ObjectivesNumerous human clinical studies have demonstrated that dietary nitrate is a significant contributor to physiological nitric oxide and associated human health benefits. Consequently, cured meats could provide a vehicle for delivery of supplemental nitrate (SN) in human diets, but information on effects of high nitrate concentrations on product properties is needed. The objectives were to evaluate physical, chemical and microbial effects of SN in products with 220 mg nitrate per 112 g serving, similar to consumption of vegetables by combining conventional sodium nitrate with celery juice powder (CJP) containing additional nitrate.Materials and MethodsEffects of SN from CJP on residual nitrite, residual nitrate, rancidity (TBARS), microbial growth, color, sensory properties, and proximate composition of frankfurters, cotto salami and boneless ham during storage (1°C) were investigated. The products were assigned one of two replicated treatments: control (156 ppm sodium nitrite) or SN (156 ppm sodium nitrite, 1718 ppm sodium nitrate and 2% CJP). Trained 9-member sensory panel parameters and proximate composition were measured once for each replication. All other analytical measurements were conducted at regular intervals for 98 d. Statistical analysis was by SAS mixed procedure.ResultsResidual nitrite did not differ (P > 0.05) between treatments for salami and hams; however, frankfurter control (15.8 ppm) and SN (11.9 ppm) were different (P < 0.05). In all three products, SN treatment did not increase residual nitrite when compared to the controls. No changes (P > 0.05) in residual nitrate levels for any products were observed during storage. There was no effect (P > 0.05) on microbial growth. TBARS differed (P < 0.05) for salami control (0.47) and SN (0.37), and for frankfurter control (0.38) and SN (0.49), but not (P > 0.05) for hams. Hunter L-values for salami control (49.65) and SN (46.94) were different (P < 0.05), and Hunter a-values for ham control (8.59) and SN (7.92) also differed (P < 0.05). In addition, internal Hunter a-values for control frankfurters (10.62) differed (P < 0.05) from SN (10.11). None of the other physical, chemical or microbial measurements conducted were affected as a result of SN treatment. Sensory evaluations (15-cm line scale) were similar to instrumental color results for salami, frankfurters, and ham treatments in that frankfurter (9.33) and ham (9.86) controls received greater intensity of pink color scores than frankfurter (6.93) and ham (6.56) SN treatments. Panelists also determined that control salami (6.65) had a lighter visual appearance than SN (9.87). Frankfurters showed no differences for sensory panel odors or flavors; salami treatments resulted in some differences in aromas and flavors, while the greatest effect on aroma and flavor occurred with hams.ConclusionThe results showed that addition of SN did not alter most physical, chemical or microbial properties of cured meat products during refrigerated storage, but product-dependent sensory effects were observed. Therefore, cured meat products could serve as a viable dietary source of nitrate, but use of CJP to achieve nitrate concentration above that allowed for conventional nitrate will be product-dependent and determined by the products sensory profile.
Spoilage microflora present on vacuum packaged frankfurters is in most cases, result of post processing contamination, at the same time this is the primary cause of contamination with Listeria monocytogenes. Since spoilage organisms are present in the same environment as a pathogen, the aim was to determine their microbial interference. Approximately 100 CFU/cm2 of a five-strain mixture of L. monocytogenes was co inoculated onto frankfurters with different concentrations (103 and 106 CFU/cm2) of spoilage microflora (bacteria from genera Lactobacillus, Bacillus, Micrococcus, and Hafnia). The frankfurters were vacuum packaged and stored at 10?C for up to 48 days. The spoilage microflora that developed during storage consisted predominantly of lactic acid bacteria. The growth of mesophilic aerobic bacteria and LAB was very similar, with populations reaching 8.0 log CFU/cm2 within 24 days and final population of >9 log CFU/cm2 within 48 days. The presence of spoilage microflora extended the lag phase of L. monocytogenes until 24 days and significantly decreased pathogen level to 4 and 3 log CFU/cm2, in samples inoculated with initial concentration 103 CFU/cm2 and 106 CFU/cm2 of spoilage microflora, respectively. L. monocytogenes populations were significantly higher (P<0.05) in the reference sample (no spoilage microflora) and reached a maximum population of 5.9 log CFU/cm2 after 34 days. These results imply that competing microorganisms present on the processed meat may inhibit the growth of L. monocytogenes in the package.
Aims: To determine the irradiation dose necessary to reduce the populations of Bacillus anthracis spores in a dry medium in postal envelopes. Methods and Results: Bacillus anthracis Sterne 34F2 spores were dispersed in non-fat dry milk and then placed into standard business postal envelopes. The spores were treated with a sequence of irradiation doses to determine the decimal reduction value (D10) in kiloGrays (kGy). The average D10 value was 3·35 ± 0·02 kGy. Conclusions: An irradiation dose of 40·2 kGy would be required to result in a process equivalent to the thermal canning process (12 D10 reduction) to eliminate Clostridium botulinum spores. Significance and Impact of the Study: Irradiation is an effective means of reducing or eliminating B. anthracis spores in a dry medium in postal envelopes.
Abstract: Contamination of poultry with pathogenic bacteria contributes to human foodborne disease, causes damage to industry brand names, and has a significant economic impact on the food industry in the form of both damage to industry brand names and losses associated with recalls. Irradiation is a safe and effective means of decontaminating poultry products, but the maximum dose strengths allowed negatively impact poultry sensory quality characteristics. The 1st objective of this study was to investigate the potential interactive inhibitory effects of natural antimicrobials as components of a vacuum‐marination in addition to various dose levels of irradiation. Tartaric acid (TA) at 2 levels and grape seed (GS) and green tea (GT) extracts were combined, vacuum‐infused into chicken breast fillets, and irradiated at 1, 2, and 3 kGy by electron beam irradiation. The 2nd objective was to use a consumer test group to evaluate TA and plant extract infusion into chicken breast fillets with and without irradiation at 2 kGy on overall impression, flavor, texture, appearance, and tenderness. The results showed that samples vacuum‐infused with TA at 37.5 and 75.0 mM and irradiated at 1 kGy significantly reduced Listeria monocytogenes ( L.m .) levels by 2 and 3 log CFU/g compared to the control after 12 d of refrigerated storage. Vacuum‐infusion of TA at 37.5 and 75.0 mM at 2 and 3 kGy irradiation, reduced L.m. to near nondetectable levels. The addition of TA and GS and GT to chicken breast fillets with and without irradiation did not significantly impact consumer preference, tenderness, appearance, or flavor. The addition of tartaric acid and natural plant extracts to chicken marinades could contribute to the prevention of L.m. contamination.
ObjectivesNumerous human clinical studies have demonstrated that dietary nitrate is a significant contributor to physiological nitric oxide and associated human health benefits. Consequently, cured meats could provide a vehicle for delivery of supplemental nitrate (SN) in human diets, but information on effects of high nitrate concentrations on product properties is needed. The objectives were to evaluate physical, chemical and microbial effects of SN in products with 220 mg nitrate per 112 g serving, similar to consumption of vegetables by combining conventional sodium nitrate with celery juice powder (CJP) containing additional nitrate. Materials and MethodsEffects of SN from CJP on residual nitrite, residual nitrate, rancidity (TBARS), microbial growth, color, sensory properties, and proximate composition of frankfurters, cotto salami and boneless ham during storage (1°C) were investigated. The products were assigned one of two replicated treatments: control (156 ppm sodium nitrite) or SN (156 ppm sodium nitrite, 1718 ppm sodium nitrate and 2% CJP). Trained 9-member sensory panel parameters and proximate composition were measured once for each replication. All other analytical measurements were conducted at regular intervals for 98 d. Statistical analysis was by SAS mixed procedure. ResultsResidual nitrite did not differ (P > 0.05) between treatments for salami and hams; however, frankfurter control (15.8 ppm) and SN (11.9 ppm) were different (P 0.05) in residual nitrate levels for any products were observed during storage. There was no effect (P > 0.05) on microbial growth. TBARS differed (P 0.05) for hams. Hunter L-values for salami control (49.65) and SN (46.94) were different (P < 0.05), and Hunter a-values for ham control (8.59) and SN (7.92) also differed (P < 0.05). In addition, internal Hunter a-values for control frankfurters (10.62) differed (P < 0.05) from SN (10.11). None of the other physical, chemical or microbial measurements conducted were affected as a result of SN treatment. Sensory evaluations (15-cm line scale) were similar to instrumental color results for salami, frankfurters, and ham treatments in that frankfurter (9.33) and ham (9.86) controls received greater intensity of pink color scores than frankfurter (6.93) and ham (6.56) SN treatments. Panelists also determined that control salami (6.65) had a lighter visual appearance than SN (9.87). Frankfurters showed no differences for sensory panel odors or flavors; salami treatments resulted in some differences in aromas and flavors, while the greatest effect on aroma and flavor occurred with hams. ConclusionThe results showed that addition of SN did not alter most physical, chemical or microbial properties of cured meat products during refrigerated storage, but product-dependent sensory effects were observed. Therefore, cured meat products could serve as a viable dietary source of nitrate, but use of CJP to achieve nitrate concentration above that allowed for conventional nitrate will be product-dependent and determined by the products sensory profile.
