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PubMed1996

Capillary electrophoresis analysis of chemical warfare agent breakdown products. I. Counterelectroosmotic separation of alkylphosphonic acids and their monoester derivatives.

An analytical method has been developed for the analysis of chemical warfare agents by capillary zone electrophoresis (CZE). Sorbate anion has been selected as indirect UV-absorbing agent and decamethonium cation reduces the electroosmotic flow. The optimized electrolyte (5 mM sorbic acid, 0.1 mM decamethonium bromide pH 6) allows the simultaneous separation of alkylphosphonic acids and their monoester derivatives in less than 15 min. The measurement of phosphonic solutes has been achieved in spiked soils using calibration curves in the 5-50 mg/l concentration range.

Alkylation↗
PubMed1994

[The influence of potassium sorbate addition on the quality of pickled zucchini fruit].

The investigation included zucchini cultivars of Polish (Astra) and foreign (Storr's Green F1) breeding. The analysed material was harvested in the investigator's experimental field. Lactic fermentation at controlled temperature of fruits 100-130 mm in length was carried out in early September, the variants consisting of souring at the concentration of 0.05% and 0.10% in the brine which filled 35% of the volume of pickling containers. The evaluation of pickles was carried out after 6 month of souring. The raw material for pickling contained 8.67-9.66% of dry matter, 2.47-2.60% of sugars, 1.84-18.9% protein (N x 6.25), 0.42-0.50% of pectic compounds, and 46.9 mg/100 g of vitamin C. The pickles were characterized by a good organoleptic quality expressed by scores from 4.39-4.96 and by the following physico-chemical composition: dry matter 8.11-8.86%, sugars 0.9-0.11%, N x 6.25 1.54-1.56%, total acidity 0.82-1.01%, sodium chloride 2.15-2.26%, pectic compounds 0.20-0.25%, volatile acidity 43-64 mg/100, ethyl alcohol 30-35 mg/100 g, and vitamin C 10.9-14.9 mg/100 g. The addition of potassium sorbinate to the brine favourably affected the chemical composition and organoleptic quality of the final product. With the level of sorbic acid in pickles rising from 0 to 26 mg/100 g (the 0.10% addition of potassium sorbinate to the brine) the total content of acids increased by 18% and the content of preserved vitamin C by 32%, while the amount of volatile acids was reduced by 25% and that of ethyl alcohol by 38%.(ABSTRACT TRUNCATED AT 250 WORDS)

Fermentation↗
PubMed2006

Effect of formulation factors on in-vitro permeation of diclofenac from experimental and marketed aqueous eye drops through excised goat cornea.

The effect of formulation factors on permeation of diclofenac from some experimental and marketed aqueous eye drops through excised goat cornea was evaluated. Raising the pH of formulation from 6.0 to 8.0 or diclofenac concentration from 0.05 to 0.15% (w/v) or adjusting tonicity with mannitol or addition of viscolizing agent decreased apparent permeability coefficient (Papp). Formulation (pH 7.4) containing sodium metabisulfite or EDTA or combination of methyl and propyl paraben showed significantly (p<0.05) higher Papp whereas benzalkonium chloride (BAC) had no effect and sorbic acid (SA) had reduced permeation. Surprisingly marketed drops containing BAC or SA, showed significantly (p<0.05) higher Papp and decreased in the order of Difen>Voveran>NSAID>Dicol>Diclolab. Lower pH (7.1-7.3) and surface tension of drops indicating presence of surfactant, could mediate increased permeation and presence of buffer could cause irritation on in vivo instillation. The marketed formulations showed corneal hydration >83% suggesting corneal damaging potential.

Adjuvants, Pharmaceutic↗
PubMed2003

Global phenotypic analysis and transcriptional profiling defines the weak acid stress response regulon in Saccharomyces cerevisiae.

Weak organic acids such as sorbate are potent fungistatic agents used in food preservation, but their intracellular targets are poorly understood. We thus searched for potential target genes and signaling components in the yeast genome using contemporary genome-wide functional assays as well as DNA microarray profiling. Phenotypic screening of the EUROSCARF collection revealed the existence of numerous sorbate-sensitive strains. Sorbate hypersensitivity was detected in mutants of the shikimate biosynthesis pathway, strains lacking the PDR12 efflux pump or WAR1, a transcription factor mediating stress induction of PDR12. Using DNA microarrays, we also analyzed the genome-wide response to acute sorbate stress, allowing for the identification of more than 100 genes rapidly induced by weak acid stress. Moreover, a novel War1p- and Msn2p/4p-independent regulon that includes HSP30 was identified. Although induction of the majority of sorbate-induced genes required Msn2p/4p, weak acid tolerance was unaffected by a lack of Msn2p/4p. Ectopic expression of PDR12 from the GAL1-10 promoter fully restored sorbate resistance in a strain lacking War1p, demonstrating that PDR12 is the major target of War1p under sorbic acid stress. Interestingly, comparison of microarray data with results from the phenotypic screening revealed that PDR12 remained as the only gene, which is both stress inducible and required for weak acid resistance. Our results suggest that combining functional assays with transcriptome profiling allows for the identification of key components in large datasets such as those generated by global microarray analysis.

ATP-Binding Cassette Transporters↗
PubMed1999

Weak organic acid treatment causes a trehalose accumulation in low-pH cultures of Saccharomyces cerevisiae, not displayed by the more preservative-resistant Zygosaccharomyces bailii.

Weak organic acid food preservatives exert pronounced culture pH-dependent effects on both the heat-shock response and the thermotolerance of Saccharomyces cerevisiae. In low-pH cultures, they inhibit this stress response and cause strong induction of respiratory-deficient petites amongst the survivors of lethal heat treatment. In higher pH cultures, 25 degrees C sorbic acid treatment causes a strong induction of thermotolerance without inducing the heat-shock response. In this study we show that trehalose, a major stress protectant, accumulates rapidly in S. cerevisiae exposed to sorbate at low pH. In pH 3.5 cultures, a 25 degrees C sorbate treatment is as effective as a 39 degrees C heat shock in inducing trehalose. This weak-acid-induced trehalose accumulation is enhanced in the pfk1 S. cerevisiae mutant, indicating that it arises through inhibition of glycolysis at the phosphofructokinase step. The more preservative-resistant food spoilage yeast Zygosaccharomyces bailii differs from S. cerevisiae in that: (1) its basal thermotolerance is not strongly affected by culture pH; (2) it does not display trehalose accumulation in response to 25 degrees C sorbate treatment at low pH; and (3) there is no induction of respiratory-deficient petites during lethal heating with sorbate. This probably reflects Z. bailii being both petite-negative and better equipped for maintenance of homeostasis during weak-acid, pH or high-temperature stress.

Food Preservatives↗
PubMed1992

The potential genotoxicity of sorbates: effects on cell cycle in vitro in V79 cells and somatic mutations in Drosophila.

Sodium sorbate, potassium sorbate and an oxidation product of sodium sorbate, 4,5-epoxy-2-hexenoic acid, were tested for their genotoxic potential in cultured V79 Chinese hamster cells and in somatic cells of Drosophila melanogaster (wing spot test, SMART). In Drosophila only the epoxide showed a weak genotoxic effect. In V79 cells, freshly prepared sodium sorbate solutions at the highest concentrations only (2.5 mg/ml, 24 hr exposure) arrested mitosis at the G2/M cell cycle phase and potassium sorbate (2.5 mg/ml) had no effect. This arrest was reversible after a 24-hr recovery interval. Sodium sorbate solutions stored for up to 208 days were cytotoxic at 2.5 mg/ml, induced cell cycle arrest in the G2/M phase and increased cellular protein content, indicating an action similar to spindle poisoning and a chemical stress reaction (adaptation processes, modification of transcription). Potassium sorbate solutions stored for 28 days were also cytotoxic. With 4,5-epoxy-2-hexenoic acid at concentrations up to 0.01 mg/ml no effects were seen. At higher concentrations (at least 0.1 mg/ml) cell killing was observed, which probably resulted from unphysiologically lowered pH in the culture medium. Overall, the results are interpreted as an indication of a weak genotoxic potential of stored sodium sorbate solutions. Thus, sorbic acid and its potassium salt at the concentrations used for food preservation can still be considered as safe for human consumption.

Animals↗
PubMed2006

Carbon requirements of some nematophagous, entomopathogenic and mycoparasitic hyphomycetes as fungal biocontrol agents.

Thirty-three carbon sources were evaluated for their effects on spore germination, hyphal growth and sporulation of 11 fungal biocontrol agents, i.e. the nematophagous fungi Paecilomyces lilacinus, Pochonia chlamydosporia, Hirsutella rhossiliensis, H. minnesotensis and Arkansas Fungus 18, the entomopathogenic fungi Lecanicillium lecanii, Beauveria bassiana and Metarhizium anisopliae, and the mycoparasitic fungus Trichoderma viride. Variations in carbon requirements were found among the fungal species or strains tested. All strains studied except for T. viride grew on most carbon sources, although B. bassiana had more fastidious requirements for spore germination. Monosaccharides and disaccharides were suitable for fungal growth. For most isolates, D-glucose, D-mannose, sucrose and trehalose were superior to pectin and soluble starch among the polysaccharides and lactic acid among the organic acids. Both ethanol and methanol could accelerate growth of most isolates but not biomass. D-mannose, D-fructose and D-xylose were excellent carbon sources for sporulation, while D-glucose, sucrose, cellobiose, trehalose, chitin, dextrin, gelatin and lactic acid were better for some isolates. Neither sorbic acid nor linoleic acid could be utilized as a single carbon source. These findings provided a better understanding of the nutritional requirements of different fungal biocontrol agents that can benefit the mass production process.

Carbon↗
PubMed1993

Evaluation of phototoxic properties of some food additives: sulfites exhibit prominent phototoxicity.

Additives are used widely to enhance the quality of food products. To identify possible phototoxic properties, 13 food additives (benzoic acid, sodium benzoate, 4-hydroxybenzoic acid, 4-hydroxybenzoic acid methyl ester, 4-hydroxybenzoic ethyl ester, 4-hydroxybenzoic acid propyl ester, p-hydroxybenzoic acid n-butyl ester, benzyl alcohol, sorbic acid, potassium sorbate, propionic acid, sodium disulfite and sodium sulfite) were evaluated in vitro by means of a photohemolysis test using suspensions of human erythrocytes. Irradiation was performed with various light sources differing with regard to their spectral irradiance. Sodium sulfite and sodium disulfite induced photohemolysis up to almost 100%, the effect depending on the concentration of the compounds and UV dose administered. Radiation rich in UVB was most effective; a sunlight-simulating lamp induced photohemolysis to a lesser degree. All other substances tested did not cause significant photohemolysis. As sulfites are frequently encountered, they may contribute to UVB sensitivity. The clinical significance of these findings has to be established by further work.

Dermatitis, Phototoxic↗
PubMed2001

[Simultaneous determination of various food additives by high performance liquid chromatography].

A novel method is proposed for the simultaneous separation and determination of eight food additives, acesulfame potassium (AK), aspartame (ASP), benzoic acid (BA), caffeine (CA), saccharin sodium (SA), sorbic acid (SOR), theobromine (TB) and theophylline (TP) by reversed-phase high performance liquid chromatography. The separation was achieved within 23 min by using an Alltech Econosphere C18 column with 10 mmol/L NaH2PO4(pH 4.00)-acetonitrile (90:10, V/V) as mobile phase. The qualification and quantitation were accomplished by using a photodiode array detector. The detection limits (S/N = 3) for all analytes were below mg/L level. Under the experimental conditions, other common food additives and organic acids such as cyclamate, citric acid, malic acid, tartaric acid and ascorbic acid, did not interfere with the determination. The method has been successfully applied to the analysis of various foods as well as pharmaceutical preparation, and the average recoveries for real samples ranged from 78.5% to 107.2%.

Benzoic Acid↗
PubMed1994

The preservation of some oral liquid preparations. The replacement of chloroform by other preservatives.

Chloroform should be considered as an obsolete preservative for pharmaceutical preparations, because of its toxicological implications and its physical instability. The effectiveness of possible alternatives for chloroform in three oral liquid pharmaceutical preparations was investigated, using a microbiological challenge test. Magnesium trisilicate mixture (British Pharmacopoeia) can be adequately preserved with methylparaben (2 g/l). Only insignificant amounts of methylparaben were absorbed by the solids present in the magnesium trisilicate mixture. Ferrous sulfate mixture (British Pharmacopoeia) can be preserved with a mixture of methylparaben (1.8 g/l) and propylparaben (0.2 g/l). Sorbic acid (1 g/l) is a suitable preservative for promethazine hydrochloride syrup.

Administration, Oral↗
PubMed2003

Efficacy of sorbates on the control of the growth of Eurotium species in bakery products with near neutral pH.

The effects of sorbic acid and potassium sorbate on growth of different Eurotium isolates when added to a bakery product analogue were tested under different environmental conditions. Water activity of the products was adjusted to values in the range of 0.75-0.90, and storage temperatures were in the range of 15-30 degrees C. Preservatives were added in concentrations ranging from 0.025% to 0.2%. It was observed that 0.025% and 0.05% concentrations always enhanced the isolates growth, while 0.1% had little preservative effect. Finally, even the highest concentration (0.2%) was not suitable as it only controlled fungal growth under certain water activity and temperature levels. It was concluded that these weak-acid preservatives are not useful when added to bakery products with near to neutral pH.

Bread↗
PubMed1976

Allergy to ingredients of vehicles.

Common ingredients of vehicles such as perfumes, antibacterial agents, emulsifiers and other surface active agents, propylene glycol, lanolin and wool alcohols were tested in eczema patients over a three-year period. Perfume allergy was detected in 3.6% of the cases, sensitivity to thiomersal in 2%, to sorbic acid in 0.8%, to parabens in only 0.3%, and to wool alcohols in 1.2%. Reactions to emulsifiers were seen over 1% of those tested.

Adult↗
PubMed1988

Influence of metabolic and physical factors on production of diacetoxyscirpenol by Fusarium sambucinum Fuckel.

Fusarium sambucinum Fuckel 8099-1 was grown on Czapek-Dox peptone-supplemented medium at 15 degrees C for 14 days, and the cultures were investigated for diacetoxyscirpenol (DAS) production by liquid-liquid extraction and gas chromatography. The addition of 150 mg of sorbic acid, a tricarboxylic acid cycle inhibitor, per liter stimulated both fungal growth and DAS production. Among the beta-hydroxy-beta-methylglutaryl coenzyme A precursors tested, isovaleric acid completely inhibited fungal growth and DAS production, ethyl isovalerate did not support a significant increase in DAS production, and L-leucine partially inhibited DAS production, showing that L-leucine and isovaleric acid catabolisms do not induce trichothecene biosynthesis. Solid particles (cork powder) were necessary for DAS production in stationary cultures but did not influence DAS production in shaken cultures. Shaking strongly stimulated DAS production and fungal growth.

Acyl Coenzyme A↗
PubMed1997

Potato pulp: microbiological characterization, physical modification, and application of this agricultural waste product.

Potato pulp, one of the agricultural waste products obtained in high quantities during starch production, contains starch, cellulose, hemicelluloses, pectin, proteins, free amino acids and salts. It exhibits physical and physicochemical properties of a typical colloid. It is mainly used, in a dried and pelleted form, as cattle feed. Its autochthonic microbial flora (bacteria, fungi) was identified and studied with a view towards the degradative potential of the microorganisms and ways of conserving the pulp for subsequent technical applications; 33 isolates (28 bacteria, 4 fungi, 1 yeast), belonging to 15 genera were characterized. Biological conservation was possible at very low oxygen pressure, brought about by the autochthonic anaerobic microorganisms causing acidification. Chemical conservation was achieved with sorbic acid. By treatment with hot water vapour under pressure (autoclaving), followed by a pressure release procedure, intact cells in the pulp (both potato cells and microorganisms, not spores) were destroyed, and their contents and wall fragments were set free. This process resulted in low drying costs and was a prerequisite for the production of a powder that can be used as glue or as animal feed.

Adhesives↗
PubMed2001

Modelling the effects of (green) antifungals, droplet size distribution and temperature on mould outgrowth in water-in-oil emulsions.

Prevention of fungal spoilage is a key microbiological issue for the shelf life of fat spreads. Our aim was to assess and model the scope of (natural) antimicrobials for extending shelf life of spreads (water-in-oil emulsions). Production conditions were established to make 60% model fat spreads with reproducible droplet size distributions. The mould vulnerabilities ranged from 1 to 20 weeks. The system allowed feasibility testing of lytic enzymes (Novozym 234) and LMW compounds against Penicillium roqueforti, a key-spoilage mould. The action of Novozym 234, carvacrol, undecanol and dihydrocarveol was benchmarked against sorbate and preservative-free controls under ambient and chilled conditions. Novozym 234 was ineffective to prevent outgrowth of P. roqueforti. Carvacrol, undecanol and dihydrocarveol had limited effects on shelf-life extension compared to sorbate. Fungal growth boundaries of (un-)preserved spreads were modelled. The emulsion droplet size distribution (DSD) was first captured in a mechanistic parameter DSD-I (I = Influence). DSD-I was a move away from the mean droplet diameter D3,3 as sole quantitative droplet-size distribution parameter for mould susceptibility of emulsions. DSD-I is a combination of available water droplets and surface area to initiate and sustain fungal outgrowth. Followup experiments showed that modelling D3,3 and distribution width (e(sigma)) instead of DSD-I gave better results for emulsions with high e(sigma). Empirical predictive models were subsequently developed for the effects of D3,3, e(sigma) and undissociated sorbic acid (HSO) on the shelf life of emulsions.

Antifungal Agents↗
PubMed2005

Rapid enrichment and analysis of yeast phosphoproteins using affinity chromatography, 2D-PAGE and peptide mass fingerprinting.

A combination of affinity purification, 2D-PAGE and peptide mass fingerprinting was employed to study the phosphoprotein complement of Saccharomyces cerevisiae. Protein extracts were first passed through a phosphoprotein affinity column, and the phosphoprotein-enriched eluate fractions were then separated on 2D gels and visualized by staining with SYPRO Ruby. Proteins were excised from the gels and identified by peptide mass fingerprinting; 11/13 protein spots identified from a gel of the phosphoprotein-enriched fraction had prior published evidence indicating that they were phosphoproteins. Additional experiments using a specific stain for phosphoproteins, prior incubation of the protein extract with alkaline phosphatase and blotting with monoclonal antibodies to phosphothreonine, phosphoserine and phosphotyrosine demonstrated that the phosphoprotein affinity column was an effective method for enriching phosphoproteins. Further validating the method, growth of yeast in the presence of sorbic acid resulted in altered phosphorylation of 17 proteins, 13 of which had prior published evidence that they were phosphoproteins or had ATP binding activity.

Alkaline Phosphatase↗