Search results for: fish sarcoplasmic protein
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 2977

Search results for: fish sarcoplasmic protein

2707 Fish Catch Composition from Gobind Sagar Reservoir during 2006-2012

Authors: Krishan Lal, Anish Dua

Abstract:

Gobind Sagar Reservoir has been created in Himachal Pradesh, India (31° 25´ N and 76 ° 25´E) by damming River Sutlej at village Bhakra in 1963. The average water spread area of this reservoir is 10,000 hectares. Fishermen have organized themselves in the form of co-operative societies. 26 fisheries co-operative societies were working in Gobind Sagar Reservoir up till 2012. June and July months were observed as closed season, no fishing was done during this period. Proper record maintaining of fish catch was done at different levels by the state fisheries department. Different measures like minimum harvestable size, mesh size regulation and prohibition of illegal fishing etc. were taken for fish conservation. Fishermen were actively involved in the management. Gill nets were used for catching fishes from this reservoir. State fisheries department is realizing 15% royalty of the sold fish. Data used in this paper is about the fish catch during 2006-2012 and were obtained from the state fisheries department, Himachal Pradesh. Catla catla, Labeo rohita, Cirrhinus mrigala, Sperata seenghala, Cyprinus carpio, Tor putitora, Hypophthalmichthys molitrix, Labeo calbasu, Labeo dero and Ctenopharyngodon idella etc., were the fish species exploited for commercial purposes. Total number of individuals of all species caught was 3141236 weighing 5637108.9 kg during 2006-2012. H. molitrix was introduced accidently in this reservoir and was making a good share of fish catch in this reservoir. The annual catch of this species was varying between 161279.6 kg, caught in 2011 and 788030.8 kg caught in 2009. Total numbers of individuals of C. idella caught were 8966 weighing 64320.2 kg. The catch of Cyprinus carpio was varying between 144826.1 kg caught in 2006 and 214480.1 kg caught in 2010. Total catch of Tor putitora was 180263.2 kg during 2006-2012. Total catch of L. dero, S. seenghala and Catla catla remained 100637.4 kg, 75297.8 kg and 561802.9 kg, respectively, during 2006-2012. Maximum fish catch was observed during the months of August (after observing Closed Season). Maximum catch of exotic carps was from Bhakra area of the reservoir which has fewer fluctuations in water levels. The reservoir has been divided into eight beats for administrative purpose, to avoid conflicts between operating fisheries co-operative societies for area of operation. Fish catch was more by co-operative societies operating in the area of reservoir having fewer fluctuations in water level and catch was less by co-operative societies operating in the area of more fluctuations in water level. Species-wise fish catch by different co-operative societies from their allotted area was studied. This reservoir is one of most scientifically managed reservoirs.

Keywords: co-operative societies, fish catch, fish species, reservoir

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2706 Anti-Nutritional Factors, In-Vitro Trypsin, Chymotrypsin and Peptidase Multi Enzyme Protein Digestibility of Some Melon (Egusi) Seeds and Their Protein Isolates

Authors: Joan O. Ogundele, Aladesanmi A. Oshodi, Adekunle I. Amoo

Abstract:

Abstract In-vitro multi-enzyme protein digestibility (IVMPD) and some anti-nutritional factors (ANF) of five melon (egusi) seed flours (MSF) and their protein isolates (PI) were carried out. Their PI have potentials comparable to that of soya beans. It is important to know the IVMPD and ANF of these protein sources as to ensure their safety when adapted for use as alternate protein sources to substitute for cow milk, which is relatively expensive in Nigeria. Standard methods were used to produce PI of Citrullus colocynthis, Citrullus vulgaris, African Wine Kettle gourd (Lageneria siceraria I), Basket Ball gourd (Lagenaria siceraria II) and Bushel Giant Gourd (Lageneria siceraria III) seeds and to determine the ANF and IVMPD of the MSF and PI unheated and at 37oC. Multi-enzymes used were trypsin, chymotrypsin and peptidase. IVMPD of MSF ranged from (70.67±0.70) % (C. vulgaris) to (72.07± 1.79) % (L.siceraria I) while for their PI ranged from 74.33% (C.vulgaris) to 77.55% (L.siceraria III). IVMPD of the PI were higher than those of MSF. Heating increased IVMPD of MSF with average value of 79.40% and those of PI with average of 84.14%. ANF average in MSF are tannin (0.11mg/g), phytate (0.23%). Differences in IVMPD of MSF and their PI at different temperatures may arise from processing conditions that alter the release of amino acids from proteins by enzymatic processes. ANF in MSF were relatively low, but were found to be lower in the PI, therefor making the PI safer for human consumption as an alternate source of protein.

Keywords: Anti-nutrients, Enzymatic protein digestibility, Melon (egusi)., Protein Isolates.

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2705 Effect of Low Temperature on Structure and RNA Binding of E.coli CspA: A Molecular Dynamics Based Study

Authors: Amit Chaudhary, B. S. Yadav, P. K. Maurya, A. M., S. Srivastava, S. Singh, A. Mani

Abstract:

Cold shock protein A (CspA) is major cold inducible protein present in Escherichia coli. The protein is involved in stabilizing secondary structure of RNA by working as chaperone during cold temperature. Two RNA binding motifs play key role in the stabilizing activity. This study aimed to investigate implications of low temperature on structure and RNA binding activity of E. coli CspA. Molecular dynamics simulations were performed to compare the stability of the protein at 37°C and 10 °C. The protein was mutated at RNA binding motifs and docked with RNA to assess the stability of both complexes. Results suggest that CspA as well as CspA-RNA complex is more stable at low temperature. It was also confirmed that RNP1 and RNP2 play key role in RNA binding.

Keywords: CspA, homology modelling, mutation, molecular dynamics simulation

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2704 Utilization of Soymilk Residue for Wheat Flour Substitution in Gyoza skin

Authors: Naruemon Prapasuwannakul

Abstract:

Soy milk residue is obtained as a byproduct from soy milk and tofu production with little economic value. It contains high protein and fiber as well as various minerals and phyto-chemical compounds. The objective of this research was to substitute soy milk residue for wheat flour in gyoza skin in order to enhance value of soy milk residue and increase protein and fiber content of gyoza skin. Wheat flour was replaced with soy milk residue from 0 to 40%. The soy milk residue prepared in this research contains 26.92% protein, 3.58% fiber, 2.88% lipid, 6.29% ash and 60.33% carbohydrate. The results showed that increasing soy milk residue decreased lightness (L*value), tensile strength and sensory attributes but increased redness (a*), yellowness (b*), protein and fiber contents of product. The result also showed that the gyoza skin substituted with 30% soy milk residue was the most acceptable (p≤0.05) and its protein and fiber content increased up to 45 % and 867 % respectively.

Keywords: Gyoza skin, sensory, soymilk residue, wheat flour

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2703 Gambusia an Excellent Indicator of Metals Stress

Authors: W. Khati, Y. Guasmi

Abstract:

The activity of acetylcholinesterase (AChE) was studied in freshwater fish exposed to two heavy metals lead and cadmium. Measurements were made after short exposures (4 and 7 days) at concentrations of 1, 5, and 7μg/L cadmium and 1.25, 2.25, and 5 mg/L of lead. Cadmium induced no significant increases in activity of AChE in the gills for the lowest dose. Except significant inhibition on 7 days. In muscle of Gambusia, under stress of metallic lead, the activity increases compared to the control are noted at 4 days of treatment and inhibitions to 7 days of exposure. The analysis of variance (time, treatment) indicates only a very significant time effect (p<0.05), and as for cadmium, a significant body effect (p<0.01) is recorded. This small fish sedentary, colonizing particularly quiet environments, polluted, can only be the ideal bioindicator of contamination and bioaccumulation of metals. The presence of lead and cadmium in the bodies of fish is a risk factor not only for the lives of these aquatic species, but also for the man who is the top predator at the end of the food chain.

Keywords: biomarkers, bioindicator, environmenlal health, metals

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2702 Distinct Antiviral Pathway for ZFP36-Like Family Members Against Flavivirus Infection

Authors: Ren-Jye Lin, Li-Hsiung Lin, Bing-Cheng Liu, Ching-Len Liao

Abstract:

The human zinc finger protein 36-like protein family, containing zinc finger protein 36-like 1 (ZFP36L1) and zinc finger protein 36-like 2 (ZFP36L2), belongs to CCCH-type zinc-finger protein identified as an RNA-binding protein that participates in controlling posttranscriptional regulation via RNA decay pathways. Recently, we demonstrated that human ZFP36L1 showed potent antiviral activity against flavivirus Infection by both 5´-3´ XRN1 and 3´-5´RNA-exosome RNA decay pathways (Journal of Virology 2022 Jan 12;96(1): e0166521). However, another zinc finger protein 36-like protein member, ZFP36L2, in the host defense response against flaviviruses has yet to be addressed. Here, we also demonstrate that ZFP36L2 functions as a host innate defender against flaviviruses, including Japanese encephalitis virus (JEV) and dengue virus (DENV). Overexpression of ZFP36L2 reduced JEV and DENV infection, and ZFP36L2 knockdown significantly promoted viral replication. Distinct from the antiviral mechanism of ZFP36L1, ZFP36L2 inhibits flavivirus infection by only a 5´-3´ XRN1-mediated RNA decay pathway but not the 3´-5´RNA-exosome RNA decay pathway. Human ZFP36L1 and ZFP36L2 can restrict flavivirus replication by directly binding and destabilizing viral RNA. Thus, for the first time, human zinc finger protein 36-like family members, ZFP36L1 and ZFP36L2, are identified as host antiviral factors that can bind and degrade flavivirus viral RNA by diverse antiviral mechanisms.

Keywords: ZFP36L1, ZFP36L2, 5'-3' exonuclease XRN1, antiviral mechansim

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2701 Mapping Protein Selectivity Landscapes

Authors: Niv Papo

Abstract:

Characterizing the binding selectivity landscape of interacting proteins is crucial both for elucidating the underlying mechanisms of their interaction and for developing selective inhibitors. However, current mapping methods are laborious and cannot provide a sufficiently comprehensive description of the landscape. Here, we introduce a distinct and efficient strategy for comprehensively mapping the binding landscape of proteins using a combination of experimental multi-target selective library screening and in silico next-generation sequencing analysis. We map the binding landscape of a non-selective trypsin inhibitor, the amyloid protein precursor inhibitor (APPI), to each of four human serine proteases (kallikrein-6, mesotrypsin, and anionic and cationic trypsins). We then use this map to dissect and improve the affinity and selectivity of APPI variants toward each of the four proteases. Our strategy can be used as a platform for the development of a new generation of target-selective probes and therapeutic agents based on selective protein–protein interactions.

Keywords: drug design, directed evolution, protein engineering, protease inhibition.

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2700 Functional Properties of Sunflower Protein Concentrates Extracted Using Different Anti-greening Agents - Low-Fat Whipping Cream Preparation

Authors: Tamer M. El-Messery

Abstract:

By-products from sunflower oil extraction, such as sunflower cakes, are rich sources of proteins with desirable functional properties for the food industry. However, challenges such as sensory drawbacks and the presence of phenolic compounds have hindered their widespread use. In this study, sunflower protein concentrates were obtained from sunflower cakes using different ant-greening solvents (ascorbic acid (ASC) and N-acetylcysteine (NAC)), and their functional properties were evaluated. The color of extracted proteins ranged from dark green to yellow, where the using of ASC and NAC agents enhanced the color. The protein concentrates exhibited high solubility (>70%) and antioxidant activity, with hydrophobicity influencing emulsifying activity. Emulsions prepared with these proteins showed stability and microencapsulation efficiency. Incorporation of protein concentrates into low-fat whipping cream formulations increased overrun and affected color characteristics. Rheological studies demonstrated pseudoplastic behavior in whipped cream, influenced by shear rates and protein content. Overall, sunflower protein isolates showed promising functional properties, indicating their potential as valuable ingredients in food formulations.

Keywords: functional properties, sunflower protein concentrates, antioxidant capacity, ant-greening agents, low-fat whipping cream

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2699 ACOPIN: An ACO Algorithm with TSP Approach for Clustering Proteins in Protein Interaction Networks

Authors: Jamaludin Sallim, Rozlina Mohamed, Roslina Abdul Hamid

Abstract:

In this paper, we proposed an Ant Colony Optimization (ACO) algorithm together with Traveling Salesman Problem (TSP) approach to investigate the clustering problem in Protein Interaction Networks (PIN). We named this combination as ACOPIN. The purpose of this work is two-fold. First, to test the efficacy of ACO in clustering PIN and second, to propose the simple generalization of the ACO algorithm that might allow its application in clustering proteins in PIN. We split this paper to three main sections. First, we describe the PIN and clustering proteins in PIN. Second, we discuss the steps involved in each phase of ACO algorithm. Finally, we present some results of the investigation with the clustering patterns.

Keywords: ant colony optimization algorithm, searching algorithm, protein functional module, protein interaction network

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2698 Effect of Extrusion Processing Parameters on Protein in Banana Flour Extrudates: Characterisation Using Fourier-Transform Infrared Spectroscopy

Authors: Surabhi Pandey, Pavuluri Srinivasa Rao

Abstract:

Extrusion processing is a high-temperature short time (HTST) treatment which can improve protein quality and digestibility together with retaining active nutrients. In-vitro protein digestibility of plant protein-based foods is generally enhanced by extrusion. The current study aimed to investigate the effect of extrusion cooking on in-vitro protein digestibility (IVPD) and conformational modification of protein in green banana flour extrudates. Green banana flour was extruded through a co-rotating twin-screw extruder varying the moisture content, barrel temperature, screw speed in the range of 10-20 %, 60-80 °C, 200-300 rpm, respectively, at constant feed rate. Response surface methodology was used to optimise the result for IVPD. Fourier-transform infrared spectroscopy (FTIR) analysis provided a convenient and powerful means to monitor interactions and changes in functional and conformational properties of extrudates. Results showed that protein digestibility was highest in extrudate produced at 80°C, 250 rpm and 15% feed moisture. FTIR analysis was done for the optimised sample having highest IVPD. FTIR analysis showed that there were no changes in primary structure of protein while the secondary protein structure changed. In order to explain this behaviour, infrared spectroscopy analysis was carried out, mainly in the amide I and II regions. Moreover, curve fitting analysis showed the conformational changes produced in the flour due to protein denaturation. The quantitative analysis of the changes in the amide I and II regions provided information about the modifications produced in banana flour extrudates.

Keywords: extrusion, FTIR, protein conformation, raw banana flour, SDS-PAGE method

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2697 Effects of Effort and Water Quality on Productivity (CPUE) of Hampal (Hampala macrolepidota) Resources in Jatiluhur Dam, West Java

Authors: Ririn Marinasari, S. Pi

Abstract:

Hampal (Hampala macrolepidota) is one of Citarum river indigenous fishes that still find in Jatiluhur dam. IUCN at 2013 said that hampal listed on redlist species category, this species was rare in Jatiluhur dam. This species more and more decreasing because change of habitats characteristic such as water quality and fishing effort. This study aims to determine and identify the influence of fishing effort and the quality of water on the productivity of fish resources hampal (Hampala macrolepidota) in Jatiluhur. The study was conducted from October to November 2013. Zones of research include lacustrine zone, transition and Riverin. Hampal fish productivity value computed by Hampal’s CPUE values. The results showed that fish MSY hampal obtained from surplus production model of Schaefer is equal to 0.2045 tons / quarterly. In the years 2011-2012 have occurred over fishing in 2013 while still under fishing. Total catches have exceeded the MSY during the year 2011 and the third quarterly of 2012 tons of fish that exceed 0.2045 hampal. The rate of utilization of fish resources hampal is equal to 80% of MSY or equal to the allowable catch (Total Allowable Catch) for fish in Jatiluhur hampal based Schaefer surplus production theory. Fishing effort, water quality parameters such as DO, turbidity and negatively correlated sulfide as H2S, while the temperature and pH positively correlated to productivity or unit catches fish hampal efforts in quarterly time series in the period 2011-2013. Shows that the higher fishing effort, DO, turbidity and sulfide in H2S and diminishing the temperature and pH of the productivity decreases. Variables that affect the productivity of fishing hampal only H2S only factor beta coefficient -0.834 which indicates a negative effect. It can be caused by H2S levels are toxic and have already exceeded the quality standard, while for other water quality parameters are still below the maximum standards allowed in the waters. Result of the study can be a reference of fishing regulation for hampal conservation in Jatiluhur dam.

Keywords: effort, hampal, productivity, water quality

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2696 Achievement of Sustainable Groundwater Exploitation through the Introduction of Water-Efficient Usage Techniques in Fish Farms

Authors: Lusine Tadevosyan, Natella Mirzoyan, Anna Yeritsyan, Narek Avetisyan

Abstract:

Due to high quality, the artesian groundwater is the main source of water supply for the fisheries in Ararat Valley, Armenia. From 1.6 billion m3 abstracted groundwater in 2016, half was used by fish farms. Yet, the inefficient water use, typical for low-intensity aquaculture systems in Ararat Valley, has become a key environmental issue in Armenia. In addition to excessive pure groundwater exploitation, which along with other sectors of groundwater use in this area resulted in the reduction of artesian zone by approximately 67% during last 20 years, the negative environmental impact of these productions is magnified by the discharge of large volumes of wastewater into receiving water bodies. In turn, unsustainable use of artesian groundwater in Ararat Valley along with increasingly strict policy measures on water use had a devastating impact on small and/or medium scale aquaculture: over the last two years approximately 100 fish farms have permanently seized their operations. The current project aims at the introduction of efficient and environmentally friendly fish farming practices (e.g., Recirculating Aquaculture Systems) in Ararat Valley fisheries in order to support current levels of fish production and simultaneously reduce the negative environmental pressure of aquaculture facilities in Armenia. Economic and environmental analysis of current small and medium scale operational systems and subsequently developed environmentally–friendly and economically sustainable system configurations will be presented.

Keywords: aquaculture, groundwater, recirculation, sustainability

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2695 Improving Cleanability by Changing Fish Processing Equipment Design

Authors: Lars A. L. Giske, Ola J. Mork, Emil Bjoerlykhaug

Abstract:

The design of fish processing equipment greatly impacts how easy the cleaning process for the equipment is. This is a critical issue in fish processing, as cleaning of fish processing equipment is a task that is both costly and time consuming, in addition to being very important with regards to product quality. Even more, poorly cleaned equipment could in the worst case lead to contaminated product from which consumers could get ill. This paper will elucidate how equipment design changes could improve the work for the cleaners and saving money for the fish processing facilities by looking at a case for product design improvements. The design of fish processing equipment largely determines how easy it is to clean. “Design for cleaning” is the new hype in the industry and equipment where the ease of cleaning is prioritized gets a competitive advantage over equipment in which design for cleaning has not been prioritized. Design for cleaning is an important research area for equipment manufacturers. SeaSide AS is doing continuously improvements in the design of their products in order to gain a competitive advantage. The focus in this paper will be conveyors for internal logistic and a product called the “electro stunner” will be studied with regards to “Design for cleaning”. Often together with SeaSide’s customers, ideas for new products or product improvements are sketched out, 3D-modelled, discussed, revised, built and delivered. Feedback from the customers is taken into consideration, and the product design is revised once again. This loop was repeated multiple times, and led to new product designs. The new designs sometimes also cause the manufacturing processes to change (as in going from bolted to welded connections). Customers report back that the concrete changes applied to products by SeaSide has resulted in overall more easily cleaned equipment. These changes include, but are not limited to; welded connections (opposed to bolted connections), gaps between contact faces, opening up structures to allow cleaning “inside” equipment, and generally avoiding areas in which humidity and water may gather and build up. This is important, as there will always be bacteria in the water which will grow if the area never dries up. The work of creating more cleanable design is still ongoing, and will “never” be finished as new designs and new equipment will have their own challenges.

Keywords: cleaning, design, equipment, fish processing, innovation

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2694 Thresholding Approach for Automatic Detection of Pseudomonas aeruginosa Biofilms from Fluorescence in situ Hybridization Images

Authors: Zonglin Yang, Tatsuya Akiyama, Kerry S. Williamson, Michael J. Franklin, Thiruvarangan Ramaraj

Abstract:

Pseudomonas aeruginosa is an opportunistic pathogen that forms surface-associated microbial communities (biofilms) on artificial implant devices and on human tissue. Biofilm infections are difficult to treat with antibiotics, in part, because the bacteria in biofilms are physiologically heterogeneous. One measure of biological heterogeneity in a population of cells is to quantify the cellular concentrations of ribosomes, which can be probed with fluorescently labeled nucleic acids. The fluorescent signal intensity following fluorescence in situ hybridization (FISH) analysis correlates to the cellular level of ribosomes. The goals here are to provide computationally and statistically robust approaches to automatically quantify cellular heterogeneity in biofilms from a large library of epifluorescent microscopy FISH images. In this work, the initial steps were developed toward these goals by developing an automated biofilm detection approach for use with FISH images. The approach allows rapid identification of biofilm regions from FISH images that are counterstained with fluorescent dyes. This methodology provides advances over other computational methods, allowing subtraction of spurious signals and non-biological fluorescent substrata. This method will be a robust and user-friendly approach which will enable users to semi-automatically detect biofilm boundaries and extract intensity values from fluorescent images for quantitative analysis of biofilm heterogeneity.

Keywords: image informatics, Pseudomonas aeruginosa, biofilm, FISH, computer vision, data visualization

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2693 Physicochemical Properties of Pea Protein Isolate (PPI)-Starch and Soy Protein Isolate (SPI)-Starch Nanocomplexes Treated by Ultrasound at Different pH Values

Authors: Gulcin Yildiz, Hao Feng

Abstract:

Soybean proteins are the most widely used and researched proteins in the food industry. Due to soy allergies among consumers, however, alternative legume proteins having similar functional properties have been studied in recent years. These alternative proteins are also expected to have a price advantage over soy proteins. One such protein that has shown good potential for food applications is pea protein. Besides the favorable functional properties of pea protein, it also contains fewer anti-nutritional substances than soy protein. However, a comparison of the physicochemical properties of pea protein isolate (PPI)-starch nanocomplexes and soy protein isolate (SPI)-starch nanocomplexes treated by ultrasound has not been well documented. This study was undertaken to investigate the effects of ultrasound treatment on the physicochemical properties of PPI-starch and SPI-starch nanocomplexes. Pea protein isolate (85% pea protein) provided by Roquette (Geneva, IL, USA) and soy protein isolate (SPI, Pro-Fam® 955) obtained from the Archer Daniels Midland Company were adjusted to different pH levels (2-12) and treated with 5 minutes of ultrasonication (100% amplitude) to form complexes with starch. The soluble protein content was determined by the Bradford method using BSA as the standard. The turbidity of the samples was measured using a spectrophotometer (Lambda 1050 UV/VIS/NIR Spectrometer, PerkinElmer, Waltham, MA, USA). The volume-weighted mean diameters (D4, 3) of the soluble proteins were determined by dynamic light scattering (DLS). The emulsifying properties of the proteins were evaluated by the emulsion stability index (ESI) and emulsion activity index (EAI). Both the soy and pea protein isolates showed a U-shaped solubility curve as a function of pH, with a high solubility above the isoelectric point and a low one below it. Increasing the pH from 2 to 12 resulted in increased solubility for both the SPI and PPI-starch complexes. The pea nanocomplexes showed greater solubility than the soy ones. The SPI-starch nanocomplexes showed better emulsifying properties determined by the emulsion stability index (ESI) and emulsion activity index (EAI) due to SPI’s high solubility and high protein content. The PPI had similar or better emulsifying properties at certain pH values than the SPI. The ultrasound treatment significantly decreased the particle sizes of both kinds of nanocomplex. For all pH levels with both proteins, the droplet sizes were found to be lower than 300 nm. The present study clearly demonstrated that applying ultrasonication under different pH conditions significantly improved the solubility and emulsify¬ing properties of the SPI and PPI. The PPI exhibited better solubility and emulsifying properties than the SPI at certain pH levels

Keywords: emulsifying properties, pea protein isolate, soy protein isolate, ultrasonication

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2692 Bacteriophage Lysis Of Physiologically Stressed Listeria Monocytogenes In A Simulated Seafood Processing Environment

Authors: Geevika J. Ganegama Arachchi, Steve H. Flint, Lynn McIntyre, Cristina D. Cruz, Beatrice M. Dias-Wanigasekera, Craig Billington, J. Andrew Hudson, Anthony N. Mutukumira

Abstract:

In seafood processing plants, Listeriamonocytogenes(L. monocytogenes)likely exists in a metabolically stressed state due to the nutrient-deficient environment, processing treatments such as heating, curing, drying, and freezing, and exposure to detergents and disinfectants. Stressed L. monocytogenes cells have been shown to be as pathogenic as unstressed cells. This study investigated lytic efficacy of (LiMN4L, LiMN4p, and LiMN17) which were previouslycharacterized as virulent against physiologically stressed cells of three seafood borne L. monocytogenesstrains (19CO9, 19DO3, and 19EO3).Physiologically compromised cells ofL. monocytogenesstrains were prepared by aging cultures in TrypticaseSoy Broth at 15±1°C for 72 h; heat injuringcultures at 54±1 - 55±1°C for 40 - 60 min;salt-stressing cultures in Milli-Q water were incubated at 25±1°C in darkness for three weeks; and incubating cultures in 9% (w/v) NaCl at 15±1°C for 72 h. Low concentrations of physiologically compromised cells of three L. monocytogenesstrainswere challenged in vitrowith high titre of three phages in separate experiments using Fish Broth medium (aqueous fish extract) at 15 °C in order to mimic the environment of seafood processing plant. Each phage, when present at ≈9 log10 PFU/ml, reduced late exponential phase cells of L. monocytogenes suspended in fish protein broth at ≈2-3 log10 CFU/ml to a non-detectable level (< 10 CFU/ml). Each phage, when present at ≈8.5 log10 PFU/ml, reduced both heat-injured cells present at 2.5-3.6 log10 CFU/ml and starved cells that were showed coccoid shape, present at ≈2-3 log10 CFU/ml to < 10 CFU/ml after 30 min. Phages also reduced salt-stressed cellspresent at ≈3 log10 CFU/ml by > 2 log10. L. monocytogenes (≈8 log10 CFU/ml) were reduced to below the detection limit (1 CFU/ml) by the three successive phage infections over 16 h, indicating that emergence of spontaneous phage resistance was infrequent. The three virulent phages showed high decontamination potential for physiologically stressed L. monocytogenes strains from seafood processing environments.

Keywords: physiologically stressed L. monocytogenes, heat injured, seafood processing environment, virulent phage

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2691 Chitosan-Whey Protein Isolate Core-Shell Nanoparticles as Delivery Systems

Authors: Zahra Yadollahi, Marjan Motiei, Natalia Kazantseva, Petr Saha

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Chitosan (CS)-whey protein isolate (WPI) core-shell nanoparticles were synthesized through self-assembly of whey protein isolated polyanions and chitosan polycations in the presence of tripolyphosphate (TPP) as a crosslinker. The formation of this type of nanostructures with narrow particle size distribution is crucial for developing delivery systems since the functional characteristics highly depend on their sizes. To achieve this goal, the nanostructure was optimized by varying the concentrations of WPI, CS, and TPP in the reaction mixture. The chemical characteristics, surface morphology, and particle size of the nanoparticles were evaluated.

Keywords: whey protein isolated, chitosan, nanoparticles, delivery system

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2690 Hydrodynamic Analysis of Fish Fin Kinematics of Oreochromis Niloticus Using Machine Learning and Image Processing

Authors: Paramvir Singh

Abstract:

The locomotion of aquatic organisms has long fascinated biologists and engineers alike, with fish fins serving as a prime example of nature's remarkable adaptations for efficient underwater propulsion. This paper presents a comprehensive study focused on the hydrodynamic analysis of fish fin kinematics, employing an innovative approach that combines machine learning and image processing techniques. Through high-speed videography and advanced computational tools, we gain insights into the complex and dynamic motion of the fins of a Tilapia (Oreochromis Niloticus) fish. This study was initially done by experimentally capturing videos of the various motions of a Tilapia in a custom-made setup. Using deep learning and image processing on the videos, the motion of the Caudal and Pectoral fin was extracted. This motion included the fin configuration (i.e., the angle of deviation from the mean position) with respect to time. Numerical investigations for the flapping fins are then performed using a Computational Fluid Dynamics (CFD) solver. 3D models of the fins were created, mimicking the real-life geometry of the fins. Thrust Characteristics of separate fins (i.e., Caudal and Pectoral separately) and when the fins are together were studied. The relationship and the phase between caudal and pectoral fin motion were also discussed. The key objectives include mathematical modeling of the motion of a flapping fin at different naturally occurring frequencies and amplitudes. The interactions between both fins (caudal and pectoral) were also an area of keen interest. This work aims to improve on research that has been done in the past on similar topics. Also, these results can help in the better and more efficient design of the propulsion systems for biomimetic underwater vehicles that are used to study aquatic ecosystems, explore uncharted or challenging underwater regions, do ocean bed modeling, etc.

Keywords: biomimetics, fish fin kinematics, image processing, fish tracking, underwater vehicles

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2689 A Foodborne Cholera Outbreak in a School Caused by Eating Contaminated Fried Fish: Hoima Municipality, Uganda, February 2018

Authors: Dativa Maria Aliddeki, Fred Monje, Godfrey Nsereko, Benon Kwesiga, Daniel Kadobera, Alex Riolexus Ario

Abstract:

Background: Cholera is a severe gastrointestinal disease caused by Vibrio cholera. It has caused several pandemics. On 26 February 2018, a suspected cholera outbreak, with one death, occurred in School X in Hoima Municipality, western Uganda. We investigated to identify the scope and mode of transmission of the outbreak, and recommend evidence-based control measures. Methods: We defined a suspected case as onset of diarrhea, vomiting, or abdominal pain in a student or staff of School X or their family members during 14 February–10 March. A confirmed case was a suspected case with V. cholerae cultured from stool. We reviewed medical records at Hoima Hospital and searched for cases at School X. We conducted descriptive epidemiologic analysis and hypothesis-generating interviews of 15 case-patients. In a retrospective cohort study, we compared attack rates between exposed and unexposed persons. Results: We identified 15 cases among 75 students and staff of School X and their family members (attack rate=20%), with onset from 25-28 February. One patient died (case-fatality rate=6.6%). The epidemic curve indicated a point-source exposure. On 24 February, a student brought fried fish from her home in a fishing village, where a cholera outbreak was ongoing. Of the 21 persons who ate the fish, 57% developed cholera, compared with 5.6% of 54 persons who did not eat (RR=10; 95% CI=3.2-33). None of 4 persons who recooked the fish before eating, compared with 71% of 17 who did not recook it, developed cholera (RR=0.0, 95%CIFisher exact=0.0-0.95). Of 12 stool specimens cultured, 6 yielded V. cholerae. Conclusion: This cholera outbreak was caused by eating fried fish, which might have been contaminated with V. cholerae in a village with an ongoing outbreak. Lack of thorough cooking of the fish might have facilitated the outbreak. We recommended thoroughly cooking fish before consumption.

Keywords: cholera, disease outbreak, foodborne, global health security, Uganda

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2688 Artificial Habitat Mapping in Adriatic Sea

Authors: Annalisa Gaetani, Anna Nora Tassetti, Gianna Fabi

Abstract:

The hydroacoustic technology is an efficient tool to study the sea environment: the most recent advancement in artificial habitat mapping involves acoustic systems to investigate fish abundance, distribution and behavior in specific areas. Along with a detailed high-coverage bathymetric mapping of the seabed, the high-frequency Multibeam Echosounder (MBES) offers the potential of detecting fine-scale distribution of fish aggregation, combining its ability to detect at the same time the seafloor and the water column. Surveying fish schools distribution around artificial structures, MBES allows to evaluate how their presence modifies the biological natural habitat overtime in terms of fish attraction and abundance. In the last years, artificial habitat mapping experiences have been carried out by CNR-ISMAR in the Adriatic sea: fish assemblages aggregating at offshore gas platforms and artificial reefs have been systematically monitored employing different kinds of methodologies. This work focuses on two case studies: a gas extraction platform founded at 80 meters of depth in the central Adriatic sea, 30 miles far from the coast of Ancona, and the concrete and steel artificial reef of Senigallia, deployed by CNR-ISMAR about 1.2 miles offshore at a depth of 11.2 m . Relating the MBES data (metrical dimensions of fish assemblages, shape, depth, density etc.) with the results coming from other methodologies, such as experimental fishing surveys and underwater video camera, it has been possible to investigate the biological assemblage attracted by artificial structures hypothesizing which species populate the investigated area and their spatial dislocation from these artificial structures. Processing MBES bathymetric and water column data, 3D virtual scenes of the artificial habitats have been created, receiving an intuitive-looking depiction of their state and allowing overtime to evaluate their change in terms of dimensional characteristics and depth fish schools’ disposition. These MBES surveys play a leading part in the general multi-year programs carried out by CNR-ISMAR with the aim to assess potential biological changes linked to human activities on.

Keywords: artificial habitat mapping, fish assemblages, hydroacustic technology, multibeam echosounder

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2687 Effects of High-Protein, Low-Energy Diet on Body Composition in Overweight and Obese Adults: A Clinical Trial

Authors: Makan Cheraghpour, Seyed Ahmad Hosseini, Damoon Ashtary-Larky, Saeed Shirali, Matin Ghanavati, Meysam Alipour

Abstract:

Background: In addition to reducing body weight, the low-calorie diets can reduce the lean body mass. It is hypothesized that in addition to reducing the body weight, the low-calorie diets can maintain the lean body mass. So, the current study aimed at evaluating the effects of high-protein diet with calorie restriction on body composition in overweight and obese individuals. Methods: 36 obese and overweight subjects were divided randomly into two groups. The first group received a normal-protein, low-energy diet (RDA), and the second group received a high-protein, low-energy diet (2×RDA). The anthropometric indices including height, weight, body mass index, body fat mass, fat free mass, and body fat percentage were evaluated before and after the study. Results: A significant reduction was observed in anthropometric indices in both groups (high-protein, low-energy diets and normal-protein, low-energy diets). In addition, more reduction in fat free mass was observed in the normal-protein, low-energy diet group compared to the high -protein, low-energy diet group. In other the anthropometric indices, significant differences were not observed between the two groups. Conclusion: Independently of the type of diet, low-calorie diet can improve the anthropometric indices, but during a weight loss, high-protein diet can help the fat free mass to be maintained.

Keywords: diet, high-protein, body mass index, body fat percentage

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2686 Region-Specific Secretory Protein, α2M, in Male Reproductive Tract of the Blue Crab And Its Dynamics during Sperm transit towards Female Spermatheca

Authors: Thanyaporn Senarai, Rapeepun Vanichviriyakit, Shinji Miyata, Chihiro Sato, Prapee Sretarugsa, Wattana Weerachatyanukul, Ken Kitajima

Abstract:

In this study, we characterized a region-specific 250 kDa protein that was secreted of MSD fluid, which is believed to play dual functions in forming a spermatophoric wall for sperm physical protection, and in sperm membrane modification as part of sperm maturation process. The partial amino acid sequence and N-terminal sequencing revealed that the MSD-specific 250 kDa protein showed a high similarity with a plasma-rich protein, α-2 macroglobulin (α2M), so termed pp-α2M. This protein was a large glycoprotein contained predominantly mannose and GlcNAc. The expression of pp-α2M mRNA was detected in spermatic duct (SD), androgenic gland (AG) and hematopoietic tissue, while the protein expression was rather specific to the apical cytoplasm of MSD epithelium. The secretory pp-α2M in MSD fluid was acquired onto the MSD sperm membrane and was also found within the matrix of the acrosome. Distally, pp-α2M was removed from spermathecal sperm membrane, while its level kept constant in the sperm AC. Together the results indicate that pp-α2M is a 250 kDa region-specific secretory protein which plays roles in sperm physical protection and also acts as maturation factor in the P. pelagicus sperm.

Keywords: alpha-2 macroglobulin, blue swimming crab, sperm maturation, spermatic duct

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2685 Ratio Energy and Protein of Dietary Based on Rice Straw Ammoniated on Productivity of Male Simenthal Cattle

Authors: Mardiati Zain, Yetti Marlida, Elihasridas Elihasridas, Erpomen Erpomen, Andri Andri

Abstract:

Background: Livestock productivity is greatly influenced by the energy and protein balance in diet. This study aimed to determine the energy and protein balance of male Simenthal cattle diet with protein and energy levels. The experimental design used was a randomized block design (RBD) 2x3x3 factorial design. There are two factors namely A level of energy diet that is 65% and 70% TDN. Factor B is a protein level of diet used were 10, 12 and 14% and each treatment is repeated three times. The weight of Simenthal cattle used ranged between 240 - 300 kg. Diet consisted of ammoniated rice straw and concentrated with ratio 40:60. Concentrate consisted of palm kernel cake, rice brain, cassava, mineral, and urea. The variables measured were digestibility of dry matter, organic matter and fiber, dry matter intake, daily gain, feed efficiency and blood characteristic. Results: There was no interaction between protein and energy level of diet on the nutrients intake (DM intake, OM intake, CP intake), weight gain and efficiency (P < 0.01). There was an interaction between protein and energy level of diet on digestibility (DM, OM, CP and allantoin urine (P > 0.01) Nutrients intake decreases with increasing levels of energy and protein diet, while nutrient digestibility, Avarage daily gain and feed efficiency increases with increasing levels of energy and protein diet. Conclusions: The result can be concluded that the best treatment was A2B1 which is energy level 70% TDN and protein 10%, where are dry matter intake 7.66 kg/d, daily gain 1.25 kg/d, feed efficiency 16.12%, and dry matter and organic matter digestibility 64.08 and 69.42% respectively.

Keywords: energy and protein ratio, simenthal cattle, rice straw ammoniated, digestibility

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2684 Easymodel: Web-based Bioinformatics Software for Protein Modeling Based on Modeller

Authors: Alireza Dantism

Abstract:

Presently, describing the function of a protein sequence is one of the most common problems in biology. Usually, this problem can be facilitated by studying the three-dimensional structure of proteins. In the absence of a protein structure, comparative modeling often provides a useful three-dimensional model of the protein that is dependent on at least one known protein structure. Comparative modeling predicts the three-dimensional structure of a given protein sequence (target) mainly based on its alignment with one or more proteins of known structure (templates). Comparative modeling consists of four main steps 1. Similarity between the target sequence and at least one known template structure 2. Alignment of target sequence and template(s) 3. Build a model based on alignment with the selected template(s). 4. Prediction of model errors 5. Optimization of the built model There are many computer programs and web servers that automate the comparative modeling process. One of the most important advantages of these servers is that it makes comparative modeling available to both experts and non-experts, and they can easily do their own modeling without the need for programming knowledge, but some other experts prefer using programming knowledge and do their modeling manually because by doing this they can maximize the accuracy of their modeling. In this study, a web-based tool has been designed to predict the tertiary structure of proteins using PHP and Python programming languages. This tool is called EasyModel. EasyModel can receive, according to the user's inputs, the desired unknown sequence (which we know as the target) in this study, the protein sequence file (template), etc., which also has a percentage of similarity with the primary sequence, and its third structure Predict the unknown sequence and present the results in the form of graphs and constructed protein files.

Keywords: structural bioinformatics, protein tertiary structure prediction, modeling, comparative modeling, modeller

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2683 Effect of Ginger, Red Pepper, and Their Mixture in Diet on Growth Performance and Body Composition of Oscar, Astronotus ocellatus

Authors: Sarah Jorjani, Afshin Ghelichi, Mazyar Kamali

Abstract:

The aim of this study was to estimate the effect of addition of ginger and red pepper and their mixture in diet on growth performance, survival rate and body composition of Astronotus ocellatus (Oscar fish). This study had been carried out for 8 weeks. For this reason 132 oscar fishes with intial weight of 2.44±0.26 (gr) were divided into 4 treatments with three replicate as compeletly randomize design test and fed by 100% Biomar diet (T1), Biomar + red pepper (55 mg/kg) (T2), Biomar + ginger (1%) (T3) and Biomar + mixture of red pepper and ginger (T4).The fish were fed in 5% of their body weight. The results showed T2 have significant differences in most of growth parameters in compare with other treatments, such as PBWI, SGR, PER and SR (P < 0.05), but there were no significant differences between treatments in FCR and FE (P > 0.05).

Keywords: red pepper, ginger, oscar fish, growth performance, body composition

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2682 Analysis of Fish Preservation Methods for Traditional Fishermen Boat

Authors: Kusno Kamil, Andi Asni, Sungkono

Abstract:

According to a report of the World Food and Agriculture Agency (FAO): the post-harvest fish losses in Indonesia reaches 30 percent from 170 trillion rupiahs of marine fisheries reserves, then the potential loss reaches 51 trillion rupiahs (end of 2016 data). This condition is caused by traditionally vulnerable fish catches damaged due to disruption of the cold chain of preservation. The physical and chemical changes in fish flesh increase rapidly, especially if exposed to the scorching heat in the middle of the sea, exacerbated by the low awareness of catch hygiene; many unclean catches which contain blood are often treated without special attention and mixed with freshly caught fish, thereby increasing the potential for faster fish spoilage. This background encourages research on traditional fisherman catch preservation methods that aim to find the best and most affordable methods and/or combinations of fish preservation methods so that they can help fishermen increase their fishing duration without worrying that their catch will be damaged, thereby reducing their economic value when returning to the beach to sell their catches. This goal is expected to be achieved through experimental methods of treatment of fresh fish catches in containers with the addition of anti-bacterial copper, liquid smoke solution, and the use of vacuum containers. The other three treatments combined the three previous treatment variables with an electrically powered cooler (temperature 0~4 ᵒC). As a control specimen, the untreated fresh fish (placed in the open air and in the refrigerator) were also prepared for comparison for 1, 3, and 6 days. To test the level of freshness of fish for each treatment, physical observations were used, which were complemented by tests for bacterial content in a trusted laboratory. The content of copper (Cu) in fish meat (which is suspected of having a negative impact on consumers) was also part of the examination on the 6th day of experimentation. The results of physical observations on the test specimens (organoleptic method) showed that preservation assisted by the use of coolers was still better for all treatment variables. The specimens, without cooling, sequentially showed that the best preservation effectiveness was the addition of copper plates, the use of vacuum containers, and then liquid smoke immersion. Especially for liquid smoke, soaking for 6 days of preservation makes the fish meat soft and easy to crumble, even though it doesn't have a bad odor. The visual observation was then complemented by the results of testing the amount of growth (or retardation) of putrefactive bacteria in each treatment of test specimens within similar observation periods. Laboratory measurements report that the minimum amount of putrefactive bacteria achieved by preservation treatment combining cooler with liquid smoke (sample A+), then cooler only (D+), copper layer inside cooler (B+), vacuum container inside cooler (C+), respectively. Other treatments in open air produced a hundred times more putrefactive bacteria. In addition, treatment of the copper layer contaminated the preserved fresh fish more than a thousand times bigger compared to the initial amount, from 0.69 to 1241.68 µg/g.

Keywords: fish, preservation, traditional, fishermen, boat

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2681 Chronic Exposure of Mercury on Amino Acid Level in Freshwater Fish Clarias batrachus (Linn.)

Authors: Mary Josephine Rani

Abstract:

Virtually all metals are toxic to aquatic organisms because of the devastating effect of these metals on humans; heavy metals are one of the most toxic forms of aquatic pollution. Metal concentrations in aquatic organisms appear to be of several magnitudes higher than concentrations present in the ecosystem. Mercury is one of the most toxic heavy metals in the environment. The principal sources of contamination in wastewater are chloralkali plants, battery factories, mercury switches, and medical wastes. Elevated levels of mercury in aquatic organisms specially fish represent both an ecological and human concern. Amino acid levels were estimated in five tissues (gills, liver, kidney, brain and muscle) of Clariasbatrachus after 28 days of chronic exposure to mercury. Free amino acids serve as precursor for energy production under stress and for the synthesis of required proteins to face the metal challenge.

Keywords: amino acids, fish, mercury, toxicity

Procedia PDF Downloads 357
2680 Bioinformatics Approach to Identify Physicochemical and Structural Properties Associated with Successful Cell-free Protein Synthesis

Authors: Alexander A. Tokmakov

Abstract:

Cell-free protein synthesis is widely used to synthesize recombinant proteins. It allows genome-scale expression of various polypeptides under strictly controlled uniform conditions. However, only a minor fraction of all proteins can be successfully expressed in the systems of protein synthesis that are currently used. The factors determining expression success are poorly understood. At present, the vast volume of data is accumulated in cell-free expression databases. It makes possible comprehensive bioinformatics analysis and identification of multiple features associated with successful cell-free expression. Here, we describe an approach aimed at identification of multiple physicochemical and structural properties of amino acid sequences associated with protein solubility and aggregation and highlight major correlations obtained using this approach. The developed method includes: categorical assessment of the protein expression data, calculation and prediction of multiple properties of expressed amino acid sequences, correlation of the individual properties with the expression scores, and evaluation of statistical significance of the observed correlations. Using this approach, we revealed a number of statistically significant correlations between calculated and predicted features of protein sequences and their amenability to cell-free expression. It was found that some of the features, such as protein pI, hydrophobicity, presence of signal sequences, etc., are mostly related to protein solubility, whereas the others, such as protein length, number of disulfide bonds, content of secondary structure, etc., affect mainly the expression propensity. We also demonstrated that amenability of polypeptide sequences to cell-free expression correlates with the presence of multiple sites of post-translational modifications. The correlations revealed in this study provide a plethora of important insights into protein folding and rationalization of protein production. The developed bioinformatics approach can be of practical use for predicting expression success and optimizing cell-free protein synthesis.

Keywords: bioinformatics analysis, cell-free protein synthesis, expression success, optimization, recombinant proteins

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2679 Isolation and Characterization of Bacteriophages Against Aeromonas Spp. Mediated Diseases in Indian Aquaculture

Authors: Mrunalini Sonne

Abstract:

Aquaculture uses a variety of broad spectrum antibiotics to manage and prevent a variety of diseases without understanding their mechanisms of action. This has led to water pollution in the modern world. The necessity for alternate control measures against bacterial illnesses in the aquaculture sector is highlighted by issues brought on by antibiotic-resistant bacteria and the dearth of effective control strategies. Bacteriophages (phages) have shown promise as therapeutic agents for the efficient management of bacterial infections in aquaculture. In the current study, a variety of investigations were conducted to determine if utilizing lytic phages to reduce Aeromonas spp. infection in fish aquaculture was appropriate. Motile Aeromonas septicaemia is a fish disease that has caused financial harm to the aquaculture sector. Currently, the production of aquaculture depends significantly on antibiotics, which adds to the worldwide problem of the rise of bacteria that are resistant to medicines and resistance genes. To decrease the usage of antibiotics in aquaculture systems, it is crucial to create efficient antibiotic substitutes. Bacteriophages are capable of acting as a natural antagonist, mostly because of their great specificity, capacity for self-replication, and ability to quickly eradicate dangerous bacteria. There is a need for research that goes beyond just isolating and characterising lytic bacteriophages to examine their morphology, stability, and efficacy in various environmental conditions. Bacteriophage (or phage) therapy is a promising technique to control dangerous microbes in farmed fish. More phage therapy research in aquaculture is required in order to effectively employ phage treatment to lessen infection in fish brought on by Aeromonas.

Keywords: aquaculture, bacteriophages, fish, freshwater

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2678 Rheological and Microstructural Characterization of Concentrated Emulsions Prepared by Fish Gelatin

Authors: Helen S. Joyner (Melito), Mohammad Anvari

Abstract:

Concentrated emulsions stabilized by proteins are systems of great importance in food, pharmaceutical and cosmetic products. Controlling emulsion rheology is critical for ensuring desired properties during formation, storage, and consumption of emulsion-based products. Studies on concentrated emulsions have focused on rheology of monodispersed systems. However, emulsions used for industrial applications are polydispersed in nature, and this polydispersity is regarded as an important parameter that also governs the rheology of the concentrated emulsions. Therefore, the objective of this study was to characterize rheological (small and large deformation behaviors) and microstructural properties of concentrated emulsions which were not truly monodispersed as usually encountered in food products such as margarines, mayonnaise, creams, spreads, and etc. The concentrated emulsions were prepared at different concentrations of fish gelatin (0.2, 0.4, 0.8% w/v in the whole emulsion system), oil-water ratio 80-20 (w/w), homogenization speed 10000 rpm, and 25oC. Confocal laser scanning microscopy (CLSM) was used to determine the microstructure of the emulsions. To prepare samples for CLSM analysis, FG solutions were stained by Fluorescein isothiocyanate dye. Emulsion viscosity profiles were determined using shear rate sweeps (0.01 to 100 1/s). The linear viscoelastic regions (LVRs) of the emulsions were determined using strain sweeps (0.01 to 100% strain) for each sample. Frequency sweeps were performed in the LVR (0.1% strain) from 0.6 to 100 rad/s. Large amplitude oscillatory shear (LAOS) testing was conducted by collecting raw waveform data at 0.05, 1, 10, and 100% strain at 4 different frequencies (0.5, 1, 10, and 100 rad/s). All measurements were performed in triplicate at 25oC. The CLSM results revealed that increased fish gelatin concentration resulted in more stable oil-in-water emulsions with homogeneous, finely dispersed oil droplets. Furthermore, the protein concentration had a significant effect on emulsion rheological properties. Apparent viscosity and dynamic moduli at small deformations increased with increasing fish gelatin concentration. These results were related to increased inter-droplet network connections caused by increased fish gelatin adsorption at the surface of oil droplets. Nevertheless, all samples showed shear-thinning and weak gel behaviors over shear rate and frequency sweeps, respectively. Lissajous plots, or plots of stress versus strain, and phase lag values were used to determine nonlinear behavior of the emulsions in LAOS testing. Greater distortion in the elliptical shape of the plots followed by higher phase lag values was observed at large strains and frequencies in all samples, indicating increased nonlinear behavior. Shifts from elastic-dominated to viscous dominated behavior were also observed. These shifts were attributed to damage to the sample microstructure (e.g. gel network disruption), which would lead to viscous-type behaviors such as permanent deformation and flow. Unlike the small deformation results, the LAOS behavior of the concentrated emulsions was not dependent on fish gelatin concentration. Systems with different microstructures showed similar nonlinear viscoelastic behaviors. The results of this study provided valuable information that can be used to incorporate concentrated emulsions in emulsion-based food formulations.

Keywords: concentrated emulsion, fish gelatin, microstructure, rheology

Procedia PDF Downloads 275