Inhibition of Salmonella on Poultry Skin Using Protein- and Polysaccharide-Based Films Containing a Nisin Formulation†

2000 ◽  
Vol 63 (9) ◽  
pp. 1268-1272 ◽  
Author(s):  
NANDINI NATRAJAN ◽  
BRIAN W. SHELDON
Keyword(s):  
Citric Acid ◽  
Salmonella Typhimurium ◽  
Calcium Alginate ◽  
Network Formation ◽  
Weight Ratio ◽  
Tween 80 ◽  
Agar Gel ◽  
Agar Gels ◽  
Gel Network ◽  
Skin Samples

The objective of this study was to examine the use of protein- and polysaccharide-based films containing bacteriocin formulations for inhibiting salmonellae on fresh broiler skin. The lethality of the films containing a nisin-based formulation was determined against Salmonella Typhimurium-contaminated broiler drumstick skin samples coated with the film. In the first study, varying concentrations of nisin (0, 100, 300, and 500 μg/ml) plus 3% citric acid, 5.0 mM EDTA, and 0.5% Tween 80 were incorporated into 0.5% calcium alginate films at a 20% level (wt/wt) and then applied to Salmonella TyphimuriumNAr-contaminated skin samples (log10 5.0) at a 1:2 weight ratio (film:skin). Salmonella TyphimuriumNAr skin population reductions ranged from 1.98 to 3.01 log cycles after a 72-h exposure at 4°C. In comparison to the 0- and 100-μg/ml nisin concentrations, significantly greater population reductions were achieved at nisin concentrations of 300 and 500 μg/ml. In related studies, the 500-μg/ml nisin formulation was incorporated into 0.75 and 1.25% agar gels and applied to contaminated broiler drumstick skin samples (log10 7.0). Salmonella TyphimuriumNAr skin population reductions following a 96-h exposure at 4°C were 1.8-(1.25% agar gel) and 4.6-log cycles (0.75% agar gel). These results demonstrated that the inclusion of nisin-based treatments into either calcium alginate or agar gels that were subsequently applied to contaminated broiler drumstick skin yielded significant Salmonella TyphimuriumNAr population reductions ranging between 1.8 to 4.6 log cycles after 72 to 96 h of exposure at 4°C. The level of kill was affected by film type and gel concentration (i.e., gel network formation), exposure time, and nisin concentration.

Efficacy of Nisin-Coated Polymer Films To Inactivate Salmonella Typhimurium on Fresh Broiler Skin†

2000 ◽  
Vol 63 (9) ◽  
pp. 1189-1196 ◽  
Author(s):  
NANDINI NATRAJAN ◽  
BRIAN W. SHELDON
Keyword(s):  
Salmonella Typhimurium ◽  
Shelf Life ◽  
Brain Heart Infusion ◽  
Tween 80 ◽  
Linear Low Density Polyethylene ◽  
Packaging Films ◽  
Gram Positive Bacteria ◽  
Subsequent Storage ◽  
Infusion Agar ◽  
Treatment Application

Nisin is an antimicrobial peptide produced by the food-grade microorganism Lactococcus lactis subsp. lactis. This peptide inhibits many gram-positive bacteria, and when combined with chelating agents it inhibits gram-negative bacteria such as Salmonella sp. The efficacy of packaging films treated with nisin-containing formulations to reduce Salmonella contamination of fresh broiler drumstick skin and increase the refrigerated shelf life was investigated. Three films (5.1 cm2) of varying hydrophobicities (polyvinyl chloride [PVC], linear low density polyethylene, nylon) were coated with one of three liquid formulations (pH 3.5 to 3.8) composed of 100 μg/ml nisin and varying concentrations of citric acid, EDTA, and Tween 80. The treated films were applied either wet or dry to 5.1-cm2 broiler drumstick skin samples inoculated with a nalidixic acid-resistant (NAr) strain of Salmonella Typhimurium. After incubation at 4°C for 24 h the populations of surviving Salmonella TyphimuriumNAr organisms were recovered from the skin and film samples using a rinse procedure and enumerated on brain heart infusion agar containing 800 ppm NA. Log reductions (untreated versus treated skin) in Salmonella TyphimuriumNAr populations ranged from 0.4 to 2.1. Treatment formulation compositions and wet versus dry treatment application also influenced the extent of kill. The shelf life of refrigerated broiler drumsticks was extended by 0.6 to 2.2 days following a 3-min immersion in a nisin-containing treatment solution and subsequent storage in a foam tray pack containing a nisin-treated PVC overwrap and a nisin-treated absorbent tray pad. These findings demonstrated that Salmonella Typhimurium and spoilage microorganism populations on the surface of fresh broiler skin and drumsticks can be significantly reduced using immersion treatments, absorbent tray pads, and packaging films treated with nisin-containing formulations.

scholarly journals Nitrogen-phosphate Fertilizers Based on Activation of Phosphorite Powder with Partially Ammoniated Mix of Phosphoric and Sulphuric Acids

2020 ◽  
pp. 1-10
Author(s):  
A. A. Rasulov ◽  
Sh. S. Namazov ◽  
B. E. Sultonov
Keyword(s):  
Citric Acid ◽  
Gross Domestic Product ◽  
Optimal Condition ◽  
Ammonium Sulphate ◽  
Weight Ratio ◽  
High Strength ◽  
Technological Parameters ◽  
Phosphate Fertilizers ◽  
First Time ◽  
Phosphoric Acids

In this article obtaining complex nitrogen-phosphate fertilizers based on activation of phosphorite powder with partially ammoniated mix of phosphoric and sulphuric acids have been studied. In order to reduce the foaming of the process, for the first time a partially ammoniated mix of acids was used. The optimal technological parameters for activation phosphorite powder with partially neutralized mixes of sulphuric and phosphoric acids are the followings: the mix of sulphuric and phosphoric acids with a ratio of SО3:Р2О5 = 1.2; рН of acids – 2.5; weight ratio of ammonium sulphate-phosphate slurry towards phosphorite powder is 100 : 20; temperature is 60°С; duration is 30 min.  The composition nitrogen-phosphate fertilizers obtained in optimal condition contains (wt., %): N – 11.55; Р2О5total -24.61; Р2О5acceptable by citric acid -21.66; Р2О5 acceptable by EDTA -20.24; Р2О5water-soluble  -13.02; CaOtotal -13.59; СаОacceptable by citric acid -11.43. In that condition, granulated products of nitrogen-phosphate can be produced with high strength. The advantage of offered promising technology concludes in reduction two times expenditure of the most expensive ammonia in comparison with ammonium sulphate production and an increase in gross domestic product.

Study of Relationship between Morphology and Mechanical Properties of SiO2-Polyacrylate Hybrid Nanocomposite

2004 ◽  
Vol 847 ◽  
Author(s):  
Yi-Hsiao Kao ◽  
Wei-Fang Su ◽  
K. C. Lin
Keyword(s):  
Network Formation ◽  
Weight Ratio ◽  
Local Strain ◽  
Experimental Result ◽  
Morphological Observation ◽  
Tetraethylene Glycol ◽  
Silicon Substrates ◽  
Microscopic Technique ◽  
Glycol Diacrylate ◽  
Atomic Force

ABSTRACTThe atomic force microscopic technique is utilized to study the spatial distribution of silica nanoparticles embedded in poly(tetraethylene glycol diacrylate) matrix. The cast samples of these hybrid materials show distinct mechanical property change as the weight ratio (SiO2/polyacrylate) reaches 40%. The morphological observation from spin-coated films on silicon substrates shows pronounced nanoparticle network formation correlated to the elasticity transition. The percolating particles reduce the local strain field, i.e. inhibit the deformation of the stratum, and cause the dramatic increase in the Young's modulus. Our experimental result is consistent with recent theoretical prediction [1].

Effect of citric acid on electrocardiographic parameters of broiler chickens with pulmonary hypertension

2009 ◽  
Vol 57 (2) ◽  
pp. 229-238 ◽  
Author(s):  
Hossein Hassanpour ◽  
Abdol Moghaddam ◽  
Hamed Zarei
Keyword(s):  
Pulmonary Hypertension ◽  
Body Weight ◽  
Citric Acid ◽  
High Altitude ◽  
Broiler Chickens ◽  
Weight Ratio ◽  
Control Groups ◽  
Lead Avr ◽  
Electrocardiographic Parameters ◽  
Cardiac Indices

To clarify the effect of orally administered citric acid on the electrocardiographic parameters of pulmonary hypertensive broilers, chicks were reared at high altitude and treated with citric acid for 45 days. Increase of cardiac indices such as right ventricle/total ventricles (RV/TV), RV/body weight and TV/body weight ratio was not observed in the treated groups as compared to the control groups. Decrease of S amplitude in the treated groups (leads II, III, aVF) was only significant (P < 0.05) at 45 days of age (leads II, aVF; 1.5 g/l of citric acid). There were significant reductions of T amplitude at 28 (lead aVR) and 36 days (lead aVL) and significant reductions of R wave at 28 (lead aVL, all doses of citric acid) and 45 days of age (lead aVR, 1 and 1.5 g/l citric acid) in the treated groups. The QRS interval was significantly higher at 28 (leads III and aVF), 36 (leads II, III and aVF, 1 g/l citric acid) and 45 days of age (leads II and aVF) in the treated groups. The QT interval was significantly (P < 0.05) increased at 28 and 45 days of age (lead aVL) and the RR interval also showed an increase at 28 (leads aVR and aVL) and 45 (lead aVL) days of age as compared to the controls. Our data indicate that citric acid modulates the induction of pulmonary hypertension at high altitude and this effect is detectable in the electrocardiographic parameters.

scholarly journals Water-in-Oleogel Emulsions—From Structure Design to Functionality

2021 ◽  
Vol 4 ◽  
Author(s):  
Khakhanang Wijarnprecha ◽  
Auke de Vries ◽  
Sopark Sonwai ◽  
Dérick Rousseau
Keyword(s):  
Aqueous Phase ◽  
Network Formation ◽  
Active Species ◽  
Structure Design ◽  
Phase Dispersion ◽  
Surface Active ◽  
Dispersed Phases ◽  
Temperature Time ◽  
Gel Network

The development of water-in-oleogel (W/Og) emulsions is highlighted, with focus placed on the key properties dictating the structuring ability of both the continuous oleogelled and dispersed phases present. The gelling ability of oleogelators is distinguished by the formation of crystalline structures, polymeric strands, or tubules. Once a dispersed aqueous phase is introduced, droplet stabilization may occur via oleogelator adsorption onto the surface of the dispersed droplets, the formation of a continuous gel network, or a combination of both. Surface-active species (added or endogenous) are also required for effective W/Og aqueous phase dispersion and stabilization. Processing conditions, namely temperature-time-shear regimes, are also discussed given their important role on dispersed droplet and oleogel network formation. The effects of many factors on W/Og emulsion formation, rheology, and stability remain virtually unknown, particularly the role of dispersed droplet size, gelation, and clustering as well as the applicability of the active filler concept to foods. This review explores some of these factors and briefly mentions possible applications of W/Og emulsions.

Inhibition and Reversal of Salmonella Typhimurium Attachment to Poultry Skin Using Zinc Chloride

2001 ◽  
Vol 64 (4) ◽  
pp. 456-461 ◽  
Author(s):  
RAJESH NAYAK ◽  
P. BRETT KENNEY ◽  
GARY K. BISSONNETTE
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Salmonella Typhimurium ◽  
Zinc Chloride ◽  
Cell Detachment ◽  
Attached Bacteria ◽  
Attachment Model ◽  
Control Water ◽  
Skin Samples ◽  
Scanning Electron

A skin attachment model was used to determine if ZnCl2 would reverse or inhibit Salmonella attachment to broiler skin. In the reversal experiments, skin samples, treated first with 1 ml of Salmonella Typhimurium suspension (108 CFU/ml) for 30 min, were then treated with 25 or 50 mM ZnCl2 for 5 or 15 min. Zinc chloride solutions were applied while the culture was present on the skin. In the inhibition experiments, ZnCl2 solutions were added first; treatment solutions were discarded after 5 or 15 min of application, and then the culture was added. Firmly and loosely attached Salmonella were enumerated on xylose lactose tergitol plates. A duplicate section of skin, subjected concurrently to the above treatments, was observed under a scanning electron microscope to enumerate attached bacteria directly. In the reversal experiments, 25 and 50 mM ZnCl2 reduced (P &lt; 0.01) firmly attached cells by 77 and 89%, respectively, when compared to the control (water). Micrographs indicated that 25 and 50 mM ZnCl2 reduced (P &lt; 0.1) Salmonella attachment by 69 and 99.9%, respectively, in the reversal experiments. In the inhibition experiments, 25 and 50 mM ZnCl2 reduced (P &lt; 0.01) firmly attached cells by 82 and 91%, respectively. Reduction of Salmonella may be attributed, in part, to the bactericidal activity of ZnCl2 in addition to bacterial cell detachment.

SURVIVAL OF SALMONELLA TYPHIMURIUM IN REFRIGERATED CULTURED MILKS1

1972 ◽  
Vol 35 (8) ◽  
pp. 489-495 ◽  
Author(s):  
H. s. Park ◽  
E. H. Marth
Keyword(s):  
Lactic Acid ◽  
Citric Acid ◽  
Lactic Acid Bacteria ◽  
Salmonella Typhimurium ◽  
Streptococcus Thermophilus ◽  
Lactobacillus Helveticus ◽  
Lactobacillus Bulgaricus ◽  
Refrigerated Storage ◽  
Streptococcus Lactis ◽  
Pure Cultures

Cultured skimmilks containing Salmonella typhimurium were prepared at 21, 30, or 42 C using different species of lactic acid bacteria (0.25, 1.0, and 5% inoculum) either singly or in combinations. Several commercial cultures also were used. Cultured skimmilks were stored at 11 C and tested at 3-day intervals for numbers of viable salmonellae and lactic acid bacteria and for pH. Survival of S. typhimurium varied from 6 to 9 days and from 3 to 6 days in milks cultured with 0.25% Streptococcus lactis at 21 and 30 C, respectively. Increasing the inoculum to 1% with incubation at 30 C yielded a product no more detrimental to S. typhimurium than when the lower inoculum was used at 30 C. Survival of S. typhimurium always exceeded 9 days when S. cremoris was used to make cultured skimmilks. Products made with commercial mixed cultures composed of S. lactis and S. cremoris allowed S. typhimurium to survive for periods intermediate between the extremes observed when pure cultures were used. Skimmilks cultured with Streptococcus diacetilactis and Leuconostoc citrovorum, even when skimmilks cultured with the latter organism were acidified with citric acid and incubated further, were essentially without effect on survival of S. typhimurium during refrigerated storage. Use of Streptococcus thermophilus (1% culture, 42 C incubation) yielded cultured skimmilks that were most detrimental to survival of salmonellae, whereas skimmilks fermented with Lactobacillus bulgaricus permitted survival of low numbers of salmonellae beyond 9 days. Milks cultured at 42 C with a 5% inoculum of S. thermophilus mixed with L. bulgaricus or Lactobacillus helveticus were free of viable salmonellae before the incubation was complete. Salmonellae grown in skimmilk at 21 C without a lactic culture were more resistant to inactivation during refrigerated storage than was S. typhimurium grown at 30 or 42 C.

Preparation and Characterization of Cordierite Powder via Tween-80 Modified Citrate Sol-Gel Method

2010 ◽  
Vol 148-149 ◽  
pp. 929-933
Author(s):  
Yu Yue Wang ◽  
Juan Juan Feng ◽  
Yi Liu
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Citric Acid ◽  
Metal Ion ◽  
Sol Gel ◽  
Chelating Agent ◽  
Particle Morphology ◽  
Tween 80 ◽  
Solvent Evaporation Process ◽  
Scanning Electron

In this paper, cordierite (2MgO•2Al2O3•5SiO2) precursors are synthesized using TEOS and aluminum and magnesium nitrates as starting materials, citric acid as chelating agent and Tween-80 as dispersant. The effect of citric acid and Tween-80 on the formation mechanism of α-cordierite phase is investigated by using X-ray diffraction (XRD), while the effect of citric acid and Tween-80 on the particle morphology of α-cordierite is examined by using scanning electron microscopy (SEM) and field emission scanning electron microscopy (FESEM). The results show that citric acid used as chelating agent can reduce the formation temperature of α-cordierite to 1150°C by forming stable salt of citric acid with all the metal ion to avoid composition deviation from the sample components during solvent evaporation process and sub-micron cordierite particles without hard agglomeration can be obtained. Nano-sized α-cordierite can be obtained with the introduction of Tween-80 as dispersant by modifying the surfaces of the colloidal sol particles.

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