Analysis of spinal-pelvic sagittal plane parameters in patients with lumbar vertebral posterior ring apophysis separation.

OBJECTIVE: To investigate the characteristics of the spinal-pelvic sagittal sequence in patients with lumbar vertebral posterior ring apophysis separation (PRAS). METHODS: A retrospective analysis was conducted on 119 hospitalized patients with PRAS, and 119 adults without symptoms of low back and leg pain were selected as the control. General data and spinal-pelvic sagittal parameters were collected and analyzed. RESULTS: Compared to the control group, the pelvic incidence (PI), sacral slope (SS), lumbar lordosis (LL), and thoracic kyphosis (TK) of the PRAS group were significantly lower, while the pelvic tilt (PT), sagittal vertical axis (SVA), and pelvic incidence minus lumbar lordosis (PI-LL) were significantly higher. There was no significant difference in thoracolumbar kyphosis (TLK) between two groups. In patients with PRAS, the LL value of lumbar curvature was moderately correlated with TK and SS, while PI, PT, and SS were pairwise correlated, indicating that the change in one parameter is often accompanied by simultaneous changes in other parameters if PRAS happens. The correlation between different parameters could provide guidance for the diagnosis of PRAS. In terms of lumbar lordosis type, PRAS group was mainly of Roussouly type I, while the control group was mainly of type II, and the difference in the composition ratio was statistically significant. CONCLUSIONS: As reflected by the spinal-pelvic sagittal parameters, the patients with PRAS exhibited reduced thoracic and lumbar curvature, posterior pelvic tilt, and fewer vertebral bodies involved in lumbar lordosis. These morphological characteristics indicate the changes of the mechanical structure of the spine.

Further sesquiterpenoids from Pittosporum qinlingense and their anti-inflammatory activity.

Four new sesquiterpenoid glycoside esters, Pitqinlingoside N-Q (1-4), together with eleven known metabolites (5-15), were isolated from 95% EtOH extract of the twigs, fruits and leaves of P. qinlingense. The structures of new compounds were elucidated on the basis of extensive spectroscopic analyses, including IR, UV, HRMS, NMR and electronic circular dichroism spectra. Unusal glycoside esters are characterized by the presence of polyacylated ß-D-fucopyranosyl and ß-d-glucopyranosyl units. Pitqinlingoside N (1), O (2), P (3), boscialin (5) and arvoside C (6) showed significant nitric oxide production inhibition in lipopolysaccharide (LPS)-induced BV-2 microglial cells with IC50 values ranging from 1.58 to 28.74 µM. Structure-activity relationships of the isolated compounds are discussed.

Effects of a cold plasma-assisted shrimp processing chain on biochemical and sensory quality alterations in Pacific white shrimps (Penaeus vannamei).

In this paper, remodeling the shrimp processing chain and the effects of the transformation on the biochemical and sensory qualities of fresh Pacific white shrimp (Penaeus vannamei) under refrigeration storage were investigated. In the proposed model, a dielectric barrier discharge atmospheric cold plasma pretreatment step using a 60 kV source for 60, 90, 120, and 150 s was introduced after the first and second wash followed by refrigeration storage at 4 ± 1 °C for 12 days. Chemical, biochemical, and sensory attributes of the shrimp were monitored and compared with those of shrimp processed through the traditional method without atmospheric cold plasma pretreatment (control). Incorporating minimal dielectric barrier discharge atmospheric cold plasma pretreatment step had more desirable quality outcomes characterized by low malondialdehyde concentration, low volatile nitrogen products content, and comparable proximate composition. Texture, pH, and color were remarkably retained at 120 and 150 s of atmospheric cold plasma pretreatment and protein degradation was negligible up to 90 s than at 120 and 150 s of pretreatment. We conclude that remodeling the shrimp processing chain through incorporating minimal dielectric barrier discharge atmospheric cold plasma pretreatment with key considerations on operation parameters can maximize the beneficial biochemical and sensory quality outcomes while minimizing the negative impacts associated with traditional shrimp processing.

A three-dimensional discrete element model of triaxial tests based on a new flexible membrane boundary.

Based on a new elastic clump model, a flexible membrane is proposed for the discrete element numerical simulations of triaxial tests. Conversional triaxial tests of sandstone under the confining pressures of 2 MPa and 8 MPa were carried out, in order to validate the effectiveness of the proposed numerical simulation method. The numerical model is validated by comparing the numerical results with the test results. The deformation and failure process of numerical model is analyzed by stress-strain curves, micro fractures, displacement fields, stress fields and energy fields. The model shows an X-shape shear failure zone, of which the angle is very close to that of the test; the dip angle of most shear fractures is close to the angle of the internal friction; and there is a large amount of slipping frictional heat generated on the failure surface. During the loading process, the stress chain and stress concentration appear in the middle of the model, which lead to displacement zoning in the model. The failure of the model is associated with the growth of the micro tensile- and shear fractures. This study provides an effective tool for the macro-micro investigation of rock failure processes.

The establishment and biological assessment of a whole tissue-engineered intervertebral disc with PBST fibers and a chitosan hydrogel in vitro and in vivo.

Intervertebral disc (IVD) degeneration (IDD) is the main cause of low back pain in the clinic. In the advanced stage of IDD, both cell transplantation and gene therapy have obvious limitations. At this stage, tissue-engineered IVDs (TE-IVDs) provide new hope for the treatment of this disease. We aimed to construct a TE-IVD with a relatively complete structure. The inner annulus fibrosus (AF) was constructed using poly (butylene succinate-co-terephthalate) copolyester (PBST) electrospun fibers, and the outer AF consisted of solid PBST. The nucleus pulposus (NP) scaffold was constructed using a chitosan hydrogel, as reported in our previous research. The three components were assembled in vitro, and the mechanical properties were analyzed. AF and NP cells were implanted on the corresponding scaffolds. Then, the cell-seeded scaffolds were implanted subcutaneously in nude mice and cultured for 4 weeks; then they were removed and implanted into New Zealand white rabbits. After 4 weeks, their properties were analyzed. The PBST outer AF provided mechanical support for the whole TE-IVD. The electrospun film and chitosan hydrogel simulated the natural structure of the IVD well. Its mechanical property could meet the requirement of the normal IVD. Four weeks later, X-ray and MR imaging examination results suggested that the height of the intervertebral space was retained. The cells on the TE-IVD expressed extracellular matrix, which indicated that the cells maintained their biological function. Therefore, we conclude that the whole TE-IVD has biological and biomechanical properties to some extent, which is a promising candidate for IVD replacement therapies. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 2305-2316, 2019.

Effect of cold plasma on maintaining the quality of chub mackerel (Scomber japonicus): biochemical and sensory attributes.

BACKGROUND: Atmospheric cold plasma (ACP) has emerged as a potential alternative to traditional methods for non-thermal food decontamination. However, few data are available about ACP treatment for seafood. In this study, dielectric barrier discharge (DBD) was applied to generate CP, and the aim of the study was to investigate the effectiveness of DBD-ACP on improving the quality of chub mackerel on the basis of chemical, microbial and sensory characteristics. RESULTS: The effect of DBD-ACP on the quality of chub mackerel (Scomber japonicus) during storage was examined. Results revealed that the optimal voltage level and exposure time of this treatment were 60 kV and 60 s respectively, and such conditions exhibited excellent inactivation efficacy and weak influence on proximate chemical compositions. Variations in total viable count (TVC), sensory scores and total volatile basic nitrogen (TVB-N) indicated that ACP treatment extended the shelf life of chub mackerel to 14 days, whereas samples without this treatment exceeded the limits of the three parameters after 6 days. The slow development rates of peroxide value (PV) and thiobarbituric acid (TBA) value implied that lipid oxidation was also effectively retarded by ACP exposure. Scanning electron microscopy confirmed that CP could effectively delay the degradation of myofibrillar proteins and enhance the stability of tissue structures. CONCLUSION: The excellent antimicrobial efficacy of ACP treatment makes it a potential and promising alternative to other seafood preservation technology. This is the first report on the application of ACP to seafood, which is essential to perishable food storage. © 2018 Society of Chemical Industry.

Insights into ice-growth inhibition by trehalose and alginate oligosaccharides in peeled Pacific white shrimp (Litopenaeus vannamei) during frozen storage.

Cryoprotective saccharides are widely accepted antifreeze additives that reduce thawing loss, maintain texture, and retard protein denaturation in frozen seafood. In this study, the inhibition effects of trehalose and alginate oligosaccharides on ice growth were investigated and compared with sodium pyrophosphate (Na4P2O7) treatment in peeled shrimp during frozen storage, especially the interactions between saccharide molecules and ice crystals. The microstructural results demonstrated that the pre-soaking of trehalose and alginate oligosaccharides before freezing exhibited marked effects on stability of muscle tissue structures and slowed the damage caused to the myofibrils by large ice crystals. The ice-growth inhibition activities might play an important role in cryoprotective effects of saccharides on frozen muscle tissue. Furthermore, molecular docking and molecular dynamics (MD) simulations proved that saccharides were generally close to the ice interface and embedded in ice layers via hydrogen bonds or hydrophobic or electrostatic interactions. The saccharides-ice complex was partially destroyed, and some dislocation and disaggregation were observed around the saccharides molecules. Thus, the incorporated saccharides suppressed the growth of ice crystals, providing protection from freeze-induced damage. Here, the obtained structural details of the ice crystals interface affected by trehalose and alginate oligosaccharides were well in agreement with the histological (H&E staining) experimental results. These findings help better understand the ice-growth inhibition mechanisms of saccharides in frozen shrimp, and these two saccharides may be potentially used as ice-growth inhibitors in frozen seafood.

Novel nano-microspheres containing chitosan, hyaluronic acid, and chondroitin sulfate deliver growth and differentiation factor-5 plasmid for osteoarthritis gene therapy.

OBJECTIVE: To construct a novel non-viral vector loaded with growth and differentiation factor-5 (GDF-5) plasmid using chitosan, hyaluronic acid, and chondroitin sulfate for osteoarthritis (OA) gene therapy. METHODS: Nano-microspheres (NMPs) were prepared by mixing chitosan, hyaluronic acid, and chondroitin sulfate. GDF-5 plasmid was encapsulated in the NMPs through electrostatic adsorption. The basic characteristics of the NMPs were observed, and then they were co-cultured with chondrocytes to observe their effects on extracellular matrix (ECM) protein expression. Finally, NMPs loaded with GDF-5 were injected into the articular cavities of rabbits to observe their therapeutic effects on OA in vivo. RESULTS: NMPs exhibited good physicochemical properties and low cytotoxicity. Their average diameter was (0.61±0.20) µm, and encapsulation efficiency was (38.19±0.36)%. According to Cell Counting Kit-8 (CCK-8) assay, relative cell viability was 75%-99% when the total weight of NMPs was less than 560 µg. Transfection efficiency was (62.0±2.1)% in a liposome group, and (60.0±1.8)% in the NMP group. There was no significant difference between the two groups (P>0.05). Immunohistochemical staining results suggested that NMPs can successfully transfect chondrocytes and stimulate ECM protein expression in vitro. Compared with the control groups, the NMP group significantly promoted the expression of chondrocyte ECM in vivo (P<0.05), as shown by analysis of the biochemical composition of chondrocyte ECM. When NMPs were injected into OA model rabbits, the expression of ECM proteins in chondrocytes was significantly promoted and the progression of OA was slowed down. CONCLUSIONS: Based on these data, we think that these NMPs with excellent physicochemical and biological properties could be promising non-viral vectors for OA gene therapy.

Understanding the influence of carrageenan oligosaccharides and xylooligosaccharides on ice-crystal growth in peeled shrimp (Litopenaeus vannamei) during frozen storage.

Cryoprotective saccharides are widely accepted antifreeze additives that reduce thawing loss, maintain texture, and retard protein denaturation in frozen seafood. In this study, the inhibition effects of carrageenan oligosaccharides and xylooligosaccharides on ice-crystal growth in peeled whiteleg shrimp were investigated and compared with sodium pyrophosphate treatment during frozen storage, especially the interactions between oligosaccharide molecules and ice crystals. The tissue microstructural results demonstrated that the fibers of shrimp muscle tissues from carrageenan oligosaccharide- and xylooligosaccharide-treated groups were arranged in a more tighter manner than those with sodium pyrophosphate treatment after 8 weeks of storage, which indicated that soaking in oligosaccharide solutions prior to freezing markedly slowed the damage caused to muscle tissues by large ice crystals. Ice-growth inhibition might play an important role in the cryoprotection of frozen shrimp. Furthermore, molecular docking and molecular dynamics (MD) simulations confirmed that oligosaccharides were generally close to the ice surface and embedded in ice layers via hydrogen bonds or hydrophobic or electrostatic interactions. The oligosaccharide-basal ice complex (ice-crystal structure) was partially destroyed, and some dislocation and disaggregation were observed around the oligosaccharide molecules. Thus, the incorporated oligosaccharides suppressed the growth of ice crystals, providing protection from freeze-induced damage. Overall, by comparing the experimental results to those from the MD simulations, a significant positive correlation existed between the oligosaccharides and ice-growth inhibition in shrimp muscle. These findings help better understand the cryoprotective mechanisms of oligosaccharides in frozen shrimp, and these two oligosaccharides may be potentially used as ice-growth inhibitors in seafood to maintain better quality during frozen storage.

Cryoprotective roles of trehalose and alginate oligosaccharides during frozen storage of peeled shrimp (Litopenaeus vannamei).

Cryoprotective saccharides are widely accepted additives that reduce thawing loss, maintain texture, and retard protein denaturation in the frozen seafood. The present study aimed to investigate the roles of trehalose and alginate oligosaccharides on cryoprotection of frozen shrimp, primarily focusing on the interactions between myosin and saccharide molecules using a molecular dynamics (MD) simulation analysis. The results indicated that soaking in the trehalose and alginate oligosaccharides solutions markedly reduced thawing and cooking losses in frozen shrimp, with respective values decreasing to 6.02%, 8.14%, and 5.99%, 8.19% after 9weeks of storage, which were significantly lower than that of fresh water treatment (9.75% and 15.09%). Our assumption was that water replacement played a leading role in cryoprotection, as shown in previous experimental results and reports. Furthermore, homology modeling and MD simulations confirmed that trehalose and alginate oligosaccharides substituted the water molecules around the myosin surface by forming hydrogen bonds with polar residues of amino acids, thereby stabilizing the structures in the absence of water during frozen storage. These conditions affected the flexibility of particular amino acid residues, enhanced the residue cross correlations within the two chains of myosin, and also increased the total interaction energy between myosin and water/saccharide molecules, thereby leading to an increase in protein stability. Finally, by comparing the experimental results to that of MD simulation, significant positive correlation existed between saccharides and the stabilization of myosin in shrimp muscle. The findings of the present study may help better understand the cryoprotective mechanisms of saccharides in frozen shrimp, and the two saccharides may be potentially used as alternative additives in seafood to maintain better quality during frozen storage.

Insights into Cryoprotective Roles of Carrageenan Oligosaccharides in Peeled Whiteleg Shrimp (Litopenaeus vannamei) during Frozen Storage.

The cryoprotective effects of carrageenan oligosaccharides on peeled whiteleg shrimp were investigated and compared with sodium pyrophosphate treatment during frozen storage, primarily the interaction mechanisms between oligosaccharides and shrimp myosin. Data revealed significant profitable effects on water-holding capacity and textural variables in oligosaccharide-treated shrimp compared to the control. Chemical analyses showed that these saccharides maintained a higher myofibrillar protein content and Ca2+-ATPase activity in frozen shrimp. Additionally, the hematoxylin and eosin staining results indicated that the saccharides significantly slowed the damage to muscle tissue structures. The assumption was that water replacement hypothesis played a leading role in cryoprotection of frozen shrimp. Furthermore, the homology modeling and molecular dynamics simulations confirmed that the saccharides substituted water molecules around the shrimp myosin surface by forming hydrogen bonds with polar residues of amino acids, thereby stabilizing the structures in the absence of water, leading to an increase in protein stability during frozen storage.

Clinical application of percutaneous endoscopic gastrostomy with the Introducer method using ultrathin gastroscopy / 中国内镜杂志

Objective To evaluate the clinical application and security of percutaneous endoscopic gastrostomy (PEG) with the Introducer method using ultrathin gastroseopy in dysphagia patients. Methods Clinical data of 22 cases dysphagia patients implemented with PEG with the Introducer method using ultrathin gastroseopy or conventional gastroseopy were retrospectively analyzed, the clinical effect and the complication were observed. Results 22 patients underwent PEG with the Introducer method using conventional gastroscopy (6 cases) or ultrathin gastroscopy (16 cases). Among the 16 patients underwent PEG using ultrathin gastroseopy by transnasal or peroral approach, 2 cases with trimus by received radiotherapy for nasopharyngeal cancer and 14 cases with pharyngeal or esophagus narrowing, could not completed PEG by conventional gastroscopy. The average procedure time of PEG was (12.2 ± 2.9) min in conventional gastroscopy group and (11.8 ± 3.2) min in control group. No complications were observed in these patients, but the patients in ultrathin gastroseopy group reported less discomfort associated with the procedure. 17 patients with advanced nasopharyngeal carcinoma and esophagus cancer who received PEG could completely finished 6 cycles of concurrent chemoradiotherapy. Paired-sample t test of nutrition indicators (hemoglobin, albumin and RBC) before and after the treatment showed significant difference (P < 0.05). Conclusion PEG with the introducer method using ultrathin gastroseopy is a safe and effective method of enteral nutrition, Ultrathin gastroscopy reduces the discomfort of the procedure, especially in patients with serious trimus and pharyngeal or esophagus narrowing. For patients with advanced nasopharyngeal carcinoma, preventative PEG improved the tolerance of chemoradiotherapy,reduce the incidence of adverse events.

Clinical application of percutaneous endoscopic gastrostomy with the Introducer method using ultrathin gastroscopy / 中国内镜杂志

Objective To evaluate the clinical application and security of percutaneous endoscopic gastrostomy (PEG) with the Introducer method using ultrathin gastroseopy in dysphagia patients. Methods Clinical data of 22 cases dysphagia patients implemented with PEG with the Introducer method using ultrathin gastroseopy or conventional gastroseopy were retrospectively analyzed, the clinical effect and the complication were observed. Results 22 patients underwent PEG with the Introducer method using conventional gastroscopy (6 cases) or ultrathin gastroscopy (16 cases). Among the 16 patients underwent PEG using ultrathin gastroseopy by transnasal or peroral approach, 2 cases with trimus by received radiotherapy for nasopharyngeal cancer and 14 cases with pharyngeal or esophagus narrowing, could not completed PEG by conventional gastroscopy. The average procedure time of PEG was (12.2 ± 2.9) min in conventional gastroscopy group and (11.8 ± 3.2) min in control group. No complications were observed in these patients, but the patients in ultrathin gastroseopy group reported less discomfort associated with the procedure. 17 patients with advanced nasopharyngeal carcinoma and esophagus cancer who received PEG could completely finished 6 cycles of concurrent chemoradiotherapy. Paired-sample t test of nutrition indicators (hemoglobin, albumin and RBC) before and after the treatment showed significant difference (P < 0.05). Conclusion PEG with the introducer method using ultrathin gastroseopy is a safe and effective method of enteral nutrition, Ultrathin gastroscopy reduces the discomfort of the procedure, especially in patients with serious trimus and pharyngeal or esophagus narrowing. For patients with advanced nasopharyngeal carcinoma, preventative PEG improved the tolerance of chemoradiotherapy,reduce the incidence of adverse events.

The effect of ferrous-chelating hairtail peptides on iron deficiency and intestinal flora in rats.

BACKGROUND: Chelating agents, such as small peptides, can decrease free iron content and increase iron bioavailability. They may have promising therapeutic potential and may prevent the pro-oxidant effects of low molecular weight iron. Hairtail is a species of fish that is rich in easily digestible proteins. We extended this strategy for iron delivery by using an enzymatic hydrolysate of hairtail as the chelating agent and found that the ferrous-chelating hairtail peptides have anti-anaemic activity in Sprague-Dawley rats with anaemia. RESULTS: The anti-anaemic activity of ferrous-chelating hairtail peptides prepared by enzymatic hydrolysis of the hairtail and ferrous chelation was studied in rat models of iron deficiency anaemia. After the end of the 35 d experiment, we noted significant differences in haemoglobin, mean corpuscular volume, haemoglobin distribution width, and ferritin concentrations between those animals supplemented with ferrous-chelating hairtail peptides and FeSO4 and healthy animals. There were no negative side effects on the animals' growth or behaviour. There was no obvious inflammation in the intestinal mucosa lamina propria and no unbalance of intestinal flora. CONCLUSION: The novel ferrous-chelating hairtail peptides may be a suitable fortificant for improving iron-deficiency status. Our findings demonstrated that this multi-tracer technique has many applications in nutritional research. © 2015 Society of Chemical Industry.

Study of Anti-Fatigue Effect in Rats of Ferrous Chelates Including Hairtail Protein Hydrolysates.

The ability of ferrous chelates including hairtail protein hydrolysates to prevent and reduce fatigue was studied in rats. After hydrolysis of hairtail surimi with papain, the hairtail protein hydrolysates (HPH) were separated into three groups by range of relative molecular weight using ultrafiltration membrane separation. Hairtail proteins were then chelated with ferrous ions, and the antioxidant activity, the amino acid composition and chelation rate of the three kinds of ferrous chelates including hairtail protein hydrolysates (Fe-HPH) were determined. Among the three groups, the Fe-HPH chelate showing the best conditions was selected for the anti-fatigue animal experiment. For it, experimental rats were randomly divided into seven groups. Group A was designated as the negative control group given distilled water. Group B, the positive control group, was given glutathione. Groups C, D and E were designated as the Fe-HPH chelate treatment groups and given low, medium, and high doses, respectively. Group F was designated as HPH hydrolysate treatment group, and Group G was designated as FeCl2 treatment group. The different diets were orally administered to rats for 20 days. After that time, rats were subjected to forced swimming training after 1 h of gavage. Rats given Fe-FPH chelate had higher haemoglobin regeneration efficiency (HRE), longer exhaustive swimming time and higher SOD activity. Additionally, Fe-FPH chelate was found to significantly decrease the malondialdehyde content, visibly enhance the GSH-Px activity in liver and reduce blood lactic acid of rats. Fe-HPH chelate revealed an anti-fatigue effect, similar to or better than the positive control substance and superior to HPH or Fe when provided alone.

Two novel antioxidant nonapeptides from protein hydrolysate of skate (Raja porosa) muscle.

In the current study, the preparation conditions of neutrase hydrolysate (SMH) from skate (Raja porosa) muscle protein were optimized using orthogonal L9(3)4 tests, and R values indicated that pH was the most important factor affecting HO· scavenging activity of SMH. Under the optimum conditions of pH 7.0, enzymolysis temperature 60 °C, enzyme/substrate ratio (E/S) 2%, and enzymolysis time 5 h, EC50 of SMH on HO· was 2.14 ± 0.17 mg/mL. Using ultrafiltration, gel filtration chromatography, and RP-HPLC, two novel antioxidant nonapeptides (SP-A and SP-B) were isolated from SMH and their amino acid sequences were found to be APPTAYAQS (SP-A) and NWDMEKIWD (SP-B) with calculated molecular masses of 904.98 Da and 1236.38 Da, respectively. Both showed strong antioxidant activities. SP-A and SP-B exhibited good scavenging activities on HO· (EC50 0.390 and 0.176 mg/mL), DPPH· (EC50 0.614 and 0.289 mg/mL), and O2-· (EC50 0.215 and 0.132 mg/mL) in a dose-dependent manner. SP-B was also effective against lipid peroxidation in the model system. The aromatic (2Trp), acidic (2Asp and Glu), and basic (Lys) amino acid residues within the sequences of SP-B might account for its pronounced antioxidant activity. The results of this study suggested that protein hydrolysate and peptides from skate muscle might be effective as food additives for retarding lipid peroxidation occurring in foodstuffs.

Effect of slurry ice on the functional properties of proteins related to quality loss during skipjack tuna (Katsuwonus pelamis) chilled storage.

The effect of slurry ice on the quality of Skipjack tuna (Katsuwonus pelamis) during chilling storage was investigated and compared to flake ice. Slurry ice-treated samples showed significantly higher springiness and chewiness variables than the blank and flake ice-treated samples (P < 0.05). The growth of microorganisms in tuna muscle treated with slurry ice was also down significantly (P < 0.05), and the total aerobic counts didn't reach higher scores than 5.0 log CFU/g during the whole chilling storage. Additionally, the myofibrillar protein, Ca(2+)-ATPase activity, and total sulfydryl (SH) content in muscle treated with slurry ice were all significantly higher than the blank and flake-iced samples (P < 0.05). This was probably due to the faster cooling, subzero final-temperature, and larger heat exchange derived from slurry ice. Standard error of mean and sodium dodecyl sulfate-polyacrylamide gel electrophoresis results also confirmed that slurry ice treatment could effectively retard the degradation of myofibrillar proteins and showed a positive effect on the stability of tissue structures.

Comparison of the cryoprotective effects of trehalose, alginate, and its oligosaccharides on peeled shrimp (Litopenaeus vannamei) during frozen storage.

The cryoprotective effects of trehalose, alginate, and its oligosaccharides on peeled shrimp (Litopenaeus vannamei) during frozen storage was investigated by monitoring thawing loss, color, texture, myofibrillar protein content, Ca2+ -ATPase activity, and performing microscopic structural analysis. Data revealed significant (p < 0.05) inhibitory effects on thawing loss and textural variables (springiness and chewiness) in trehalose-, alginate oligosaccharides-, and sodium pyrophosphate-treated shrimp compared with the control and alginate-treated batches. L* values revealed that these saccharides had a positive effect on color stability during frozen storage. In addition, the results of chemical analyses showed that trehalose and alginate oligosaccharide treatments effectively maintained an increased myofibrillar protein content and Ca2+ -ATPase activity in frozen shrimp. In addition, hematoxylin & eosin staining and SDS-PAGE confirmed that these cryoprotective saccharides slowed the degradation of muscle proteins and the damage to muscle tissue structures. Overall, the application of trehalose and alginate oligosaccharides to peeled frozen shrimp might maintain better quality and extend the commercialization of these refrigerated products.

Purification and characterization of three antioxidant peptides from protein hydrolyzate of croceine croaker (Pseudosciaena crocea) muscle.

Three antioxidant peptides were purified from protein hydrolysate of croceine croaker (Pseudosciaena crocea) muscle prepared using pepsin and alcalase, and identified as Tyr-Leu-Met-Ser-Arg (PC-1), Val-Leu-Tyr-Glu-Glu (PC-2), and Met-Ile-Leu-Met-Arg (PC-3) with molecular weights of 651.77, 668.82, and 662.92Da, respectively. PC-1 exhibited the highest scavenging activities on DPPH (EC50 1.35mg/ml), superoxide (EC50 0.450mg/ml), and ABTS (EC50 0.312mg/ml) radicals, but PC-2 exhibited the strongest hydroxyl radical scavenging activity (EC50 0.353mg/ml) among the three peptides. PC-1 also showed effective inhibition on lipid peroxidation in the model system. The good activities of isolated peptides might be benefit from the smaller size and hydrophobic and/or aromatic amino acids within their sequences.