Effects of Reduced Sodium Chloride and Added Phosphates on Physical and Sensory Properties of Turkey Frankfurters

Turkey frankfurters containing 20 and 40% salt (NaCl) reductions were manufactured and evaluated in comparison to a standard formulation containing 2.5% sodium chloride. Additionally, either 0.4% sodium tripolyphosphate (TPP), sodium hexametaphosphate (HMP), or sodium acid pyrophosphate (SAPP) were incorporated into frankfurters containing similar salt reductions. Phosphates improved emulsion stability and yields, especially in formulas with 40% salt reductions. TPP increased frankfurter firmness compared to that provided by SAPP or HMP regardless of salt level, but TPP had a deleterious effect on freshness at the 2.0% salt level. SAPP was more effective than HMP in improving plumpness and enhancing salt flavor intensity. Overall, SAPP appeared to provide greater benefits than either HMP or TPP as a single polyphosphate for reduced salt turkey frankfurters.     

Microstructure of Reduced Salt Meat Batters as Affected by Polyphosphates and Chopping Time

Microstructural and textural changes due to salt reduction (2.5% to 1.5%), 0.4% tripolyphosphate (TPP), hexametaphosphate (HMP) or sodium acid pyrophosphate (SAPP) addition and chopping time (40 vs 100 cutter revolutions) were studied in poultry meat batters. Salt reduction significantly increased liquid and fat losses in the long chopping but not in the short chopping treatments. Scanning electron micrographs of reduced salt batters revealed fat globules which lost fat during cooking. HMP and SAPP addition significantly improved emulsion stability. Average fat globule size decreased as chopping time increased and/or salt decreased. Hardness was higher in the NaCl treatments in the short chopping as compared to the long chopping. The opposite was observed when phosphates were added.     

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.     

Gamma-Irradiation of CIostridium botulinum Inoculated Turkey Frankfurters Formulated with Different Chloride Salts and Polyphosphates

The effects of gamma-irradiation doses (0, 0.5, and 1.0 Mrad) on C. botulinum toxin production in turkey frankfurters formulated with three different chloride salts (NaCl, KCl, and MgCl₂) at isoionic strength (equal to 2.5% NaCl) and three types of phosphates added to 2.0% NaCl frankfurters were studied. The use of 2.5% NaCl together with 0.5 or 1.0 Mrad was substantially more effective at inhibitinlg botulinal toxin production when frankfurters were incubated at 27°C than the combination of irradiation with KCl or MgC1₂ (40, 9, and 4 days, respectively, when treated with 1 Mrad). Phosphate addition revealed that 0.4% sodium acid pyrophosphate addition was the most inhibitory for botulinal toxin production followed by hexametaphosphate and tripolyphosphate addition.     

Effect of Phosphate Type and Concentration, Salt Level and Method of Preparation on Binding in Restructured Beef Rolls

The effect of combinations of phosphate type [tetrasodium pyrophosphate (PP), sodium tripolyphosphate (TPP), sodium tetrapolyphosphate (TTPP), and sodium-hexametaphosphate(HMP)], phosohate concentration (0.125%-0.500%). and salt level (0.6%-2.0%) on the binding in restructured beef rolls was studied. The rolls were prepared either with or without a homogenate that contained all the added salts. Preparation method had little effect on binding. The effectiveness of the phosphates was: PP > TPP > TTPP > HMP. Changes in binding produced by varying phosphate type, phosphate concentration and salt level could be explained in terms of changes in ionic strength and pH. Between 90% and 96% of the variation in binding could be explained in terms of these two variables.     

Inhibition of Clostridium perfringens Spore Germination and Outgrowth by Lemon Juice and Vinegar Product in Reduced NaCl Roast Beef

Abstract: Inhibition of Clostridium perfringens spore germination and outgrowth in reduced sodium roast beef by a blend of buffered lemon juice concentrate and vinegar (MoStatin LV1) during abusive exponential cooling was evaluated. Roast beef containing salt (NaCl; 1%, 1.5%, or 2%, w/w), blend of sodium pyro‐ and poly‐phosphates (0.3%), and MoStatin LV1 (0%, 2%, or 2.5%) was inoculated with a 3‐strain C. perfringens spore cocktail to achieve final spore population of 2.5 to 3.0 log CFU/g. The inoculated products were heat treated and cooled exponentially from 54.4 to 4.4 °C within 6.5, 9, 12, 15, 18, or 21 h. Cooling of roast beef (2.0% NaCl) within 6.5 and 9 h resulted in <1.0 log CFU/g increase in C. perfringens spore germination and outgrowth, whereas reducing the salt concentration to 1.5% and 1.0% resulted in >1.0 log CFU/g increase for cooling times longer than 9 h (1.1 and 2.2 log CFU/g, respectively). Incorporation of MoStatin LV1 into the roast beef formulation minimized the C. perfringens spore germination and outgrowth to <1.0 log CFU/g, regardless of the salt concentration and the cooling time. Practical Application: Cooked, ready‐to‐eat meat products should be cooled rapidly to reduce the risk of Clostridium perfringens spore germination and outgrowth. Meat processors are reducing the sodium chloride content of the processed meats as a consequence of the dietary recommendations. Sodium chloride reduces the risk of C. perfringens spore germination and outgrowth in meat products. Antimicrobials that contribute minimally to the sodium content of the product should be incorporated into processed meats to assure food safety. Buffered lemon juice and vinegar can be incorporated into meat product formulations to reduce the risk of C. perfringens spore germination and outgrowth during abusive cooling.     

Effects of Varying Levels of Chloride Salts on Clostridium Botulinum Toxin Production in Turkey Frankfurters

Inhibitory effects of sodium chloride (NaCl), potassium chloride (KCl), and magnesium chloride (MgCl₂) on C. botulinum inoculated turkey frankfurter emulsions were determined. Ionic strengths (I.S.) of 0.42, 0.55, and 0.68 were compared (equivalent to 2.5%, 3.25%, and 4.0% NaCl). Sodium nitrite levels were constant at 150 ppm. Inoculated emulsions (10³ spores/g) were incubated and maintained at 27°C. In-creasing NaCl from I.S. 0.42 to 0.68 delayed toxin production from 4 days to at least 40 days. KCl was almost as effective as NaCl at I.S. 0.42, but inferior at higher levels. MgCl₂ did not demonstrate any inhibitory effect. Fifty percent substitution of 2.5% NaCl with KCl or MgCl₂ generally reduced time for toxin production to occur.     

Protein Extraction From Chicken Myofibrils Irrigated with Various Polyphosphate and NaCl Solutions

Physical changes in chicken gastrocnemius myofibrils incubated in 0.1 to 1.0 M NaCl solutions with or without 10 mM ortho-(P), pyro-(PP), tripoly-(TPP) or hexameta- (HMP) phosphate at pH 6.0 were examined by phase-contrast microscopy, electrophoresis, and solubility. PP and TPP performed similarly in promoting protein extraction, P had no apparent effect, and HMP exhibited an intermediate effect. PP, TPP, and HMP treatments markedly improved protein solubility in 0.3 and 0.4 M NaCl through the release of myosin, but the phosphate effect diminished in ≥ 0.6 M NaCl. Overall, phosphates influenced the ultrastructure of myofibrils and extraction of their constituents in the order: PP ∼ TPP > HMP > P ∼ nonphosphate control.     

Low dose gamma irradiation effects on Clostridium botulinum inoculated turkey frankfurters containing various sodium chloride levels

Low dose gamma irradiation (0, 0·5 and 1·0 Mrad) at two irradiation temperatures (+ 1°C and −30°C) of turkey frankfurters containing various levels of sodium chloride (NaCl; 3·25%, 2·5% or 1·5%) or 1·5% NaCl plus 0·4% sodium tripolyphosphate (TPP) was evaluated for its effect on C. botulinum toxin production in frankfurters held at 27°C. A radiation dose of 0·5 Mrad or greater was sufficient to inhibit botulinal toxin production for 40 days in inoculated frankfurters containing 2·5% or greater concentrations of NaCl, regardless of the irradiation temperature. Neither 0·5 Mrad nor 1·0 Mrad inhibited toxin production in products containing 1·5% NaCl with or without TPP. NaCl should be reduced in processed meats with care; gamma radiation treatments cannot totally compensate for NaCl reduction.     

Effect of Sodium Acid Pyrophosphate and/or Potassium Sorbate on Staphylococcus aureus FRI-100 Growth and Toxin Production

The effect of food-grade sodium acid pyrophosphate (SAPP) alone or in combination with potassium sorbate (PS) on growth and toxin production by an enterotoxin A producing strain of Staphylococcus aureus was investigated. Growth of cultures was monitored by absorbancy readings (640 nm) at 5-hr intervals. Toxin production was determined by an Enzyme Linked Immunosorbent Assay (ELISA). SAPP (0.04%) in combination with PS (0.26%) was the most favorable treatment for inhibition of S. aureus growth. Concentration of toxin correlated with amount of growth in all treatments studied.     

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.     

Phosphates and antioxidants as cryoprotectants in meat batters

The gelation and rheological properties of minced beef frozen and stored at -18°C for 6 months without additives, with salt (1·5% NaCl), tripolyphosphate (TPP 0·5%), sodium acid pyrophosphate (SAPP 0·5%) and an antioxidant mix (BHA + BHT, 200 ppm) were studied. The relationships between shear rate and shear stress for the different treatments were nonlinear and resembled the Bingham pseudoplastic behaviour. Continuous evaluation of the modulus of rigidity (G) during cooking (0·5°C/min) revealed higher G values for the unfrozen phosphate treatments. Salt addition resulted in significantly lower G values of the stored meat compared to the control. Antioxidant addition retarded some of these effects. Among the phosphates, TPP was the best in maintaining the same G values as the control. Water-holding capacity (after salt addition) was increased after phosphate addition in the unfrozen meat and did not change after storage. The control, NaCl and antioxidant treatments showed an increase in WHC during storage.     

Inhibition of Clostridium botulinum Growth from Spore Inocula in Media Containing Sodium Acid Pyrophosphate and Potassium Sorbate with or without added Sodium Chloride

The effects of sodium acid pyrophosphate (SAPP), sodium chloride (NaCl) and/or potassium sorbate (PS) on the growth from heat-activated spores of three individual strains or a mixture of ten strains of Clostridium botulinum in peptone-yeast extract-glucose broth at pH 5.55 or 5.85 were measured spectrophotometricalty at A_630nm. Growth ratios (GR = treatment/control) based on time to reach A₆₃₀= 0.35 or 0.04 were calculated and used to compare effects of additives on strains. SAPP, NaCl, PS, and pH exhibited independent significant main effects (p≦0.01) on delaying growth in most C. botulinum strains tested. Combinations of additives without NaCl consistently caused an increase in the GR and an increase in organism sensitivity to additives in the medium. Treatments containing SAPP (0.2 or 0.4%) and PS (0.13 or 0.26%) were more effective for delaying growth than other formulations tested.     

Effect of the combination of various NaCl levels and soy protein isolate on the quality characteristics of smoked pork loins

The objectives of this study were to evaluate the physicochemical, textural and sensory properties of smoked pork loins (PL) containing various levels of NaCl (0.0–2.0%) alone or in combination with soy protein isolates (SPI; 1.0%). The pH values, moisture, fat, and protein contents (%) of smoked PL were 5.97–6.17, 63.3–69.1%, 2.64–4.26%, and 20.2–26.6%, respectively. Increased NaCl levels increased moisture contents (%) and sensory scores, as well as reduced Hunter redness and yellowness and cooking loss (CL, %) (P < 0.05). A NaCl level of 1.0% had resulted in a CL (%) level similar to those at regular‐salt levels (1.5% and 2.0% NaCl). When 1.0% SPI was incorporated with smoked PL, the NaCl level of 0.5% was also similar to the CL (%) at higher NaCl levels and improved sensory scores. Thus, a NaCl level of at least 1.0% was required for the manufacture of smoked PL; however, smoked PL could be manufactured with 0.5% salt when 1.0% SPI was included as part of the manufacture of smoked PL to effect quality characteristics similar to those achieved with regular‐salt (1.5% and 2.0% NaCl) smoked PL.     

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.     

Effects of Salt Levels in Prerigor Blends and Cooked Sausages on Water Binding, Released Fat and pH

Prerigor pork was used to make preblends of 0, 1, 2, 3 or 4% salt and 125 ppm sodium nitrite. Sausages formulated with 1.5 or 2.0% salt were made from all preblends; sausages formulated with 1.0% salt were made from preblends of 0, 1, 2 and 3% salt. Sausages made with nonsalted preblends had less water binding capacity (WBC) and more released fat (RF) than sausages made with preblends of 2, 3, or 4% salt (P < 0.05). Levels of salt in preblends did not affect (P > 0.05) WBC when salt contents of sausages were reduced from 2.0 to 1.5%; however, these WBC values were lowered somewhat when preblends with 0 or 1.0% salt were used. Water binding capacity decreased (P < 0.05) when salt contents of sausages were reduced from 1.5 to 1.0%, and when these sausages were made with preblends containing 2.0 or 3.0% salt. Data suggest that salting of prerigor pork is beneficial for optimizing WBC in sausages made with low salt contents.     

Effects of Reduced Salt (NaCI) Levels on Sensory and Instrumental Evaluation of Frankfurters

Frankfurters were manufactured with beef-pork mixtures using commercial procedures and varying levels (2.5%, 2.0%, 1.5%, 1.0%) of two types of NaCl (granulated, flake). Parameters investigated were sensory color, texture, flavor and overall acceptability, and instrumental texture and color during storage at 8°C. Sensory scores for color were acceptable and similar among treatments with varying salt levels, except for products with 1.0% salt. As emulsion stability decreased, however, frankfurter skin color became darker. In general, a reduction in salt by more than 20% (<2.0% salt) resulted in frankfurters of softer and less firm texture. Scores for flavor and overall acceptability were lower (P<0.05) for frankfurters with 1.5% or 1.0% vs 2.5% salt and deteriorated with increasing storage for all salt treatments. Flavor deterioration with storage was more pronounced in products with reduced salt levels (1.5% and 1.0%).     

Characterization of starter-free Queso Fresco made with sodium-potassium salt blends over 12 weeks of 4°C storage

Development of reduced-sodium cheese to meet the demands of consumers concerned about sodium levels in their diet is challenging when a high-moisture, higher pH, fresh cheese, such as Queso Fresco (QF), depends on its NaCl salt content to obtain its signature flavor and quality traits. This study evaluated the effects of different Na-K salt blends on the compositional, sensorial, microbial, functional, and rheological properties of QF stored for up to 12 wk at 4°C. Queso Fresco curd from each vat was divided into 6 portions and salted with different blends of NaCl-KCl (Na-K, %): 0.75-0.75, 1.0-0.5, 1.0-1.0, 1.0-1.3, 1.0-1.5, and 2.0-0 (control). Within this narrow salt range (1.5 to 2.5% total salt), the moisture, protein, fat, and lactose levels; water activity; pH; and the textural and rheological properties were not affected by salt treatment or aging. The total salt, sodium, potassium, and ash contents reflected the different Na-K ratios added to the QF. Total aerobic microbial count, overall proteolysis, the release of casein phosphopeptides, and the level of volatile compounds were affected by aging but not by the salt treatment. Only the 1.0-1.3 and 1.0-1.5 Na-K cheeses had sensory saltiness scores similar to that of the 2.0-0 Na-K control QF. Loss of free serum from the cheese matrix increased steadily over the 12 wk, with higher losses found in QF containing 1.5% total salt compared with the higher Na-K blends. In conclusion, KCl substitution is a viable means for reduction of sodium in QF resulting in only minor differences in the quality traits, and levels of 1.0-1.3 and 1.0-1.5 Na-K are recommended to match the saltiness intensity of the 2.0-0 Na-K control. The findings from this study will aid cheese producers in creating reduced-sodium QF for health-conscious consumers.     

Resistance of Microencapsulated <Emphasis Type="Italic">Lactobacillus acidophilus</Emphasis> LA1 to Processing Treatments and Simulated Gut Conditions

This investigation reports the effect of microencapsulation using sodium alginate and starch on the tolerance of probiotic Lactobacillus acidophilus LA1 to selected processing conditions and simulated gastrointestinal environments. The organism survived better in the protected form at high temperatures (72, 85, and 90 °C) and at high salt concentrations (1%, 1.5%, and 2%). The free cells were completely destroyed at 90 °C whereas the microencapsulated cells reduced by 4.14 log cycles. The log cycle reduction was 5.67 and 2.30, respectively, in free and protected cells when incubated for 3 h with 2% (w/v) NaCl. Homogenization did not affect the viability of the cells but led to the disruption of the protective encapsulating material around the cells. Microencapsulation provided better protection at simulated conditions of gastric pH (1.0, 1.5, and 2.0) and at high bile salt concentrations (1.0%, 1.5%, and 2.0%). The free and protected cells registered 5.47 and 2.16 log cycle reduction, respectively, after 3-h incubation at 2% bile salt (w/v). The release of the microencapsulated organisms in simulated colonic pH required 2.5 h. These studies demonstrated that microencapsulation of probiotic L. acidophilus LA1 in sodium alginate is an effective technique of protection against extreme processing conditions and under simulated gastrointestinal environment.     

Effect of the Parabens With and Without Nitrite on Clostridium botulinum and Toxin Production in Canned Pork Slurry

Antimiciobials were evaluated in thioglycollate broth at pH 6.5 for the ability to inhibit growth and toxin production by C. botulinum 12885A and ATCC 7949 (Type B). Methyl, ethyl, propyl, and butyl parabens (0.1%) and sorbic acid (0.2%) were effective in inhibiting growth of C. botulinum 12885A and ATCC 7949 in broth. Ethyl, propyl, and butyl parabens (0.1%) and sorbic acid (0.2%) inhibited toxin production by both strains in culture medium. Ethyl, propyl, butyl parabens (0.1%) and sorbic acid (0.2%) were individually added to a comminuted pork slurry having salt and sugar, with or without 40 ppm sodium nitrite. Cans were inoculated with a mixture of C. botulinum 12885A and ATCC 7949 spores. The canned product was abused by holding at 27°C and was observed over a 3-month period for swollen cans. Swollen cans were examined for botulinal toxin by the mouse bioassay. Propyl and butyl paraben did not inhibit or delay toxin production. Ethyl paraben with or without nitrite delayed toxin production for 4 wk. Sorbic acid inhibited toxin for 3 wk; when 40 ppm nitrite was added to the sorbic acid treatment, toxin production was delayed for 4 wk.