Effects of lactic and acetic acid salts on quality characteristics of enhanced pork during retail display

The objective of this study was to evaluate the sensory and physical characteristics of pork chops from loins enhanced to 110% of original weight with either (1) potassium lactate, potassium diacetate, phosphate and salt, (2) sodium lactate, phosphate and salt, (3) potassium lactate, phosphate and salt, (4) sodium acetate, phosphate and salt, or (5) phosphate and salt. A trained sensory panel evaluated pork flavor, saltiness, bitterness, soapy flavor, acid flavor, juiciness and tenderness of cooked chops. Visual color of raw chops was also evaluated. After 96 h in display, chops enhanced with lactate/diacetate had significantly lower (P<0.01) aerobic plate counts than control (unpumped) chops, or those pumped with other solutions. Lactate/diacetate-enhanced chops maintained higher a* and b* values during display, and had less visual discoloration after 96 h display. Chops pumped with lactate, acetate or the lactate/diacetate mixture were more tender and juicy, and had more pork flavor than controls or those pumped with phosphate/salt only. There appears to be a significant advantage to using a lactate/diacetate enhancement solution over either lactate or acetate alone.     

PHYSICAL AND SENSORY CHARACTERISTICS OF PRECOOKED, REHEATED PORK CHOPS WITH ENHANCEMENT SOLUTIONS

Pork loins were pumped to 110% of original weight with solutions containing 0.35% salt and 0.35% phosphate (P), salt and phosphate plus 3% sodium lactate (SL), or salt and phosphate plus 2.5% potassium lactate/potassium acetate (PL/PA). Chops were evaluated freshly cooked and precooked, stored (4C, 2 days) and reheated. Chops from SL and PL/PA chops experienced lower cook losses than unpumped controls. Reheating produced additional cook losses which were unaffected by enhancement treatment. Enhancement produced reheated chops with lower shear values and higher tenderness scores than those of freshly cooked controls, and addition of either SL or PL/PA produced even more dramatic results. Warmed-over flavor after reheating precooked chops was reduced by the SL enhancement solution.     

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

Microbiological 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<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<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.     

Shelf life characteristics of enhanced modified atmosphere packaged pork

The objective of these studies was to identify a chemical indicator for predicting performance of enhanced pork during storage, then select raw materials with the potential for color and shelf life instability and enhance them with antimicrobial solutions in an attempt to overcome their initial deficits. The purpose of Study 1 was to evaluate the use of pH, glycolytic potential, and glucose levels in the drip to assess shelf life characteristics of modified atmosphere packaged (MAP), enhanced pork loin chops during display. Chops from higher pH carcasses had higher color scores and aerobic plate counts, and less discoloration. Study 2 evaluated shelf life characteristics of chops derived from high pH (>5.75) raw materials enhanced with solutions containing salt and phosphate, and/or lactate and/or acetate. Overall, pH was the best indicator of color and microbiological stability. Raw materials with high ultimate pH were least stable. MAP chops derived from high pH raw materials and enhanced with a sodium acetate-containing solutions had better color and microbiological shelf life than those enhanced with other solutions.     

Effect of carbon monoxide and high oxygen modified atmosphere packaging and phosphate enhanced, case-ready pork chops

The objective of this study was to evaluate the effects of CO-MAP compared to traditional high oxygen MAP (HiOx-MAP) packaging and enhanced with different phosphate on enhanced pork quality. Pork loins were enhanced to 10.5% over initial weight to contain 0.3% salt and 0.4% phosphate (either sodium tripolyphosphate [STP] or a blend of STP and sodium hexametaphosphate) on a finished weight basis. Chops were cut, packaged in atmospheres containing 0.4% CO/30.0% CO₂/69.6% N₂ (CO-MAP) or 80% O₂/20% CO₂ (HiOx-MAP), aged in the dark, then placed in a lighted retail display case for 48 h. Chops packaged in CO-MAP were redder (higher Minolta a^* values) and darker (lower Minolta b^* values) than chops packaged in HiOx-MAP. Based on sensory scores, the CO-MAP chops were pinker than the HiOx chops after cooking. CO-MAP chops also experienced less purge loss than chops in HiOx-MAP. Results indicate that CO-MAP had no effect on flavor or consumer acceptability and only minimal effects on other characteristics.     

EFFECT OF RN GENOTYPE ON YIELD AND SENSORY CHARACTERISTICS OF ENHANCED LONGISSIMUS SECTIONS

Pumping treatments with water or 4.5% sodium tripolyphosphate (STP) were evaluated on the fresh longissimus from pigs of different Rendement Napole genotypes. The longissimus muscle (32 RN/rn, 32 rn⁺/rn⁺) was divided into 3 sections and allocated to the: nonpumped, water pumped, and 4.5% STP, treatments. Following aging (14 days) chops were cut, packaged, and frozen. Boneless loin chops were cooked to internal temperatures of either 70C or 80C. Nonpumped loins resulted in the least amount of purge loss, whereas STP loins had the highest raw yield. Pumping loin sections with water and STP increased raw and cooked moisture contents. Pumping with STP increased juiciness and tenderness ratings. Increasing the endpoint temperature decreased juiciness and cooked moisture percentage. Pork from RN/rn⁺ pigs had lower shear force and higher tenderness and juiciness. These data indicate that increasing end point cooking temperature reduced pork palatability while STP pumping and the RN gene improved sensory properties.     

THE EFFECT OF OXYGEN SCAVENGERS ON THE COLOR STABILITY AND SHELF-LIFE OF CO, MASTER PACKAGED PORK

Pork chops were stored with and without O₂ scavengers in a modified atmosphere (50% CO₂/50% N, or 100% CO₂) master pack system at 0C for up to 21 days, At 7-day intervals, the chops were displayed at ca. 4.5C for 96 h. Color (L, a, b, hue and chroma); panelist assessments of color and odor; and drip losses were recorded. Oxygen scavengers reduced O₂ levels, resulting in chops that were generally as red as flesh, but tended to have higher hue angles at 0 h, and towards the end of display (P<0.05). Visually, chops packaged in 50% CO₂/50% N₂ were less acceptable than flesh (P<0.05). There were no odor differences between flesh and packaged chops. Fresh chops had lower drip losses than packaged (P<0.05). An acceptable display life was obtained for pork chops stored for up to 21 days in a modified atmosphere CO₂ master pack containing O₂ scavengers.     

Chemical, Microbiological, and Sensory Quality of Cod Products Salted in Different Brines

ABSTRACT: Studies were carried out on the effect of different brines containing high concentrations of calcium chloride (CaCl₂, 0.8%w/w), magnesium chloride (MgCl₂, 0.4%w/w), and potassium chloride (KCl, 50%) on the chemical (chloride and moisture contents), microbial (total viable counts, total coliforms, enterococci, and staphylococci), and sensory quality of salted cod. The brines were prepared from combinations of the Ca, Mg, and K ions and sodium chloride (NaCl) at pH 6.5 and 8.5. Additionally, 3 salts (one composed solely of NaCl, another commercial sea salt from the southern Europe and, finally, a natural salt from northern Europe) were also tested. Principal component analysis structured the chemical and microbiology data in 3 clusters: (1) an extreme cluster, formed by cod brined in the commercial sea salt, which achieved the highest microbiological counts, namely 4.1 log CFU/g on plate count agar (PCA) and 1250 coliforms/g; (2) an intermediate cluster composed of cod salted in brine containing 50% NaCl, 0.4% MgCl₂, and 49.6% KCl (pH 6.5); and (3) a central cluster, including all the other treatments, which presented the lowest microbiological counts, namely 2.4 log CFU/g on PCA and 20 coliforms/g. Although the batches of the intermediate cluster presented slightly higher total viable and staphylococci counts than the central cluster, the presence of Mg and K ions improved the color of the salted product. In the assayed concentrations, CaCl₂, MgCl₂, and KCl can be used in the brining of cod without adversely affecting the microbiological and sensory quality of the salted cod.     

Effects of Anions and Cations on Sugar Utilization in Cucumber Juice Fermentation

ABSTRACT: :
The extent of glucose and fructose utilization during cucumber juice fermentation was affected differentially by the addition of 10 to 360 mM of selected anions (chloride, nitrate, sulfate, phosphate, acetate, lactate, and citrate) and cations (Na⁺, K⁺, NH₄⁺, Ca²⁺, Mg²⁺, and Mn²⁺). Inorganic anions generally suppressed utilization of both sugars, particularly at higher concentrations. Acetate and lactate increased utilization of fructose, but not glucose, while citrate increased utilization of both sugars. Of the cations tested, 10-60 mM Mn⁺² significantly (P < 0.05) increased utilization of both sugars, but higher concentrations reduced utilization, as compared with the control. Evidence indicates that brine composition can significantly influence sugar utilization during cucumber fermentation, and may be important in developing controlled fermentation strategies for brined cucumbers.     

Effects of calcium salts on beef longissimus quality

The objective of this research was to evaluate the effects of injection marination with calcium salts on beef longissimus quality traits. Strip loins were injected (11% by weight) with distilled water or a 0.1, 0.2, or 0.3 M solution of calcium ascorbate, calcium chloride, or calcium lactate. Non-injected loins served as controls. Visual and instrumental color evaluations indicated that calcium ascorbate accelerated myoglobin oxidation, and increasing molar concentration of any calcium salt caused faster (P<0.05) discoloration. Aerobic microbial plate counts were lower (P<0.05) for treatments containing calcium lactate than those with calcium chloride or calcium ascorbate. Calcium ascorbate inhibited lipid oxidation whereas calcium lactate and calcium chloride appeared to be pro-oxidants of lipid oxidation. No differences for Warner-Bratzler shear force or sensory panel tenderness were found among the calcium salts; however, 0.3 M treatments had lower shear values and were judged more tender than 0.1 M treatments. Calcium ascorbate and calcium chloride treatments resulted in less (P<0.05) beef flavor and more (P<0.05) off-flavors than calcium lactate treatments. In addition, 0.1 M treatments had higher (P<0.05) beef flavor scores while 0.3 M treatments had higher (P<0.05) off-flavor scores. Considering the effects on color life, microbial inhibition, shear force, and sensory traits, we recommend injecting beef longissimus with a 0.1 M solution of calcium lactate to enhance both uncooked and cooked quality.     

Effects of Low-dose Gamma Irradiation on the Shelf Life and Quality Characteristics of Cut Romaine Lettuce Packaged under Modified Atmosphere

Cut romaine lettuce, packaged under modified atmosphere, was subjected to 0.15 and 0.35 kGy gamma irradiation. Irradiation at 0.35 kGy decreased aerobic plate counts by 1.5 logs and yeast and mold counts by 1 log; these differences were maintained through the 22-d storage. Irradiation at 0.15 kGy caused smaller reductions in microbial counts. A decrease in headspace CO₂ was observed in the 0.35-kGy-treated lettuce, although CO₂ concentrations increased in all samples with storage. O₂ concentration was not affected by irradiation. Ten percent loss in firmness was observed at 0.35 kGy, while other sensory attributes such as color, generation of off-flavor, and appearance of visual defects were not affected.     

Potassium acetate and potassium lactate enhance the microbiological and physical properties of marinated catfish fillets

Sodium or potassium salts such as lactate and acetate can be used to inhibit the growth of spoilage bacteria and food-borne pathogens, and thereby prolong the shelf-life of refrigerated seafood. However, minimal information is available regarding the combined effects of potassium salts (acetate and lactate) with an agglomerated phosphate blend on the quality and safety of refrigerated catfish fillets. The objective of this study was to determine the microbiological and quality characteristics of marinated catfish fillets treated with organic acid salts. Catfish fillets were vacuum-tumbled with a brine solution with and without the added organic acid salts, at 10% over initial, raw weight prior to tray-packing and storage at 4 °C for 14 d. Fillets were evaluated for yields, color, pH, tenderness, consumer acceptability, and shelf-life. No differences (P > 0.05) existed among the treated and untreated fillets with regards to solution pick-up and pH, but all treated fillets increased (P < 0.05) cooking yields and Intl. Commission on Illumination (CIE) a* values, and decreased (P < 0.05) CIE L* and b* values in the catfish fillets when compared to the untreated fillets. The fillets treated with a combination of potassium acetate and potassium lactate had lower (P < 0.05) psychrotrophic plate counts and lower spoilage scores than the control treatments on days 7, 10, and 14. In addition, consumers preferred (P < 0.05) treated catfish fillets (fried) with respect to appearance, flavor, and overall acceptability over the negative control. In conclusion, the combination of potassium acetate and potassium lactate enhanced sensory quality and extended the shelf-life of refrigerated catfish fillets.     

Effects of Low-dose Gamma Irradiation and Conventional Treatments on Shelf Life and Quality Characteristics of Diced Celery

ABSTRACT: The effects of 0.5 and 1.0 kGy gamma irradiation on microbial and sensory characteristics of diced celery were compared to conventional treatments such as acidification, blanching, and chlorination. Aerobic plate counts for the irradiated celery did not exceed 10⁷ CFU/g, in contrast, the acidified, blanched, chlorinated, and control samples surpassed aerobic microbial counts of 10⁸ CFU/g in 22, 19, 12, and 8 d, respectively. Importantly, the 1.0-kGy treatment eliminated inoculated Listeria monocytogenes and E. coli. While the acidified and blanched samples had significantly different sensory profiles compared to the other treatments, the irradiated samples maintained their color, texture, and aroma longer and were preferred in the sensory tests. The sensory shelf life of the 1.0-kGy-treated celery was 29 d compared to 22 d for the control, chlorinated, and 0.5 kGy, and 15 d for the acidified and blanched celery.     

Effects of Shelf-Life Enhancers on E. coli K12 Survival in Solutions Used to Enhance Beef Strip Steaks

ABSTRACT:  The objective of this study was to evaluate the effects of enhancement solutions containing sodium lactate or sodium lactate/sodium diacetate on E. coli K12 transmission to beef strip steaks and in purge. Solutions containing salt, phosphate, and shelf-life enhancers were injected to 10% over initial weight of the steaks. Lactate or lactate/diacetate addition to a solution inoculated with 6 log₁₀ E. coli K12 CFU/mL was equally effective in limiting growth resulting in a 1-2 log₁₀ CFU/g reduction when compared to salt/phosphate in steaks. When inoculation level was 3 log₁₀ CFU/mL in the enhancement solution, microbial growth was detectable only in the purge of steaks enhanced with salt/phosphate only. Lactate increased CIE L* value and b* and decreased a* values when compared to the control. Lactate-/diacetate-containing solutions decreased L* values when compared to lactate alone. Lactate/diacetate also reduced purge loss from steaks compared to lactate and salt/phosphate solutions.     

Electrodialysis Desalination of Fish Sauce: Electrodialysis Performance and Product Quality

ABSTRACT:  Fish sauce has a unique, pleasant flavor, but contains high levels of sodium chloride, which is nowadays not desirable for health-conscious consumers. Although many researchers have attempted to solve this problem by substituting sodium with potassium in fish sauce, potassium-based products are still unsuitable for patients with kidney disease. Thus, electrodialysis (ED) desalination of fish sauce was carried out. The rate of salt removal, evolution of total soluble solids, and electrical conductivity of the electrodialysis-treated fish sauce were investigated. Moreover, the system performance in terms of yield, energy consumption, and current efficiency were examined. Density, viscosity, ion concentrations (that is, Na⁺, K⁺), total nitrogen, amino nitrogen, and color were investigated at various values of input voltage (6, 7, and 8 V) and remaining salt concentration (22%, 18%, 14%, 10%, 6%, and 2%[w/w]). The results indicated that an increase in the input voltage led to an increase in the rates of salt removal, electrical conductivity, and total soluble solids. The energy consumption increased whereas current efficiency and yield decreased significantly with an increase in input voltage and the salt removal level. Physicochemical properties of the treated fish sauce, in terms of the total soluble solids, density, viscosity, ion concentrations (that is, Na⁺, K⁺), total nitrogen, and color were significantly affected by the input voltage and the salt-removal level.     

CHANGES ON BEEF ADIPOSE TISSUE FOLLOWING DECONTAMINATION WITH CHEMICAL SOLUTIONS OR WATER OF 35C OR 74C

Spray-washing reduced aerobic plate counts (APC) by 0.88 to 2.83 log colony forming units (CFU)/cm², with hot water (74C) being the most effective treatment. Counts exceeded 6 log CFU/cm² in 1–3, 7–11, 11–16, 16–23 and 23–29 days of storage for unwashed, washed with hydrogen peroxide, washed with 35C water or ozonated water or trimmed/washed with 35C water, washed with commercial sanitizer, and washed with trisodium phosphate, respectively. Samples washed with acetic acid or water of 74C reached only 4.31 and 4.36 log CFU/cm², respectively, at 29 days of storage. Increases in the concentration of thiobarbituric acid reactive-substances (TBARS) were slowest in samples washed with trisodium phosphate. Spray-washing with 2% acetic acid or 74C water were the most effective treatments for reducing microbial growth, followed by trisodium phosphate which also reduced lipid oxidation during storage of beef.     

DISPLAY LIFE OF FRESH BEEF CONTAINING DIFFERENT LEVELS OF VITAMIN E AND INITIAL MICROBIAL CONTAMINATION

Strip loins from beef cattle fed diets supplemented or not supplemented with α-tocopheryl acetate (vitamin E; 500 IU·animal⁻¹·d^-1) were fabricated into steaks inoculated at three initial levels (1.7 to 1.9; 2.3 to 2.5; 6.4 to 7.1 log CFU/cm²) of bacterial contamination (from over aged retail steaks) and evaluated for psychrotrophic plate counts (PPC), overall appearance and color during 6 days of simulated retail display (0 to 4C). Initial contamination affected changes in PPC (P < 0.05) during display, while the highest level of initial contamination eliminated benefits of high vitamin E concentrations on product color within 4 days of retail display. However, increased vitamin E concentrations in steaks were associated with higher (P < 0.05) CIE a* values appearance scores when the level of initial contamination was less than 2.5 CFU/cm². Results indicated that vitamin E supplementation does not mask high levels of bacterial contamination.     

Strategies to eliminate atypical aromas and flavors in sow loins-part II: consumer acceptance of loins marinated with sodium tripolyphosphate and sodium bicarbonate

An identified challenge in using sow loins as a raw material for value added enhanced whole muscle products is to eliminate or minimize objectionable atypical aromas and flavors (“sow taint,” ST) that may occur in some sow carcasses. The objective of this study was to determine consumer acceptance of sow loins exhibiting atypical aromas and flavors marinated with a solution of salt, sodium tripolyphosphate and sodium bicarbonate. Sow loins (N=34) with atypical aromas and flavors and commodity loins (N=6) were fabricated into anterior and posterior loin sections and marinated with one of four ST marinade treatment combinations (15% pump, 0.5% PO₄, 0.70 M NaHCO₃; 15% pump, 0.25% PO₄, 0.70 M NaHCO₃; 15% pump, 0.25% PO₄, 0.35 M NaHCO₃; and 15% pump, 0.25% PO₄, 0.35 M NaHCO₃), or a control marinade (0.25% sodium tripolyphosphate, 15% injection level) and evaluated by a consumer sensory panel. Sensory ratings determined that ST loin chops injected with a 15% solution of sodium tripolyphosphate (0.50%) and sodium bicarbonate (0.35 M) were not different (P>0.05) than loin chops from marinated commodity control loin sections (N=12) for flavor, texture, juiciness, and overall acceptability. These results indicate that a solution containing sodium tripolyphosphate and sodium bicarbonate minimized the detection of atypical aromas and flavors in sow loins.     

Effects of meat piece size and phosphate on maximum slicing rate, cooking loss and sensory quality of a re-formed pigmeat shoulder product

Summary Two pre-tumbling treatment variables (meat piece size; raw product phosphate content) were evaluated for their effects on maximum slicing rate (MSR), cooking loss and sensory quality of a commercially produced, cooked re-formed pigmeat shoulder product. At 0.457% phosphate, incremental reductions in meat piece size which increased specific surface from 0.60 to 0.93 cm² cm⁻³ enabled MSR to increase from 300 to 400 slices min⁻¹, reduced cooking losses from 0.875 to 0.60% and gave a more tender product. At 0.60 cm² cm⁻³ specific surface, increasing phosphate incrementally from 0.457 to 0.532% produced similar positive effects on MSR and cooking loss but at phosphate above 0.482% sensory quality declined. Combination of optimal specific surface (0.93 cm² cm⁻³) and phosphate (0.482%) permitted a MSR of 420 slices min⁻¹, reduced cooking loss to 0.50% and gave an acceptable product. These process modifications can thus be advocated for improved production rate, yield and sensory quality.     

Effect of irradiation and modified atmosphere packaging on the microbiological and sensory quality of pork stored at refrigeration temperatures

The effect of combining low-dose irradiation (1.75 kGy) with modified atmosphere packaging (MAP) on the microbiological and sensory quality of pork chops stored at refrigeration temperatures was studied. The microflora of irradiated MAP pork was almost exclusively composed of lactic acid bacteria, predominantly Lactobacillus spp. Modified atmospheres containing either 25 or 50% CO₂, balance N₂, resulted in the best microbial control in irradiated pork held at 4°C, compared to an unirradiated MAP control, and these atmospheres were subsequently used in sensory studies. The atmosphere containing 25% CO₂ 75% N₂ maintained the uncooked colour and odour of irradiated pork chops more effectively than 50% CO₂ 50% N₂. Therefore packaging in a modified atmosphere containing 25% CO₂, balance N₂, followed by irradiation to a dose of 1.75 kGy is recommended to improve the microbiological and sensory quality of pork chops.