Showing papers on "Sodium propionate published in 2008"

Formulation of food-grade microemulsions with glycerol monolaurate : effects of short-chain alcohols, polyols, salts and nonionic surfactants

Abstract: The formulation of food-grade microemulsions with glycerol monolaurate (GML) for antimicrobial applications has been studied. The compositions included water, GML, short-chain alcohols (such as ethanol), polyols (propylene glycol and glycerol), salts (organic, such as sodium benzoate, sodium lactate and sodium propionate, and inorganic, such as NaCl) and several nonionic surfactants [such as ethoxylated sorbitan esters, sucrose esters (SEs)]. The phase behavior of these systems is discussed with respect to the influence of composition on the degree of oil solubilization in the aqueous phase. The oil solubilization was dramatically improved in the presence of the short-chain alcohols and polyols, organic salts contributed to the improvement of oil solubilization as hydrotropes. Tween 20 being the most hydrophilic surfactant in Tweens solubilized the maximum oil, but in the presence of SEs it is hard to form oil-in-water microemulsions. Viscosity measurements along selected dilution lines indicate that at a certain composition the system inverts from a water-in-oil to an oil-in-water microemulsion.

Separation of Carboxylic Acids from Carboxylates by Diffusion Dialysis

Abstract: Acetic acid/sodium acetate and propionic acid/sodium propionate were separated by the diffusion dialysis technique using Neosepta AFN‐7 and Selemion DSV membranes. Accounting for molarities of carboxylic acids and salts in broths produced by the pH controlled bacterial fermentation (pH 4–6), the experiments were carried out with carboxylates in excess of acids. The sorption equilibria established for acetic acid, propionic acid, and the sodium salts of both acids (single solute experiments) revealed a high sorption of acids in both membranes and the rejection of carboxylates. The partition coefficients were found to be from unity up to 2 for the acids and 0.04–0.05 for the salts. Reflecting a high sorption, the fluxes for the acids amounted from 1.5 to 2.0 mol · m−2 · h−1 and only 0.07–0.08 mol · m−2 · h−1 for the salts (one molar solutions). The separation factors computed upon the experiments performed with the ternary solutions were found between 20 to 37 for the Neosepta AFN‐7 membrane and ab...

Stability of staphylococcal enterotoxin a to selected conditions encountered in foods

Abstract: Changes in serological activity of enterotoxin A were measured by an immuno-diffusion method. The reducing sugars xylose, lactose, glucose, maltose and fructose did not react with enterotoxin so as to reduce titer under various conditions of concentration, pH, temperature and time but all of these sugars exhibited an enterotoxin protective effect when systems were heated at 60°C. Sodium propionate, sodium benzoate and sodium nitrite at various concentrations did not alter enterotoxin titer when systems were incubated up to 9 days at 21 or 37°C. Sodium sulfite at a solution concentration of 1000 ppm decreased titers under specific conditions that suggest weak complex formation with the enterotoxin. Luxuriant growth of bacteria belonging to the genera Bacillus, Micrococcus, Brevibacterium, Aeudomonas, Proteus, Escherichia, Enterobacter, and yeasts of the genera Candida and Saccharomyces, in several media containing enterotoxin A did not significantly alter exterotoxin titer. Titer was substantially reduced by several species of lactic acid bacteria including L. acidophilus, L. helveticus, L. plantatum, L. mesenteroides, Strep. thermophilus, Strep. faecalis var. liquefaciens, Strep. lactis and P: pentosaceus in MRS broth and by five of the above species in APT broth. Reductions in titer were not simply due to decreases in pH by these organisms. Studies on heat inactivated enterotoxm revealed partial reactivation in phosphate-buffered saline incubated at 30 and 37°C for 72 hr but not at several other conditions of lower temperature and shorter time.

Concomitant changes in progesterone catabolic enzymes, cytochrome P450 2C and 3A, with plasma insulin concentrations in ewes supplemented with sodium acetate or sodium propionate

Abstract: Progesterone is essential for maintaining pregnancy, and several authors have suggested that low peripheral concentrations of progesterone may be responsible for high rates of embryonic loss. The primary organ involved in the catabolism of progesterone is the liver, and cytochrome P450 2C and 3A sub-families account for a large proportion of this catabolism. Elucidating a mechanism to decrease progesterone catabolism, thereby increasing embryonic and uterine exposure to progesterone, seems a logical approach to ameliorate high rates of embryonic loss. The objectives of the current experiment were to determine the pattern of insulin secretion after supplementing feed with either sodium acetate or sodium propionate and to determine any association between the differential patterns of insulin secretion with the hepatic activity of cytochrome P450 2C and 3A and progesterone clearance. Sixteen ovariectomized ewes were fed 3 kg/day for 10 days of a diet consisting of 50% corn silage, 38% triticale haylage, 12% soybean meal and 600 ml of 3.5 M sodium acetate (energy control; n = 8) or 2.0 M sodium propionate (gluconeogenic substrate; n = 8). Equal portions of the ration (1 kg as-fed basis along with 200 ml of 3.5 M sodium acetate or 2.0 M sodium propionate) were offered three times daily at 0600, 1400 and 2200 h. Concentrations of insulin in plasma were determined immediately before feeding and at 15, 30, 60, 90, 120, 180, 240 and 300 min after feeding. Progesterone clearance from peripheral circulation (ng/ml per min) was measured by giving a 5 mg injection of progesterone into the left jugular vein and collecting blood via the right jugular vein at 0, 2, 4, 6, 8, 10, 15, 20 and 30 min afterwards. Liver biopsies were taken 1 h after feeding to determine cytochrome P450 2C and 3A activities. Insulin concentrations in ewes supplemented with sodium propionate were elevated at 15, 30 and 60 min after feeding compared to the sodium acetate group. Cytochrome P450 2C and 3A activities were decreased 1 h after feeding in the sodium propionate-treated ewes relative to sodium acetate. Insulin appears to down-regulate cytochrome P450 activity, which could be used to decrease the catabolism of progesterone during early gestation, thereby increasing peripheral concentrations of progesterone and, consequently, embryonic exposure to progesterone.

Resistance of Nutrient-Deprived Listeria monocytogenes 10403S and a ΔsigB Mutant to Chemical Stresses in the Presence or Absence of Oxygen

Abstract: Nutrient-deprived Listeria monocytogenes have increased resistance to processing control measures. Heat-stressed L. monocytogenes cells produce higher counts under anaerobic conditions and SigB reportedly contributes to the survival of environmentally stressed Gram-positive bacteria. In this study, a wild type (wt) strain, L. monocytogenes 10403S, and a DeltasigB mutant, FSLA1-254, were stressed by starvation in phosphate buffered saline coupled with exposure to chemicals with/without oxygen. In the absence of chemicals, the mutant survived starvation almost as well as the wt, suggesting that the starvation survival response (SSR) in L. monocytogenes was SigB-independent. Conversely, in the presence of chemical stresses the SSR results differed depending on the chemical used. In the presence of sodium chloride (SC), both strains were able to express an SSR under aerobic conditions but not under anaerobic conditions. However, in the presence of sodium propionate (SP), the mutant yielded counts that were 2 log CFU/mL lower than the controls and their aerobic counterparts. In the presence of sodium lactate (SL), the mutant yielded counts that were approximately 3 log CFU/mL lower than the wt under anaerobic conditions. Thus, for the chemical stress produced by SC, the SSR appeared to be SigB-independent. The SSR of L. monocytogenes appeared to be SigB-dependent following exposure to SP or SL under anaerobic conditions. Following exposure to sodium diacetate or lauric acid, both strains were unable to express an SSR. No detectable CFUs were observed after 14 to 21 d under either aerobic or anaerobic incubation. Therefore, these 2 chemicals could be used in biocidal formulations against L. monocytogenes cells under aerobic or anaerobic conditions.

Electric conductivity of concentrated aqueous solutions of propionic acid, sodium propionate and their mixtures

Abstract: Specific electric conductivity (EC) of concentrated aqueous solutions of propionic acid (PA), sodium propionate (SP), and water/PA/SP mixtures is measured in the temperature range of 15–90°C. Specific EC passes a maximum at the increase in the electrolyte concentration in the mixtures of water/PA, water/SP, and water/PA/SP containing a similar PA concentration. The maximum EC value of the aqueous PA solution at the given temperature is used as the generalizing term. It is shown that the values of reduced EC (ratio of EC and its maximum value at the given temperature) fall on a single curve in the whole studied range of temperatures and concentrations of the water/PA mixture. The EC activation energy is calculated for all the studied solutions. It is found that the EC activation energy of these solutions decreases at the temperature increase and grows at the increase of the concentration of electrolyte.

Effect of Sodium Alkanoates on Micellization of Dodecylbenzyldimethylammonium Chloride in Aqueous Medium

Abstract: The present study deals with the interaction of sodium alkanoates viz. sodium acetate, sodium propionate, sodium butanoate, sodium hexanoate and sodium benzoate on the micellization of dodecylbenzyldimethylammonium chloride using conductometeric and flourscence quenching experiments carried out at 25°C. The analysis has been made through study of variation of critical micelle concentration (cmc), degree of counterion binding (β), aggregation number (N), and micropolarity with the concentration of these hydrophobic salts. The differentiation between the effects of hydrophobic and inorganic salts was made by comparing the above results with the influence of NaCl on cmc, β, and N.

Composition of food additives of piglets containing beta-glucan and yeast organic iron

Abstract: A feed additive composition for a piglet, and a pharmaceutical composition containing the composition are provided to prevent and treat the diarrhea of a piglet A feed additive composition for a piglet contains beta-glucan and the yeast organic iron in a ratio of 1-4 : 4-1 by weight Preferably the feed additive composition for a piglet comprises further at least one selected from the group consisting of lactic acid, glucanase, sodium propionate, lactose, crystalline cellulose and magnesium stearate