potentially high biological activity, and non-toxic. After synthesizing these peptides, NWYR showed the best inhibitory effect on α-glucosidase with IC50 = 0.200±0.040 mg/mL, and it can regulate a variety of biological processes, play a variety of molecular functions in different cellular components, and play a hypoglycemic role by participating in diabetic cardiomyopathy and IL-17 signaling pathway. Molecular docking results showed that NWYR had the best binding effect with the core target DPP4 (4n8d), with binding energy of -8.8 kcal/mol. NWYR mainly bonded with the target protein through hydrogen bonding, and bound with various amino acid residues such as Asp-729, Gln-731, Leu-765, etc., thus affecting the role of the target in each pathway. It is the best core target for adjuvant treatment of T2DM. In short, NWYR has the potential to reduce type 2 diabetes, providing a basis for further research or food applications as well as improved utilization of pig by-products. However, in subsequent studies, it is necessary to further verify the hypoglycemic ability of porcine collagen active peptide (NWYR), and explore the hypoglycemic mechanism of NWYR from multiple perspectives such as key target genes, protein expression levels and differences in metabolites in animal models of hyperglycemia, which will provide further theoretical support for its improvement in the treatment of T2DM.

Improvement in the gelling properties of myofibrillar protein from the razor clam (Sinonovacula constricta) through phosphorylation and structural characterization of the modified protein.

This study investigated the modification of myofibrillar protein (MP) from the razor clam through phosphorylation by using various phosphate salts, namely, sodium tripolyphosphate (STPP), sodium trimetaphosphate (STMP), sodium polyphosphate (STTP) and sodium pyrophosphate (TSPP), and their mechanisms of action for functional and gelling properties. Fourier transform infrared spectrometry (FTIR) showed that MP introduced phosphate groups during phosphorylation; these phosphates changed the secondary structure. Moreover, MP after phosphorylation led to an increase in solubility, which was more evident in the case of TSPP phosphorylation, leading to the improvement of gel properties. Therefore, TSPP was the phosphate with the best gel properties in the modification of MP, showing the highest phosphorus content, which resulted in better gelling properties owing to its relatively shorter chains. These results showed that phosphate was able to improve protein cross-linking through ion interactions and electrostatic interactions, which ultimately improved the gelling properties of the razor clam protein.

Marine Chitosan-Oligosaccharide Ameliorated Plasma Cholesterol in Hypercholesterolemic Hamsters by Modifying the Gut Microflora, Bile Acids, and Short-Chain Fatty Acids.

This study evaluated the cholesterol-alleviating effect and underlying mechanisms of chitosan-oligosaccharide (COS) in hypercholesterolemic hamsters. Male hamsters (n = 24) were divided into three groups in a random fashion, and each group was fed one particular diet, namely a non-cholesterol diet (NCD), a high-cholesterol diet (HCD), and an HCD diet substituting 5% of the COS diet for six weeks. Subsequently, alterations in fecal bile acids (BAs), short-chain fatty acids (SCFAs), and gut microflora (GM) were investigated. COS intervention significantly reduced and increased the plasma total cholesterol (TC) and high-density lipoprotein-cholesterol (HDL-C) levels in hypercholesteremic hamsters. Furthermore, Non-HDL-C and total triacylglycerols (TG) levels were also reduced by COS supplementation. Additionally, COS could reduce and increase food intake and fecal SCFAs (acetate), respectively. Moreover, COS had beneficial effects on levels of BAs and GM related to cholesterol metabolism. This study provides novel evidence for the cholesterol-lowering activity of COS.

Food Technology Neophobia Scales in cross-national context: Consumers' acceptance of food technologies between Chinese and New Zealand.

An increasing number of novel food technologies have been developed to meet consumers' growing desire for safe and high-quality foods. However, consumers can be cautious of novel food technologies, and their acceptance cannot be guaranteed. Food Technology Neophobia Scales (FTNS) have been proven to be an effective tool to predict consumers' behavior toward novel food technologies in a range of individual countries, but not for cross-national contexts. To fill the gap, this study designed a survey involving 604 Chinese and 614 New Zealand respondents, investigating the influence of consumers' food technology neophobia (FTN) on their acceptance of food technologies. Chinese respondents' FTNS score (50.62) was lower than that of New Zealand respondents (55.02), which was in line with the finding that Chinese respondents' acceptance of all tested food technologies was higher than New Zealand respondents (0.34-0.86 in a Likert-7 scale). Chinese respondents' acceptance was determined by their perception of benefits, whereas New Zealand respondents were influenced by their perception of both benefits and risks. The findings conclude that FTNS is a valid tool to reflect consumers' acceptance of novel food technologies in cross-national contexts, although the influence of FTN varies among consumers from different countries. PRACTICAL APPLICATION: China has the largest food market, and New Zealand is a leading food exporter. Understanding their consumers' acceptance of and attitudes toward food technologies will help food companies implement appropriate strategies in developing and using novel technologies. Because FTNS first was constructed in 2008, it has been applied in Australia, Italy, Canada, Finland, Korea, China, Chile, Brazil, and Uganda; the findings of this study will allow these individual studies on FTNS to better connect, help food companies predict consumer acceptance of food technologies in the global market, and help them identify early adopters of novel food technologies in new food markets.

Monosaccharide-induced glycation enhances gelation and physicochemical properties of myofibrillar protein from oyster (Crassostrea gigas).

Glycation offers a promising potential to improve protein gelling properties in food industries. Therefore, the study was aimed to illustrate the effect of five monosaccharides (erythrose-aldotetrose, xylose-aldopentose, glucose-aldohexose, galactose-aldohexose, and fructose-ketohexose) with different carbon numbers and structure on the structure-gelling relationship of myofibrillar protein (MP) from oyster (Crassostrea gigas). Results showed that monosaccharides significantly increased the glycation degree of MP by increasing sulfhydryl content, forming stable tertiary conformation and decreasing surface hydrophobicity. Moreover, the gel properties of MP like gel strength, water holding capacity, water mobility were improved by alleviating aggregation including the increase of solubility and the decrease of particle sizes. Oyster MP glycated by glucose (aldohexose) possessed the optimal gel properties. Molecular docking simulation showed that hydrogen bonds and hydrocarbon bonds were the mainly non-covalent binding modes. The study will provide a theoretical basis for oyster protein glycation and expand its application on food gel.

Protocols for extraction and purification of rutin from leafy by-products of asparagus (Asparagus officinalis) and characterization of the purified product.

Valorization of asparagus leafy by-products as a potential source of rutin through selected extraction and purification protocols was investigated. Protocol resulting in the highest extraction yield was first selected. Crude extract was subject to purification via multiple liquid-liquid back extraction using ethanol, methanol or water as a solvent; selection of the most appropriate purification solvent was made based on rutin solubility. The proposed purification protocol yielded yellow-color crystals, which were characterized by fluorescence microscopy, Fourier-transform infrared spectroscopy and liquid chromatography-mass spectrometry to confirm them as rutin. Purity of rutin was confirmed by ultra-performance liquid chromatography at 97.6%; yield of the purified rutin was determined to be 78.2%. The remaining rutin (21.8%) was found in the liquids collected at various stages of purification; such liquids could be recycled using the same purification process. The proposed protocols are simple, yet effective for rutin extraction and purification from asparagus leafy by-products.

Wool keratin as a novel alternative protein: A comprehensive review of extraction, purification, nutrition, safety, and food applications.

The growing global population and lifestyle changes have increased the demand for specialized diets that require protein and other essential nutrients for humans. Recent technological advances have enabled the use of food bioresources treated as waste as additional sources of alternative proteins. Sheep wool is an inexpensive and readily available bioresource containing 95%-98% protein, making it an outstanding potential source of protein for food and biotechnological applications. The strong structure of wool and its indigestibility are the main hurdles to achieving its potential as an edible protein. Although various methods have been investigated for the hydrolysis of wool into keratin, only a few of these, such as sulfitolysis, oxidation, and enzymatic processes, have the potential to generate edible keratin. In vitro and in vivo cytotoxicity studies reported no cytotoxicity effects of extracted keratin, suggesting its potential for use as a high-value protein ingredient that supports normal body functions. Keratin has a high cysteine content that can support healthy epithelia, glutathione synthesis, antioxidant functions, and skeletal muscle functions. With the recent spike in new keratin extraction methods, extensive long-term investigations that examine prolonged exposure of keratin generated from these techniques in animal and human subjects are required to ascertain its safety. Food applications of wool could improve the ecological footprint of sheep farming and unlock the potential of a sustainable protein source that meets demands for ethical production of animal protein.

Chinese Consumers' Acceptance of Novel Technologies Designed To Control Foodborne Bacteria.

ABSTRACT: Chinese consumers (n = 604) were asked three times to rate their acceptance of traditional thermal processing and several newer technologies (high pressure processing, irradiation, bacteriophages, antimicrobial packaging, pulsed electric fields, and rinsing meat carcasses with antimicrobial solutions) designed to control foodborne bacteria in food (i) based on their existing knowledge, (ii) after the provision of information about L. monocytogenes, and (iii) after further reading a brief description of the technology. Thermal processing (6.00 of 7 on Likert scale) and high pressure processing (5.73 of 7) were rated the most acceptable technologies, and rinsing with antimicrobial solutions (4.43 of 7) was rated the least acceptable technology. Information outlining the benefits of a technology had a larger positive effect on acceptance of every novel technology discussed (increases of 0.14 to 0.49 units depending on the technology) than information about L. monocytogenes and a brief description of the technology. This research has shown that providing information about foodborne bacteria and a technology designed to control them will improve consumers' acceptance of the technology, with the provision of information being of most importance for technologies for which the consumers are less familiar. Chinese consumers accepted or rejected a food technology for a variety of reasons; however, consumers with a greater awareness of foodborne bacteria rated the acceptability of novel technologies designed to kill bacteria higher than those with a low awareness (0.56 to 1.71 units depending on the technology). The results of this research will be of benefit to food companies considering adopting novel technologies to control foodborne bacteria because they provide insights that will enable them to develop more effective communication and implementation strategies.

PHNQ from Evechinus chloroticus Sea Urchin Supplemented with Calcium Promotes Mineralization in Saos-2 Human Bone Cell Line.

Polyhydroxylated naphthoquinones (PHNQs), known as spinochromes that can be extracted from sea urchins, are bioactive compounds reported to have medicinal properties and antioxidant activity. The MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) cell viability assay showed that pure echinochrome A exhibited a cytotoxic effect on Saos-2 cells in a dose-dependent manner within the test concentration range (15.625-65.5 µg/mL). The PHNQ extract from New Zealand sea urchin Evechinus chloroticus did not induce any cytotoxicity within the same concentration range after 21 days of incubation. Adding calcium chloride (CaCl2) with echinochrome A increased the number of viable cells, but when CaCl2 was added with the PHNQs, cell viability decreased. The effect of PHNQs extracted on mineralized nodule formation in Saos-2 cells was investigated using xylenol orange and von Kossa staining methods. Echinochrome A decreased the mineralized nodule formation significantly (p < 0.05), while nodule formation was not affected in the PHNQ treatment group. A significant (p < 0.05) increase in mineralization was observed in the presence of PHNQs (62.5 µg/mL) supplemented with 1.5 mM CaCl2. In conclusion, the results indicate that PHNQs have the potential to improve the formation of bone mineral phase in vitro, and future research in an animal model is warranted.

In vitro antioxidant and antimicrobial activities, and in vivo anti-inflammatory activity of crude and fractionated PHNQs from sea urchin (Evechinus chloroticus).

This study investigated the bioactivities of polyhydroxyl-1,4-naphthoquinone (PHNQ) extracts from Evechinus chloroticus shell waste. PHNQs were extracted from E. chloroticus shells and spines using different solvents and the crude extracts were fractionated by HPLC. The antioxidant activity of the PHNQ extracts were evaluated by the DPPH, ABTS, ORAC and FRAP assays. Ethyl acetate was the best extraction solvent and spine extracts showed better antioxidant activity than shell extracts (p < 0.05). The HPLC fraction containing spinochrome E showed the highest antioxidant activity (p < 0.05). The Minimum Inhibitory Concentration of the PHNQ crude extracts and the HPLC fractions ranged from 250 to 2500 µg/mL depending on the PHNQ extract and microbial species tested. Treatment by PHNQ extracts resulted in alteration of the morphology of the microbial cell wall as observed by transmission electron microscopy. PHNQ extracts also exhibited anti-inflammatory activity in rats (ED50 = 8.26 ± 0.22 µg), comparable to that of Celecoxib (6.12 ± 0.18 µg).

Effect of pulsed electric fields (PEF) on physico-chemical properties, ß-carotene and antioxidant activity of air-dried apricots.

Fresh apricots pre-treated by pulsed electric fields at different intensities [LPEF, 0.65 kV/cm, 100 Hz, 20 µs and total treatment time 30 s; HPEF1, 1.25 kV/cm, 100 Hz, 20 µs and total treatment time 30 s; HPEF2, 1.25 kV/cm, 100 Hz, 20 µs and total treatment time 60 s], along with controls [non-treated, non-treated and sulphite treated, and heat pre-treatment at 80 °C, for 10 min (HC)] and soaked in 0.2% sodium sulphite solution for 1 h and then were subject to hot air drying. The changes in drying rate, polyphenol oxidase, peroxidase, and ß-carotene contents as well as antioxidant activity and colour in pre-treatment and hot air-dried apricot samples were investigated. PEF and heat treatments increased the drying rate of apricots. PEF treatments had no effect on the PPO activity and decreased the POD activity (p < 0.05). HPEF2 treatment retained more ß-carotene, higher antioxidant activity and suffered less browning during processing. Overall, the results indicate that combining sulphite treatment with PEF produces dried apricots with more ß-carotene and antioxidant activity, and better colour.

Marine Waste Utilization as a Source of Functional and Health Compounds.

Consumer demand for convenience has led to large quantities of seafood being value-added processed before marketing, resulting in large amounts of marine by-products being generated by processing industries. Several bioconversion processes have been proposed to transform some of these by-products. In addition to their relatively low value conventional use as animal feed and fertilizers, several investigations have been reported that have demonstrated the potential to add value to viscera, heads, skins, fins, trimmings, and crab and shrimp shells by extraction of lipids, bioactive peptides, enzymes, and other functional proteins and chitin that can be used in food and pharmaceutical applications. This chapter is focused on reviewing the opportunities for utilization of these marine by-products. The chapter discusses the various products and bioactive compounds that can be obtained from seafood waste and describes various methods that can be used to produce these products with the aim of highlighting opportunities to add value to these marine waste streams.

Extraction, structural characterization and stability of polyhydroxylated naphthoquinones from shell and spine of New Zealand sea urchin (Evechinus chloroticus).

The extraction of polyhydroxylated naphthoquinone (PHNQ) pigments from the shell and spines of the New Zealand sea urchin Evechinus chloroticus was evaluated using six different macroporous resins as an alternative to using organic solvent extraction alone. Four of the resins evaluated in this study (D4006, D4020, D101 and NKA-9) provided the best extraction of PHNQ pigments in terms of the overall adsorption and desorption of E. chloroticus PHNQ pigments from the resins. Organic solvents alone had a higher yield of PHNQs than the resins. The PHNQ composition was characterised by high-performance liquid chromatography (HPLC) with diode-array detection and mass spectrometry. Five PHNQ compounds (spinochromes E, B, C, A and echinochrome A), and three aminated PHNQ compounds (spinamine E, echinamines A and B) were identified. The pigments were found to be prone to degradation on exposure to light, with the aminated PHNQ pigments being the least stable.

Naphthoquinones of the spinochrome class: occurrence, isolation, biosynthesis and biomedical applications.

Quinones are widespread in nature and have been found in plants, fungi and bacteria, as well as in members of the animal kingdom. More than forty closely related naphthoquinones have been found in echinoderms, mainly in sea urchins but occasionally in brittle stars, sea stars and starfish. This review aims to examine controversial issues on the chemistry, biosynthesis, functions, stability and application aspects of the spinochrome class, a prominent group of secondary metabolites found in sea urchins. The emphasis of this review is on the isolation and structure of these compounds, together with evaluation of their relevant biological activities, source organisms, the location of origin and methods used for isolation and identification. In addition, the studies of their biosynthesis and ecological function, stability and chemical synthesis have been highlighted. This review aims to establish a focus for future spinochrome research and its potential for benefiting human health and well-being.

The protective effect of clay minerals against damage to adsorbed DNA induced by cadmium and mercury.

The adsorption of Salmon Sperm DNA on three kinds of raw clay (rectorite, montmorillonite and sericite) was investigated as a function of pH, ionic strength and the concentrations of DNA and phosphate ions in solution. The DNA adsorption was reduced in the following order: rectorite>montmorillonite>sericite. Based on these findings, there is a strong evidence that the mechanisms for DNA adsorption on clay involve electrostatic forces, cation bridging and ligand exchange. Cyclic voltammetry (CV) and UV-vis absorption and fluorescence spectroscopy were used to compare the properties of unbound DNA and the absorbed DNA on rectorite, both in the absence and presence of Cd(2+) and Hg(2+) inaqueous solutions. The interaction of heavy metals with the unbound DNA was evidenced by the disappearance of reduction peaks in CV, a small bathochromic shift in UV-vis spectroscopy and an incomplete quenching in the emission spectra. Such changes were not observed in the DNA-rectorite hybrids, which is evidence that adsorption on the clay can reduce the extent of the DNA damage caused by heavy metals. Therefore, in these experience the rectorite played an important role in protecting DNA against Cd(2+) and Hg(2+) induced damage.