Effect of Sodium Chloride Concentration, Water Activity, Fermentation Method and Drying Time on the Viability of Trichinella spiralis in Genoa Salami

1982 ◽  
Vol 45 (9) ◽  
pp. 816-819 ◽  
Author(s):  
A. B. CHILDERS ◽  
R. N. TERRELL ◽  
T. M. CRAIG ◽  
T. J. KAYFUS ◽  
G. C. SMITH
Keyword(s):  
Sodium Chloride ◽  
Water Activity ◽  
Salt Concentration ◽  
Trichinella Spiralis ◽  
Starter Culture ◽  
Salt Content ◽  
Drying Time ◽  
Raw Meat ◽  
Meat Weight ◽  
Definite Effect

Pork from pigs experimentally infected with Trichinella spiralis was used to manufacture Genoa salami. In Experiment I, Genoa salami was formulated to include: (a) in-going sodium chloride of 2.00 or 3.33% based on raw meat weight; (b) either commercial starter culture or no starter culture and held for fermentation at either 35°C (95°F) or 46.1 °C (115°F). Lower water activity (aw) was found (P<0.0001) in salami manufactured either with 3.33% salt or processed by high fermentation temperature. Lower pH values resulted from use of a starter culture. An interaction between salt concentration and fermentation temperature was seen after 20 days of drying. Salt concentration appeared to exert a definite effect of trichina viability. In Experiment II, Genoa salami was formulated to include: (a) in-going sodium chloride of 0.00, 1.67 or 3.33% based on raw meat weight; (b) all salami contained starter culture and held for fermentation at 46.1 °C. Salami made with 3.33% salt had higher pH and lower aw values than did that made with no or 1.67% salt. The salt content and drying time interaction was greatest in salami made with 3.33% salt. The 3.33% salt content also appeared to exert a definite effect on trichina viability.

Behavior of Staphylococcus aureus in Cheddar Cheese Made with Sodium Chloride or a Mixture of Sodium Chloride and Potassium Chloride

1982 ◽  
Vol 45 (11) ◽  
pp. 996-1002 ◽  
Author(s):  
SUSAN KOENIG ◽  
ELMER H. MARTH
Keyword(s):  
Staphylococcus Aureus ◽  
Sodium Chloride ◽  
Potassium Chloride ◽  
Starter Culture ◽  
Salt Content ◽  
Cheddar Cheese ◽  
Ph Values ◽  
Radio Immunoassay ◽  
Low Levels ◽  
And Storage

Stirred-curd Cheddar cheese was manufactured from milk artificially contaminated with < 1000 Staphylococcus aureus cells/ml. Lactic starter culture was added to the milk at the rate of 1.0 or 0.5% (v/v). Curds were divided and salted with either NaCl or a mixture of KCl/NaCl to achieve final salt concentrations of approximately 2.4 or 1.2%. Some portions of curd remained unsalted. Cheeses were analyzed for moisture and salt content and were stored at 4 or 10°C for 8 weeks. Bacterial counts and pH values were determined during manufacture and storage of cheeses. Unsalted cheeses had the lowest and the 2.4%-salted cheese had the highest S. aureus counts. Cheeses salted with KCI/NaCl had considerably lower S. aureus and non-S. aureus counts than did cheeses salted with NaCl. All cheeses made with 1.0% starter culture had appreciably lower counts of S. aureus than did cheeses made with 0.5% starter culture. Low levels (0.05 to 0.52 ng/g) of enterotoxin A were found in 16 of 17 samples tested with the radio immunoassay procedure. Presence of enterotoxin was not directly associated with the kind or amount of salt used to produce the cheese.

scholarly journals The effect of additives supplementation on the limitation of lipid and protein oxidation in dried snakehead fish (Channa striata)

Food Research ◽  
2020 ◽  
Vol 4 (6) ◽  
pp. 2265-2271
Author(s):  
B.L. Tran ◽  
V.M. Nguyen ◽  
T.T. Tran
Keyword(s):  
Ascorbic Acid ◽  
G Protein ◽  
Water Activity ◽  
Peroxide Value ◽  
Protein Oxidation ◽  
Salt Content ◽  
Activity Level ◽  
Drying Time ◽  
Lipid And Protein Oxidation ◽  
Channa Striata

The study was carried out to assess the effects of additives (glycerol and sorbitol) and the role of supplement rate of ascorbic acid on reducing lipid and protein oxidation in dried snakehead fish (Channa striata). The research results revealed that adding additives increased the amount of dry matter of the material, leading to a shorter drying process. The addition of glycerol and sorbitol at different ratios were the causes of the change of drying time and sulfhydryl index, peroxide value, TBARS index, salt content, color, and water activity level of the dried snakehead fish. Using 3% glycerol combined with 4% sorbitol, the drying time was 26.21 hrs. Dried snakehead fish product had a salt content of 6.04%, a water activity of 0.576, a brightness of 43.90, a peroxide value of 0.064 meq/kg lipid, a TBARS of 4.40 mg MDA/kg, a total sulfhydryl of 30.22 µmol/g protein, and an available sulfhydryl of 11.41 µmol/g protein. When ascorbic acid was added, the oxidation indexes of dried snakehead fish were significantly reduced; however, ascorbic acid showed a superiority at 0.04% with peroxide indices of 0.04 mEq/kg lipid, TBARS was 4.28 mg MDA/kg a total sulfhydryl of 31.60 µmol/g protein and sulfhydryl available reached to 11.94 µmol/g protein. The difference between the experiment of adding ascorbic acid was even more significant after four weeks of storage when the dried snakehead fish was less lipid and protein oxidation.

Behavior of Staphylococcus aureus in Turkish Feta Cheese During Manufacture and Ripening

1995 ◽  
Vol 58 (11) ◽  
pp. 1201-1205 ◽  
Author(s):  
OSMAN ERKMEN
Keyword(s):  
Salt Concentration ◽  
Storage Time ◽  
Starter Culture ◽  
Salt Content ◽  
Storage Period ◽  
Plate Count ◽  
Ph Values ◽  
Feta Cheese ◽  
Aerobic Plate Count ◽  
And Storage

S. aureus was enumerated during the manufacture and ripening period of Turkish feta cheeses with particular reference to different inoculation levels of S. aureus, the addition of starter culture, salt concentration, and storage time. Cheeses were also examined periodically for aerobic plate count, pH values, moisture, fat, and salt content. An increase in the number of S. aureus cells was observed during manufacture. Following salting and throughout the storage period, the number of S. aureus cells decreased at a rate depending on the salt concentration, starter activity, and the storage time. The initial inoculation level did not affect the survival of S. aureus during the storage period.

scholarly journals Evaluation o Different Starter Cultures in Dry Salami

2021 ◽  
Vol 14(63) (2) ◽  
pp. 129-136
Author(s):  
Mirabela I. LUPU ◽  
Keyword(s):  
Sodium Chloride ◽  
Moisture Content ◽  
Protein Content ◽  
Technological Process ◽  
Experimental Research ◽  
Starter Culture ◽  
Salt Content ◽  
Chloride Content ◽  
Starter Cultures

The main objective of this paper is to evaluate the influence of starter culture (fast and slow) on the technological process and the quality of dried salami. For each finished product were made the same analyzes: the fat content, protein, sodium chloride content, nitrite and moisture content. Following the experimental research, it was found that for slow culture, higher values were obtained in the case of protein content (15.2%) and salt content (2.98%). In the case of fast culture, higher values were obtained for the following properties: moisture (38.32%), fat (29.57%) and nitrites (5.42 ppm). The evolution of the pH every 24 hours in the first 7 days was also monitored, and it can be notice that after 6 days the pH reached the same value for both cultures (6.9) although initially in the case of slow starter cultures the pH was slightly higher.

scholarly journals Influence of Salt on the Self-Organization in Solutions of Star-Shaped Poly-2-alkyl-2-oxazoline and Poly-2-alkyl-2-oxazine on Heating

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1152
Author(s):  
Tatyana Kirila ◽  
Anna Smirnova ◽  
Alla Razina ◽  
Andrey Tenkovtsev ◽  
Alexander Filippov
Keyword(s):  
Phase Separation ◽  
Salt Concentration ◽  
Monomer Unit ◽  
Salt Content ◽  
The Self ◽  
Self Organization ◽  
Phase Separation Temperature ◽  
The Core ◽  
Separation Temperature ◽  
Water Salt

The water–salt solutions of star-shaped six-arm poly-2-alkyl-2-oxazines and poly-2-alkyl-2-oxazolines were studied by light scattering and turbidimetry. The core was hexaaza[26]orthoparacyclophane and the arms were poly-2-ethyl-2-oxazine, poly-2-isopropyl-2-oxazine, poly-2-ethyl-2-oxazoline, and poly-2-isopropyl-2-oxazoline. NaCl and N-methylpyridinium p-toluenesulfonate were used as salts. Their concentration varied from 0–0.154 M. On heating, a phase transition was observed in all studied solutions. It was found that the effect of salt on the thermosensitivity of the investigated stars depends on the structure of the salt and polymer and on the salt content in the solution. The phase separation temperature decreased with an increase in the hydrophobicity of the polymers, which is caused by both a growth of the side radical size and an elongation of the monomer unit. For NaCl solutions, the phase separation temperature monotonically decreased with growth of salt concentration. In solutions with methylpyridinium p-toluenesulfonate, the dependence of the phase separation temperature on the salt concentration was non-monotonic with minimum at salt concentration corresponding to one salt molecule per one arm of a polymer star. Poly-2-alkyl-2-oxazine and poly-2-alkyl-2-oxazoline stars with a hexaaza[26]orthoparacyclophane core are more sensitive to the presence of salt in solution than the similar stars with a calix[n]arene branching center.

Effect of Salt Level and Nitrite on Toxin Production by Clostridium botulinum Type E Spores in Smoked Great Lakes Whitefish1

1987 ◽  
Vol 50 (3) ◽  
pp. 212-217 ◽  
Author(s):  
S. L. CUPPETT ◽  
J. I. GRAY ◽  
J. J. PESTKA ◽  
A. M. BOOREN ◽  
J. F. PRICE ◽  
...  
Keyword(s):  
Great Lakes ◽  
Water Activity ◽  
Salt Concentration ◽  
Clostridium Botulinum ◽  
Toxin Production ◽  
Water Phase ◽  
Salt Level ◽  
Botulinum Type ◽  
Clostridium Botulinum Type E ◽  
Average Water

The effect of salt level and nitrite on botulinal safety of smoked whitefish was investigated. An average water-phase (wp) salt concentration of 4.4% inhibited outgrowth of Clostridium botulinum type E spores (103 spores/g) for over 35 d in temperature-abused (27°C) smoked whitefish. Incorporation of nitrite (220 mg/kg) during brining to the smoked salted (4.4%, wp) whitefish inhibited toxin production for 56 d at 27°C. An average salt concentration of 6.2% (wp), with or without nitrite, totally inhibited toxin production for the duration of the study (83 d). The effect of pH and water activity in temperature-abused smoked whitefish as a means of controlling toxin production by C. botulinum type E spores was evaluated.

Lactic Acid Bacteria in Cheddar Cheese Made with Sodium Chloride, Potassium Chloride or Mixtures of the Two Salts

1995 ◽  
Vol 58 (1) ◽  
pp. 62-69 ◽  
Author(s):  
K. ANJAN REDDY ◽  
ELMER H. MARTH
Keyword(s):  
Lactic Acid ◽  
Sodium Chloride ◽  
Lactic Acid Bacteria ◽  
Potassium Chloride ◽  
Starter Culture ◽  
Cheddar Cheese ◽  
Starter Cultures ◽  
Detectable Effect ◽  
Agar Media ◽  
Cheese Curd

Three different split lots of Cheddar cheese curd were prepared with added sodium chloride (NaCl) potassium chloride (KCl) or mixtures of NaCl/KCl (2:1 1:1 1:2 and 3:4 all on wt/wt basis) to achieve a final salt concentration of 1.5 or 1.75%. At intervals during ripening at 3±1°C samples were plated with All-Purpose Tween (APT) and Lactobacillus Selection (LBS) agar. Isolates were obtained of bacteria that predominated on the agar media. In the first trial (Lactococcus lactis subsp. lactis plus L. lactis subsp. cremoris served as starter cultures) L. lactis subsp.lactis Lactobacillus casei and other lactobacilli were the predominant bacteria regardless of the salting treatment Received by the cheese. In the second trial (L. lactis subsp. lactis served as the starter culture) unclassified lactococci L. lactis subsp. lactis unclassified lactobacilli and L. casei predominated regardless of the salting treatment given the cheese. In the third trial (L. lactis subsp. cremoris served as the starter culture) unclassified lactococci unclassified lactobacilli L. casei and Pediococcus cerevisiae predominated regardless of the salting treatment applied to the cheese Thus use of KCl to replace some of the NaCl for salting cheese had no detectable effect on the kinds of lactic acid bacteria that developed in ripening Cheddar cheese.

TURBIDITY OF SUSPENSIONS AND MORPHOLOGY OF RED HALOPHILIC BACTERIA AS INFLUENCED BY SODIUM CHLORIDE CONCENTRATION

1960 ◽  
Vol 6 (5) ◽  
pp. 535-543 ◽  
Author(s):  
Dinah Abram ◽  
N. E. Gibbons
Keyword(s):  
Sodium Chloride ◽  
Salt Concentration ◽  
Morphological Changes ◽  
Halophilic Bacteria ◽  
Chloride Concentration ◽  
Chloride Content ◽  
Wall Structure ◽  
Abrupt Decrease ◽  
High Sodium ◽  
Rigid Cell Wall

The optical densities of suspensions of cells of Halobacterium cutirubrum, H. halobium, or H. salinarium, grown in media containing 4.5 M sodium chloride, increase as the salt concentration of the suspending medium decreases, until a maximum is reached at about 2 M; below this concentration there is an abrupt decrease in optical density. The cells are rod shaped in 4.5 M salt and change, as the salt concentration decreases, through irregular transition forms to spheres; equal numbers of transition forms and spheres are present at the point of maximum turbidity, while spheres predominate at lower salt concentrations. Cells suspended in 3.0 M salt, although slightly swollen, are viable, but viability decreases rapidly with the more drastic changes in morphology at lower salt concentrations. Cells grown in the presence of iron are more resistant to morphological changes but follow the same sequence. Cells "fixed" with formaldehyde, at any point in the sequence, act as osmometers and do not rupture in distilled water although their volume increases 10–14 times. The results indicate that the red halophilic rods require a high sodium chloride content in their growth or suspending medium to maintain a rigid cell wall structure.

Humectant Permeability Influences Growth and Compatible Solute Uptake by Staphylococcus aureus Subjected to Osmotic Stress

2002 ◽  
Vol 65 (6) ◽  
pp. 1008-1015 ◽  
Author(s):  
ODDUR VILHELMSSON ◽  
KAREN J. MILLER
Keyword(s):  
Staphylococcus Aureus ◽  
Sodium Chloride ◽  
Water Activity ◽  
Glycine Betaine ◽  
Compatible Solutes ◽  
Foodborne Pathogen ◽  
Compatible Solute ◽  
Solute Uptake ◽  
Stressed Cells ◽  
Carnitine Uptake

The effects of different humectants (sodium chloride, sucrose, and glycerol) on the growth of and compatible solute (glycine betaine, proline, and carnitine) uptake by the osmotolerant foodborne pathogen Staphylococcus aureus were investigated. While growth in the presence of the impermeant humectants sodium chloride and sucrose induced the accumulation of proline and glycine betaine by cells, growth in the presence of the permeant humectant glycerol did not. When compatible solutes were omitted from low-water-activity media, growth was very poor in the presence of impermeant humectants. In contrast, the addition of compatible solutes had essentially no effect on growth when cells were grown in low-water-activity media containing glycerol as the humectant. Carnitine was found to accumulate to high intracellular levels in osmotically stressed cells when proline and glycine betaine were absent, making it a potentially important compatible solute for this organism.

scholarly journals Effects of water activity on the performance of potassium sorbate and natamycin as preservatives against cheese spoilage moulds

2017 ◽  
Vol 56 (1) ◽  
pp. 85-92 ◽  
Author(s):  
P. Marín ◽  
C. Ginés ◽  
P. Kochaki ◽  
M. Jurado
Keyword(s):  
Sodium Chloride ◽  
Water Activity ◽  
Penicillium Chrysogenum ◽  
Potassium Sorbate ◽  
Mucor Racemosus ◽  
Food Preservatives ◽  
Glycerol Water ◽  
Fungal Inhibition ◽  
Growth Of Fungi ◽  
Different Levels

AbstractThis work investigated the effects of the food preservatives potassium sorbate and natamycin, combined with different levels of ionic (sodium chloride) and non-ioinic (glycerol) water activity (aw), on growth of fungi involved in cheese spoilage. In general, the combined effect of water stress and presence of preservatives enhanced fungal inhibition. However, some doses of potassium sorbate (0.02%) and natamycin (1, 5 and 10 ppm) were able to stimulate growth of Aspergillus varians, Mucor racemosus, Penicillium chrysogenum and P. roqueforti at awvalues in the range of 0.93–0.97. P. solitum was the only species whose growth was consistently reduced by any doses of preservative. The results also showed that sodium chloride and glycerol differentially affected the efficacy of preservatives. This study indicates that awof cheese is a critical parameter to be considered in the formulation of preservative coatings used against fungal spoilage.

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