Influence of high pressure application on the nutritional, sensory and microbiological characteristics of sliced skin vacuum packed dry-cured ham. Effects along the storage period

High-pressure processing enhances saltiness perception and sensory acceptability of raw but not of cooked cured pork loins-leveraging salty and umami taste

The salt (NaCl) content in processed meats must be reduced because of its adverse effects on cardiovascular health. However, reducing salt in meat products typically leads to a lower taste intensity and, thus, consumer acceptability. Industry interventions must reduce salt content while maintaining taste, quality, and consumer acceptability. In this context, high-pressure processing (HPP) has been proposed to enhance saltiness perception, though there are contradictory reports to date. The present work aimed to conduct a targeted experiment to ascertain the influence of HPP (300/600 MPa) and cooking (71°C) on saltiness perception and sensory acceptability of meat products. HPP treatment (300/600 MPa) did enhance those two sensory attributes (approx. +1 on a 9-point hedonic scale) in raw (uncooked) cured pork loins but did not in their cooked counterparts. Further, the partition coefficient of sodium (PNa+), as an estimate of Na+ binding strength to the meat matrix, and the content of umami-taste nucleotides were investigated as potential causes. No effect of cooking (71°C) and HPP (300/600 MPa) could be observed on the PNa+ at equilibrium. However, HPP treatment at 300 MPa increased the inosine-5'-monophosphate (IMP) content in raw cured pork loins. Finally, hypothetical HPP effects on taste-mediating molecular mechanisms are outlined and discussed in light of boosting the sensory perception of raw meat products as a strategy to achieve effective salt reductions while keeping consumer acceptability.

Assessing the Impact of Pomegranate Peel Extract Active Packaging and High Hydrostatic Pressure Processing on Color and Oxidative Stability in Sliced Nitrate/Nitrite-Reduced Iberian Dry-Cured Loins

Our study aimed to assess the impact of active packaging with pomegranate peel extract (0.06 mg gallic acid eq./cm2) and/or high-pressure treatment (600 MPa, 7 min) on the instrumental color, lipid, and protein oxidation of Iberian dry loins formulated with reduced nitrate/nitrite levels (0, 37.5, and 150 mg/kg) during 100-day refrigerated storage (4 °C). CIE L*a*b* coordinates were measured, and malondialdehyde, carbonyls, and free thiol contents served as markers for lipid and protein oxidation. Active packaging lowered CIE L* (35.4 vs. 34.1) and a* (15.5 vs. 14.5) and increased yellowness (15.6 vs. 16.3) and hue (45.2 vs. 48.4), while pressurization increased CIE L* (33.1 vs. 36.3) and diminished a* values (16.1 vs. 13.9). Ongoing nitrate/nitrite amounts significantly influenced lipid peroxidation, protein carbonyl formation, and free thiol loss. Active packaging and high-pressure processing had varying effects on carbonyl and thiol contents. Neither pressurization nor active packaging impacted malondialdehyde formation. Pressurization enhanced the formation of 4-HNE (503 vs. 697 pg/g). Protein oxidation proved more sensitive to changes, with active packaging offering protection against protein carbonylation (15.4 vs. 14.7 nmol carbonyls/mg protein), while pressurization induced thiol loss (34.3 vs. 28.0 nmol Cys eq./mg protein). This comprehensive understanding provides essential insights for the meat industry, emphasizing the necessity for customized processing conditions to enhance color stability, lipid preservation, and protein integrity in dry-cured loin slices.

Principles and Applications of Non-Thermal Technologies for Meat Decontamination

Meat contains high-value protein compounds that might degrade as a result of oxidation and microbial contamination. Additionally, various pathogenic and spoilage microorganisms can grow in meat. Moreover, contamination with pathogenic microorganisms above the infectious dose has caused foodborne illness outbreaks. To decrease the microbial population, traditional meat preservation methods such as thermal treatment and chemical disinfectants are used, but it may have limitations for the maintenance of meat quality or the consumers acceptance. Thus, non-thermal technologies (e.g., high-pressure processing, pulsed electric field, non-thermal plasma, pulsed light, supercritical carbon dioxide technology, ozone, irradiation, ultraviolet light, and ultrasound) have emerged to improve the shelf life and meat safety. Non-thermal technologies are becoming increasingly important because of their advantages in maintaining low temperature, meat nutrition, and short processing time. Especially, pulsed light and pulsed electric field treatment induce few sensory and physiological changes in high fat and protein meat products, making them suitable for the application. Many research results showed that these non-thermal technologies may keep meat fresh and maintain heat-sensitive elements in meat products.

Effect of sodium salt on meat products and reduction sodium strategies - A review

Sodium salt is one of the important additives in food processing. However, excessive intake of sodium salt may cause a series of cardiovascular diseases. Nowadays, sodium intake in most countries is higher than the World Health Organization recommends maximum consumption (5 g/d). 20% of the sodium intake in diets comes from meat products. Therefore, reducing the content of sodium salt in meat products and developing sodium salt-reduction meat products have attracted more and more attention for consumers. In this paper, the roles of sodium salt in meat product processing were reviewed. At the same time, sodium salt reduction strategies and existing problems were summarized and discussed. Multiple factors need to be considered to improve the salt-reduction meat product's quality. Relying on a single technology has a narrow application area, and it is difficult to achieve salt reduction. Therefore, a combination of multiple strategies could obtain a more ideal effect.

Effect of Partial Substitution of Sodium Chloride (NaCl) with Potassium Chloride (KCl) Coupled with High-Pressure Processing (HPP) on Physicochemical Properties and Volatile Compounds of Beef Sausage under Cold Storage at 4 °C

This study aimed to evaluate the effects of partial substitution of sodium chloride (NaCl) with potassium chloride (KCl) in combination with high-pressure processing (HPP) on the physicochemical properties and volatile compounds of beef sausage during cold storage at 4 °C. Significant differences were found in the volatile compounds of beef sausages with 0%, 25%, and 50% NaCl contents partially substituted with KCl subjected to 28 days of storage and were well-visualized by heat map analysis. A total of 75 volatile compounds were identified and quantified in the beef sausages at the end of 28 days of storage, including 12 aldehydes, 4 phenols, 2 ketones, 18 alcohols, 8 acids, 3 esters, 14 terpenes, and 14 alkanes. Thirteen compounds had low odor activity values (OAV) (OAV < 1); however, high OAV (OAV > 1) were obtained after partial substitution of NaCl by KCl at 25% and 50% with HPP treatment compared to the non-HPP treated samples. In addition, 50% NaCl substitution with KCl in conjunction with HPP treatments increased thiobarbituric acid reactive substances (TBARS) by (0.46 ± 0.03 mg/MDA) compared with no HPP treatments. Replacement of 25% and 50% NaCl with KCl decreased TBARS by an average of 10.8% and 11.10%, respectively, compared to 100% NaCl coupled with HPP beef sausages. In summary, HPP and partial substitution of NaCl with KCl at 25% and 50% can be used to compensate for the reduction of NaCl in beef sausage by keeping the physical and flavor fraction at required levels.

Combined Effect of High-Pressure Processing with Spice Extracts on Quality of Low-Salt Sausage during Refrigerated Storage

The study evaluated the combined effect of high-pressure processing (HPP) and spice extracts on low-salt sausages during refrigerated storage. Physicochemical and microbiological characteristics of the sausages were determined. HPP treatment increased the thiobarbituric acid reactive substances (TBARS) value and the carbonyl content of the samples (p < 0.05), which meant lipid and protein oxidation was accelerated. Adding clove and cinnamon extracts can retard the oxidation caused by HPP (p < 0.05). The pH of the sausages treated with both the spice extracts and HPP maintained a higher pH value during the storage (p > 0.05). Compared with the samples treated with HPP or with the spice extracts alone, the combined treatment observably inhibited the growth of spoilage bacteria (p < 0.05) and improved the microbial community. The results demonstrated that the use of clove and cinnamon extracts in conjunction with HPP improved the storage quality and prolonged the shelf-life of the low-salt sausages. Thus, the combined use of spice extracts and HPP can be developed as a promising way to preserve low-salt meat products.

Volatile compounds in high-pressure-treated dry-cured ham: A review

The use of high pressure processing (HPP) for the treatment of dry-cured ham and other meat products has considerably increased worldwide. Its well-documented lethal effect on pathogenic and spoilage bacteria ensures the microbial safety of dry-cured ham and extends its shelf life. However, the effects of HPP on the volatile compounds, odor and aroma of dry-cured ham are less known. In the present review, the effects of HPP on the enzymes and microorganisms responsible for the generation of volatile compounds in dry-cured ham and the changes in the levels of the main groups of volatile compounds resulting from different HPP treatments are discussed. Particular attention is devoted to the fate of odor-active compounds after HPP treatments and throughout further commercial storage. The use of efficient sensory techniques yielding odor and aroma outputs closer to those perceived by consumers is encouraged. Needs for future research on the volatile compounds, odor and aroma of HPP-treated dry-cured ham are highlighted.

Sodium Reduction in Traditional Fermented Foods: Challenges, Strategies, and Perspectives

Sodium salt is a pivotal ingredient in traditional fermented foods, but its excessive consumption adversely affects human health, product quality, and production efficiency. Therefore, reducing sodium salt content in traditional fermented foods and developing low-sodium fermented foods have attracted increasing attention. Given the essential role of sodium salt in the safety and quality of fermented foods, appropriate approaches should be applied in the production of low-sodium fermented foods. In this review, the challenges of sodium reduction in traditional fermented foods are presented, including the possible growth of pathogenic bacteria, the formation of hazardous chemicals, flavor deficiency, and texture deterioration. Physical, chemical, and biological strategies are also discussed. This review provides references for improving the quality and safety of low-sodium fermented foods.

Effect of high-pressure treatment and storage temperature on top-quality (Montanera) Iberian dry-cured pork sausages (chorizo)

The stability after hydrostatic high pressure (HHP) (600 MPa/8 min/10 °C) and 180 days of storage at 4 and 20 °C was evaluated on Iberian dry-cured pork sausages (chorizo) packaged sliced or as half-pieces from pigs raised outdoors. Microbiological, physical-chemical, oxidative, and sensory changes were analyzed. The evolution of mesophilic aerobic and molds and yeasts counts was different in the half and sliced packaged pork sausages after processing and during storage. Sliced and half-packaged pork sausages had instrumental color stability after HHP and during storage. TBA-RS values were quite stable in both products. Protein oxidation values of pork sausage in half-products were increased by at 20 °C. In sliced pork sausage, both HPP and 20 °C storage favored the development of protein oxidation at the end of storage. In the sensory analysis, the sliced product developed more rancidity than the half-pieces during the storage. Therefore, the storage temperature has great importance for the preservation of dry-cured pork sausages, the increases of protein oxidation, and rancidity could reduce the shelf-life at these conditions. The presentation of the product is also relevant when HHP is applied, and this would also compromise the stability of the product when it is stored at room temperature. PRACTICAL APPLICATION: Chorizo is a traditional dry-fermented pork sausage that is generally considered to be microbiologically safe. However, the initial contamination of the raw materials, and some processes, such as the slicing or packaging, can compromise the safety of these products. Additionally, packaged dry-cured sausages require long shelf-life, and although they are normally stored at refrigeration temperature; sometimes, they are preserved at room temperature. The application of hydrostatic high pressure could increase the safety of dry-cured meat products even when they are stored at room temperature. Initial characteristics of each type of pork sausage could determine their technological behavior during processing or during storage under different conditions.

Effect of Breed Purity and Rearing Systems on the Stability of Sliced Iberian Dry-Cured Ham Stored in Modified Atmosphere and Vacuum Packaging

The long-term storage stability of three quality categories of sliced Iberian dry-cured ham defined by the Spanish Iberian Quality Standard (Black, purebred Iberian reared outdoors in Montanera system; Red, Iberian × Duroc crossed (50%) pigs reared outdoors in Montanera system;, and White, Iberian × Duroc crossed (50%) pigs commercially fed) and packaged under vacuum and modified atmosphere packaging (MAP) was studied. Commercial category affected the shelf life, being Black and Red presented the highest lipid oxidation during storage, whereas the effect of packaging was not as clear as the effect of commercial category. MAP preserved more the colour and the antioxidants content than vacuum packaging, while this latter reduced lipid oxidation development and maintained better the brightness and flavour of slices than MAP.

Effect of high-pressure processing and chemical composition on lipid oxidation, aminopeptidase activity and free amino acids of Serrano dry-cured ham

Lipid oxidation and proteolysis are essential processes in Serrano dry-cured ham quality. The influence of high pressure processing (HPP) at 600 MPa for 6 min on lipid oxidation, aminopeptidase (AP) activities and free amino acids (FAA) in ripened Serrano hams of different chemical composition after 5 months at 4 °C were studied. HPP increased lipid peroxidation indexes. Composition influenced both indexes, with higher levels in hams of medium or high intramuscular fat (IMF) content and in hams of low or medium salt content or salt-in-lean ratio. HPP lowered AP activities by more than 50%. Composition also affected AP activities, with lower levels in hams of low a_w, high IMF content, low salt content or low salt-in-lean ratio. At the end of refrigerated storage, HPP only affected Arg and Tyr levels. Many of the individual FAA reached higher levels in hams of low a_w, medium or high IMF content, low or medium salt content, or low or medium salt-in-lean ratio.

MODERN PRODUCTION TRENDS OF FERMENTED MEAT PRODUCTS

The work aims to the generalization and analysis of the main problems of production of fermented meat products, which are reflected in scientific publications of the meat processing industry experts. The modern researches of scientists all over the world are aimed to the achievement of bio- and microbiological safety, structure formation, use of new kinds of raw materials, features of color formation, formation of sensory properties, increase of biological value of smoked and uncooked products. The work emphasizes that the quality of finished products and the stability of the technological process depends on the quality of raw materials, the properties of their own microbiota of raw materials and/or introduced starter cultures of microorganisms. The possibility of improving the sanitary condition of raw materials and reducing the impact of pathogenic microorganisms due to the use of ultrasound, hydrostatic high pressure, high-intensity pulsating electric field, cold plasma are described in the work. Also, in addition to physical processing methods, the use of competing microflora, extracts of spicy-aromatic plants, combining salt mixtures, packaging are effective. It is stated that the formation of the structure of the finished product depends on the parameters of the technological process, the activity of exo-endoenzymes and prescription composition. It is shown that the color of fermented meat products and their stability depend on the content of natural pigments and the conditions of their interaction with nitrites under the action of microorganisms with nitrite reductase activity and pH of the environment. The possibility of obtaining a characteristic pink-red color of meat products without the use of nitrites was noted. The results of investigations of the possibility of varying the organoleptic parameters of the finished product by modeling the ingredient composition and fermentation conditions are presented. The possibilities of creation of new types of fermented meat products of functional purpose by the introduction of ω-3 fatty acids, probiotics, macro-, microelements and more are described.

Monitoring oxidation during the storage of pressure-treated cooked ham and impact on technological attributes

High-pressure processing is a post-processing preservation method commonly used on meat products. However, it can affect the structural properties and the physico-chemical properties of the meat. The aim of this study was to compare the physical properties, lipid and protein oxidation of control and treated (500 MPa, 20 °C, 5 min) cooked ham during subsequent storage (21 days at 4 °C). High pressure processing induced increase of hardness and syneresis after 7 days of storage. The redness (a*) was slightly affected by the high pressure treatment but not the lightness (L*) and the yellowness (b*). However, the fluctuation of color was not clearly visible. Evaluation of primary (conjugated dienes) and secondary (malondialdehyde MDA and thiobarbituric reactive substances TBA-RS) lipid oxidation products showed that pressure increases oxidation of lipids. Whereas, high pressure processing had no immediate effect on MDA and TBA-RS content, higher amount compared to control were observed during the refrigerated storage. This lipid oxidation could be due to the release of prooxidant iron from hemoproteins after the high pressure treatment. Finally, the determination of free and accessible thiols showed that the high pressure treatment leads to a protein oxidation.

Microbiota of Iberian dry-cured ham as influenced by chemical composition, high pressure processing and prolonged refrigerated storage

The effect of high pressure processing (HPP) on the microbiota of ripened Iberian ham of different water activity, salt concentration and intramuscular fat content was investigated before and after a 5-month refrigeration period. At the beginning of the refrigeration period, the only significant effects of chemical composition were those of water activity on psychrotrophs and Micrococcaceae in untreated hams, and of the salt-in-lean ratio on lactic acid bacteria in HPP-treated hams. At the end of the refrigeration period, the only significant effect was that of intramuscular fat content on moulds and yeasts in HPP-treated samples. All microbial groups were significantly affected by HPP, with reductions ranging from 1.7 to 2.0 log cycles after treatment. A significant recovery of all microbial groups took place in HPP-treated hams during the refrigeration period, with increases ranging from 0.5 to 1.1 log cycles. In spite of this recovery, microbial levels in HPP-treated hams remained significantly lower than in untreated hams. Staphylococcus accounted for 93.4% of Iberian ham bacterial isolates, with S. equorum as the most abundant species. Representatives of the Tetragenococcus, Carnobacterium and Streptomyces genera, not previously reported in dry-cured ham, were also isolated. Most of the yeast isolates (75.0%) were identified as Debaryomyces hansenii.

New Approaches to Production of Turkish-type Dry-cured Meat Product "Pastirma": Salt Reduction and Different Drying Techniques

In this study, the possible changes in the quality characteristics of pastırma, Turkish-type dry-cured meat product, produced by using two different salts (NaCl-KCl) in a curing mixture and two different production techniques (natural and controlled condition) were examined. Moisture, pH, salt, sodium, potassium, TBA, fat, water activity, instrumental colour, texture, and sensory analyses were implemented in order to determine the possible effects of these applications. Fat, aw, pH, colour, tiobarbituric acid (TBA), texture, salt, Na and K values may allow these desired modifications in pastirma production to be limited. The substitution of 15% KCl instead of NaCl was acceptable in terms of the sensorial properties of the pastirma. However, the sensory analyses did not allow for using a higher KCl instead of NaCl because both the hardness and chewiness in the texture of the pastirma samples salted with 30% of KCl were not scored positively. Besides this, negative effects, which may occur during the pastirma production under natural conditions, can be eliminated by the production being under controlled conditions.

Current and future prospects for the use of pulsed electric field in the meat industry

Pulsed electric field (PEF) is a novel non-thermal technology that has recently attracted the attention of meat scientists and technologists due to its ability to modify membrane structure and enhance mass transfer. Several studies have confirmed the potential of pulsed electric field for improving meat tenderness in both pre-rigor and post-rigor muscles during aging. However, there is a high degree of variability between studies and the underlying mechanisms are not clearly understood. While some studies have suggested physical disruption as the main cause of PEF induced tenderness, enzymatic nature of the tenderization seems to be the most plausible mechanism. Several studies have suggested the potential of PEF to mediate the tenderization process due to its membrane altering properties causing early release of calcium ions and early activation of the calpain proteases. However, experimental research is yet to confirm this postulation. Recent studies have also reported increased post-mortem proteolysis in PEF treated muscles during aging. PEF has also been reported to accelerate curing, enhance drying and reduce the numbers of both pathogens and spoilage organisms in meat, although that demands intense processing conditions. While tenderization, meat safety and accelerated curing appears to be the areas where PEF could provide attractive options in meat processing, further research is required before the application of PEF becomes a commercial reality in the meat industry. It needs to deal with carcasses which vary biochemically and in composition (muscle, fat, and bones). This review critically evaluates the published reports on the topic with the aim of reaching a clear understanding of the possible applications of PEF in the meat sector in addition to providing some insight on critical issues that need to be addressed for the technology to be a practical option for the meat industry.

Influence of physicochemical parameters and high pressure processing on the volatile compounds of Serrano dry-cured ham after prolonged refrigerated storage

One hundred and three volatile compounds were detected by solid-phase microextraction followed by gas chromatography-mass spectrometry in 30 ripened Serrano dry-cured hams, submitted or not to high pressure processing (HPP) and afterwards held for 5months at 4°C. The effect of ham physicochemical parameters and HPP (600MPa for 6min) on volatile compounds was assessed. Physicochemical parameters primarily affected the levels of acids, alcohols, alkanes, esters, benzene compounds, sulfur compounds and some miscellaneous compounds. Intramuscular fat content was the physicochemical parameter with the most pronounced effect on the volatile fraction of untreated Serrano ham after refrigerated storage, influencing the levels of 38 volatile compounds while aw, salt content and salt-in-lean ratio respectively influenced the levels of 4, 4 and 5 volatile compounds. HPP treatment affected 21 volatile compounds, resulting in higher levels of alkanes and ketones and lower levels of esters and secondary alcohols, what might affect Serrano ham odor and aroma after 5months of refrigerated storage.

Combined effects of high-pressure and thermal treatments on lipid oxidation and enzymes in pork

The relationship between lipid oxidation and related enzymes in pork during combined pressure-heat treatments was investigated. Minced pork was treated under a pressure range of 0.1-750 MPa and a temperature range of 30-60°C for 20 min. Thiobarbituric acid-reactive substances (TBARS) values and activities of acid lipase (AL), neutral lipase (NL), phospholipase (PL), and lipoxygenase (LOX) in pork were evaluated. NL and LOX were completely inactivated at 600 MPa-50°C and 450 MPa-60°C, and AL at 600MPa-55°C. PL had the greatest stability and was completely inactivated at 600 MPa-60°C and 750 MPa-50°C. PL activity was strongly related to lipid oxidation caused by high pressure, followed by AL and LOX. TBARS values at 600 and 750 MPa were strongly related to the inactivation rate and the ratio of PL during treatment. PL was the most important enzyme related to lipid oxidation induced by pressure.

Postharvest intervention technologies for safety enhancement of meat and meat based products; a critical review

Globally, the demand for safe, healthy and nutritious meat and allied products possesses improved taste with extended shelf life is mounting. Microbial safety is among the imperative challenges that prevails in meat products because they provide an ideal medium for the growth of microorganisms particularly pathogenic bacteria. The incidence of these microbes can result quality deterioration of products leading towards food borne diseases when consumed by peoples. Several preservation technologies like chemical and biological interventions are effective to retard or inactivate the growth of micro-organisms most commonly related to food-borne diseases. Despite these, innovative approaches like hydrostatic pressure processing, active packaging, pulse electric field, hurdle approach and use of natural antimicrobials can be deployed to enhance the safety of meat and meat products. The objective of review is to describe the current approaches and developing technologies for enhancing safety of meat and allied meat products.