Effect of Poly- and Pyrophosphates on the Natural Bacterial Flora and Inoculated Clostridium sporogenes PA 3679 in Cooked Vacuum packaged Bratwurst

Survival and growth of inoculated Clostridium sporogenes PA 3679 and of natural aerobic and anaerobic bacterial flora were studied in cooked, vacuum packed bratwurst containing 0.5% phosphates during refrigerated (5°C) and subsequent temperature abuse storage (24°C). Sodium acid pyrophosphate (SAPP), sodium tripolyphosphate (STPP), tetrasodium pyrophosphate (TSPP) and sodium polyphosphate glassy (SPG) were tested. No significant bacterial inhibition by any phosphate was observed during refrigerated storage, nor was there appreciable growth in the control bratwurst. However, SAPP significantly inhibited aerobic and anaerobic bacteria (including C. sporogenes) upon temperature abuse, followed in effect by TSPP and STPP. Cooking to 65.5°C helped retain antimicrobial properties of phosphates to some extent. Enzymatic hydrolysis of phosphates is postulated as a major factor in loss of antimicrobial properties of phosphates in processed meats.     

Effect of Phosphates on Bacterial Growth in Refrigerated Uncooked Bratwurst

The effects of 0.5% sodium acid pyrophosphate (SAPP), sodium tripolyphosphate (STPP), tetrasodium pyrophosphate (TSPP) and sodium polyphosphate glassy (SPC) on aerobic mesophilic and psychrotrophic bacterial growth and on survival of inoculated Stuphylococcus aureus Z 88 were investigated in uncooked bratwurst stored at 5°C for 7 days. No significant microbial inhibition by phosphates was found, although SAPP addition resulted in consistently lower total aerobic plate counts. Phosphate-induced pH differences in the sausages had no effect on bacterial numbers. The possible role of meat enzymes in the hydrolysis of condensed phosphates to microbiologically inactive species is discussed.     

Effect of Sodium Acid Pyrophosphate in Combination with Sodium Nitrite or Sodium Nitrite/Potassium Sorbate on Clostridium botulinum Growth and Toxin Production in Beef/Pork Frankfurter Emulsions

Combinations of sodium acid pyrophosphate (SAPP) with added sodium nitrite and/or potassium sorbate were tested at various pH levels to determine effectiveness in delaying Clostridium botulinum growth and toxin production in frankfurter emulsions. Formulations containing sodium nitrite (40 ppm), potassium sorbate (0.26%) and SAPP (0.4%) resulted in a greater delay of toxin production (12–18 days) than other combinations (6–12 days) having similar pH values. Treatments containing 0.4% SAPP appeared to be more inhibitory than their counterparts without SAPP, displaying less numbers of toxic samples during the 53-day storage period at 27°C. Aerobic mesophilic colony counts and residual nitrite data showed little difference among treatments.     

Effect of Sodium Erythorbate on Residual Nitrite, pH and Bacterial Growth in Liver Sausage Formulated with Different Levels of Mechanically Separated Pork

Some microbiological, chemical, and physical characteristics of liver sausage formulated with 0, 25, 50, and 75% mechanically separated pork (MSP), 156 ppm sodium nitrite and 0 or 550 ppm sodium erythorbate were studied during refrigerated storage (5°C, 6 days) and subsequent elevated-temperature holding (20–24°C, 48 hr). Growth of inoculated Clostridium sporogenes was inhibited by 156 ppm nitrite in all sausages even after 48 hr at 20–24°C, regardless of MSP level. Growth of aerobic mesophiles and facultative anaerobes at 20–24°C was also inhibited in sausage formulated with 156 ppm nitrite and 550 ppm erythorbate. Erythorbate addition and increased MSP levels resulted in higher Hunter a color values. Residual nitrite, pH values, and total iron content of liver sausage increased with increasing MSP content.     

Effect of Acid and Alkaline Pyrophosphate Blends on the Natural Flora of a Cooked Meat System

Cooked pork sausage was prepared by using tetrasodium pyrophosphate (TSPP) and sodium acid pyrophosphate (SAPP) at 0 and 0.4% of the meat weight either separately or in different combinations. Samples were vacuum packaged and held in a refrigerated display case at 5°C for 21 days. Samples were also stored at room temperature (20-22°C) for 24 and 48 hr. Neither phosphate had an effect on microbial counts during refrigerated storage up to 21 days, but SAPP caused significantly lower counts of mesophilic and facultative anaerobic organisms after 48 hr of temperature abuse. The organisms affected were streptococci or very similar coccobacilli.     

Effect of Mechanically Separated Pork, Sodium Erythorbate and Sodium Nitrite Combinations on Clostridium sporogenes Survival and Growth in Liver Sausage

Liver sausage formulated with 50 or 75% mechanically separated pork (MSP), 75 or 150 ppm sodium nitrite and 0, 550 or 1100 ppm sodium erythorbate was examined for Clostridium sporogenes PA3679 survival and growth during refrigerated temperature storage (5°C, 6 days) and during subsequent exposure to elevated temperatures (22–24°C, 2 d). Sodium nitrite at 150 ppm inhibited clostridial growth in sausage held at 22–24°C, regardless of MSP content, if 550 ppm sodium erythorbate were also present. Sodium nitrite at 75 ppm combined with erythorbate at 550 and 1100 ppm did not inhibit C. sporogenes growth during simulated temperature mishandling of liver sausage. Residual nitrite decreased (P<0.05) with erythorbate addition but was unaffected by MSP.     

Effect of Acid and Neutral Pyrophosphates on the Natural Bacterial Flora of a Cooked Meat System

The microbiological effects of selected pyrophosphates were studied in cooked, vacuum-packaged pork sausage stored at 7°C for 21 days, or at 20–22°C for 24 and 48 hr. Neutral trisodium pyrophosphate (PYRO-3) and sodium acid pyrophosphate (SAPP) were tested at 0 and 0.4% meat weight, separately or in combinations. Both phosphates had an effect after 21 days refrigerated storage (7°C), with lower mesophilic counts than controls with no phosphate. Both phosphates also resulted in significantly lower counts of mesophilic and facultative anaerobic microorganisms in sausage after 48 hr elevated temperature (20–22°C) holding. The organisms affected were mainly streptococci.     

Effect of Inorganic Polyphosphates on Ground Beef Characteristics: Microbiological Effects on Frozen Beef Patties

Microbiological effects of 0.4% sodium tripolyphosphate (STPP), tetrasodium pyrophosphate (TSPP), and three commercial phosphate blends were studied in frozen (90 days, ?20°C) and subsequently temperature-abused (24–25°C, 24 hr) beef patties. Phosphates did not significantly (p>0.05) reduce mesophilic, psychrotrophic, presumptive 5. aureus and lactic acid bacterial numbers during frozen storage of the patties, but one of the commercial blends and TSPP inhibited bacterial growth upon subsequent elevated-temperature abuse. However, bacterial inhibition by phosphates during temperature abuse was not sufficient to prevent spoilage of the patties.     

Packaging Film Permeability in Conjunction with Sodium Nitrite, Potassium Sorbate or Lactic Acid Starter Culture for Control of Clostridium sporogenes (PA3679) Growth in Sliced Bologna

A sliced bologna was prepared and inoculated with Clostridium sporogenes (PA3679), packaged in films ranging in oxygen permeability from 0.1 cc/m²/24 hr to 120 cc/m²/24 hr and stored at 5°C, 15°C or 25°C. Subsequent bologna preparations included either 156 ppm sodium nitrite, 0.26% potassium sorbate or a lactic acid starter culture. Water activity, pH, TBA number and PA3679 counts were monitored during 28 days of storage. TBA numbers increased in packages with over 60 cc/m²/24 hr permeability but PA3679 counts did not change as a function of packaging film. Nitrite and sorbate were equally effective as inhibitors. At 15°C and 25°C, the lactic acid culture allowed the least PA3679 growth. Oxygen permeability did not alter any inhibitory effects even when increased TBA numbers resulted from using an oxygen-permeable film.     

Inhibition of Salmonella by Sodium Nitrite and Potassium Sorbate in Frankfurters

All beef frankfurters and beef-pork frankfurters containing various levels of sodium nitrite (0, 50, or 156 ppm) or potassium sorbate (0, 0.26, or 0.39%) alone or in combination (50 ppm nitrite + 0.26% sorbate) were prepared. Frankfurters were inoculated with nalidixic acid resistant Salmonella and incubated at 15°C and 27°C for up to 21 days. Frankfurters formulated with 50 or 156 ppm nitrite and incubated at 27°C, or 50 ppm nitrite and incubated at 15°C failed to inhibit the growth of Salmonella. Sorbate alone and sorbate in combination with 50 ppm nitrite were equally effective in inhibiting Salmonella at either temperature and were equivalent to 156 ppm nitrite in inhibiting Salmonella at 15°C.     

Effects of Sodium Chloride Reduction and Polyphosphate Addition on Clostridium Botulinum Toxin Production in Turkey Frankfurters

Mechanically deboned turkey meat emulsions were made with 1.0, 1.5, 2.0, 2.5, or 3.0% salt (NaCl), or with combinations of 1.5% or 2.0% salt with 0.4% sodium tripolyphosphate (TPP), sodium hexametaphosphate (HMP), or sodium acid pyrophosphate (SAPP). Sodium nitrite levels were constant at 150 ppm. Emulsions were inoculated with a mixture of 10 strains of C. botulinum (10³/g) and incubated at 27°C. Increasing NaCl content from 1.0% to 3.0% delayed toxin production by 3 days on the average. Toxin production was detected earlier when TPP was added, HMP had no effect, and SAPP delayed toxin production.     

Effects of Polyphosphates on Cell Numbers, Enterotoxin A, and Extracellular Protein in Staphylococcus aureus 196E

Effects of sodium salts of pyro- (SAPP), tripoly- (STPP), and hexametaphosphate (SHMP) on cell numbers, enterotoxin A (SEA) and extracellular protein production (ECP) of Staphylococcus aureus strain 196A were studied in 4% N-Z amine broth plus 1% yeast extract after 24 hr at 30°C. At pH 7.0, concentrations lower than 56 mM (1.2%) SAPP, 27 mM (1%) STPP or 3 mM (0.4%) SHMP had no antibacterial effects and a bacteriostatic effect showed at slightly higher concentrations. SAPP was the least effective inhibitor at neutral pH, but displayed enhanced inhibitory effects at pH 5.5. Reduction in SEA and ECP paralleled cell growth suppression; their concentrations were 1400 ng/mL and 1.5 mg/mL, respectively, in phosphate free broth (9 × 10⁹ CFU/mL), and nondetectable when cell numbers were ≤10⁶ per mL.     

Effects of Selected Commercial Phosphate Products on the Natural Bacterial Flora of a Cooked Meat System

Four commercial phosphate blends and a neutral pyrophosphate were used at three levels (0.30–0.65%) in the preparation of cooked sausage. Control treatments contained no phosphate. Vacuum-packaged sausage was stored at 5°C for 21 days or held at room temperature (20–22°C) for up to 48 hours after 7 days of refrigerated storage. Mesophilic and facultative anaerobic bacterial counts were highest in control treatments after 14 and 21 days at 5°C and after 24 and 48 hr at 20–22°C. For each phosphate, the level of addition was the determining factor in bacterial inhibition, since the highest phosphate level resulted in the lowest bacterial counts in sausage held at 5°C and 20–22°C. The level of phosphate was more important in prolonging shelf life than was the type of phosphate.     

Microbiology of a Ham-Type Product Made from Soy-Extended Cured Beef and Inoculated with Clostridium sporogenes PA3679

The microbiological stability of a new ham-type product made from soy-extended cured beef was examined under wholesale (2–4°C) and retail (5°C) refrigerated storage conditions, and during abuse-temperature holding for 24 and 48 hr at 24-25°C after inoculation with Closrridium sporogenes PA3679. No microbiological effects (P >0.05) could be attributed to the level of soy protein isolate in the injection brine (0, 5, 7.5 or 9%) on the basis of mesophilic, psychrotrophic, anaerobic and lactic bacterial counts. Samples held at 2-4°C did not exceed 10⁴ CFU/g after 4 wk for any bacterial type examined. Product shelf-life was > 3 wk at 5°C and 2 wk at 8–10°C. Inoculated PA3679 did not grow in the product during 24 or 48 hr simulated mishandling (24-2°C).     

Effect of Storage Temperature and Time on the Quality of Vacuum Packaged Dry-Cured Ham Slices

Hams were cured and aged by three methods, two using nitrite and nitrate but with long or short aging times at controlled temperature, and one using no nitrite or nitrate with ambient aging temperature. Hams were sliced, vacuum-packaged and stored at 0°C, 10°C or 21°C for 8 wk and examined weekly for white film, aroma, and aerobic, staphylococci, lactobacilli, yeast and mold counts. White film development was erratic. Aroma was closely related to aerobic counts. At 0°C bacterial counts and aroma remained normal for 8 wk. At 10°C many packages had acceptable counts and aroma at 8 wk but some were unacceptable by 4 or 5 wk. At 21°C many slices were unacceptable microbiologically and sensorily by 3 wk. Storage at or near 0°C is recommended for long shelf life.     

Sodium Acetate and Bifidobacteria Increase Shelf-Life of Refrigerated Catfish Fillets

Microbiological and sensory evaluations of catfish fillets treated with sodium acetate (SA) and bifidobacteria were studied at 4°C. Cultures of Bifidobacterium adolescentis, B. infantis, or B. longum (2.5% V/W) extended lag phase, but not generation time of aerobic bacteria. One-half percent (W/W) SA increased lag phase and generation time. SA and bifidobacteria reduced counts more than either alone, extending shelf-life by 3 days. Amount of culture (1.5–4.5%) or culture age (24–72 hr) had no effect on inhibition. Treated fillets odor and appearance resembled fresh fillets for up to 6 days, while untreated fillets were unacceptable aher 3 days. SA, either alone or combined with bifidobacteria, extended refrigerated shelf-life of catfish fillets.     

EFFECT OF PHOSPHATE AND PECTIN ON QUALITY AND SHELF-LIFE OF MARINATED CHICKEN BREAST

Fresh split chicken breasts were injected with 5% sodium acid pyrophosphate (SAPP), 5% sodium tripolyphosphate (STPP), 2.5% Genu pectin (GENU), or the combination of 5% SAPP with 2.5% GENU and 5% STPP with 2.5% GENU. Calcium lactate (0.1 M) solution was sprayed on the surface of chicken marinated in pectin. Marinated samples were stored at 4C for 7 days to evaluate changes in the psychrotrophic bacterial count and quality. STPP injected chicken breast had highest (α=0.05) marinade pickup, net weight increase, cook yield and moisture content. SAPP injected chicken had intermediate marinade pickup, but lowest retention in the muscle among all treatments. Marinades with pectin or pectin combined with phosphate had lower pickup but higher marinade retention compared with SAPP injected breasts. The water holding capacity (WHC) of STPP and GENU injected cooked chicken breast was higher than SAPP injected samples or control. All marinated chicken breasts had significantly lower shear force than noninjected control. Neither phosphate nor pectin had a significant influence on microbial activity of marinated chicken.     

Interaction of Reduced NaCl, Sodium Acid Pyrophosphate and pH on the Antimicrobial Activity of Comminuted Meat Products

Meat (beef-pork) batters were formulated with NaCl (2.3% and 4.1% brine) and with 0.5% sodium acid pyrophosphate (SAPP) in combination with 2.3% brine. The adjusted pH of raw batters resulted in cooked meat pH values of 5.7, 6.0, and 6.3. Inoculated (Clostridium sporogenes spores) and uninoculated batters in cans were cooked to 70°C and stored for abuse at 27°C. Microbial growth was delayed and the short shelf-life of low brine (2.3%) products was extended with SAPP in the formulation. The antimicrobial properties of treatments with SAPP were due to both declining pH and presence of phosphate in the formulation. Potential mechanisms of microbial inhibition by SAPP are discussed.     

Extension of the Shelf-Life of Fresh Ground Pork with Polyphosphates

The antimicrobial effects of 1.0% sodium acid pyrophosphate (SAPP) and sodium orthophosphate monobasic (ORTHO), alone or combined, were studied in fresh ground pork held at 2–4°C for 6 days. Addition of 1.0% SAPP to the meat inhibited psychrotrophic bacterial growth (P<0.01) and resulted in 50% longer meat shelf-life (equivalent to 2 days) in relation to control samples or to meat treated with 0.5% or 1.0% ORTHO. Addition of a 0.5% SAPP/0.5% ORTHO combination was less inhibitory to meat bacteria than 0.5% SAPP alone. Bacterial inhibition did not correlate with soluble orthophosphate content in ground pork.     

Effect of Nitrite and Sorbate on Total Number of Aerobic Microorganisms in Chicken White and Dark Meat Patties

The effects of nitrite, sorbate and combinations of these two ingredients plus salt on the number of aerobic microorganisms in chicken white and dark meat patties were examined. All patties were stored at 4–5°C for 12 days. Nitrite concentrations of 400 and 2500 ppm were effective in preventing bacterial growth in chicken white meat patties while 2500 ppm was required to prevent growth in dark meat. A reduction in bacterial growth (4–10 days) was demonstrated with 100 and 150 ppm nitrite in chicken white meat patties. Four hundred ppm nitrite reduced bacterial growth in dark meat patties for 6 days. In white meat patties, the use of sorbate (0.26%) in combination with nitrite (40 ppm) was as effective in reducing bacterial growth as higher concentrations of nitrite, salt (2.5%) alone or in combination with sorbate (0.26%) or nitrite (40 ppm) inhibited bacterial growth in both white and dark meat patties during the first 4–6 days of storage.