Potassium Sorbate Solution Research Articles

Quality of hurdle treated pork sausages during refrigerated (4 ± 1°C) storage.

Pork sausages developed using hurdle technology was evaluated during refrigerated storage (4 ± 1°C). Hurdles incorporated were low pH, low water activity, vacuum packaging and post package reheating. Dipping in potassium sorbate solution prior to vacuum packaging was also tried. Hurdle treatment significantly (p <0.05) reduced the rate of deterioration of quality characteristics of pork sausages during storage, as indicated by TBARS and tyrosine values. Incorporation of hurdles decreased the growth of different spoilage and pathogenic microorganisms. Combination of pH, water activity, vacuum packaging and reheating inhibited the growth of yeast and molds up to 12 days, while additional dipping of sausages in 1% potassium sorbate solution prior to packaging inhibited their growth even on 30(th) day of storage. Incorporation of hurdles resulted in initial reduction in all the sensory attributes, but they helped to maintain these attributes for significantly longer period compared to control. Hurdle treated sausages exhibited no spoilage signs even on day 30, while the control sausages were found acceptable only up to 18 days.

Sanitizing effect of salts on experimentally inoculated organisms on pork carcasses

Pork forequarters procured from freshly slaughtered animals were decontaminated with hot water and inoculated with Staphylococcus aureus, Escherichia coli, Salmonella typhimurium, Yersinia enterocolitica, Listeria monocytogenes, Serratia marcescens, Pseudomonas aeruginosa and Proteus vulgaris. The forequarters were individually spray washed with 5% potassium sorbate and a combination of 5% sodium chloride and 2.5% each of sodium acetate, sodium citrate, sodium lactate and potassium sorbate solutions. The total viable count (TVC) of the treated meat samples was reduced by 0.96 and 1.31 log units by spraying with salt and salt combination respectively with marginal changes in colour and odour scores. Inoculated organisms were found to be highly sensitive to salt combination treatment as compared to potassium sorbate alone. Shelf-life of salt and salt combination treated samples was increased to 8 and 11 days as against 4 days in untreated samples. Carcass washing with salt and salt combination was found to be suitable for extension of shelf-life and improvement in the sensory and microbiological quality of meat.

Reprint of “Potassium sorbate solutions as copper chemical mechanical planarization (CMP) based slurries”

Copper depassivation and repassivation characteristics in potassium sorbate solutions, subsequent to mechanical abrading are reported. The identification of copper repassivation kinetics obtained subsequent to mechanical damage of copper protective films formed in sorbate based solutions is discussed. The repassivation rate of copper in sorbate based solutions was measured by means of a slurryjet system capable of measuring single particle impingments on microelectrodes. Copper repassivation rates measured by this slurryjet system in sulfate solutions containing 10 g L −1 potassium sorbate were found to be in the range of 0.5–1.5 ms. An increase in the potassium sorbate concentration leads to a decrease in copper repassivation time at potentials ranging from 200 to 600 mV Ag/AgCl. The impingement angle between the copper surface and a single abrasive particle has no impact on copper repassivation time nor peak current ( I max) values. XPS studies revealed that copper passivation in potassium based solution was due to the formation of a thin film which is constituted of: Cu 2O, Cu(OH) 2 and Cu(II)-sorbate, while copper(II)-sorbate is mainly present at the top levels of the passive film. It is therefore recommended that the use of potassium sorbate as a passivating component in conjunction with the addition of strong oxidizing agents in chemical mechanical planarization (CMP) slurry design should be considered.

Effect of hot-boned pork on the quality of hurdle treated pork sausages during ambient temperature (37 ± 1 °C) storage

The study was aimed at evaluating the suitability of hot-boned pork and pork fat for processing shelf-stable pork sausages using hurdle technology and the different hurdles incorporated were low pH, low water activity, dipping in potassium sorbate solution, vacuum-packaging and post-package reheating. Emulsion stability and cooking yield did not Izatnagardiffer significantly among hot- and cold-processed sausages. Despite the same emulsion pH, the sausages from hot-boned pork had significantly higher fat content. Colour and texture profiles of pork sausages were significantly ( P < 0.05) influenced by hot processing. During storage at ambient temperature (37 ± 1 °C), various physico-chemical characteristics, namely pH, TBARS and tyrosine values, of hot- and cold-processed sausages, did not differ. Hot-processing markedly increased the total plate counts of the sausages, but a significant difference was absent for anaerobic counts between treatments at any particular storage interval. Cold-processed sausages had the higher lactobacillus counts throughout the storage period. Sensory evaluation revealed that hurdle-treated pork sausages from hot-boned pork were equally suitable as those from cold-boned pork up to day 6 at ambient temperature.

Development of shelf stable pork sausages using hurdle technology and their quality at ambient temperature (37 ± 1 °C) storage

Shelf stable pork sausages were developed using hurdle technology and their quality was evaluated during ambient temperature (37 ± 1 °C) storage. Hurdles incorporated were low pH, low water activity, vacuum packaging and post package reheating. Dipping in potassium sorbate solution prior to vacuum packaging was also studied. Reheating increased the pH of the sausages by 0.17 units as against 0.11 units in controls. Incorporation of hurdles significantly decreased emulsion stability, cooking yield, moisture and fat percent, yellowness and hardness, while increasing the protein percent and redness. Hurdle treatment reduced quality deterioration during storage as indicated by pH, TBARS and tyrosine values. About 1 log reduction in total plate count was observed with the different hurdles as were reductions in the coliform, anaerobic, lactobacilli and Staphylococcus aureus counts. pH, a w and reheating hurdles inhibited yeast and mold growth up to day 3, while additional dipping in 1% potassium sorbate solution inhibited their growth throughout the 9 days storage. Despite low initial sensory appeal, the hurdle treated sausages had an overall acceptability in the range ‘very good’ to ‘good’ up to day 6.

Potassium sorbate solutions as copper chemical mechanical planarization (CMP) based slurries

Copper depassivation and repassivation characteristics in potassium sorbate solutions, subsequent to mechanical abrading are reported. The identification of copper repassivation kinetics obtained subsequent to mechanical damage of copper protective films formed in sorbate based solutions is discussed. The repassivation rate of copper in sorbate based solutions was measured by means of a slurryjet system capable of measuring single particle impingments on microelectrodes. Copper repassivation rates measured by this slurryjet system in sulfate solutions containing 10 g L −1 potassium sorbate were found to be in the range of 0.5–1.5 ms. An increase in the potassium sorbate concentration leads to a decrease in copper repassivation time at potentials ranging from 200 to 600 mV Ag/AgCl. The impingement angle between the copper surface and a single abrasive particle has no impact on copper repassivation time nor peak current ( I max) values. XPS studies revealed that copper passivation in potassium based solution was due to the formation of a thin film which is constituted of: Cu 2O, Cu(OH) 2 and Cu(II)-sorbate, while copper(II)-sorbate is mainly present at the top levels of the passive film. It is therefore recommended that the use of potassium sorbate as a passivating component in conjunction with the addition of strong oxidizing agents in chemical mechanical planarization (CMP) slurry design should be considered.

Effect of potassium sorbate washing on the growth of Listeria monocytogenes on fresh poultry

This work evaluated the effect of potassium sorbate washing on the growth of Listeria monocytogenes on poultry legs stored at 4 °C for 7 days. Fresh inoculated chicken legs were dipped into either a 2.5% (w/v) or 5% potassium sorbate solution or distilled water (control). Changes in mesophiles, pychrotrophic counts and sensorial characteristics (odor, color, texture and overall appearance) were also evaluated. The shelf life of the samples washed with potassium sorbate was extended by at least 2 days over the control samples washed with distilled water. Legs washed with 5% potassium sorbate showed a significant ( p < 0.05) inhibitory effect on L. monocytogenes compared to control legs, with a decrease of about 1.3 log units after 7 days of storage. Sensory quality was not adversely affected by potassium sorbate.

Application of Organic and Inorganic Salts to Field-Grown Potato Tubers Can Suppress Silver Scurf During Potato Storage.

Silver scurf, caused by Helminthosporium solani, is an economically important postharvest disease of potato tubers. Organic and inorganic salts were evaluated for their ability to suppress silver scurf lesion development and sporulation of H. solani on potato tubers. Tubers were treated immediately after harvest with 0.2-M solutions of potassium sorbate, calcium propionate, sodium bicarbonate, sodium carbonate, ammonium bicarbonate, or water. Tween 20 was added as a surfactant to most treatments. Potassium sorbate (0.1 M), acidified potassium sorbate and calcium propionate treatments (0.2 M), and calcium chloride treatments (0.136 M) were included in additional experiments. Tubers were stored under commercial storage conditions for 4 to 6 months prior to disease evaluation. The extent of disease suppression varied among experiments; however, some treatments consistently reduced disease. Lesion formation on the tuber surface was reduced by 26 to 60% using potassium sorbate (in three of four experiments) compared to water-treated or untreated tubers. Sporulation was suppressed by 0.2 M potassium sorbate (78 to 99% reduction) in all four experiments. Sodium carbonate reduced lesion formation in two experiments and sporulation in three of four experiments. Other treatments inconsistently suppressed lesion formation or sporulation, or did not reduce disease. Addition of Tween or acidification of organic salt solutions did not improve silver scurf suppression in most cases. Potassium sorbate has very low mammalian toxicity and great potential as an innocuous and inexpensive postharvest fungicide for suppression of silver scurf during potato storage.

Microbial and Sensory Quality of Fresh Camel Meat Treated with Organic Acid Salts and/or Bifidobacteria

ABSTRACTFresh camel meat samples were treated by dipping in solutions of sodium acetate (10% w/w), potassium sorbate (1.5% w/w), sodium lactate (5% v/v of 60% solution), or trisodium citrate (1.5%w/w) alone or combined with Bifidobacterium breve cell suspension (5%) and stored at 4°C. The pH, psychrotrophs, and sensory attributes were evaluated. Sodium acetate alone or combined with bifidobacteria maintained pH level, extended microbial shelf life (&gt;12 days) and minimized surface discoloration. Bifidobacteria cell suspension when applied alone had negligible effects on microbial and sensory attributes. However, when combined with sodium acetate or potassium sorbate, bifidobacteria exhibited an additive effect on suppressing spoilage microorganisms.

THE INFLUENCE OF INDUSTRIAL DEHYDRATION ON QUALITY OF FIG FRUITS

The effectiveness of a dehydration process on the quality of Niedda longa fig fruits was studied. Drying was carried out either with an industrial two-stage dehydration system, requiring no blanching treatment, or with a simulated sun-drying procedure. During the industrial process fruits were: (a) initially moved for 3 hours in a tunnel with a gradient air temperature from 95°C to 85°C; (b) then moved into a second tunnel at 85°C for 14 h. Sun-drying was simulated keeping fruits for 120 h at 32°C and 35% of relative humidity (RH). Finally dehydrated figs were rehydrated, or equilibrated with environmental RH (sun-dried figs), and both treated with potassium-sorbate solution, then film-packaged into hermetically sealed air tight bags. Moreover, half of the bags were packed in-modified atmosphere (MAP). Fruits were, then, stored at 20°C for 6 months. A 11 h dehydration time was sufficient to obtain microbially stable fruits without chemical treatments, reaching a dry matter content (DM) of 88 % and water activity (aw) of 0.60, whereas after 17 h DM and aw were 91% and 0.57, respectively. DM of industrial rehydrated figs and environmental equilibrated sun-dried figs were 71% and 74%, respectively, requiring a potassium-sorbate treatment. After packaging and 6 months of shelf life, no microbial growth was revealed on fruits. MAP resulted in no additional improvement on the microbial quality of the product. Based on these results we can state that industrial dehydration performed well, even if fruit calibration is needed before drying.

Prolongation of the keeping quality of Mozzarella cheese by treatment with sorbate.

An attempt was carried out for prolongation of the shelf-life of Mozzarella cheese by incorporation of potassium sorbate into the cheese. Three manufacturing techniques were used: a) addition of potassium sorbate to kneading water (at level of 6%), b) addition during brine salting (at level of 0.5%) and c) dipping the cheese into potassium sorbate solution (6%) directly prior to packaging. Control cheese was made without potassium sorbate treatment. The resulting cheeses were divided into two portions, one of which was contaminated with Penicillium roqueforti and then packaged, while the second one was packaged without contamination. Both were stored at refrigerator (5 +/- 1 degree C) temperature and analysed periodically until spoilage. The results showed that treatment with potassium sorbate did not affect the organoleptic properties of the cheeses, except that a slight objectionable bitter flavour was observed in fresh cheeses treated with sorbate using the techniques of dipping or in brine salting then it was disappeared during storage. However, the overall acceptabilities of the sorbate-treated cheese were increased up to 10 weeks of storage compared with 4 weeks for untreated cheeses. Treatment with potassium sorbate in kneading water or brine appeared to be more effective than dipping. Addition of potassium sorbate inhibited microbial growth, especially that of moulds and yeasts. The sorbate-treated cheeses had higher moisture, pH values and lower acidity than the control. Fat, salt and total nitrogen were unaffected during storage. Levels of soluble N, non-protein N and total volatile fatty acids in sorbate-treated cheeses were slightly higher than in the control. Furthermore, addition of potassium sorbate increased the meltability and improved the fat leakage of Mozzarella cheese.

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 G 2/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 G 2/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-hexonoic 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.

MAINTAINING THE STORAGE QUALITY OF TROPICAL DRIED FRUIT MIX WITH GLYCEROL

Tropical dried fruit-mix was prepared from pineapple, papaya and banana. Pineapple and papaya cubes were prepared by soaking in a 60% sugar solution containing 0.4% sodium metabisulfite and glycerol at 0, 15 and 20%. Banana cubes were treated with 0.4% potassium sorbate solution containing 0, 15 and 20% glycerol without sugar. The fruit cubes were oven-dried at 65–75°C for 5–10 h and the dried fruits were mixed at a ratio of 1:1:1 (pineapple: papaya: banana). A 300 g sample of the mixture was packed in polypropylene bags (0. 04 mm) and stored at room temperature in cardboard boxes for a year. The glycerol-treated fruit-mix had higher moisture content but lower water activity than the control. Glycerol treatment improved the color of tropical dried fruit-mix. During storage, the color of glycerol-treated banana darkened whereas glycerol-treated papaya became lighter and more red than the control. The glycerol-treated fruit-mix, which retained more sulfur dioxide during storage, contained lower mold and bacterial counts. Use of 15 or 20% glycerol resulted in better color, texture, flavor and appearance of fruit mixture than the control samples.

Effects of Potassium Sorbate, Sodium Acetate, Phosphates and Sodium Chloride Alone or in Combination on Shelf Life of Vacuum‐Packaged Pork Chops

ABSTRACTMicrobiological and some physical and chemical effects of treating pork chop surfaces with sodium acid pyrophosphate, a commercial phosphate blend, potassium sorbate and phosphate/sorbate/sodium acetate solutions, with or without sodium chloride, before packaging were studied in pork chops vacuum‐packaged and stored at 2–4°C for 10 weeks. All treatments containing potassium sorbate reduced (P&lt;0.05) counts of mesophiles, psychrotrophs, EnterobacteriaCeae, facultative anaerobes, and lactobacilli. Treatment of chops with 10% phosphates/ 10% potassium sorbate solutions improved pork color and decreased purge. Potassium sorbate alone reduced microbial counts more than it did when combined with phosphates, but chops were darker and had more exudate (P&lt;0.05). Combined use of 10% phosphates/10% potassium sorbate extended shelf life in vacuum‐packaged fresh pork chops to 10 weeks at 2–4°C compared with 4 weeks for untreated pork and protected meat color.

Control of Microbial Spoilage on Fresh Poultry using a Combination Potassium Sorbate/Carbon Dioxide Packaging System

ABSTRACTThe effects of potassium sorbate combined with vacuum or carbon dioxide modified atmosphere packaging on natural poultry spoilage flora were examined. Fresh chicken thighs were dipped into either 2.5% potassium sorbate solution or distilled water, adjusted to pH 6.0 and packaged on trays in Nylon/Plexar/Surlyn bags. Atmospheres of either air, vacuum or 100% C02 were created in the packages which were then stored at 10 ± 1°C for 10 days. Changes in aerobic plate counts, lactic acid bacteria and pseudomonads were monitored. The combination of CO2 packaging and sorbate treatment provided the most effective inhibitory system against the poultry spoilage organisms, especially Pseudomonas species, without creating a selective environment for the growth of lactic acid bacteria and premature souring of the product. The shelf life of the sorbate/CO2 samples was extended 3 days over the control/air samples at 10°C.

Control of Two Major Pathogens on Fresh Poultry Using a Combination Potassum Sorbate/Karbon Dioxide Packaging Treatment

Salmonella enteriditis and Staphylococcus aureus were separately inoculated onto fresh chicken thighs prior to dipping in 0, 1.0, 2.5, or 5.0% potassium sorbate solutions adjusted to pH 6.0. Treated samples were packaged in Nylon/Plexar/Surlyn bags under air, vacuum, 20%, 60%, or 100% CO2 atmospheres and stored at 10°C ± 1.0°C for 10 days. Changes in gaseous headspace composition, sorbate concentrations, surface pH, and microbial numbers were monitored during the storage period. S. enteriditis was more sensitive to potassium sorbate than S. aureus; growth on poultry of the latter organism was more effectively inhibited by exposure to high levels of CO2. Increased concentrations of sorbate dip solutions in combination with higher concentrations of CO2 in the package environment provided a more effective inhibitory system against growth of both pathogens on fresh poultry.

Potassium Sorbate and Recovery of Pectinolytic Psychrotrophs from Vacuum-Packaged Pork

Pork loins were divided into small roasts. Thirty roasts were uninoculated and 30 were inoculated by dipping in 1 % peptone water containing 100 Colony-forming units (CFU)/ml of pectinolytic Yersinia enterocolitica. Twenty-four each of the uninoculated and inoculated roasts were sprayed with or dipped in 5 or 10% solutions of potassium sorbate. All roasts were then vacuum-packaged and stored at 5°C. After storage for 1 or 21 d, three roasts from each group were examined for psychrotrophic plate count (PPC) and the 3-tube most probable number of pectionolytic bacteria. Counts of psychrotrophs on lean surfaces of untreated controls increased by nearly 3.4 log10. Numbers on sorbate-treated lean surfaces increased about 2.0 log10. Growth and differences in counts on fatty surfaces were less. Numbers of pectinolytic bacteria on lean surfaces of controls increased by nearly 2.0 log10, but numbers of pectinase producers did not change significantly during storage of sorbate-treated samples. Of 30 pectinolytic isolates identified from roasts stored 21 d at 5°C, 87% were Yersinia spp. and 13% were Klebsiella oxytoca. Since most of the pectinolytic isolates were psychrotrophs of public health significance, inhibition of their growth by sorbate is of particular importance.

Electron spin resonance studies of the reactions of sorbate with nitrite in the presence of a spin trap

An esr spectrum was generated when a spin trap, t-nitroso butane (tNB), was added to potassium sorbate solution at pH of 6.4. This spectrum can be explained by the abstraction of allylic hydrogen by NO2, generated by the decomposition of tNB, followed by spin trapping of the radical product. With increasing concentration of NO2, which was accomplished by either the addition of sodium nitrite or by lowering the pH to cause rapid decomposition of tNB, a different esr spectrum was observed. This spectrum can be accounted for by a radical formed by addition of NO2 to the 4,5 double bond of the sorbate and subsequent trapping by tNB.

Effects of Vacuum Packaging and Potassium Sorbate on Yield, Yeast and Mold Growth, and Quality of Dry‐Cured Hams

ABSTRACTTwo trials were conducted. In the first trial hams were cured by a standard process and aged 1 month at 24°C. Group I hams were not packaged or treated. Group II hams were vacuum packaged and Group III hams were dipped in a 2.5% potassium sorbate solution and also vacuum packaged. All hams were examined after 1 month and the treated group was dipped in a 5% sorbate solution, vacuum packaged and aged an additional 2 months. Vacuum packaging practically eliminated further weight loss while potassium sorbate reduced but did not eliminate mold growth. In the second trial hams were again cured by a standard process and aged at 24°C until they were officially country hams (18% weight loss). Group I hams were not treated whereas group II hams were dipped in a 10% potassium sorbate solution. All were vacuum packaged. After aging one month they were unpacked, weighed, and examined for molds. No significant weight loss had occurred but mold counts were lower in the dipped group. The dipping procedure was reversed so that group I hams were treated and group II hams were not treated. All hams were again vacuum packaged and held a second month. No additional weight loss was noted. Mold growth, though not eliminated, was minimal, and visual and aroma scores for the cut hams were similar and highly acceptable. Tenderness, flavor, saltiness, and overall satisfaction scores for cooked slices were similar and highly acceptable. In general, mold growth can be greatly reduced by the use of potassium sorbate and weight loss can be controlled by vacuum packaging.

Microbiology of Poultry Parts Dipped in Potassium Sorbate ,

Fresh broiler drumsticks were used to study the effectiveness of a potassium sorbate dip to control bacterial growth. Some pieces were inoculated with Salmonella typhimurium before being dipped. Other pieces, used to determine total counts, were not inoculated with Salmonella. Treated drumsticks were held at 4, 10, or 22 C.When stored at 4 C, untreated pieces had counts of 106 in about 6 days, but parts dipped in 10% potassium sorbate took nearly 10 days to reach the same total counts. At 22 C, potassium sorbate extended the shelf-life only about 1 day. Potassium sorbate solutions of 5% strength were nearly as effective as the 10% solution on drumsticks held at 4 C, but not at 22 C. The 10% dip (for only 30 sec) effectively reduced numbers of Salmonella after 2 days storage at 22 C. These data support earlier findings that sorbates can be used to control growth of spoilage organisms associated with fresh poultry parts.