Turkey Ham Research Articles

Comparative assessment of plate count and PMA-qPCR methods for modeling the growth of lactic acid bacteria in smoked Turkey ham

This study compared the quantitative polymerase chain reaction (qPCR) method combined with propidium monoazide (PMA) and the plate count (PC) method, both combined with predictive modeling, to describe the behavior of lactic acid bacteria (LAB) in vacuum-packaged sliced smoked turkey ham (STH). The PMA-qPCR method does not allow the DNA amplification of died cells but allow the amplification of viable cells, including the non-culturable. The standard curves relating quantification cycle (Cq) and log10 CFU/g demonstrated good linearity (R2 > 0.95), evidencing its accuracy and reproducibility. These curves were used to quantify Leuconostoc mesenteroides and Weissella viridescens in artificially inoculated STH samples stored at different isothermal temperatures (8, 10, 12, 16 and 20 °C). Firstly, the PMA-qPCR and PC methods were compared, and the analysis demonstrated a good correlation (R2 = 0.99) and agreement between the results. However, the PC method underestimated the quantification of W. viridescens cells by 0.76 log10 CFU/g at 8 °C, suggesting bacterial stress at this temperature, which was not observed for L. mesenteroides. In terms of growth, the maximum specific growth rate increased with rising temperature for both LAB. Predictive modeling indicated that the growth of L. mesenteroides and W. viridescens at 8 °C suggests a shelf life of approximately 4.25 days for STH based on PC data, and 4.13 days based on PMA-qPCR data. In conclusion, the PMA-qPCR method presented an advantage in terms of accuracy, especially under bacterial stress conditions, and proved to be a promising alternative for the quantification of LAB in refrigerated ready-to-eat meat products. The predictive models used were suitable for describing microbial growth, reinforcing the importance of the PMA-qPCR method in shelf life and food safety studies.

Multivariate analysis for understanding spoilage in cooked Turkey ham

SummaryThis study aimed to comprehend the spoilage of cooked turkey ham caused by various Leuconostoc species using multivariate analysis to link the growth of these microorganisms, pH kinetics, and mesophilic counts for predicting ham spoilage at 8 and 12 °C. The methodology assesses changes in Leuconostoc spp. growth behaviour using the Baranyi and Roberts model, pH kinetics employing the Weibull model, and milkiness and swelling through quantitative descriptive analysis during storage at 8 and 12 °C, with artificial contamination of Leuconostoc carnosum and L. mesenteroides at 102 and 104 CFU g−1. Multivariate analysis encompasses linear quadratic discriminant and Pearson correlation analysis. Biokinetic growth parameters do not significantly differ among Leuconostoc species, temperatures, or inoculum levels. In discriminant analysis, pH is the most influential variable in spoilage grade classification, followed by LAB log counts. Furthermore, correlation analysis reveals a strong positive correlation between the rate of pH reduction and the storage time for spoilage onset.

Nanocomposite Films of Babassu Coconut Mesocarp and Green ZnO Nanoparticles for Application in Antimicrobial Food Packaging.

In this work, novel nanocomposite films based on babassu coconut mesocarp and zinc oxide nanoparticles (ZnO NPs), synthesized by a green route, were produced for application as food packaging films. The films were prepared using the casting method containing different contents of ZnO NPs (0 wt%, 0.1 wt%, 0.5 wt%, and 1.0 wt%). The films were characterized by Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), instrumental color analysis, and optical properties. The water vapor permeability (WVP) and tensile strength of films were also determined. The antimicrobial activity of the films against cooked turkey ham samples contaminated with Staphylococcus aureus was investigated. The results showed that incorporating ZnO NPs into babassu mesocarp matrices influenced the structure of the biopolymer chains and the color of the films. The BM/ZnO-0.5 film (0.5 wt% ZnO NPs) showed better thermal, mechanical, and WVP properties. Furthermore, the synergistic effect of babassu mesocarp and ZnO NPs in the BM/ZnO-0.5 film improved the antimicrobial properties of the material, reducing the microbial count of S. aureus in cooked turkey ham samples stored under refrigeration for 7 days. Thus, the films produced in this study showed promising antimicrobial packaging materials for processed foods.

Investigation of volatile N-nitrosamine contents of hams with different ingredients produced in Turkey

This study focuses on ham, a product prevalent in Turkey, which has received comparatively less attention in the literature regarding volatile nitrosamine (VNA) content. The research identified VNA levels in hams from different brands and determined VNA levels in ham produced from turkey and chicken meat—categories less studied in the existing literature. VNA determination is performed using gas chromatography-mass spectrometry (GC-MS). Accordingly, the lowest total VNA content was identified in chicken ham (1.46 µg/kg), while the highest total VNA content was observed in smoked turkey ham (21.51 µg/kg). The results of the research indicate that as the brand and composition of ham change, the formations and quantities of VNA derivatives also vary. Additionally, there is a strong relationship between not only the brand and composition of ham but also between the combined effect of brand and composition, and the total volatile N-nitrosamine level. This study demonstrates that the nitrosamines in ham may exceed the maximum standards set by the WHO (10 µg/kg). The study sheds light on potential health implications and underscores the necessity for broader sample accessibility in future studies, despite the limitation of insufficient availability of turkey and chicken ham products in the market.

Characterization of Moringa oleifera Seed Oil for the Development of a Biopackage Applied to Maintain the Quality of Turkey Ham.

Moringa oleifera has a high level of active chemicals that are useful in the food industry, and they have antibacterial and food preservation properties. The characterization of M. oleifera seed oil (MOS) may vary due to agronomic and environmental factors. Therefore, it was necessary to know the composition of lipids present in our oil extracted under pressing at 180 °C and thus determine if it is suitable to produce a biopackaging. Within the characterization of the oil, it was obtained that MOS presented high-quality fatty acids (71% oleic acid) with low values of acidity (0.71 mg KOH/g) and peroxide (1.74 meq O2/kg). Furthermore, MOS was not very sensitive to lipoperoxidation by tert-butyl hydroperoxide (tBuOOH) and its phenolic components, oleic acid and tocopherols, allowed MOS to present a recovery of 70% after 30 min of treatment. Subsequently, a biopackaging was developed using a multiple emulsion containing corn starch/carboxymethylcellulose/glycerol/MOS, which presented good mechanical properties (strength and flexibility), transparency, and a barrier that prevents the transfer of UV light by 30% and UV-C by 98%, as well as a flux with the atmosphere of 5.12 × 10-8 g/ m.s. Pa that prevents moisture loss and protects the turkey ham from O2. Hence, the turkey ham suffered less weight loss and less hardness due to its preservation in the biopackaging.

Application of physical, chemical, and biological preservation strategies and their effect on the shelf life of different types of cooked hams

AbstractImprovement of hygiene practices and process control in meat product facilities is an ongoing topic of importance. Consequently, the meat industry must explore alternatives to extend the shelf‐life of meat products. This study aimed to assess the effectiveness of chemical, biological, and physical strategies at the formulation, pre‐packaging, and post‐packaging stages, respectively, to extend the shelf‐life of cooked ham. Three strategies were tested on different formulations of cooked ham: (1) inclusion of organic acid salts with and without buffered vinegar in the formulation, (2) application of biopreservation cultures during pre‐packaging for the four developed formulations, and (3) high hydrostatic pressure processing (HPP) applied to two pork ham formulations during post‐packaging with and without buffered vinegar. The effect of these strategies was evaluated by measuring shelf life based on lactic acid bacteria (LAB) and mesophilic counts, monitoring pH kinetics, and conducting sensory evaluations focused on indicators of spoilage such as milkiness and swelling. Results revealed that the HPP strategy was the most effective, significantly extending the shelf life of cooked pork ham up to 97 days, with no significant differences observed when combined with buffered vinegar. In contrast, the use of organic acid salts with or without buffered vinegar did not significantly extend the shelf life compared to control hams without preservatives (p > 0.05). Furthermore, significant variations in shelf life were found between batches and types of ham (p < 0.05). Notably, the biopreservation strategy led to a reduction in shelf life reduction.Practical applicationsSliced‐packaged ham is highly susceptible to spoilage, and previous studies investigating the application of organic acid salts, biopreservation cultures, and physical interventions have demonstrated limited effectiveness in extending shelf life under industrial and Colombian market conditions. Moreover, some of these approaches have resulted in alterations to the product's sensory attributes. Consequently, there is a critical need to evaluate alternative strategies that can be easily implemented with current technology, are cost‐effective, acceptable to consumers, and can be validated in an industrial setting. Furthermore, it is crucial to investigate the potential synergistic effects of combining high hydrostatic pressure processing (HPP) with chemical interventions, such as buffered vinegar. Implementing these measures holds the potential to minimize food waste and contribute to enhancing food security. Additionally, the findings of this study present a hypothesis that can contribute to understanding the variations in spoilage between pork and turkey hams.

Antimicrobial Activity of Cobalt (II)-Citrate against Common Foodborne Pathogens and Its Potential for Incorporation into Food Packaging Material

Novel antimicrobial compounds can be added to foods directly or incorporated into packaging materials in order to improve food safety and shelf life. One such potential antimicrobial compound is the bioinorganic complex Co(II)-citrate (NH4)4[Co(C6H5O7)2] (Co-cit). Its antimicrobial activity against Listeria monocytogenes, Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa was investigated in solution, both alone and in combination with existing preservatives. The antimicrobial activity of poly(lactic acid) films (PLA) with incorporated Co-cit (23.3% w/w) against L. monocytogenes was determined using culture medium and model foods (slices of turkey ham and smoked salmon). In nutrient broth, without preservatives, all four bacteria were significantly (p < 0.05) inhibited by 0.5 mM Co-cit, and L. monocytogenes and P. aeruginosa were the most sensitive. The addition of preservatives to the broth increased the antimicrobial activity of Co-cit in many cases, but not in a way that was consistent between the different bacteria investigated and was likely due to additional physiological stress exerted on the cells rather than any effect on the activity of the Co-cit itself. PLA films with Co-cit were bacteriostatic against L. monocytogenes on artificial media and on foods. However, in the latter case, the PLA film itself was the main contributor to the inhibition. Composite PLA-(Co-cit) films exhibited antimicrobial activity against foodborne bacteria and have potential application as active packaging materials to enhance food safety.

Morphological, textural and physico-chemical characterization of processed meat products during their shelf life

Abstract A good characterization of the morphology and physico-chemical properties of processed meat products is crucial to develop new preservation techniques. The present work reports a thorough characterization of three of such products: pork ham, turkey ham and bacon; the products were analysed in fresh and after 35 days of refrigerated storage. The results obtained uncover significant differences regarding the volatile compounds of the products and expose texture changes during the storage of the different sliced foods. In bacon, the muscle fibres were the less damaged ones (SEM and Cryo-SEM analysis) and the muscle fibres of pork ham were among the most damaged of all, due to the longer cooking time. The main volatile compounds found by the GC–MS study were aromatics, alkanes and esters. At the end of the recommended shelf life period for the studied products (35 days) significant differences in volatiles (changes in concentration and type) were found. Meat dehydration and the change of the type of volatile compounds in the package atmosphere were successfully identified and are believed to be the main reason for the lower acceptance of the aged products by consumers.

Combination of Isotope Labeling and Molecular Networking of Tandem Mass Spectrometry Data To Reveal 69 Unknown Metabolites Produced by Penicillium nordicum.

The secondary metabolome of Penicillium nordicum is poorly documented despite its frequent detection on contaminated food and its capacity to produce toxic metabolites such as ochratoxin A. To characterize metabolites produced by this fungi, we combined a full stable isotopes labeling with the dereplication of tandem mass spectrometry (MS/MS) data by molecular networking. First, the untargeted metabolomic analysis by high-resolution mass spectrometry of a double stable isotope labeling of P. nordicum enabled the specific detection of its metabolites and the unambiguous determination of their elemental composition. Analyses showed that infection of substrate by P. nordicum lead to the production of at least 92 metabolites and that 69 of them were completely unknown. Then, curated molecular networks of MS/MS data were generated with GNPS and MetGem, specifically on the features of interest, which allowed highlighting 13 fungisporin-related metabolites that had not previously been identified in this fungus and 8 that had never been observed in any fungus. The structures of the unknown compounds, namely, a native fungisporin and seven linear peptides, were characterized by tandem mass spectrometry experiments. The analysis of P. nordicum growing on its natural substrates, i.e. pork ham, turkey ham, and cheese, demonstrated that 10 of the known fungisporin-related metabolites and three of the new metabolites were also synthesized. Thus, the curation of data for molecular networking using a specific detection of metabolites of interest with stable isotopes labeling allowed the discovery of new metabolites produced by the food contaminant P. nordicum.

Caracterização microbiológica de presuntos de peru fatiados embalados a vácuo e em embalagem convencional comercializados em Mossoró, Brasil

The consumption of turkey ham has been increasing considerably. This product can be marketed sliced, and thus, it is subjected to intense manipulation and presents a high microbial load, which compromises its quality and safety. The objective of this study was to characterize microbiologically vacuum-packed and conventionally packed sliced turkey hams marketed in Mossoro, state of Rio Grande do Norte, Brazil. The analyses consisted of mold and yeast, viable aerobic mesophilic microorganism, and coagulase positive Staphylococcus counts, determination of the most probable number of total coliforms and thermotolerant coliforms, and presence of Salmonella spp. Turkey hams present high microbiological counts regardless of their packaging, but conformity for coliforms at 45 °C. Some samples had low quality, denoting that a greater care in the manipulation and conservation of this product is necessary to ensure the safety and absence of risks of this product to public health.

Quality Assessment of Pork and Turkey Hams Using FT-IR Spectroscopy, Colorimetric, and Image Analysis.

The implementation of fast and nondestructive methods in meat products and colds cuts have become increasingly important to evaluate their quality in relation to different factors such as origin, type of processing, freshness, adulteration, and authenticity. In this study, Fourier Transform Infrared Spectroscopy (FT-IR), colorimetric, and image-analysis methods were implemented to characterize and classify ham cold cuts in terms of meat type, processing, and shelf life during refrigerated storage. Two types of commercial hams (made from pork and turkey) and three types of processing (boiled, smoked, and roasted) were selected. By using the most appropriate color parameters, a*, h, and C*, as well as the textural features’ angular second moment, long-running emphasis, and standard deviation of image intensity from the hams’ images, high-classification values for the different ham samples were achieved. The FT-IR analysis revealed the presence of absorbance bands of proteins, triglycerides, fatty acids, and carbohydrates with different intensities according to meat type and processing. Refrigeration storage caused significant alterations of color parameters and a partial degradation of triglycerides and proteins. Moreover, the image-analysis findings indicated that storage period caused significant degradation of ham images relating to local linearity, and structural and textural continuum.

Synergistic Effect of Phages and Organic Acid Salts on Listeria Contaminated Ready to Eat Turkey Ham

ObjectivesReady To Eat (RTE) are foods that have already been cooked and needs no further heating, making it easy and fast for consumers to prepare meals. For this reason that most RTE do not undergo any lethality steps at consumer level before consumption, companies must care to deliver “Listeria-free” foods.In this study ability of PhageGuard Listex (a natural bacteriophage solution against Listeria) in combination with buffered vinegar or a commercially available solution comprising potassium lactate (72.8%) and sodium diacetate (5.2%), to control Listeria during the shelf-life (120 d) of sliced RTE turkey meat was assessed.Materials and MethodsCooked turkey slices were inoculated with a cocktail of 4 Listeria monocytogenes strains at 1 Log cfu/cm2 (duplicate sample per treatment). Contaminated samples were treated by spraying either only PhageGuard Listex (2 × 107 PFU (Plaque Forming Units)/cm2), PhageGuard Listex plus buffered vinegar and PhageGuard Listex plus potassium lactate/sodium diacetate on the surface of the turkey slices. Other samples were sequentially treated with just either of the organic acids and tap water (untreated) and were used as negative controls. Subsequently, all samples were vacuum packed and stored at 40°F/4°C. During the shelf-life of 120 d, samples were retrieved in peptone buffered water to detect and enumerate Listeria.ResultsWhen applied on artificially contaminated turkey ham, the phage solution or buffered vinegar alone kept Listeria concentration below detection limit for 20 and 30 d respectively (mean value of 2 individual experiments). However, when a combination of phages with buffered vinegar was applied, Listeria was kept below detection limit for 120 d (mean value of 2 individual experiments). A similar though less strong, effect was observed when turkey slices were sequentially treated with a combination of phages and potassium lactate/sodium diacetate. In this case, Listeria was not detected for 30 d (mean value of 2 individual experiments) and Listeria was kept below 2 logs outgrowth (compared to the initial contamination) for 70 d (mean value of 2 individual experiments). Application of just potassium lactate/sodium diacetate alone resulted in more than 2 logs outgrowth after 40 d.ConclusionA clear synergistic effect was observed when combining a bacteriophage product against Listeria with 2 different organic acid solutions on Listeria contaminated cooked turkey slices. Results showed combining phages with buffered vinegar, Listeria levels were kept below detection limits for an additional 90 d when compared to buffered vinegar alone. Combining such Listeria-specific phage product with these organic acids has the added beneficial effect of inhibiting the outgrowth of spoilage bacteria.All in all, these results establish the combined effect of PhageGuard Listex and organic acids as an effective anti-listeria hurdle during processing of RTE meals, leading to an increase in consumer safety.

The Inhibitory Effect of a Sodium Free Powder Preservative on the Growth of Listeria Monocytogenes and Lactic Acid Bacteria in Turkey Ham Applications

ObjectivesOrganic acids are proven effective antimicrobials against Listeria and LAB. However, current organic acid based preservatives are liquid in most cases and powder forms contain sodium. This document evaluates the antimicrobial efficacy of an organic acid based powder without any sodium content.ObjectiveThe purpose of this research is to evaluate the effects of sodium free ProvianK powder and 60% potassium lactate and sodium diacetate (PL-SD) solution on Listeria monocytogenes and Lactic acid bacteria in cured and uncured turkey hams.Materials and MethodsManufacture of Turkey hams. Deli-style turkey formulations were prepared containing boneless, skinless turkey breasts, 2.0% starch, 1.8% salt, 1.0% dextrose, 1.0% carrageenan, 0.4% sodium tripolyphosphate, appropriate concentrations of antimicrobials and balance added water. Analyzed treatments: Control (no antimicrobials), 2.5% potassium lactate–sodium diacetate, 60% sol.(PL-SD), ProvianK (potassium acetate- potassium diacetate), 0.25, 0.5, and 0.75%. Finished product targets included 75% moisture, 1.9% salt and 6.2 to 6.4 pH. Cured products contained 156 ppm sodium nitrite and 547 sodium erythorbate. Turkey formulations in casings were cooked to 73.9°C (165°F), cooled overnight according to USDA Appendix B and aseptically sliced.Inoculum Surface was inoculated with approximately 3log CFU/g using a cocktail of various serotypes of L. monocytogenes or a cocktail or different species of LAB isolated from meat products. Inoculated slices were vacuum packaged in gas-impermeable bag. Packages were stored at 4 and 7°C.Microbial analysis Inoculated samples of each treatment (n = 3) were assayed by rinsing meat in Butterfield’s phosphate buffer and hand massaging externally for 3 min. Rinsate was serially diluted and enumerated on appropriate media. Listeria populations were determined by surface plating on MOX agar (35°C, 48 h); LAB plate counts were determined by plating on APT agar with bromcresol purple (25°C, 48 h). Statistical significance was determined using ANOVA.ResultsFood Safety control in cured turkey and uncured turkey (Listeria inhibition). At 4°C all treatments show complete inhibition of Listeria for 12 wk. At 7°C 0.5% ProvianK shows comparable inhibition to with 2.5% PL/SD (P < 0.05). In uncured meat 0.25% ProvianK shows comparable performance to 2.5% PL/SD (P < 0.05).Shelf life extension in uncured turkey (LAB inhibition), see Table 1.Table 1Time (d) to end of shelflife (6 logs LAB CFU/g)TreatmentTime (days) to end of shelflife at 4°CTime (days) to end of shelflife at 7°CControl without preservatives5.52.5KL/SD 60% solution, 2.5%7.54.5Provian K 0.5%95Provian–K 1.5%126.5ConclusionThis research shows a significant improvement of antimicrobial efficacy of a sodium free powder antimicrobial compared to current used sodium containing antimicrobials. This research provides meat industry with a powerful acetate based antimicrobial powder to replace current sodium containing preservatives.

Application of a virulent bacteriophage cocktail leads to reduction of Salmonella enterica serovar Enteritidis counts in processed meat products

ABSTRACTSalmonella enterica serotype Enteritidis (SE) is a major cause of food-borne disease outbreaks worldwide. We evaluated the effectiveness of five lytic bacteriophages applied as a cocktail to reduce the counts of SE in two types of processed meat products: cooked (turkey ham (TB) and chicken sausage (CS)) and cured sausage (Italian salami (IS) and barbecue sausage (BS)). Groups of 25 samples each were contaminated with SE, treated with a phage cocktail using a multiplicity of infection of 105 and then incubated for ten days at 18°C and 4°C. A significant reduction in bacteria was obtained on days 3, 6 and 10 in all matrices incubated at 18°C (from 0.48 to 2.12 log Colony Forming Units (CFU) g−1) and at 4°C (from 0.23 to 2.06 log CFU g−1), with the exception of BS at day 3 at 4°C, and IS at both incubation temperatures throughout the trial. The viral titre remained stable in all matrices analysed except in BS. These results show the effectiveness of this bacteriophage cocktail against S. enterica serovar Enteritidis in some processed meat products such as CS, BS and TB.

Differences in transcription and expression of staphylococcal enterotoxin C in processed meat products

Staphylococcus aureus is a major foodborne pathogen contaminating meat products where it is able to produce thermostable enterotoxins. Staphylococcal enterotoxin C (SEC) together with other classical toxins are the most frequently detected enterotoxins associated with staphylococcal food poisoning (SFP) outbreaks. This study investigated the transcription and formation of SEC in four heat-processed meat products: chicken ham, pork ham, pepper beef salami and turkey ham. Meat samples were inoculated with four SEC producing strains of S. aureus individually at a level of approximately 5 log CFU/cm2. The expression and production of SEC was examined during the growth of S. aureus in meat compared to routinely used laboratory media. Results indicate that the expression of sec in meat products varied significantly and was dependent upon the different levels of fat content compared to the laboratory medium. Meat varied in salt content and pH and this influences SEC production. Increased SEC and sec expression was observed in chicken and pork ham and was approx. 24–35 times higher compared with other meat products. Lower levels of sec expression and SEC production were found in turkey ham with SEC concentration 378 times lower than in chicken ham at 72 h. The varying meat environment affected the transcription and formation profiles of SEC, however staphylococcal growth remained reasonably constant. Staphylococcal strains were able to produce quantities of SEC under room temperature conditions that would be sufficient to cause food poisoning in susceptible individuals (mainly in children). Our data is important with respect to food contamination by S. aureus and contributes to an improved understanding of SEC production capabilities of these pathogens in meat containing food products.

Procesos simples que disminuyen el contenido de sodio y nitritos en jamones

Introducción: El jamón, producto altamente consumido por la sociedad, contiene algunos elementos que lo convierten en un alimento no recomendable, por lo que se ha buscado eliminar o reducir esos componentes.Material y Métodos: Se compararon los contenidos de sodio, nitritos, índice de peróxidos y coliformes totales resultantes de los procesos de Lavado (L) y Cocción Simple (CS) aplicados al jamón de pavo y de cerdo en un estudio transversal analítico experimental. Además, se evaluó la aceptación sensorial de las muestras a través de una prueba de aceptación de cinco puntos. Se aplicó la prueba ANOVA de 1 vía con post hoc de Bonferroni para valorar la diferencia de medias entre grupos. El valor de p≤0,05 se consideró estadísticamente significativo.Resultados: Ambos procesos redujeron la cantidad de sodio en ambos tipos de jamón de manera estadísticamente significativa (p≤0,001). El mayor porcentaje de reducción se presentó con CS: 73,4% para el jamón de pavo y 63,5% para el jamón de cerdo. Asimismo, el mayor porcentaje de reducción de nitritos fue de 50,6% con la técnica de CS en el jamón de cerdo (p≤0,05). El índice de peróxidos disminuyó con ambas técnicas en ambos jamones sin significancia estadística. El conteo de coliformes totales se mantuvo constante en todas las muestras. Se observó una mayor aceptación sensorial de L sobre CS en todas las características sensoriales.Conclusiones: Las técnicas de L y CS reducen sodio, nitritos e índice de peróxidos sin afectar la sanidad de los jamones. Asimismo, L es aceptada sensorialmente en todas sus categorías. Se recomienda utilizar la técnica de L antes del consumo del producto.

Microbial Inactivation by Ultrasound Assisted Supercritical Fluids

A method combining supercritical carbon dioxide (SC-CO2) and high power ultrasound (HPU) has been developed and tested for microbial/enzyme inactivation purposes, at different process conditions for both liquid and solid matrices. In culture media, using only SC-CO2, the inactivation rate of E. coli and S. cerevisiae increased with pressure and temperature; and the total inactivation (7-8 log-cycles) was attained after 25 and 140min of SC-CO2 (350bar, 36°C) treatment, respectively. Using SC-CO2+HPU, the time for the total inactivation of both microorganisms was reduced to only 1-2min, at any condition selected. The SC-CO2+HPU inactivation of both microorganisms was slower in juices (avg. 4.9min) than in culture media (avg. 1.5min). In solid samples (chicken, turkey ham and dry-cured pork cured ham) treated with SC-CO2 and SC-CO2+HPU, the inactivation rate of E. coli increased with temperature. The application of HPU to the SC-CO2 treatments accelerated the inactivation rate of E. coli and that effect was more pronounced in treatments with isotonic solution surrounding the solid food samples. The application of HPU enhanced the SC-CO2 inactivation mechanisms of microorganisms, generating a vigorous agitation that facilitated the CO2 solubilization and the mass transfer process. The cavitation generated by HPU could damage the cell walls accelerating the extraction of vital constituents and the microbial death. Thus, using the combined technique, reasonable industrial processing times and mild process conditions could be used which could result into a cost reduction and lead to the minimization in the food nutritional and organoleptic changes.

Preliminary study using visible and SW-NIR analysis for evaluating the loss of freshness in commercially packaged cooked ham and Turkey ham

A non-destructive Vis-NIR spectroscopy (400&amp;ndash;1000 nm) method was developed to evaluate the loss of freshness of sliced and commercially packaged cooked ham and turkey ham without any sample manipulation. The spectra were recorded at 0, 30, 40, and 60 days using a camera, spectral filter (400&amp;ndash;1000 nm) and a halogen floodlighting system which had been were developed and calibrated for the purpose. Physico-chemical, biochemical, and microbiological properties such as pH, total volatile basic nitrogen (TVB-N), ATP breakdown compounds, and colony-forming units were determined to predict the degradation of freshness. The image spectra obtained from visible and SW-NIR&amp;nbsp; spectroscopy were related to the storage time of the samples. A PLS-DA model was developed independently for packaged or unpackaged samples using the second derivative of the spectra. Mean R&lt;sup&gt;2&lt;/sup&gt; prediction obtained for cooked ham was 0.915 and 0.949 for Turkey ham. The technique developed could be applied to monitoring the freshness of commercial packed cooked ham and turkey ham as a non-destructive technique. Further studies will be needed to check the spectra obtained from samples of different commercial brands in order to evaluate more precisely the efficiency of the method.

Effects of micronized sodium chloride on the sensory profile and consumer acceptance of turkey ham with reduced sodium content

The impact of sodium chloride reduction and its substitution for micronized salt on consumer acceptance of turkey ham was investigated. Five formulations - F1 (control - 2.0% NaCl), F2 (1.7% NaCl), F3 (1.4% NaCl), F4 (1.7% micronized NaCl), and F5 (1.4% micronized NaCl) - were evaluated with respect to sodium chloride content and by consumers using a nine-point hedonic scale for overall acceptability and CATA (check-all-that-apply) using 24 sensory descriptors. Trained panelists characterized the products using the flash profiling technique. Reductions in the salt content by up to 30% did not affect the overall acceptability of the samples by the consumers. However, the consumers characterized the formulations with lower salt content as salty and less seasoned in comparison to the contents in the control. Products containing 1.7% NaCl were considered very similar to the control. The results obtained indicate that it is possible to reduce NaCl content by 30% without affecting consumer acceptance of the product. The use of micronized salt did not affect the sensory characteristics when compared with those of formulations containing the same level of sodium chloride indicating that micronized salt does not influence perception of salt.

Prediction of moisture, color and pH in cooked, pre-sliced turkey hams by NIR hyperspectral imaging system

The investigation was conducted to develop a hyperspectral imaging system in the near infrared (NIR) region (900–1700nm) to predict the moisture content, pH and color in cooked, pre-sliced turkey hams. Hyperspectral images were acquired by scanning the ham slices (900–1700nm) originated from different quality grade of turkey hams. Spectral data were then extracted and analyzed using partial least-squares (PLSs) regression, as a multivariate calibration method, to reduce the high dimensionality of the data and to correlate the NIR reflectance spectra with quality attributes of the samples considered. Instead of using a wide range of spectra, the number of wavebands was reduced for more stable, comprehensive and faster model in the subsequent multispectral imaging system. From this point of view, important wavelengths were selected to improve the predictive power of the calibration models as well as to simplify the model by avoiding repetition of information or redundancies. With the help of PLS regression analysis, nine wavelengths (927, 944, 1004, 1058, 1108, 1212, 1259, 1362 and 1406nm) were selected as the optimum wavelengths for moisture prediction, eight wavelengths (927, 947, 1004, 1071, 1121, 1255, 1312 and 1641nm) for pH prediction and nine wavelengths (914, 931, 991, 1115, 1164, 1218, 1282, 1362 and 1638nm) were identified for color (a*) prediction. With the identified reduced number wavelengths, good coefficients of determination (R2) of 0.88, 0.81 and 0.74 with RMSECV of 2.51, 0.02 and 0.35 for moisture, pH and color, respectively, were achieved, reflecting reasonable accuracy and robustness of the models.