Ham Formulation Research Articles

Antioxidant Activity of Bougainvillea spectabilis Bracts as an Alternative to Nitrites in Cooked Pork Ham.

In this study, the impact of incorporating Bougainvillea spectabilis powder into ham formulation as a potential color replacement for nitrites was evaluated. Three drying methods were proposed to preserve the antioxidant properties of bougainvillea: foam-mat drying, air drying, and oven drying. Antioxidant assays (DPPH, ABTS, and FRAP) assays revealed that the presence of bougainvillea powders enhanced the antioxidant properties and maintained the stability of the ham over 8 weeks of storage at 4 °C. In addition, total polyphenolic content and presence of thiobarbituric acid reactive substances (TBARS) were evaluated and showed higher and lower scores, respectively, in the samples with the incorporation of bougainvillea compared to the control samples, suggesting their potential to replace nitrite salts by providing natural antioxidant protection. Sensorial analysis also revealed no significant differences in sensory attributes in hams with 0.1% bougainvillea powder compared to nitrite samples. The incorporation of the bougainvillea powders in the ham formulation improved the sensorial attributes and consumer overall acceptance even after 8-week cold storage at 4 °C.

Enhancing High-Pressure Bacterial Inactivation by Modified Atmosphere Packaging: Effect of Exposure Time and Cooked Ham Formulation

AbstractHigh-pressure processing (HPP) is a non-thermal preservation technology that can be applied as a control measure to inactivate pathogens and spoilage microorganisms once RTE meat products are packaged in a convenient format. HPP efficacy highly depends on product characteristics, but the impact of the sodium-reduced formulations and the effect of packaging atmosphere are scarcely known. The aim of the present work was to assess the effect of standard and sodium-reduced formulations from two different brands (A, B) under different packaging (vacuum and modified atmosphere packaging (MAP)) on the HPP inactivation kinetics of Listeria monocytogenes and spoilage lactic acid bacteria in cooked ham. Slices of cooked ham with standard and sodium-reduced formulations were inoculated with L. monocytogenes CTC1034 and Latilactobacillus sakei CTC746 (slime producer), packaged in vacuum and MAP (CO2:N2, 20:80), and pressurized (400 MPa/0–15 min) after 1 h (vacuum, MAP) or 24 h (MAP-exposed). Parameters of HPP inactivation kinetics were estimated by fitting the Weibull model to log reduction data. Results showed that the efficacy of HPP in sodium-reduced cooked hams tended to decrease compared to standard formulations, being the difference statistically significant for L. sakei. For L. monocytogenes, a significant enhancing effect of MAP was observed when HPP was applied just after packaging (1 h, MAP) of cooked ham of brand A. In the case of L. sakei, the inactivation by HPP was only enhanced in MAP-exposed samples. Therefore, the use of HPP as a control measure must be applied through a product-oriented approach considering the type of packaging and the time period between packaging and HPP.

Effects of a human amniotic membrane extract on ARPE-19 cells

BackgroundHuman Amniotic Membrane (hAM) is endowed with several biological activities and might be considered an optimal tool in surgical treatment for different ophthalmic pathologies. We pioneered the surgical use of hAM to treat retinal pathologies such as macular holes, tears, and retinal detachments, and to overcome photoreceptor damage in age-related macular degeneration. Although hAM contributed to improved outcomes, the mechanisms of its effects are not yet fully understood. The characterization and explanation of the effects of hAM would allow the adoption of this new natural product in different retinal pathologies, operative contexts, and hAM formulations. At this end, we studied the properties of a hAM extract (hAME) on the ARPE-19 cells.Methods and resultsA non-denaturing sonication-based technique was developed to obtain a suitable hAME. Viability, proliferation, apoptosis, oxidative stress, and epithelial-mesenchymal transition (EMT) were studied in hAME-treated ARPE-19 cells. The hAME was able to increase ARPE-19 cell viability even in the presence of oxidative stress (H2O2, TBHP). Moreover, hAME prevented the expression of EMT features, such as EMT-related proteins, fibrotic foci formation, and migration induced by different cytokines.ConclusionsOur results demonstrate that the hAME retains most of the properties observed in the whole tissue by others. The hAME, other than providing a manageable research tool, could represent a cost-effective and abundant drug to treat retinal pathologies in the future.

Clean labelling sodium nitrite at pilot scale: In-situ reduction of nitrate from plant sources and its effects on the overall quality and safety of restructured cooked ham

Growing health and environmental concerns have increased demand for all-natural products, with a focus on clean labelling. Sodium nitrite is the most widely used additive in the meat industry because it imparts the typical cured flavour and colour to meat products and, most importantly, their microbiological safety. However, due to health concerns, the European Commission is proposing revised regulations to reduce nitrate and nitrite levels in meat products. As a result, the meat industry is actively seeking alternatives. This study explored the production of four cooked hams utilising nitrate-rich vegetable sources combined with two different nitrate-reducing commercial food cultures, alongside a control ham prepared with sodium nitrite (150 ppm). Microbiological, physico-chemical (pH, water activity, nitrate and nitrite concentration, lipid profile, lipid oxidation) and sensory (texture and colour profile) characterisation of the products was carried out. Challenge tests for Listeria monocytogenes, Clostridium sporogenes and Clostridium perfringens have been performed to assess the growth of pathogens, if present in the products. Results revealed comparable microbiological and physico-chemical profiles across ham formulations, with minor differences observed in colour parameters for sample C. The sensory analysis showed that for the pilot ham formulations A and D, there were no significant differences in consumer perception compared to the control ham. In the challenge tests, L. monocytogenes levels were similar in both control and tested hams. There were no significant differences in C. sporogenes and C. perfringens counts at any temperature or between test and control samples. These results indicate that this technology has a potential future in the cured meat sector, as regulators mandate the reduction of added synthetic chemicals and consumers seek healthier and more natural ingredients in their daily diets.

Exploring Propolis as a Sustainable Bio-Preservative Agent to Control Foodborne Pathogens in Vacuum-Packed Cooked Ham.

The search for natural food additives makes propolis an exciting alternative due to its known antimicrobial activity. This work aims to investigate propolis' behavior as a nitrite substitute ingredient in cooked ham (a ready-to-eat product) when confronted with pathogenic microorganisms of food interest. The microbial evolution of Listeria monocytogenes, Staphylococcus aureus, Bacillus cereus, and Clostridium sporogenes inoculated at known doses was examined in different batches of cooked ham. The design of a challenge test according to their shelf life (45 days), pH values, and water activity allowed the determination of the mesophilic aerobic flora, psychotropic, and acid lactic bacteria viability. The test was completed with an organoleptic analysis of the samples, considering possible alterations in color and texture. The cooked ham formulation containing propolis instead of nitrites limited the potential growth (δ < 0.5 log10) of all the inoculated microorganisms until day 45, except for L. monocytogenes, which in turn exhibited a bacteriostatic effect between day 7 and 30 of the storage time. The sensory analysis revealed the consumer's acceptance of cooked ham batches including propolis as a natural additive. These findings suggest the functionality of propolis as a promising alternative to artificial preservatives for ensuring food safety and reducing the proliferation risk of foodborne pathogens in ready-to-eat products.

Valorization of avocado (Persea americana) residual paste: Microwave-assisted extraction, optimization and addition to an artisanal pork ham

ABSTRACT Recovering biocompounds from industrial by-products is crucial to avoid food waste. Microwave-assisted extraction (MAE) has been employed to recover some biocompounds from vegetal matrices using ethanol and his solutions as solvent. Optimization of MAE conditions over total soluble polyphenols (TSP) and antioxidant capacity (DPPH and FRAP) from avocado residual paste (ARP) from oil industry was carried out. Optimal extract was used to elaborate an artisanal ham. Using response surface methodology (RSM), optimal conditions for MAE were 480 W of power, absolute ethanol as solvent, and extraction time of 180 s. The extract contained TSP of 31.24 mg GAE/g DW, DPPH inhibition of 24.51 mg TE/g DW and FRAP inhibition of 21.58 mg TE/g DW. The extract was added in the ham formulation at 0, 0.5, 1, and 1.5% w/w. Ham with 1% extract had the highest scores for acceptance. Extracts from ARP may be used in ham with adequate sensory attributes.

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 &gt; 0.05). Furthermore, significant variations in shelf life were found between batches and types of ham (p &lt; 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.

Control of Clostridium perfringens spore germination and outgrowth by potassium lactate and sodium diacetate in ham containing reduced sodium chloride

The effect of potassium lactate and sodium diacetate mixture (Opti.Form PD4®) on Clostridium perfringens spore germination and outgrowth during abusive cooling of reduced sodium ham was evaluated. A ham formulation containing NaNO2 (0 or 100 ppm), NaCl (1 or 2%) and Opti.Form PD4® (0, 1.5 or 2.5%) was prepared. Meat (10 g) was vacuum-packaged, stored under refrigeration (5 °C) for 3 or 24 h and inoculated with a three-strain C. perfringens spore cocktail. Samples were vacuum-packaged, heat treated (75 °C, 20 min) and cooled from 54.4 °C to 7.2 °C within 9, 15 or 21 h. C. perfringens population increases of 5.18 and 4.26 log CFU/g were observed in non-cured ham (control; stored for 3 h) formulated with 1 or 2% of NaCl, respectively and cooled exponentially within 21 h. Incorporation of Opti.Form PD4® (1.5%) inhibited C. perfringens spore germination and outgrowth regardless of the cooling rate (9, 15 or 21 h). Addition of NaNO2 (100 ppm) enhanced antimicrobial activity of Opti.Form PD4®. In general, abusive cooling (≥15 h) of ham after 24 h of storage resulted in greater populations of C. perfringens. Addition of NaNO2, Opti.Form PD4® and processing immediately resulted in greater inhibition of C. perfringens spore germination and outgrowth.

Addition of essential oils and inulin for production of reduced salt and fat ham

It has been estimated that approximately 75% of the human’s sodium intake is added during industrial manufacturing. Processed meats can also contain relatively high amounts of saturated fats, and high levels of fat, associated with increased risk of obesity, diabetes and cancers, especially colon cancers. In contrast, dietary fiber intake (ex. inulin) has been associated with health benefits, including a suggested protective effect against colorectal cancer due to an inverse association with colorectal cancer risk. Nutritional and health concerns indicate that consumption of these two elements should be reduced. This study aimed to develop a ham with reduced levels of salt and fat. We added essential oils of oregano and rosemary to preserve the ham as a substitute for fat, for which inulin was also added. Six ham formulations were prepared (control, fat reduction + inulin, salt reduction, salt reduction + essential oils, salt reduction + no fat, and salt reduction + no fat + essential oils). The physical-chemical and microbiological quality parameters were evaluated. The addition of inulin did not interfere with the chemical composition of the formulated ham, presenting itself as a promising alternative for reducing the addition of fat in baked ham. The administration of essential oils in combination caused a significant decrease in native flora of cooked ham. These results suggest that a combination of essential oils and inulin may be a promising alternative in the production of meat products with lower salt and fat levels.

Effect of hydrocolloids on the quality of restructured hams with duck skin

We investigated the quality of duck ham restructured with various hydrocolloids (Alginic acid, Konjac, Carrageenan) on proximate composition, cooking loss, emulsion stability, pH, color, texture profile analysis (TPA), protein solubility, sensory characteristics, and apparent viscosity. Restructured duck ham was prepared as follows: control with no hydrocolloids, T1 (Alginate 1%), T2 (Alginate 0.5% + Konjac 0.5%), T3 (Alginate 0.7% + Konjac 0.3%), T4 (Alginate 0.5% + Carrageenan 0.5%), and T5 (Alginate 0.7% + Carrageenan 0.3%). The restructured duck hams with hydrocolloids had higher value for moisture content, ash content, and apparent viscosity than the control (P < 0.05). The cooking loss, total expressible fluid and fat separation, redness, hardness, cohesiveness, gumminess, and chewiness of restructured duck hams with hydrocolloids was lower than those of the control (P < 0.05). The sensory score for overall acceptability of restructured duck ham with T1 (1% alginate) and T2 (0.5% alginate + 0.5% konjac) was higher than that of the control (P < 0.05). Thus, this study showed that adding 1% alginate or 0.5% alginate + 0.5% konjac in restructured duck ham formulations results in optimized quality characteristics.

Antimicrobial Efficacy Comparison of Cultured Cane Sugar and Vinegar Powder against Vinegar Powder on Listeria Monocytogenes Inhibition in Ham

ObjectivesThe objective of this study was to evaluate the antimicrobial efficacy of Verdad Opti. Powder N60 cultured sugar and vinegar (CSV-P) versus vinegar powder solution (DV) in ham formulation. The efficacy was evaluated on L. monocytogenes growth inhibition in different product treatments incubated at 40°F for 140 d.Materials and MethodsPork semimembranosus was injected at 33% pump level of brine solution containing water, sea salt, cane sugar, sodium nitrite, and varying levels of antimicrobial interventions. Each treatment was macerated independently, tumbled, stuffed, and cooked in a steam cabinet to an internal temperature of 162°F. Table 1 outlines the treatment structure, proximate values for the treatments and the L. monocytogenes outgrowth data.Each of these treatments were independently inoculated with a 5 strain cocktail of L. monocytogenes, vacuum packaged, and incubated at 40°F. The treatments were sampled in duplicate at regular time intervals, enumerated for L. monocytogenes using selective Palcam media. Water activity, pH, and moisutre content analysis was performed for all the treatments.ResultsThe water activity values for CSV-P treatments were generally lower than control treatment and dried vinegar treatments (Table 1). The lactic acid bacteria outgrowth is significantly influenced by water activity values and lower aw values correspond to lower growth rate of lactic acid bacteria strains, thereby preventing early spoilage by providing an additional preservation hurdle. The pH values show similar results for different antimicrobial treatments indicating no major impact on ionic strength of the formulations.The use of 0.5% DV, 0.7% DV, 1.5% CSV-P and 1.8% CSV-P enhanced control in outgrowth of L. monocytogenes compared to the control treatment. The 1 and 2 log10 CFU/g outgrowth for L. monocytogenes was reached in 7 and 12 d for control treatment, respectively. Addition of 0.5% DV treatment reduced the L. monocytogenes outgrowth to less than 2 log10 CFU/g until 50 d. Increasing the DV concentration to 0.7% further reduced the L. monocytogenes outgrowth to less than 2 log10 CFU/g until 125 d. For the other 2 treatments (1.5% and 1.8% CSV-P), an inhibition (< 1 log outgrowth) of L. monocytogenes was observed during 140 d of incubation, respectively.ConclusionThis research verifies the antimicrobial efficacy of Verdad Opti. Powder N60 cultured cane sugar and vinegar powder in ham to control L. monocytogenes outgrowth and provides the industry with an effective, natural, and clean label ingredient solution to enhance the food safety and shelf life in sensitive meat formulations.

Effects of Plant Extract Addition on Listeria Monocytogenes Growth in Highly Extended Sliced Cooked in Ham

ObjectivesThe objective of this study was to evaluate the effect of a plant extract blend containing rosemary and citrus extract on controlling the growth of Listeria monocytogenes in highly extended sliced cook-in ham during refrigerated storage at 7°C.Materials and MethodsThe experiment comprised 2 treatments, control (no plant extract addition) and 0.4% of rosemary-citrus extract blend (Cleanatis M1, Naturex). This study was conducted using a standard ham formulation yielding an end product weighing 170% of the raw material used, in this case pork leg meat cuts. The different ham muscles obtained from the pork leg were injected with a brine solution containing water, sodium chloride, phosphates, sodium nitrite, sodium erythorbate, hydrolyzed corn syroup 40DE, monosodium glutamate, carrageenan and aromas. Each lot included one batch of samples tumbled (7 cycles/min) under vacuum, at controlled temperature between 0 and 4°C for 9 h and stuffed in polyamide impermeable casings (60 mm diameter to form cooked ham pieces with approximately 1.2 kg each. The ham pieces were cooked in water tanks (80°C) at a commercial pilot plant to reach 72°C. Cooking time was approximately 1 h and 30 min. After the cooking stage, samples were cooled with ice and refrigerated at 0 to 4°C overnight The ham pieces were transported to CTC/ITAL on ice box and immediately sliced for microbiological analysis at arrival. The ham slices (2 to 3 mm) were inoculated with 0.1 mL of of L. monocytogenes ATCC7644, to yield approximately 4 log CFU/g. Inoculated samples were vacuum packaged in gas-impermeable pouches and stored at abuse temperature (7°C), very common in Brazilian retail market, for up to 16 d. Bacterial populations were determined following ISO 11290–2:2017 method. Triplicate samples of each treatment were assayed at 0 time and after 2, 4, 6, 8, 10, and 12 d of storage for L. monocytogenes populations. In addition, triplicate inoculated samples were assayed for lactic acid bacteria populations following ISO 15214:1998 method. Data Interactions and main effects were considered significant at P < 0.05. The data were submitted to analysis of variance to evaluate the effect of the treatments, storage time and the treatment × time interaction using Statistica 7.0 (StaSoft Inc). The difference between the mean values was evaluated by Tukey´s test at the 95% confidence level.ResultsDuring storage, the difference between L. monocytogenes counts in the treatment containing the plant extracts and control was 0.5 log CFU/g. There was a significant effect (P < 0.05) of the interaction treatment versus time on L. monocytogenes growth, the counts remained 0.5 log lower on samples containing the plant extract blend. Lactic acid bacteria counts were below 1.0 Log CFU/g during shelf life for both treatments.ConclusionThese data suggest that the plant extracts blend can enhance the safety of sliced cook in ham. It is important to evaluate the effect in meat systems without nitrite addition or along with other interventions that inhibit growth, like post packaging pasteurization.

Effect of the Duck Skin on Quality Characteristics of Duck Hams

This study was conducted to investigate the effect of duck skin on cooking loss, emulsion stability, pH, color, protein solubility, texture profile analysis (TPA), apparent viscosity, and sensory characteristics of press type duck ham with different ratio of duck breast meat and duck skin. Five duck ham formulations were produced with the following compositions: T1 (duck breast 70% + duck skin 30%), T2 (duck breast 60% + duck skin 40%), T3 (duck breast 50% + duck skin 50%), T4 (duck breast 40% + duck skin 60%), and T5 (duck breast 30% + duck skin 70%). The cooking loss and fat separation were lower in T1, and the total expressible fluid separations were lower in T1 and T2 than others. The pH ranged from 6.48 to 6.59, with the highest values in T4 and T5. T5 had the highest CIE L*-value, and T1 and T2 had the highest CIE a*-values; however, CIE b*-values did not differ significantly between the duck ham samples. The protein solubility and TPA (hardness, springiness, cohesiveness, gumminess, and chewiness) were the highest in T1. T1 and T2 had higher scores for color, tenderness, and overall acceptability. T1, T2, and T3 showed significantly higher values, but there were no significant differences for flavor and juiciness. Regarding apparent viscosity properties, T1 and T2 had higher viscosity values than the other formulations. In conclusion, the T1 (duck breast 70% + duck skin 30%) and T2 (duck breast 60% + duck skin 40%) duck hams show the highest quality characteristics.

Utilization of Phosphate Alternatives to Produce Chunked and Formed Deli Ham

ObjectivesThe objective of this study was to determine the efficacy of replacing phosphate with a natural alternative in chunked and formed deli ham.Materials and MethodsBoneless biceps femoris muscles were chunked into 2.54-cm cubes. Each treatment formulation (6 kg) consisted of approximately 77% pork (85% cubed meat and 15% finely chopped trim to improve protein binding), 20% water, 1.8% salt, 0.9% dextrose, 120 ppm sodium nitrite, 450 ppm sodium erythorbate and the following treatment effects: positive control (0.4% sodium tripolyphosphate, STP), negative control (no phosphate, NP), a 1.3% Fiber Dry Vinegar (FDV) blend, and a 1.1% whey protein concentrate blend (WPC). The ham formulations were vacuum tumbled (25 mm/hg of mercury) for four 20 min intervals with 10 min rest periods in-between. After the rest period of the third interval, the trim was added and the formulation was vacuum tumbled for the final 20 min. The contents of the tumbler were then stuffed into cellulose casings, tipper tied, heat processed in a smokehouse to an internal temperature of 74 C, and sliced into 1.27 cm slices for color and protein bind analysis Consumer acceptability testing (n = 60 panelists) was also conducted using a 9-point hedonic scale. A completely randomized design with 2 replications was utilized to evaluate treatment effects. When significant differences occurred (P < 0.05) among treatments, Fisher’s Protected Least Significance Test was utilized to separate treatment meansResultsThe STP treatment had less cooking loss than all other treatments (P < 0.05) at 9.3%. The cooking loss for the WPC treatment was less (P < 0.05) than that of the NP treatment % but was not different (P > 0.05) from the FDV treatment. The STP treatment had greater protein bind (P < 0.05) than all other treatments. In addition, the FDV treatment had greater protein bind than the WPC and NP treatments. On average, no differences (P < 0.05) existed between treatments with respect to consumer acceptability. Cluster analysis was conducted to determine if any variability could be determined among treatments since all hams were liked. Results indicated that 88% of consumers rated the STP treatment like moderately or greater, 73% of the panelists liked the NP treatment moderately or greater, and 85% of panelists liked the WPC and fiber treatments at least like moderately.ConclusionApplication of WPC or FDV may help meat processors meet current clean label trends if the decrease in cooking yields and firmness of texture was acceptable to processors and or consumers.

Effects of Different Nitrite Concentrations from a Vegetable Source with and without High Hydrostatic Pressure on the Recovery of Listeria monocytogenes on Ready-to-Eat Restructured Ham

Sodium nitrite exerts an inhibitory effect on the growth of Listeria monocytogenes. The objective of this study was to investigate the effects of various nitrite concentrations from a vegetable source with and without high hydrostatic pressure (HHP) on the recovery and growth of L. monocytogenes on ready-to-eat restructured ham. A preconverted celery powder was used as the vegetable source of nitrite. Targeted concentrations of natural nitrite investigated were 0, 50, and 100 mg/kg. HHP treatments evaluated were 400 MPa for 4 min and 600 MPa for 1 or 4 min at 12 ± 2°C (initial temperature of the pressurization fluid). Viable L. monocytogenes populations were monitored on modified Oxford medium and thin agar layer medium through 98 days of storage at 4 ±1°C. Populations on both media did not differ. The HHP treatment at 600 MPa for 4 min resulted in L. monocytogenes populations below the detection limit of our sampling protocols throughout the storage period regardless of the natural nitrite concentration. The combination of HHP at 400 MPa for 4 min or 600 MPa for 1 min with natural nitrite resulted in initial inhibition of viable L. monocytogenes. Ham formulations that did not contain natural nitrite allowed faster growth of L. monocytogenes than did those with nitrite, regardless of whether they were treated with HHP. The results indicate that nitrite from a vegetable source at the concentrations used in this study resulted in slower growth of this microorganism. HHP treatments enhanced the inhibitory effects of natural nitrite on L. monocytogenes growth. Thus, the combination of natural nitrite plus HHP appears to have a synergistic inhibitory effect on L. monocytogenes growth.

Effects of high hydrostatic pressure and varying concentrations of sodium nitrite from traditional and vegetable-based sources on the growth of Listeria monocytogenes on ready-to-eat (RTE) sliced ham

The objective of this study was to determine the effect the source of added nitrite and high hydrostatic pressure (HHP) had on the growth of Listeria monocytogenes on ready-to-eat (RTE) sliced ham. Use of 600MPa HHP for 3min resulted in an immediate 3.9–4.3log CFU/g reduction in L. monocytogenes numbers, while use of 400MPa HHP (3min) provided less than 1log CFU/g reduction. With the 600MPa HHP treatment, sliced ham with a conventional concentration of sodium nitrite (200ppm) was not different in L. monocytogenes growth from use with 50 or 100ppm of sodium nitrite in pre-converted celery powder. Instrumental color values as well as residual nitrite and residual nitrate concentrations for cured (sodium nitrite and nitrite from celery powder) and uncured ham formulations are discussed.

Technological and sensory quality of restructured low-fat cooked ham containing liquid whey

The use of liquid whey to replace water (at 0, 25, 50, 75 or 100%) in a restructured cooked ham formulation was studied and several technological and sensory quality properties were determined. The test results showed no statistically significant differences (P &lt; 0.05) in weight loss attributes (cooking yield, storage loss, reheating loss and refreezing loss) and instrumental texture (TPA test) parameters. However, for CIELAB color, samples were (P &gt; 0.05) less reddish (a* value reduction) and more grayish and yellowish (lesser C* and higher h values) with higher whey additions. A lower (P &lt; 0.05) flavor preference among samples with 25 and 50% liquid whey substitution was observed. Also, the sensory color was different (P &lt; 0.05) in the products formulated with more than 25% of this adjunct, although the overall sensory impression was not affected (P &gt; 0.05). These results suggest that up to 38% natural fresh liquid whey can be added to a restructured cooked ham formulation with similar results to products cured with a conventional formulation.

Effect of l-Glucose and d-Tagatose on Bacterial Growth in Media and a Cooked Cured Ham Product

Cured meats such as ham can undergo premature spoilage on account of the proliferation of lactic acid bacteria. This spoilage is generally evident from a milkiness in the purge of vacuum-packaged sliced ham. Although cured, most hams are at more risk of spoilage than other types of processed meat products because they contain considerably higher concentrations of carbohydrates, ∼2 to 7%, usually in the form of dextrose and corn syrup solids. Unfortunately, the meat industry is restricted with respect to the choice of preservatives and bactericidal agents. An alternative approach from these chemical compounds would be to use novel carbohydrate sources that are unrecognizable to spoilage bacteria. l-Glucose and d-tagatose are two such potential sugars, and in a series of tests in vitro, the ability of bacteria to utilize each as an energy source was compared to that of d-glucose. Results showed that both l-glucose and d-tagatose are not easily catabolized by a variety of lactic bacteria and not at all by pathogenic bacteria such as Escherichia coli O157:H7, Salmonella Typhimurium, Staphylococcus aureus, Bacillus cereus, and Yersinia enterocolitica. In a separate study, d-glucose, l-glucose, and d-tagatose were added to a chopped and formed ham formulation and the rate of bacterial growth was monitored. Analysis of data by a general linear model revealed that the growth rates of total aerobic and lactic acid bacteria were significantly (P < 0.05) slower for the formulation containing d-tagatose than those containing l-or d-glucose. Levels of Enterobacteriaceae were initially low and these bacteria did not significantly (P < 0.20) change in the presence of any of the sugars used in the meat formulations. Compared to the control sample containing d-glucose, the shelf life of the chopped and formed ham containing d-tagatose at 10°C was extended by 7 to 10 days. These results indicate that d-tagatose could deter the growth of microorganisms and inhibit the rate of spoilage in a meat product containing carbohydrates.

A RESEARCH NOTE EVALUATION OF RESTRUCTURED LOW‐FAT HAM CONTAINING WHEY

ABSTRACT Restructured, low‐fat boneless ham was formulated with 0 (control samples), 20, and 30% liquid whey to replace water in the cure formulation. Sensory characteristics, visual traits, objective color, tenderness measurements, weight and cooking loss, proximate analysis, and microbial load were determined to compare this product with that from a conventional cure formulation. No differences (P&gt;0.05) in traits (except percentage moisture) were found among samples with 0, 20, and 30% liquid whey in the formulated hams. A lower (P&lt;0.05) moisture content among samples with 30% of this adjunct when compared to the controls was observed. However, samples with 20% liquid whey addition did not differ (P&gt;0.05) from those with 0 and 30%. These results suggest that up to 30% liquid whey may be incorporated in a cured, low‐fat ham formulation with similar results to products cured with a conventional formulation.

Optimization of a ham formulation

SummaryThe functionality of a ham formulation was examined with respect to variation in both blend and amount of added ingredients. This allowed the determination of how the individual attributes: cooking loss, syneresis and gel strength, changed in response to ingredient addition. Optimizing the ingredient proportions and addition level that determined acceptable functionality was addressed using a method that took account of how cooking loss, syneresis and gel strength change over the blend/amount region. the optimization led to the identification of a suitable formulation. the more general problem of how best to identify an optimum in food systems when faced with differing units of measurement and differing ranges of individual response is discussed by examining specialized distance measures, or metrics. By allowing the performance of the food system to be monitored these allow a compromise to be determined between possibly conflicting optimal values on individual responses.