P.V. Suresh

Comparative assessment of physico-chemical characteristics and fibril formation capacity of thermostable carp scales collagen

Collagen and collagen fibers have been widely documented as a potential and competitive biomaterial for medical applications. However, the searches for safe and realistic new collagen sources are still underway. Currently, fishery by-products (scales), a promising collagen source are usually discarded. In the present study, in vitro fibril-forming ability of the extracted fish scale collagen is reported. The aim of the investigation was to evaluate the concomitant comparison of fibril-forming abilities and characteristics of acid and pepsin soluble collagens from the scales of Indian major carp catla (Catla catla) and rohu (Labeo rohita). The extracted collagens were characterized as type I, with a total yield of 2.80-4.11% (w/w). Denaturation temperature determined for all collagens were between 35.9 and 37.7°C. All collagens exhibited high solubility in acidic pH and low NaCl concentrations. SEM clarified the lyophilized collagens and their fibril-forming capacity. Amino acid content and radical scavenging efficacy were also analyzed for the extracted collagen. The results revealed that extracted scale collagen from a renewable biological source could be used as biomaterials in various sectors. It might be suitable for preparing collagen gel for biomedical devices or as a scaffold for cell culture because of its high stability and fibril formation capacity.

Chitooligomers preparation by chitosanase produced under solid state fermentation using shrimp by-products as substrate.

Solid state fermentation (SSF) conditions were statistically optimized for the production of chitosanase by Purpureocillium lilacinum CFRNT12 using shrimp by-products as substrate. Central composite design and response surface methodology were applied to evaluate the effect of variables and their optimization. Incubation temperature, incubation time, concentration of inoculum and yeast extract were found to influence the chitosanase production significantly. The R(2) value of 0.94 indicates the aptness of the model. The level of variables for optimal production of chitosanase was 32 ± 1°C temperature, 96 h incubation, 10.5% (w/v) inoculum, 1.05% (w/w) yeast extract and 65% (w/w) moisture content. The chitosanase production was found to increase from 2.34 ± 0.07 to 41.78 ± 0.73 units/g initial dry substrate after optimization. The crude chitosanase produced 4.43 mM of chitooligomers as exclusive end product from colloidal chitosan hydrolysis. These results indicate the potential of P. lilacinum CFRNT12 for the chitosanase production employing cost effective SSF using shrimp by-products.

Microbial collagenases: challenges and prospects in production and potential applications in food and nutrition

Microbial collagenases are promising enzymes in view of their extensive industrial and biological applications. The emerging evidence of potential food applications and health benefits have revealed that microbial collagenase shows significant promise as a main component for bioactive functional ingredients and the preparation of peptides. Collagenases are important virulence factors which play a crucial role in the global degradation of the extracellular matrices of animals, due to their collagen degradation ability. There is a lack of scientific consensus on a well-defined and proper screening of collagenase-producing microorganisms. A vast controversy can be found in the literature regarding the correct identification of microbial collagenase. This review summarizes the current technologies and strategies used to improve the screening, production, and purification of microbial collagenase with a comprehensive insight, especially focusing on the classification, structures and collagen-degrading mechanisms of M9 family representative collagenases. It also highlights the potential of microbial collagenase in the development of a process for meat tenderization and bioactive “true” collagen peptides, or the preparation of hydrolysates. In addition, the critical challenges and various strategies for potential applications of collagenase in food, nutrition, biotechnological and medical sectors are highlighted.

Antioxidant and neuroprotective potential of chitooligomers in Caenorhabditis elegans exposed to Monocrotophos

The objectives of this investigation were to establish the propensity of the chitooligomers (COS) to ameliorate neurodegeneration and oxidative stress in Caenorhabditis elegans induced by an organophosphorus insecticide, Monocrotophos (MCP). COS was prepared from α-chitosan by the enzymatic method using chitosanase and characterized by HPLC and electron spray ionization-TOF-(ESI-TOF)-MS. We exposed age synchronized L4 C. elegans worms (both wild type N2 and transgenic strain BZ555 (Pdat-1:GFP) to sublethal concentration of MCP (0.75mM) for 24h in the presence or absence of COS (0.2mM). The neuroprotective effect of COS was examined in N2 worms in terms of brood size, lifespan, egg laying, dopamine content, acetylcholinesterase and carboxylesterase activity and by direct visualization and quantification of degeneration of dopaminergic neurons in BZ555. Exposure to COS extended lifespan, normalized egg laying, increased brood size, decreased the dopaminergic neurodegeneration, increased the dopamine content and increased AChE and carboxylesterase activity in C. elegans treated with MCP. COS induced a significant decrease in reactive oxygen species and increased the reduced glutathione level as well as increased superoxide dismutase and catalase activity. Our findings demonstrate that COS significantly inhibits the dopaminergic neurodegeneration and associated physiological alterations induced by MCP in C. elegans by attenuating the oxidative stress as well.

Physico-chemical characteristics and fibril-forming capacity of carp swim bladder collagens and exploration of their potential bioactive peptides by in silico approaches

This study explores the sustainable valorization of carp swim bladder by-products. The high-value molecule collagens were successfully extracted from carp swim bladder with a yield of ∼60% (dry weight basis) and characterized by sodium dodecyl sulfate polyacrylamide gel electrophoresis, UV-spectrum and Fourier transform infrared spectroscopy. The extracted collagens showed the fibril-forming ability and high denaturation temperature (38-39°C). Furthermore, the extracted collagens subjected to preparing bioactive collagen hydrolysates with potential antioxidant activities. In vitro and In silico approaches (PepDraw, BIOPEP, PeptideRanker, Pepcalc and ToxinPred) were employed to evaluate the potential of carp collagens as a potential source of bioactive peptides. Furthermore, primary structure, biological potential, physicochemical, sensory and toxicity characteristics of the theoretically release antioxidative collagen peptides were predicted. Overall, the present study highlights the carp collagens hydrolysate could be a promising precursor of bioactive peptides for developing functional food or nutraceutical products.

Inclusion of poultry based food ingredients in the formulation of noodles and their effects on noodle quality characteristics

Incorporating exogenous proteins into food products is a better practice for improving nutritional attributes of food commodities. In the search for a way to improve the product and nutritional quality of noodles, this study was aimed to evaluate the impact of the incorporation of poultry based ingredients egg yolk powder (EYP) and chicken mincemeat (CMM) in noodles at different levels (5, 10 and 15%, w/w). The incorporated noodles were subjected to evaluation of the cooking, texture, colour, sensory and microstructure properties. The results showed that the incorporation of poultry based food ingredient types and amount influence the nutritional content of noodles. Simultaneously, poultry based ingredients incorporated noodles showed the acceptable firmness and colour charatertistics. Scanning electron micrograph of the incorporated noodles showed the gelatinized starch granules enveloped by protein matrix, and also indicating a better structure as compared to the control. The sensory profile of incorporated noodles was showed significant (p ≤ 0.05) high overall quality. The result of this study showed that 10% (w/w) EYP and 15% (w/w) CMM incorporated noodles showed a better overall noodles quality attributes (texture, colour, sensory and microstructure). The results also provide ideas about the inclusion of the appropriate levels of poultry based ingredients (EYP and CMM) with a better sensory and nutritional profile. Therefore, this study may be useful in the food industry for the production of poultry based ingredients noodles with enhanced quality characteristics.

Performance Analysis of Channel Allocation Scheme for A System Model Based On Urban Structure

AbstractFrequency channels are scarce resource and available in a limit. Due to this limitation user may experience call termination and call blocking as the traffic increases. We can limit call termination and call blocking by allocating permanent channel to home (apartment) and office user due to very limited movement. They are almost fixed if they communicate with each other frequently and this is the normal scenario in urban areas. By using this strategy these users will not feel any disconnection due to inaccessibility of frequency channel in cell. To achieve this we have proposed a scheme based on fixed channel and analyze the performance for both normal channel allocation and preserved channel allocation for home and office users. We have performed and compared the results of call blocking probability, handover failure probability, call termination due to successful handover probability and probability for not completed calls.