Functional, rheological, microstructural and antioxidant properties of quinoa flour in dispersions as influenced by particle size.

Nutritionally, particle size has significant impact on food digestibility in the gastrointestinal system. Controlling the rheological behaviors of particles in dispersion has been of major interest in the industry. In this work, the quinoa seed was ground into flour, followed by fractionating into a selected particle size [+30-mesh (>595-µm) to +200-mesh (>74-µm)]. The effect of particle size on composition, antioxidant, and several functional and mechanical properties of all particle fractions were studied. The protein, crude fat, crude fiber, dietary fiber contents increased with decreasing the particle size while the starch content decreased. The water holding capacity and sediment volume fraction increased with the reduction of particles. Rheological measurement indicated that there were significant differences among rheograms between coarser and finer particles of QF. The finest particles produced a lower complex viscosity and lower mechanical rigidity. The final and setback viscosities decreased as particle size decreased. Microscopy showed irregular-shaped polygon structure for the QF. The particle fractions ranged between +100 and +200-mesh showed compositional resemblances and, subsequently, the properties. The highest extractability of phenolics and antioxidant properties were observed for the finest particles. The information generated from this work would help the industry to develop products with the desired particle size with optimum functional and nutritional properties.

Novel findings on ultrastructural protection of skeletal muscle fibers during hibernation of Daurian ground squirrels: Mitochondria, nuclei, cytoskeleton, glycogen.

We examined ultrastructure protective phenomena and mechanisms of slow and fast muscles in hibernating Daurian ground squirrels (Spermophilus dauricus). Some degenerative changes such as slightly decreased sarcomere length and vacuolization occurred in hibernation, but periaxonal capsular borders in intrafusal fibers remained distinct and the arrangement of extrafusal fibers and Z-lines unscathed. In soleus samples, the number of glycogenosomes more than tripled during hibernation. The expression of phosphorylated glycogen synthase remained unaltered while that of glycogen phosphorylase decreased during hibernation. The number of extensor digitorum longus glycogenosomes decreased and the expression of phosphorylated glycogen synthase decreased, while glycogen phosphorylase expression remained unaltered. The nuclei number remained unchanged. Kinesin and desmin, preventors of nuclear loss and damage, were maintained or just slightly reduced in hibernation. The single-fiber mitochondrial concentration and sub-sarcolemmal mitochondrial number increased in both muscle types. The expression of vimentin, which anchors mitochondria and maintains Z-line integrity, was increased during and after hibernation. Also, dynamin-related protein 1, mitochondrial fission factor, and adenosine triphosphate synthase were elevated in both muscle types. These findings confirm a remarkable ultrastructure preservation and show an unexpected increase in mitochondrial capacity in hibernating squirrels.

Active Chicken Meat Packaging Based on Polylactide Films and Bimetallic Ag-Cu Nanoparticles and Essential Oil.

Plasticized polylactide (PLA) composite films with multifunctional properties were created by loading bimetallic silver-copper (Ag-Cu) nanoparticles (NPs) and cinnamon essential oil (CEO) into polymer matrix via compression molding technique. Rheological, structural, thermal, barrier, and antimicrobial properties of the produced films, and its utilization in the packaging of chicken meat were investigated. PLA/PEG/Ag-Cu/CEO composites showed a very complex rheological system where both plasticizing and antiplasticizing effects were evident. Thermal properties of plasticized PLA film with polyethylene glycol (PEG) enhanced considerably with the reinforcement of NPs whereas loading of CEO decreased glass transition, melting, and crystallization temperature. The barrier properties of the composite films were reduced with the increase of CEO loading (P < 0.05). Their optical properties were also modified by the addition of both CEO and Ag-Cu NPs. The changes in the molecular organization of PLA composite films were visualized by FTIR spectra. Rough and porous surfaces of the films were evident by scanning electron microscopy. The effectiveness of composite films was tested against Salmonella Typhimurium, Campylobacter jejuni and Listeria monocytogenes inoculated in chicken samples, and it was found that the films loaded with Ag-Cu NPs and 50% CEO showed maximum antibacterial action during 21 days at the refrigerated condition. The produced PLA/Ag-Cu/CEO composite films can be applied to active food packaging. PRACTICAL APPLICATION: The nanoparticles and essential oil loaded PLA composite films are capable of exhibiting antimicrobial effects against Gram (+) and (-) bacteria, and extend the shelf-life of chicken meat. The bionanocomposite films showed the potential to be manufactured commercially because of the thermal stability of the active components during the hot-press compression molding process. The developed bionanocomposites could have practical importance and open a new direction for the active food packaging to control the spoilage and the pathogenic bacteria associated with the fresh chicken meat.

Polylactide/graphene oxide nanosheets/clove essential oil composite films for potential food packaging applications.

Antimicrobial nanopackaging films were developed by incorporating clove essential oil (CLO) (15-30% w/w) and graphene oxide (GO) nanosheets (1% w/w) into polylactide (PLA), suitable for use as food packaging, via solution casting. Addition of CLO into PLA matrix improved the flexibility of the composite films by lowering tensile stress, complex viscosity (η*), and glass transition temperature (Tg). GO improved the Tg, η* and lowered the oxygen permeability of the plasticized PLA matrix. Optical and anti-UV properties of the film were influenced by both GO and CLO incorporation. FTIR spectra exhibited a change in the molecular organization of the plasticized PLA film after incorporation with CLO. Microstructural studies revealed that the reinforcement of GO prevented porosity of plasticized PLA/CLO film surface. The developed composite film showed excellent antibacterial activity against Staphylococcus aureus and Escherichia coli and therefore, has a potential to be used as active packaging material for food safety and preservation.

Remarkable plasticity of Na+, K+-ATPase, Ca2+-ATPase and SERCA contributes to muscle disuse atrophy resistance in hibernating Daurian ground squirrels.

We investigated cytosolic calcium (Ca2+) and sarcoplasmic reticulum Ca2+ regulation in skeletal muscle fibers of hibernating Daurian ground squirrels (Spermophilus dauricus), non-hibernating hindlimb-unloaded (HLU) squirrels, and HLU rats to clarify the molecular mechanisms involved in preventing muscle atrophy in hibernators. The Na+, K+-ATPase and Ca2+-ATPase activities in the soleus muscle (SOL) of squirrels were maintained in hibernation, decreased during interbout arousal (IB-A), and increased to autumn/pre-hibernation (AUT/Pre-H) levels in torpor after interbout arousal (Post-IBA), whereas activities in the extensor digitorum longus muscle (EDL) were stable during hibernation, but increased during post-hibernation (Post-H). Activities increased in the SOL of HLU rats, but were stable in HLU squirrels. Sarco/endoplasmic reticulum Ca2+-ATPase (SERCA) activity in the SOL decreased in IB-A squirrels, but returned to AUT/Pre-H levels in the Post-IBA group; no significant changes were found in the EDL. SERCA activity increased in the EDL of HLU squirrels and SOL of HLU rats. Compared with AUT/Pre-H, SERCA type 2 protein expression increased in the SOL and EDL of IB-A and Post-IBA squirrels, but increased in the SOL only in HLU animals. We also describe the protein kinase A changes in this paper. Thus, hibernating ground squirrels displayed remarkable Na+, K+-ATPase, Ca2+-ATPase, and SERCA plasticity.

Tetramethylpyrazine ameliorated disuse-induced gastrocnemius muscle atrophy in hindlimb unloading rats through suppression of Ca2+/ROS-mediated apoptosis.

The purpose of this study was to examine the possible mechanism underlying the protective effect of tetramethylpyrazine (TMP) against disuse-induced muscle atrophy. Sprague-Dawley rats were randomly assigned to receive 14 days of hindlimb unloading (HLU, a model of disuse atrophy) or cage controls. The rats were given TMP (60 mg/kg body mass) or vehicle (water) by gavage. Compared with vehicle treatment, TMP significantly attenuated the loss of gastrocnemius muscle mass (-33.56%, P < 0.01), the decrease of cross-sectional area of slow fiber (-10.99%, P < 0.05) and fast fiber (-15.78%, P < 0.01) during HLU. Although TMP failed to further improve recovery of muscle function or fatigability compared with vehicle treatment, it can suppress the higher level of lactate (-22.71%, P < 0.01) induced by HLU. Besides, TMP could effectually reduce the increased protein expression of muscle RING-finger protein 1 induced by HLU (-14.52%, P < 0.01). Furthermore, TMP can ameliorate the calcium overload (-54.39%, P < 0.05), the increase of malondialdehyde content (-19.82%, P < 0.05), the decrease of superoxide dismutase activity (21.34%, P < 0.05), and myonuclear apoptosis (-78.22%, P < 0.01) induced by HLU. Moreover, TMP significantly reduced HLU-induced increase of Bax to B-cell lymphoma 2 (-36.36%, P < 0.01) and cytochrome c release (-36.16%, P < 0.05). In conclusion, TMP attenuated HLU-induced gastrocnemius muscle atrophy through suppression of Ca2+/reactive oxygen species increase and consequent proteolysis and apoptosis. Therefore, TMP might exhibit therapeutic effect against oxidative stress, cytosolic calcium overload, and mitochondrial damage in disuse-induced muscle atrophy.

Structure Prediction: New Insights into Decrypting Long Noncoding RNAs.

Long noncoding RNAs (lncRNAs), which form a diverse class of RNAs, remain the least understood type of noncoding RNAs in terms of their nature and identification. Emerging evidence has revealed that a small number of newly discovered lncRNAs perform important and complex biological functions such as dosage compensation, chromatin regulation, genomic imprinting, and nuclear organization. However, understanding the wide range of functions of lncRNAs related to various processes of cellular networks remains a great experimental challenge. Structural versatility is critical for RNAs to perform various functions and provides new insights into probing the functions of lncRNAs. In recent years, the computational method of RNA structure prediction has been developed to analyze the structure of lncRNAs. This novel methodology has provided basic but indispensable information for the rapid, large-scale and in-depth research of lncRNAs. This review focuses on mainstream RNA structure prediction methods at the secondary and tertiary levels to offer an additional approach to investigating the functions of lncRNAs.

Shelf-life extension of refrigerated sea bass slices wrapped with fish protein isolate/fish skin gelatin-ZnO nanocomposite film incorporated with basil leaf essential oil.

Microbiological, chemical and sensory changes of sea bass slices wrapped with fish protein isolate (FPI)/fish skin gelatin (FSG) films incorporated with 3 % ZnO nanoparticles (ZnONP) (w/w, based on protein content) and 100 % basil leaf essential oil (BEO) (w/w, based on protein content) during storage of 12 days at 4 °C were investigated. Sea bass slices wrapped with FPI/FSG-ZnONP-BEO film had the lowest growth of psychrophilic bacteria, lactic acid bacteria and spoilage microorganisms including Pseudomonas , H2S-producing bacteria and Enterobacteriaceae throughout storage of 12 days in comparison with those wrapped with FPI/FSG-BEO, FPI/FSG-ZnONP, FPI/FSG film, polypropylene film (PP film) and the control (without wrapping), respectively (P < 0.05). Lowered increases in pH, total volatile base, peroxide value and TBARS value were found in FPI/FSG-ZnO-BEO film wrapped samples, compared with others (P < 0.05). Sensory evaluation revealed that shelf-life of sea bass slices was longest for samples wrapped with FPI/FSG-ZnONP-BEO film (12 days), as compared to the control (6 days) (P < 0.05).

Undesirable Enzymatic Browning in Crustaceans: Causative Effects and Its Inhibition by Phenolic Compounds.

Undesirable enzymatic browning mediated by polyphenol oxidase (E.C. 1.14.18.1) on the surface of seafood from crustaceans have been a great concern to food processors, causing quality losses of seafood products. Seafoods especially from crustaceans are worldwide consumed due to their delicacy and nutritional value. However, black spot formation (melanosis) is the major problem occurring in crustaceans during postmortem handling and refrigerated storage induce deleterious changes in organoleptic properties and, therefore, decreases commercial value. Polyphenoloxidase (PPO), the copper-containing metalloprotein involved in oxidation of phenol to quinone is the major biochemical reaction of melanosis formation. This enzymatic mechanism causes unappealing blackening in postharvest crustaceans. To alleviate the melanosis formation in crustaceans, use of phenolic compounds from plant extract can serve as antimelanotics and appears to be a good alternative to the conventional sulfites which are associated with health-related disorders. In this review, we focuses on the unique features about the structure, distribution, and properties of PPO as well as mechanism of melanosis formation and provide a comprehensive deeper insight on the factors affecting melanosis formation and its inhibition by various antimelanotics including newly discovered plant phenolic compounds.

Effect of imidacloprid on hepatotoxicity and nephrotoxicity in male albino mice.

Imidacloprid (IC) is a systemic insecticide related to the tobacco toxin nicotine. IC is a toxic substance frequently used into combat insects, rodents and plants pests and other creatures that can pose problems for agriculture. We, therefore, planned this study to assess risk factors, biochemical and histological alterations associated with hepatotoxicity and nephrotoxicity. Forty-eight adult male albino mice were divided into four groups of 12 animals each. All the animals were given standard synthetic pellet diet. One group served as control, and the other three were served as experimental groups. Decrease in the body weight of the high dose group was observed at 15 mg/kg/day, and no mortality occurred during the treatment period. High dose of imidacloprid caused a significant elevation of serum clinical chemistry parameters, serum glutamic oxaloacetic transaminase (SGOT), serum glutamic pyruvate kinase (SGPT), alkaline phosphatase (ALP) and total bilirubin (TBIL). Histology of liver and kidney indicates hepatotoxicity and nephrotoxicity at a high dose of imidacloprid. Based on the morphological, biochemical and histopathological analysis, it is evident that imidacloprid induced toxicological effects at 15 mg/kg/day to mice. The results of the present study demonstrate that IC had significant effects on body weight, liver functions and kidney (p < 0.05) at a dose of 15 mg/kg body weight. IC treatment 5 and 10 mg/kg/day may be considered as no observed adverse effect level (NOAEL) for mice. It was concluded that IC can cause hepatotoxicity and nephrotoxicity at a dose much lower than the LD50 (131 mg/kg body weight) in mice.

Effect of zinc sulphate on gelling properties of phosphorylated protein isolate from yellow stripe trevally.

Impacts of zinc sulphate (ZnSO4) (0-140 µmol/kg) on gel properties of yellow stripe trevally surimi added with sodium tripolyphosphate (STPP) (0.25% and 0.5%, w/w) and protein isolate phosphorylated with STPP at 0.25% and 0.5% (w/w) were studied. Gels from surimi added with 60 µmol ZnSO4/kg in the absence and presence of 0.5% STPP had the increases in breaking force and deformation by 20.9% and 33.3%, and 11.6% and 18.6%, respectively, compared with the control surimi gel (without additives). Gel of protein isolate phosphorylated with 0.5% STPP containing 100 µmol ZnSO4/kg had the increases in breaking force and deformation by 14.87% and 5.6%, respectively, compared with the gel from non-phosphorylated protein isolate at the same ZnSO4 level, suggesting that the phosphorylated protein isolate was more crosslinked by Zn(2+). The addition of ZnSO4 at the suitable level lowered the expressible moisture content, but increased whiteness of surimi or protein isolate gels (P<0.05). Non-covalent bonds, more likely salt bridge and ionic interactions, played a major role in cross-linking of proteins in both surimi and protein isolate added with ZnSO4, regardless of phosphates incorporated. Microstructure study revealed that a gel having highly interconnected and denser network with smaller voids was formed when protein isolate phosphorylated with 0.5% STPP was added with ZnSO4 at a level of 100 µmol/kg. Thus, gel with improved properties could be obtained from protein isolate from yellow stripe trevally phosphorylated with STPP in conjunction with addition of ZnSO4 at an appropriate level.