Development of a quantitative microbiological spoilage risk assessment (QMSRA) model for cooked ham sliced at retail.

A quantitative microbiological spoilage risk assessment model (QMSRA) for cooked ham sliced at retail was developed based on a stochastic growth model for lactic acid bacteria (LAB), which are considered as the specific spoilage organisms (SSO), and a "spoilage-response" relationship characterizing the variability in consumer's perception of spoilage. In a simulation involving 10,000 cooked ham purchases, the QMSRA model predicted a median of zero spoilage events for up to 4.5 days of storage. After storage times of 5 and 6 days, the model predicted 1,790 and 8,570 spoilage events, respectively. A sensitivity analysis showed that domestic storage temperature was the most significant factor affecting LAB concentration in cooked ham, followed by the LAB contamination level at slicing. A scenario analysis was performed testing better temperature control of consumer's refrigerators, better hygiene conditions during slicing and a combination of the two strategies. Among the tested scenarios, a 2 log reduction in the LAB contamination at slicing combined with a 2 °C decrease in domestic storage temperature resulted in zero risk of spoilage for up to 12 days of storage. The QMSRA model developed in the present study can be a useful tool for quality management decisions.

Effects of ultrasound-assisted intermittent tumbling on the quality of cooked ham through modifying muscle structure and protein extraction.

BACKGROUND: Tumbling treatment is widely used in the production of cooked ham. However, traditional intermittent tumbling (IT) treatment is time-consuming. To enhance the tumbling efficiency, high-intensity ultrasound was used to assist IT treatment (UIT). RESULTS: UIT treatment reduced the tumbling time and significantly improved the water holding capacity, tenderness, sliceability and texture of cooked ham compared to IT treatment. Furthermore, more violent destruction of meat tissue was exhibited in the UIT treatment. This change facilitated extraction of more salt-soluble protein, which in turn welded meat pieces tightly and improved the quality of the cooked ham. CONCLUSION: UIT treatment could accelerate the tumbling process and enhance the quality of cooked ham. These results may provide guidance on effective strategies for a high-quality meat production process. © 2023 Society of Chemical Industry.

Development and Innovation in Cooked Ham Produced in Spain.

The production of cooked ham has been gaining popularity in recent years in Spain. In general, the production process carried out by the companies remains traditional, and different production methods are therefore being sought to innovate and improve the quality of the product. This is either through pig crossbreeding, varying additives and ingredients, improving some stages of the production process, or providing nutritional and health claims that are useful to guiding the purchasing decision of consumers. Obviously, this series of changes must be subject to Spanish and European regulations in order to be marketed inside and outside the country.

Selection of food cultures with protective properties for cooked ham.

Sliced cooked ham stored in modified atmosphere packaging (MAP) can be spoiled by lactic acid bacteria (LAB) which are dominating under psychrotrophic conditions. Depending on the strains, the colonization can result in a premature spoilage characterized by off-flavors, gas and slime production, discoloration, and acidification. The purpose of this study was the isolation, identification and characterization of potential food culture with protective properties, able to prevent or delay spoilage in cooked-ham. The first step was to identify by means of microbiological analysis, the microbial consortia both in unspoiled and in spoiled lots of sliced cooked ham by the use of media for the detection lactic acid bacteria and total viable count. Counts ranged from values lower than 1 Log CFU/g to 9 Log CFU/g in spoiled and unflawed samples. The interaction between consortia was then studied in order to screen for strains able to inhibit spoilage consortia. Strains showing antimicrobial activity were identified and characterized by molecular methods and tested for their physiological features. Among a total of 140 strains isolated, nine were selected for their ability to inhibit a large number of spoilage consortia, to grow and ferment at 4 °C and to produce bacteriocins. The effectiveness of the fermentation made by food culture was evaluated, through challenge tests in situ, analysing the microbial profiles of artificially inoculated cooked-ham slices during storage by high throughput 16 S rRNA gene sequencing. The native population in situ resulted competitive against the inoculated strains and only one strain was able to significantly reduce the native populations reaching about 46.7% of the relative abundance. The results obtained in this study provide information about the selection of autochthonous LAB on the base of their action against spoilage consortia, in order to select protective potential cultures able to improve the microbial quality of sliced cooked ham.

Evaluation of Commercial Anti-Listerial Products for Improvement of Food Safety in Ready-to-Eat Meat and Dairy Products.

In ready-to-eat products, such as cooked ham, fresh cheese, and fuet in which Listeria monocytogenes is a concern, the use of biopreservation techniques represents an additional hurdle to inhibit pathogen growth during storage. The objective of this study was to apply several biopreservation techniques in three different food matrices to reduce the growth of Listeria innocua, used as a surrogate of L. monocytogenes. Several lactic acid bacteria, the bacteriocin nisin, the bacteriophage PhageGuard ListexTM P100, and the enzyme lysozyme were evaluated. Cooked ham treated with the bacteriophage PhageGuard ListexTM at 0.5% or with the lactic acid bacteria SafePro® B-SF-43 (25 g/100 kg) reduced L. innocua population to below the detection limit after 7 days of storage (4 °C plus modified atmosphere packaging). In fresh cheese, the application of PhageGuard ListexTM at 0.2 and 0.5% reduced L. innocua counts by more than 3.4 logarithmic units after 6 days at 4 °C. In fuet, the 1.0% of PhageGuard ListexTM reduced L. innocua population by 0.7 ± 0.2 logarithmic units in front of control with no significant differences to other evaluated biopreservative agents. The present results confirm that the application of biopreservation techniques was able to inhibit L. innocua in fuet, cooked ham, and fresh cheese, and suggest that the type of food matrix and its physicochemical characteristics influence the biopreservative efficacy.

Target analysis and retrospective screening of contaminants in ready-to-eat cooked ham samples through UHPLC-Q-Orbitrap HRMS.

The use of veterinary drugs (VDs) is widely administered to animals for both therapeutic and prophylactic purposes. However, their improper use may involve their occurrence in the final products intended for human consumption. In this scientific work, a method for the investigation of target (n = 30) VDs residues and retrospective suspect screening followed by confirmation using analytical standards of others 38 contaminants in ready-to-eat cooked ham by ultra-high performance liquid chromatography coupled with high-resolution mass spectrometry (UHPLC-Q-Orbitrap HRMS) was developed. The extraction was performed based on the QuEChERS approach and validated in accordance with the European Regulation 2021/808. The application of the in-house validated method to ready-to-eat cooked ham showed the occurrence of fourteen VDs residues. Despite the important incidence, the concentration levels found were below the maximum residue limits set for VDs in porcine muscle, except for colchicine. Constant monitoring of animals derived food is strongly recommended to ensure the food safety of consumers.

Reddish Colour in Cooked Ham Is Developed by a Mixture of Protoporphyrins Including Zn-Protoporphyrin and Protoporphyrin IX.

The nitrosyl-heme complex is considered the pigment responsible for the development of reddish colour in cooked hams. However, the same reddish colour was observed in a nitrite-free product elaborated with polyphenols, suggesting the presence of other red pigments that can contribute to generate this colour. In this study, the protoporphyrins composition of the pigment solution obtained from nitrite and nitrite-free cooked hams was analysed using 80% (v/v) acetone/water solution for extraction. Chromatographic analysis using a combination of diode array and fluorescence detectors revealed the presence of protoporphyrin IX and Zn-protoporphyrin IX in this solution, and these protoporphyrins were subsequently identified with complete certainty by mass spectrometry. These results show how the colour of cooked hams can be developed by a mixture of different protoporphyrins and also demonstrate the absence of selectivity of acetone/water extraction for measuring the content of nitrosyl-heme in cooked hams.

Microbiota Survey of Sliced Cooked Ham During the Secondary Shelf Life.

Sliced cooked ham packaged in a modified atmosphere is a popular ready-to-eat product, subjected to abundant microbial contamination throughout its shelf life that can lead to deterioration of both sensorial properties and safety. In this study, the microbial load and the chemical-physical features of cooked ham of five producers were monitored for a period of 12 days after the opening of the packages (i.e., the secondary shelf life), during which the products were stored in a domestic refrigerator at 5.2 ± 0.6°C. The sensorial properties presented a perceivable decay after 8 days and became unacceptable after 12 days. High-performance liquid chromatography analysis and solid-phase microextraction coupled with gas chromatography profiling of volatile metabolites indicated that lactic acid, ethanol, acetic acid, acetoin, 3-methyl-1-butanol, and 2-3 butanediol were the main metabolites that characterized the evolution of the analyzed cooked ham. The microbiota was monitored by 16S ribosomal RNA gene profiling and culture-dependent techniques. Already at the opening of packages, all the products presented high microbial load, generally dominated by lactic acid bacteria, with evident differences among the products. The increase of lactic acid bacteria somehow protected samples from abundant contamination by other bacteria, concurring with the evolution of more safe products. This role was exerted by numerous Latilactobacillus, Leuconostoc, and Carnobacterium species, among which the most frequently detected were Latilactobacillus sakei, Latilactobacillus sakei carnosum, Leuconostoc mesenteroides, and Carnobacterium divergens. Some products presented more complex communities that encompassed Proteobacteria such as Moellerella wisconsensis, Proteus hauseri, Brochothrix thermosphacta, and less frequently Pseudomonas, Erwinia, and Massilia. Opportunistic pathogenic bacteria such as Escherichia coli and Vibrio sp. were found in small quantities. The yeasts Kazachstania servazzii and Debaryomyces hansenii occurred already at 0 days, whereas various species of Candida (Candida zeylanoides, Candida sake, Candida norvegica, and Candida glaebosa) were abundant only after 12 days. These results indicated that the microbiological contaminants overgrowing during the secondary shelf life did not derive from environmental cross-contamination at the opening of the tray but were already present when the packages were opened, highlighting the phases of production up to the packaging as those crucial in managing the safety risk associated to this product.

Development of GLM regression models to predict the consumer acceptability of cooked ham based on analytical parameters.

Due to concerns about meat quality, health, sustainability and animal welfare, the typical Belgian meat products such as cooked ham are being threatened by a negative reputation. To address these concerns, an objective quality assessment tool was developed that could predict the consumer acceptability for a range of sensorial descriptors based on analytical parameters. A total of 28 commercial cooked hams were evaluated by a sensorial panel of consumers while simultaneously, a broad range of analytical tests were conducted on the same hams. Per sensorial descriptor, the analytical results and consumer acceptability for all cooked hams were processed by Generalized Linear Modelling (GLM). This holistic approach makes it possible to predict the consumer acceptability of a sensorial descriptor with great reliability and robustness by only using objective analytical parameters. An efficient R&D tool was developed to optimize the sensorial and analytical quality of the cooked ham that meets consumer demands.

Combination of High-Pressure Treatment at 500 MPa and Biopreservation with a Lactococcus lactis Strain for Lowering the Bacterial Growth during Storage of Diced Cooked Ham with Reduced Nitrite Salt.

We investigated the combined effects of biopreservation and high-pressure treatment on bacterial communities of diced cooked ham prepared with diminished nitrite salt. First, bacterial communities of four commercial brands of diced cooked ham from local supermarkets were characterized and stored frozen. Second, sterile diced cooked ham, prepared with reduced levels of nitrite, was inoculated with two different microbiota collected from the aforementioned commercial samples together with a nisin-producing Lactococcus lactis protective strain able to recover from a 500 MPa high-pressure treatment. Samples were then treated at 500 MPa for 5 min, and bacterial dynamics were monitored during storage at 8 °C. Depending on samples, the ham microbiota was dominated by different Proteobacteria (Pseudomonas, Serratia, Psychrobacter, or Vibrio) or by Firmicutes (Latilactobacillus and Leuconostoc). Applied alone, none of the treatments stabilized during the growth of the ham microbiota. Nevertheless, the combination of biopreservation and high-pressure treatment was efficient in reducing the growth of Proteobacteria spoilage species. However, this effect was dependent on the nature of the initial microbiota, showing that the use of biopreservation and high-pressure treatment, as an alternative to nitrite reduction for ensuring cooked ham microbial safety, merits attention but still requires improvement.

Review: Pork quality attributes from farm to fork. Part II. Processed pork products.

Pork is often consumed in a very wide variety of products, processed from integral cuts or minced meat using different conservation methods (curing, smoking, cooking, drying, fermenting). Quality of pork products results from a combination between the properties of the raw material and the processing conditions to elaborate the final products. The influence of primary production factors, slaughtering and carcass processing on the quality of fresh pork has been reviewed (part 1), considering quality as an integrative combination of various attributes: commercial, organoleptic, nutritional, technological, convenience, and societal image, the latter denotes cultural, ethical (including animal welfare) and environment dimensions related to the way pork is produced, processed, and its geographical origin. This review (part 2) focuses on the influence of primary production factors and processing techniques on the quality of two important and economically significant processed pork products issued from contrasting processing techniques: cooked ham and dry-cured ham. As with fresh pork, many factors influence the quality of processed products, and one factor can affect several attributes. Moreover, in the case of processed products, numerous factors in both animal production and processing steps interact to determine their quality attributes. The quality of cooked ham depends on the properties of the raw material (in particular pH, colour, water holding capacity, presence of destructured meat defect, etc.) which are determined by pig husbandry practices (especially the genotype), pre-, postslaughter and processing conditions including the composition of curing mixture (ingredients, additives), salting, mixing and heat treatment. Processing techniques of cooked ham aim at homogenising the product quality within a given quality category (e.g. 'standard' or 'superior') or brand. Therefore, the variability of raw material is problematic for the cooked ham processing industry, which generally seeks uniformity and homogeneity of fresh hams. Likewise, pig husbandry conditions exert even greater impact on dry-cured ham quality. Indeed, the properties of raw material (including weight of fresh ham, fat thickness, pH, intramuscular fat and antioxidants content, fatty acid profile, etc.) that result from combined effects of primary production factors (genotype, feeding, production system, etc.) interact with processing conditions (salting, drying, ripening conditions and duration, etc.) to elaborate the quality attributes of the final products. Synergies can be sought between the primary production factors and processing techniques leading to specific organoleptic characteristics (texture, taste, aroma, flavour, etc.) that can be valued by quality labels. Quality of products is thus built along the whole chain from farm to fork.

The Microbiota of Modified-Atmosphere-Packaged Cooked Charcuterie Products throughout Their Shelf-Life Period, as Revealed by a Complementary Combination of Culture-Dependent and Culture-Independent Analysis.

Although refrigeration and modified-atmosphere packaging (MAP) allow for an extended shelf life of cooked charcuterie products, they are still susceptible to bacterial spoilage. To obtain better insights into factors that govern product deterioration, ample information is needed on the associated microbiota. In this study, sliced MAP cooked ham and cooked chicken samples were subjected to culture-dependent and culture-independent microbial analysis. In total, 683 bacterial isolates were obtained and identified from 60 samples collected throughout the storage period. For both charcuterie types, lactic acid bacteria (LAB) constituted the most abundant microbial group. In cooked ham, Brochothrix thermosphacta was highly abundant at the beginning of the shelf-life period, but was later overtaken by Leuconostoc carnosum and Lactococcus piscium. For cooked chicken products, Latilactobacillus sakei was most abundant throughout the entire period. Additionally, 13 cooked ham and 16 cooked chicken samples were analyzed using metabarcoding. Findings obtained with this method were generally in accordance with the results from the culture-dependent approach, yet they additionally demonstrated the presence of Photobacterium at the beginning of the shelf-life period in both product types. The results indicated that combining culture-dependent methods with metabarcoding can give complementary insights into the evolution of microorganisms in perishable foods.

Effects of the Consumption of Low-Fat Cooked Ham with Reduced Salt Enriched with Antioxidants on the Improvement of Cardiovascular Health: A Randomized Clinical Trial.

The aim of the study was to analyze how cardiovascular risk factors can be modified using nutritionally improved cooked ham enriched with a pool of antioxidants to influence relevant metabolic targets. Sixty-five untreated subjects (49.2% males, 50.8% females, mean age 40.92 ± 9.03 years) with total cholesterol level ≥180 mg/dL or LDL cholesterol ≥130 mg/dL participated in a 8-weeks randomized, double-blind controlled trial. Participant in the intervention group (51.5% males, 48.5% females, mean age 41.6 ± 9.8 years and mean BMI 25.1 ± 3.6 kg/m2) consumed cooked ham enriched with antioxidants (100 g/d) and controls (49.9% males, 53.1% females, mean age 40.2 ± 8.3 years and mean BMI 26.3 ± 3.2 kg/m2) received placebo. At 8 weeks, oxidized LDL decreased significantly between experimental and placebo groups (p < 0.036). Experimental group differences were also significant (p < 0.05). Similar findings in malondialdehyde, total cholesterol, high-sensitivity C-reactive protein, and interleukin 6 were observed in the intervention group. Significant between-group differences in these variables were also found, except for total cholesterol and interleukin 6. The effects on inflammation and oxidation support the direct action of these antioxidants on the etiopathogenic factors of atheromatous plaque. We also observed an improvement in the lipid profiles among the subjects.

Basil Essential Oil: Composition, Antimicrobial Properties, and Microencapsulation to Produce Active Chitosan Films for Food Packaging.

The essential oil (EO) from basil-Ocimum basilicum-was characterized, microencapsulated by vibration technology, and used to prepare a new type of packaging system designed to extend the food shelf life. The basil essential oil (BEO) chemical composition and antimicrobial activity were analyzed, as well as the morphological and biological properties of the derived BEO microcapsules (BEOMC). Analysis of BEO by gas chromatography demonstrated that the main component was linalool, whereas the study of its antimicrobial activity showed a significant inhibitory effect against all the microorganisms tested, mostly Gram-positive bacteria. Moreover, the prepared BEOMC showed a spheroidal shape and retained the EO antimicrobial activity. Finally, chitosan-based edible films were produced, grafted with BEOMC, and characterized for their physicochemical and biological properties. Since their effective antimicrobial activity was demonstrated, these films were tested as packaging system by wrapping cooked ham samples during 10 days of storage, with the aim of their possible use to extend the shelf life of the product. It was demonstrated that the obtained active film can both control the bacterial growth of the cooked ham and markedly inhibit the pH increase of the packaged food.

Large microbiota survey reveals how the microbial ecology of cooked ham is shaped by different processing steps.

Cooked ham production involves numerous steps shaping the microbial communities of the final product, with consequences on spoilage metabolites production. To identify the main factors driving the ecology of ham and its spoilage, we designed a study encompassing five variables related to ham production: type of storage during meat transportation, churning speed, drain-off time, slicing line and O2 packaging permeability. About 200 samples from the same facility were obtained and characterized with respect to i) their microbiota based on gyrB amplicon sequencing ii) their production of spoilage-related metabolites based on E-Nose analysis and enzymatic assays. The slicing was the most critical step, shaping two general types of microbiota according to the slicing line: one dominated by Carnobacterium divergens and another one dominated by Leuconostoc carnosum and Serratia proteamaculans. Regarding metabolites production, L. carnosum was associated to d-lactic acid, ethanol and acetic acid production, whereas Serratia proteamaculans was associated to acetic acid production. This last species prevailed with highly O2-permeable packaging. Within a given slicing line, campaign-based variations were observed, with Lactobacillus sakei, Leuconostoc mesenteroides and Carnobacterium maltaromaticum prevalent in summer. L. sakei was associated with l-lactic acid production and C. maltaromaticum with formic and acetic acid productions.

Application of Natural Pigments in Ordinary Cooked Ham.

The possibility of obtaining a carmine or pink color on ordinary cooked ham by applying natural dyes from three plant species, namely red radish (Raphanus sativus L.), hibiscus (Roselle sabdariffa L.) and red beetroot (Beta vulgaris L.), was investigated. The extracts were evaluated for the stability at physical-chemical parameters and subjected to cytotoxicity assays in the gastric cell line AGS Encapsulation of the extracts in soybean lecithin liposomes and maltodextrin microcapsules was performed. Lyophilized extracts before and after encapsulation in maltodextrin were applied in the formulation of ordinary cooked ham and used in a pilot scale of production. The color of cooked ham samples from different assays was evaluated visually and by colorimetry. The results suggest that the coloration of ordinary cooked ham obtained with extracts of red beetroot is very promising for future applications in this type of meat product.

Impact of raw ham quality and tumbling time on the technological properties of polyphosphate-free cooked ham.

The effect of tumbling time (5 h30, 19 h and 26 h) and raw ham quality (superior, inferior or mixed quality) on the quality of polyphosphate-free cooked ham was investigated. The water holding capacity and total yield of the polyphosphate-free tumbled hams were dependent on both tumbling time and ham quality. Higher values of both parameters were obtained with an increase in tumbling time from 5 h30 to 19 h and with superior hams. The exudate after 19 h and 26 h tumbling showed a higher gel forming ability compared to 5 h30, which, in case of polyphosphate-free cooked hams produced with mixed and inferior meat quality, resulted in a better sliceability (less holes). However, tumbling time did not affect hardness, which was only influenced by ham quality, resulting in a softer polyphosphate-free cooked ham produced with inferior ham quality compared to the other quality classes.

Regulation of Inflammatory Response and the Production of Reactive Oxygen Species by a Functional Cooked Ham Reformulated with Natural Antioxidants in a Macrophage Immunity Model.

Nowadays, more consumers demand healthier products. A way to offer such products is to functionalize them using health-promoting bioactive compounds. Meat and meat products are high in essential nutrients; however, their excessive consumption implies a high intake of other substances that, at levels above recommended uptake limits, have been linked to certain non-communicable chronic diseases. An effective way to reduce this danger is to reformulate meat products. In this study, natural botanical extracts rich in anti-inflammatory and antioxidant compounds were used to improve the health properties of a cooked ham with an optimal nutritional profile (i.e., low in fat and salt). The RAW 264.7 mouse cell line was used as an inflammatory model and was stimulated with Escherichia coli lipopolysaccharide to evaluate changes in inflammatory biomarkers such as tumour necrosis factor alpha, the interleukins (ILs) IL-1ß and IL-6, nitric oxide and intracellular reactive oxygen species (ROS). The results showed that the use of natural extracts in optimized cooked ham significantly downregulated inflammatory markers and reduced the levels of intracellular ROS. Thus, the present study proposed a new functional cooked ham with potential health properties via anti-inflammatory and antioxidant in vitro activity.

Protein aggregation in cooked pork products: New details on the supramolecular organization.

The molecular weight distribution of protein aggregates from raw meat and cooked pork products was assessed by size exclusion-high performance liquid chromatography (SE-HPLC). Electrophoretic analysis under reducing conditions showed that the high molecular weight SE-HPLC peak (peak 1) of the cooked products contained protein aggregates in addition to high molecular weight muscle proteins, while the second peak (peak 2) still contained aggregates and <50 kDa proteins. The protein aggregates composition was investigated by HPLC-tandem mass spectrometry. Different classes of proteins were identified and the cooked products showed a more complex composition and organization, according to the muscle structure and the technological procedures, respectively. The key role of actin in the building of the protein networks was also confirmed. The different multi-protein systems found in the cooked products suggest protein re-organization in heat-induced supramolecular structures, which might be responsible for the texture and the structural properties of the final products.

Effect of cranberry pomace extracts isolated by pressurized ethanol and water on the inhibition of food pathogenic/spoilage bacteria and the quality of pork products.

Ethanol and water extracts were prepared from defatted cranberry pomace by pressurized liquid extraction and tested in bacterial cultures of L. monocytogenes, B. thermospacta, P. putida, lactic acid bacteria (LAB), aerobic mesophilic bacteria (AMB), and pork meat products. Anthocynanins (glucosides, galactosides and arabinosides of cyanidin and peonidins), phenolic compounds and organic acids (quinic, chlorogenic, malic and citric acids; procyanidin B3, myricetin and quercetin derivatives) were determined in the extracts. The extracts effectively inhibited the growth of tested bacteria at higher than 3.3% concentration. The effect of 2% ethanol extract additive on the inhibition of the same bacteria was also determined in non-inoculated and inoculated with bacteria pork slurry, pork burgers, and cooked ham. The results showed a significant growth inhibition of pathogenic L. monocytogenes and some other species in pork slurry, burgers and cooked ham with cranberry pomace ethanol extract as compared with the control samples. The extract also effectively inhibited the formation of oxidation indicator malondialdehyde in meat products. Slight impact of extract on some physico-chemical properties of meat products such as pH, metmyoglobin content was also observed, while it did not have significant influence on water activity. Extract addition imparted some color changes; however, it did not have negative effect on the overall sensory quality of burgers and cooked ham. High effectiveness of extract additive against pathogenic L. monocytogenes and some other tested bacteria in pork slurry, burgers and cooked ham during refrigerated storage for 16, 16 and 40 days, respectively, suggest that ethanol extract of defatted cranberry pomace may be a promising natural ingredient of meat products for increasing their microbiological safety and improving oxidative stability.