Production of heterocyclic aromatic amines in meat: Chemistry,health risks and inhibition. A review

Heterocyclic aromatic amines are compounds produced in meat subjected to high temperature cooking. Formation of these substances is highly influenced by cooking method, cooking time, cooking temperature, and type of meat. Heterocyclic amines contain heterocyclic rings and nitrogen containing groups within their structure. Risks of colon, pancreas, gastrointestinal tract, lung, liver, prostate, skin and breast cancers are decidedly associated with the consumption of heterocyclic amines. These mutagenic compounds can be attenuated by addition of different fruits and vegetable extracts. Several spices and antioxidants can also be used for the reduction of these heterocyclic amines. The level of heterocyclic amines can be reduced by cooking at low temperature and by decreasing the cooking time. Formation of heterocyclic amines can also be prevented by marinating the meat before frying or grilling and by microwave pre-treatments. Objectives of this review are to create awareness about health risks, and to stimulate further research on other suitable ways to reduce the cancer risks associated with the consumption of cooked meat products.     

Removal of heavy metals by adsorption on Pleurotus ostreatus

The present study explores the adsorption potential of Pleurotus ostreatus (a macro-fungus) to remove copper, nickel, zinc and chromium from water all together. Different operational parameters such as the effect of pH, biomass dose, equilibrium time, stirring intensity, temperature and initial metal ion concentrations were studied. Maximum adsorption of Ni(II), Cu(II) and Zn(II) took place in the pH range 4.5-5.0, whereas for Cr(VI) ion, best results were achieved at pH 2.5. Nearly 150 min are required to gain sorption equilibrium. Temperature has no significant effect on biosorption in the range of 20-45 °C. The maximum biosorption capacity of fungus was 8.06, 20.40, 3.22 and 10.75 mg g⁻¹ for Cu(II), Ni(II), Zn(II) and Cr(VI) in that order. FTIR analysis pointed out the involvement of amine (-NH₂) and carboxylic (-COOH) groups in the adsorption process. Simple and adjusted Langmuir and Freundlich isotherm models were used to explain the sorption phenomenon. For real effluents of electroplating, biosorption capacities were 2.73, 8.45, 0.88 and 4.45 mg g⁻¹ for Cu(II), Ni(II), Zn(II) and Cr(VI) ions, respectively. Moreover, used P. ostreatus was recycled repeatedly and used many times to evaluate the adsorption efficacy on reuse, but findings pointed out that capacity decreased, to some extent, on recycling.     

Effect of pre-crack length on Mode I fracture toughness of 3-D angle-interlock woven composites from finite element analyses

Fracture toughness is a key factor to design impact behaviors of composite materials. This paper reports the influence of pre-crack length on Mode I fracture toughness of 3-D angle-interlock woven composites. Double cantilever beam specimens with different pre-crack lengths were tested to obtain load-displacement curves and strain energy release rates. A finite element analysis model at microstructure level was established to reveal the fracture damage development and stress distribution in the specimens. We found that the fracture toughness decreases with increase in pre-crack length. The higher pre-crack length resulted in increased stress concentration at crack tip position and the enhanced crack propagation. The higher strength through-thickness yarns are recommended for improving fracture toughness.     

Online complete coverage path planning using two-way proximity search

This paper presents an efficient online approach for complete coverage path planning of mobile robots in an unknown workspace based on online boustrophedon motion and an optimized backtracking mechanism. The presented approach first performs a single continuous boustrophedon motion until a critical point is reached. In order to completely cover the environment, next starting point is decided by using the accumulated knowledge of the environment map. An efficient backtracking technique based on proposed Two-way Proximity Search algorithm is used to plan a path from the critical point to the new starting point. Simulation results show the efficiency of proposed backtracking approach with improved total coverage time, coverage path length and memory requirements.     

Sorption studies for Cd(II) sequestration from aqueous solution on chemically modified Albizia lebbeck

In the present work, a new sorbent was successfully prepared by chemically modifying pods of Albizia lebbeck (AL) by Fenton’s reagent, followed by sodium silicate. Sorption studies were carried out by batch process. The optimum pH was found to be 6. Equilibrium isotherm data were analysed by non-linear curve fitting analysis, to fit Langmuir, Freundlich and Temkin isotherm models. Based on the Langmuir isotherm model, maximum monolayer sorption capacity (qm) was found to be 21.22 mg.g^?1 at 50°C. Breakthrough and exhaustive capacities were found to be 10 and 50 mg.g^?1, respectively. Desorption study showed 95% recovery of Cd(II) ions.     

The structural,morphological and thermal properties of grafted pH-sensitive interpenetrating highly porous polymeric composites of sodium alginate/acrylic acid copolymers for controlled delivery of diclofenac potassium

In present investigation new formulations of Sodium Alginate/Acrylic acid hydrogels with high porous structure were synthesized by free radical polymerization technique for the controlled drug delivery of analgesic agent to colon. Many structural parameters like molecular weight between crosslinks (M_c), crosslink density (M_r), volume interaction parameter (v_2,s), Flory Huggins water interaction parameter and diffusion coefficient (Q) were calculated. Water uptake studies was conducted in different USP phosphate buffer solutions. All samples showed higher swelling ratio with increasing pH values because of ionization of carboxylic groups at higher pH values. Porosity and gel fraction of all the samples were calculated. New selected samples were loaded with the model drug (diclofenac potassium).The amount of drug loaded and released was determined and it was found that all the samples showed higher release of drug at higher pH values. Release of diclofenac potassium was found to be dependent on the ratio of sodium alginate/acrylic acid, EGDMA and pH of the medium. Experimental data was fitted to various model equations and corresponding parameters were calculated to study the release mechanism. The Structural, Morphological and Thermal Properties of interpenetrating hydrogels were studied by FTIR, XRD, DSC, and SEM.     

Exploiting encapsulated Himalayan walnut oil as a vivid source of essential fatty acids for the development of novel functional bread

The basic aim of the study was to utilise Himalayan Walnut oil (HWO) encapsulated in soy protein isolate (SPI)–maltodextrin (MD)–pectin (Pec) complex as a potential source of omega fatty acids for bread fortification. Encapsulated HWO was integrated with bread for enhanced quality and technological aspects compared to control: it contained protein (9–19%), fat (6–8%), alpha-linolenic acid (37.50%) with lower carbohydrate (35–42%) content. The baked loaves depicted higher specific loaf volume (3.85–4.85 cm³ g⁻¹) with low hardness (4.24–5 N) due to the presence of hydrocolloids. Crust and crumb colour revealed a significant effect on the appearance of bread, with an increase in the antioxidant activity as assessed by 1,1-diphenyl-2-picrylhydrazyl (80%), 2,2′-Azino-bis (3-Ethylbenzothiazoline-6-Sulfonic Acid) (100%) and Metal Chelating Activity (10%). Compared to control, addition of encapsulated HWO increased final product quality by lowering oil oxidation during storage period. Scanning electron microscopic analysis showed intact encapsulated oil bodies in crumb after baking, thereby demonstrating high omega fatty acid retention.     

Nitric Oxide as a Target for Phytochemicals in Anti-Neuroinflammatory Prevention Therapy

Nitric oxide (NO) is a neurotransmitter that mediates the activation and inhibition of inflammatory cascades. Even though physiological NO is required for defense against various pathogens, excessive NO can trigger inflammatory signaling and cell death through reactive nitrogen species-induced oxidative stress. Excessive NO production by activated microglial cells is specifically associated with neuroinflammatory and neurodegenerative conditions, such as Alzheimer’s and Parkinson’s disease, amyotrophic lateral sclerosis, ischemia, hypoxia, multiple sclerosis, and other afflictions of the central nervous system (CNS). Therefore, controlling excessive NO production is a desirable therapeutic strategy for managing various neuroinflammatory disorders. Recently, phytochemicals have attracted considerable attention because of their potential to counteract excessive NO production in CNS disorders. Moreover, phytochemicals and nutraceuticals are typically safe and effective. In this review, we discuss the mechanisms of NO production and its involvement in various neurological disorders, and we revisit a number of recently identified phytochemicals which may act as NO inhibitors. This review may help identify novel potent anti-inflammatory agents that can downregulate NO, specifically during neuroinflammation and neurodegeneration.