Preparation of 1,2-benzenedialdehyde-crosslinked oligo-gelatin conjugates and poly-gelatin nanoparticles to stabilize traditional and Pickering emulsions, respectively.

This research aimed to develop a desolvation and 1,2-benzenedialdehyde crosslinking method to prepare crosslinked gelatin substances for emulsion stabilization. The oligo-gelatin conjugates and poly-gelatin nanoparticles could be formed at the 1,2-benzenedialdehyde concentration of 50 g/L and ≥ 150 g/L, respectively. The formation mechanism involved intra/inter-molecular amine-benzenedialdehyde-thiol and amine-benzenedialdehyde-amine crosslinking reactions. With increasing 1,2-benzenedialdehyde preparation concentrations (50-450 g/L), the crosslinked gelatin substance sizes increased from 81.5 ± 20.1 nm to 105.5 ± 20.8 nm in the dried state, and increased (from 35 ± 8 nm to 220 ± 36 nm) then decreased to 115 ± 28 nm in the water. Furthermore, the fish oil emulsions stabilized by the crosslinked gelatin substances showed different creaming stability: 250 g/L (43.5 ± 1.5 %) > 350 g/L (41.4 ± 1.0 %) > 450 g/L (37.5 ± 2.2 %) > 150 g/L (11.2 ± 0.4 %) > 50 g/L (0.0 ± 0.0 %). The results suggested this method was useful for preparing oligo-gelatin conjugates and poly-gelatin nanoparticles to stabilize traditional and Pickering emulsions, respectively.

Preparation, Optimization, and Characterization of Bovine Bone Gelatin/Sodium Carboxymethyl Cellulose Nanoemulsion Containing Thymol.

The aim of this study is to produce a biodegradable food packaging material that reduces environmental pollution and protects food safety. The effects of total solids content, substrate ratio, polyphenol content, and magnetic stirring time on bovine bone gelatin/sodium carboxymethylcellulose nanoemulsion (BBG/SCMC-NE) were investigated using particle size, PDI, turbidity, rheological properties, and zeta potential as evaluation indexes. The micro, structural, antioxidant, encapsulation, and release properties were characterized after deriving its optimal preparation process. The results showed that the nanoemulsion was optimally prepared with a total solids content of 2%, a substrate ratio of 9:1, a polyphenol content of 0.2%, and a magnetic stirring time of 60 min. SEM showed that the nanoemulsion showed a dense and uniform reticulated structure. FTIR and XRD results showed that covalent cross-linking of proteins and polysaccharides altered the structure of gelatin molecular chains to a more compact form but did not change its semi-crystalline structure. DSC showed that the 9:1 BBG/SCMC-NE had a higher thermal denaturation temperature and greater thermal stability, and its DPPH scavenging rate could reach 79.25% and encapsulation rate up to 90.88%, with excellent slow-release performance. The results of the study provide basic guidance for the preparation of stable active food packaging with excellent properties.

Effects of polyphenol and gelatin types on the physicochemical properties and emulsion stabilization of polyphenol-crosslinked gelatin conjugates.

Herein, six types of polyphenol-crosslinked gelatin conjugates (PGCs) with ≥ two gelatin molecules were prepared using a covalent crosslinking method with two types of polyphenols (tannic acid and caffeic acid) and three types of gelatins (bovine bone gelatin, cold water fish skin gelatin, and porcine skin gelatin) for the emulsion stabilization. The structural and functional properties of the PGCs were dependent on both polyphenol and gelatin types. The storage stability of the conjugate-stabilized emulsions was dependent on the polyphenol crosslinking, NaCl addition, and heating pretreatment. In particular, NaCl addition promoted the liquid-gel transition of the emulsions: 0.2 mol/L > 0.1 mol/L > 0.0 mol/L. Moreover, NaCl addition also increased the creaming stability of the emulsions stabilized by PGCs except tannic acid-crosslinked bovine bone gelatin conjugate. All the results provided useful knowledge on the effects of molecular modification and physical processing on the properties of gelatins.

Effects of Long-Term Administration of Bovine Bone Gelatin Peptides on Myocardial Hypertrophy in Spontaneously Hypertensive Rats.

The research purpose was to investigate the effects and the underlying molecular mechanisms of bovine bone gelatin peptides (BGP) on myocardial hypertrophy in spontaneously hypertensive rats (SHR). BGP relieved myocardial hypertrophy and fibrosis in SHR rats in a dose-dependent manner by reducing the left ventricular mass index, myocardial cell diameter, myocardial fibrosis area, and levels of myocardial hypertrophy markers (atrial natriuretic and brain natriuretic peptide). Label-free quantitative proteomics analysis showed that long-term administration of BGP changed the left ventricle proteomes of SHR. The 37 differentially expressed proteins in the high-dose BGP group participated in multiple signaling pathways associated with cardiac hypertrophy and fibrosis indicating that BGP could play a cardioprotective effect on SHR rats by targeting multiple signaling pathways. Further validation experiments showed that a high dose of BGP inhibited the expression of phosphoinositide 3-kinase (Pi3k), phosphorylated protein kinase B (p-Akt), and transforming growth factor-beta 1 (TGF-ß1) in the myocardial tissue of SHR rats. Together, BGP could be an effective candidate for functional nutritional supplements to inhibit myocardial hypertrophy and fibrosis by negatively regulating the TGF-ß1 and Pi3k/Akt signaling pathways.

Construction and evaluation of environment-friendly POSS multi-crosslinked mulch film based on bone gelatin.

The non-degradable traditional polyethylene (PE) mulch film has caused great harm to both the ecological environment as well as human health. Therefore, the biodegradable bone gelatin (B-Gel) was innovatively selected to build the mulch film. To further enhance the toughness of the B-Gel mulch films, a POSS star-shaped polymer/bone gelatin (P(POSS-AGE-HEA)/B-Gel) composite was prepared by introducing POSS star-shaped polymer into B-Gel via in situ polymerization using polyhedral oligomeric silsesquioxane (POSS), allyl glycidyl ether (AGE) and hydroxyethyl acrylate (HEA) as raw material, and then was cast to obtain the P(POSS-AGE-HEA)/B-Gel mulch film. The epoxy group of POSS star-shaped polymer with the -COOH and -NH2 of B-Gel forms a covalent bond, and the hydroxyl group with the active groups of B-Gel forms hydrogen bonds. Meanwhile, the multiple side chains of POSS star-shaped polymer are intertwined with B-Gel. These covalent and hydrogen bonds as sacrificial bonds for effective energy dissipation giving the bone gelatin-based film excellent mechanical properties with a tensile strength of 7.56 ± 0.64 MPa and elongation at break of 197.49 ± 17.63 %. Additionally, it also demonstrated sound water vapor barrier, surface hydrophobicity, light transmittance and the effect of facilitating the growth and germination ratio (93.75 %) of wheat.

Curcumin-encapsulated hydrophilic gelatin nanoparticle to stabilize fish oil-loaded Pickering emulsion.

Herein, pH-cycle method was explored to prepare curcumin-encapsulated hydrophilic bovine bone gelatin (BBG/Cur) nanoparticle and then the obtained nanoparticle was applied to stabilize fish oil-loaded Pickering emulsion. The nanoparticle had a high encapsulation efficiency (93.9 ± 0.5 %) and loading capacity (9.4 ± 0.1 %) for curcumin. The nanoparticle-stabilized emulsion had higher emulsifying activity index (25.1 ± 0.9 m2/g) and lower emulsifying stability index (161.5 ± 18.8 min) than BBG-stabilized emulsion. The pH affected the initial droplet sizes and creaming index values of the Pickering emulsions: pH 11.0 < pH 5.0 ≈ pH 7.0 ≈ pH 9.0 < pH 3.0. Curcumin provided obvious antioxidant effect for the emulsions, which was also dependent on pH. The work suggested pH-cycle method could be used to prepare hydrophobic antioxidant-encapsulated hydrophilic protein nanoparticle. It also provided basic information on the development of protein nanoparticles for Pickering emulsion stabilization.

Hyaluronic acid-rich burger separator edible disc prepared from slaughterhouse waste.

In this study, the edible films from chicken feet (CF), ovine muscle fascia (MF), and bovine bone gelatin (Gel) were prepared and their characteristics were analyzed, and we also evaluated the sensory quality of raw and cooked hamburgers using the edible films. The quantities of the CF and MF hyaluronic acid were evaluated using colorimetry and spectrophotometry. The CF, MF, and Gel films were prepared by solvent casting method. Results indicated that the concentration of hyaluronic acid in CF (124.11 ppm) was greater than MF (101.11 ppm). The antioxidative property of the CF film (18.47%) was greater than the Gel (1.88%) and MF (Undetectable) film. The CF film was more resistant to water vapor permeability (2.75 × 10-9 g/m.s.pa) than the MF (1.57 × 10-8 g/m.s.pa) and Gel (1.5 × 10-7 g/m.s.pa) films. The Gel film had more appropriate mechanical properties than CF and MF films. The films kept burgers patties independent from one another and prevented them from sticking and freezing together. MF and CF films were able to promote the organoleptic properties of raw and cooked hamburgers in taste and texture.

Edible hyaluronic acid-rich burger separator discs prepared from slaughterhouse waste.

In this study, edible films from chicken feet extract (CF), ovine muscle fascia extract (MF), and bovine bone gelatin powder (Gel) were prepared and their characteristics were analyzed. We also used the films as separators of burger cuts and evaluated the organoleptic characteristics of cooked burgers. Hyaluronic acid quantities of CF and MF were measured using colorimetric and spectrophotometry. Results indicated that the concentration of hyaluronic acid in CF (124.11 ppm) was greater than MF (101.11 ppm). The antioxidative property of the CF film (18.47%) was greater than the Gel (1.88%) and MF (Undetectable) films. The CF film was more resistant to water vapor permeability (2.75 × 10-9 g/m.s.pa) than the MF (1.57 × 10-8 g/m.s.pa) and Gel (1.5 × 10-7 g/m.s.pa) films. The Gel film had more appropriate mechanical properties than CF and MF films. The films kept burgers patties independent from one another and prevented them from sticking and freezing together. MF and CF films were able to promote the organoleptic properties of cooked burgers in taste and texture.

Bovine Bone Gelatin-Derived Peptides: Food Processing Characteristics and Evaluation of Antihypertensive and Antihyperlipidemic Activities.

This study aimed to evaluate the food processing properties of bovine bone gelatin-derived peptides (BGPs) and their effects and mechanisms on hypertension and hypertension complications in spontaneously hypertensive rats (SHRs). BGPs had good acid, high temperature, and NaCl resistance abilities in vitro. Additionally, Maillard reaction of BGPs with low-dose reducing sugar (≤15%) exhibited a free radical scavenging effect. BGPs significantly reduced the blood pressure, triglyceride levels, and the low-density lipoprotein cholesterol/high-density lipoprotein cholesterol ratio in SHRs through downregulated angiotensin converting enzyme (ACE), angiotensin II (Ang II), and Ang II type 1 receptor (AT1R) levels and the upregulated Ang II type 2 receptor (AT2R) level. In brief, BGP could alleviate hypertension and dyslipidemia in SHRs by inhibiting ACE/Ang II/AT1R and activating the Ang II/AT2R signaling pathway. Our study suggests that BGP has good food processing properties and could be a potential nutraceutical for antihypertensive and antihyperlipidemic issues.

Effect of carbon numbers and structures of monosaccharides on the glycosylation and emulsion stabilization ability of gelatin.

Herein, the effect of saccharide glycosylation by nine monosaccharides on bovine bone gelatin for the stabilization of fish oil-loaded emulsions was explored. The gelatin modification was analyzed and then the emulsifying properties of monosaccharide-modified gelatins were analyzed at pH 9.0 and 3.0. The results demonstrated that glycosylated gelatin structure, droplet stability, creaming stability, and liquid-gel transition time were dependent on monosaccharide carbon numbers, monosaccharide structures, and solution pH. Glycosylation modification of gelatins did not obviously change the emulsion droplet stability at pH 9.0, whereas it increased the emulsion droplet stability at pH 3.0. Glycosylation modification of gelatins did not obviously change the emulsion creaming index values (5.1%-8.4% at pH 9.0 and 25.8%-33.1% at pH 3.0). Three-carbon and four-carbon monosaccharides glycosylation significantly increased emulsion liquid-gel transition times. This work provided useful information to understand the effects of carbon numbers and structures of monosaccharides on the protein modification.

The Anti-Inflammatory Effect of Bovine Bone-Gelatin-Derived Peptides in LPS-Induced RAW264.7 Macrophages Cells and Dextran Sulfate Sodium-Induced C57BL/6 Mice.

The bioactive peptides hydrolyzed from bone collagen have been found to possess health-promoting effects by regulating chronic diseases such as arthritis and hypertension. In the current study, the anti-inflammatory effect of bovine bone gelatin peptides (GP) was evaluated in 264.7 macrophages cells and followed by animal trials to investigate their interference on inflammatory cytokines and gut microbiota compositions in dextran sodium sulfate (DSS)-induced C57BL/6 mice. The GP was demonstrated to alleviate the extra secretion of interleukin-6 (IL-6), nitric oxide (NO) and tumor necrosis factor-α(TNF-α) in lipopolysaccharide (LPS)-induced RAW264.7 cells. In DSS-induced colitis mice, the gavage of GP was demonstrated to ameliorate the IBD symptoms of weight loss, hematochezia and inflammatory infiltration in intestinal tissues. In serum, the proinflammatory cytokines (TNF-α,IL-6, MCP-1, IL-1ß) were suppressed along with the decreasing effect on toll-like receptor 4 and cyclooxygenase-2 by GP treatment. In the analysis of gut microbiota, the GP was checked to modulate the abundance of Akkermansia, Parasutterella, Peptococcus, Bifidobacterium and Saccharibacteria. The above results imply that GP could attenuate DSS-induced colitis by suppressing the inflammatory cytokines and regulating the gut microbiota.

Anhydride structures affect the acylation modification and emulsion stabilization ability of mammalian and fish gelatins.

In this work, ring-like anhydrides (C4, C5, and C6) with different sizes and succinic anhydrides (C4, C10, C12, C14, and C16) with different side chain lengths were used to modify bovine bone gelatin (BBG) and cold-water fish skin gelatin (CFG), and the effect of acylated gelatins on fish oil-loaded emulsions stability was explored. The results showed that the degree of N-acylation decreased with increased ring sizes or side chain lengths, and the surface hydrophobicity of acylated gelatins increased with increased anhydride carbon numbers. Acylated CFGs had higher droplet stability and lower liquid-gel transition time than acylated BBGs. Only BBG-C12 had a slight increase on the creaming stability among these acylated gelatins. These results demonstrated that the gelatins could be modified by all the anhydrides and their emulsion stabilization ability was dependent on the gelatin type and anhydride structure. The results could be beneficial for protein-based emulsifier development and application.

Distinguishing tissue origin of bovine gelatin in processed products using LC/MS technique in combination with chemometrics tools.

Gelatin, as a by-product of the meat industry, is extracted from bone and skin of mainly bovine and porcine origins. It is used widely in the food, drug, and cosmetic industries. Authenticity testing methods can be used to confirm whether labelled ingredients are present in the product. Generally, studies on gelatin are concerned mainly with determining species, but detecting tissue origin is also important from religious, health, and commercial perspectives. In the present study, for the first time, liquid chromatography/mass spectrometry (HPLC/MS) was used to differentiate bovine bone gelatin from gelatin derived from bovine skin. Tryptic-digested gelatins were measured using HPLC/MS and, subsequently, two powerful chemometrics approaches (i.e., PCA and PLS-DA) were used to classify samples as either skin or bone gelatins. Origin of bovine gelatins in different test samples were predicted accurately using this method. The results showed both the stability and reliability of the proposed procedure.

Antihypertensive Effects in Vitro and in Vivo of Novel Angiotensin-Converting Enzyme Inhibitory Peptides from Bovine Bone Gelatin Hydrolysate.

In this study, we investigated the antihypertensive effects in vitro and in vivo of novel angiotensin-converting enzyme inhibitory (ACEI) peptides purified and identified from bovine bone gelatin hydrolysate (BGH). Thirteen ACEI peptides were identified from BGH, and among which, RGL-(Hyp)-GL and RGM-(Hyp)-GF exhibited high ACE inhibition with IC50 values of 1.44 and 10.23 µM. Molecular docking predicted that RGM-(Hyp)-GF and ACE residues of Glu384, His513, and Lys511 formed hydrogen-bonding interactions at distances of 2.57, 2.99, and 2.42 + 3.0 Å. RGL-(Hyp)-GL formed hydrogen bonds with Lys511 and Tyr523 and generated hydrogen-bonding interactions with His387 and Glu411 in the zinc(II) complexation motif at distances of 2.74 and 3.03 + 1.93 Å. The maximal decrements in systolic blood pressure in spontaneously hypertensive rats induced by one-time gavage of RGL-(Hyp)-GL and RGM-(Hyp)-GF at 30 mg/kg were 31.3 and 38.6 mmHg. RGL-(Hyp)-GL had higher enzyme degradation resistance than that of RGM-(Hyp)-GF in vitro incubation in rat plasma, and they were sequentially degraded into pentapeptides and tetrapeptides within 2 h. Our results indicate that BGH can serve as a nutritional candidate to control blood pressure.

Corrigendum: Viscoelastic and Functional Properties of Cod-Bone Gelatin in the Presence of Xylitol and Stevioside.

[This corrects the article DOI: 10.3389/fchem.2018.00111.].

Viscoelastic and Functional Properties of Cod-Bone Gelatin in the Presence of Xylitol and Stevioside.

The physical, rheological, structural and functional properties of cod bone gelatin (CBG) with various concentrations (0, 2, 4, 6, 10, and 15%) of low-calorie sweeteners [xylitol (X) and stevioside (S)] to form gels were investigated. The gel strength of CBGX increased with increased xylitol due presumably to hydrogen bonds between xylitol and gelatin, but with CBGS the highest gel strength occurred when S concentration was 4%. Viscosity of CBGS samples were higher than CBGX due to S's high molecular mass. The viscoelasticity (G' and G''), foaming capacity and fat binding capacity of CBGX were higher while foam stability was lower. The emulsion activity and emulsion stability of CBGX were a little lower than CBGS at the same concentration. The structure of X is linear making it easier to form a dense three-dimensional network structure, while the complex cyclic structure of S had more difficulty forming a network structure with cod bone gelatin. Therefore, X may be a better choice for sweetening gelatin gels.

EFFECTS OF CROCODILE BONE GELATIN ON STRESS REACTION AND BLOOD-FORMING FUNCTION IN MICE / 中国海洋药物

To investigate the effects of Crocodile Bone Gelatin(CBG) on stress reaction and blood forming function in mice. Results showed CBG increased staying power for high temperature and low temperature, but didn′t increase anti exhaustion ability and hypoxia tolerance of mice. CBG increased platelet count, didn′t increase white blood cell count on Cyclophosphamidum causing blood forming functional obstruction.