Proteolysis and sensory properties of dry-cured bacon as affected by the partial substitution of sodium chloride with potassium chloride

Effects of ultrasound-assisted dry-curing on water holding capacity and tenderness of reduced‑sodium pork by modifying salt-soluble proteins

This study investigated the effects of ultrasound-assisted dry-curing (UADC) on water holding capacity (WHC) and tenderness of pork at different powers and times, and the mechanism was discussed by considering the functional and structural properties of salt-soluble proteins (SSP). The results showed the application of appropriate UADC treatments (300 W, 60 min) have disruptively affected the muscle structure and decreased the size of the SSP particles (P < 0.05), resulting in the increased concentration of active sulfhydryl and surface hydrophobicity (P < 0.05). These modifications facilitated the dissociation of the myofibrillar structure and the dissolution of more connected proteins, which in turn improved the WHC and tenderness of the pork (P < 0.05). Nevertheless, extended periods of high-power UADC treatments negatively affected the WHC and tenderness of dry-cured pork (P < 0.05). In general, using SSP modified by UADC provides a novel strategy for enhancing the WHC and tenderness of dry-cured products.

Quality and Flavor Difference in Dry-Cured Meat Treated with Low-Sodium Salts: An Emphasis on Magnesium

The present study aimed to develop low-sodium curing agents for dry-cured meat products. Four low-sodium formulations (SPMA, SPM, SP, and SM) were used for dry-curing meat. The physicochemical properties and flavor of the dry-cured meat were investigated. The presence of Mg2+ ions hindered the penetration of Na+ into the meat. The weight loss, moisture content, and pH of all low-sodium salt groups were lower than those of S. Mg2+ addition increased the water activity (Aw) of SPMA, SPM, and SM. Dry-curing meat with low-sodium salts promoted the production of volatile flavor compounds, with Mg2+ playing a more prominent role. Furthermore, low-sodium salts also promoted protein degradation and increased the content of free amino acids in dry-cured meat, especially in SM. Principal component analysis (PCA) showed that the low-sodium salts containing Mg2+ were conducive to improving the quality of dry-cured meat products. Therefore, low-sodium salts enriched with Mg2+ become a desirable low-sodium curing agent for achieving salt reduction in dry-cured meat products.

Characterization of the Effects of Low-Sodium Salt Substitution on Sensory Quality, Protein Oxidation, and Hydrolysis of Air-Dried Chicken Meat and Its Molecular Mechanisms Based on Tandem Mass Tagging-Labeled Quantitative Proteomics

The effects of low-sodium salt mixture substitution on the sensory quality, protein oxidation, and hydrolysis of air-dried chicken and its molecular mechanisms were investigated based on tandem mass tagging (TMT) quantitative proteomics. The composite salt formulated with 1.6% KCl, 0.8% MgCl2, and 5.6% NaCl was found to improve the freshness and texture quality scores. Low-sodium salt mixture substitution significantly decreased the carbonyl content (1.52 nmol/mg), surface hydrophobicity (102.58 μg), and dimeric tyrosine content (2.69 A.U.), and significantly increased the sulfhydryl content (74.46 nmol/mg) and tryptophan fluorescence intensity, suggesting that protein oxidation was inhibited. Furthermore, low-sodium salt mixture substitution significantly increased the protein hydrolysis index (0.067), and cathepsin B and L activities (102.13 U/g and 349.25 U/g), suggesting that protein hydrolysis was facilitated. The correlation results showed that changes in the degree of protein hydrolysis and protein oxidation were closely related to sensory quality. TMT quantitative proteomics indicated that the degradation of myosin and titin as well as changes in the activities of the enzymes, CNDP2, DPP7, ABHD12B, FADH2A, and AASS, were responsible for the changes in the taste quality. In addition, CNDP2, ALDH1A1, and NMNAT1 are key enzymes that reduce protein oxidation. Overall, KCl and MgCl2 composite salt substitution is an effective method for producing low-sodium air-dried chicken.

Sodium Replacement with KCl and MSG: Attitudes, Perception and Acceptance in Reduced Salt Soups

Sodium intake is linked to multiple negative health outcomes, particularly hypertension, the leading cause of premature death globally. Sodium intake levels in human populations are high, due in part to our desire for palatable salty-tasting foods. Two leading salt replacement strategies are the use of potassium chloride (KCl) and monosodium glutamate (MSG), the latter of which still contains some sodium, but both of which can replace some salty taste in foods while reducing net sodium levels. In this report, we employed a trained descriptive sensory panel to optimize saltiness in sodium-reduced aqueous samples using various concentrations of KCl and MSG. Following this, we assessed consumer attitudes to sodium-reduction strategies in a model food, canned soup, known to typically be high in sodium. Finally, in a large consumer test, we verified that these optimized levels of KCl and MSG did not lead to a drop in liking for the reduced-sodium soups with saltiness subsidized in this manner. Our results showed that sodium can be readily reduced in soups by 18% while actually scoring higher in liking, and in some cases being perceived as even more salty tasting, but that consumers are more open to sodium reduction in this manner when sodium replacements are not specifically highlighted, and when percentage sodium reduction is stated over absolute levels.

Effects of Partial Replacement of NaCl with KCl on Protein Properties and Quality Attributes of Lightly Salted Tilapias Fillets

The evolution of quality attributes and their association with the protein properties of lightly tilapias fillets salted with different replacement proportions of NaCl with KCl (0%, 10%, 30%, 50%, 70%, 100%) at the same ionic strength were investigated. KCl replacements using optimal substitution (50% of KCl) contributed to maintaining desired quality properties. Further, KCl replacement (about 50~70% of KCl) led to the insolubilization and weakened stability of myofibrillar proteins, represented by the unfolding of the myofibrillar protein, increased surface hydrophilic points, and strengthened internal protein-protein interaction, resulting in the structurally reinforced hardness and lower water-holding capacity. Excessive replacement (more than 70% of KCl) showed apparent deterioration in taste quality, coloration, and hardness received by sensory sensation caused by immoderate hydrolysis and aggravated oxidation of the myofibrillar protein. In this sense, insights into KCl replacements on protein properties might be a positive approach to improving quality attributes of lightly salted tilapias fillets.

Flavour Profile of Traditional Dry Sausage Prepared with Partial Substitution of NaCl with KCl

The effects of partial substitution of NaCl with 0%, 20%, 30% and 40% KCl on the physical characteristics, bacterial community and flavour profile of traditional dry sausage were investigated in this study. With the increase in KCl substitution ratio, the moisture content, astringency, bitterness and umami increased significantly, and the saltiness gradually decreased (p < 0.05). The high-throughput sequencing results showed that the dry sausages with KCl substitution had relatively high abundances of Staphylococcus. For volatile compounds, increasing the KCl substitution ratio reduced the formation of aldehydes, ketones and some alcohols, but promoted the formation of acids and esters (p < 0.05). Sensory evaluation and partial least square regression analysis showed that the dry sausages with 20% and 30% KCl were similar in overall physical and microbial properties, flavour profiles and sensory attributes, and the sausages with 40% KCl were characterized by taste defects. Overall, partial substitution of NaCl with 30% KCl could ensure the acceptable flavour and sensory attributes of dry sausages.

Sodium Reduction in Traditional Dry-Cured Pork Belly Using Glasswort Powder (Salicornia herbacea) as a Partial NaCl Replacer

Sodium chloride (NaCl) is a key ingredient in the processing of traditional dry-cured meat products by improving microbial safety, sensory attributes and technological properties. However, increasing concern about the consumption of sodium and health has been supporting the development of low-sodium meat products. Several strategies to reduce sodium in dry-cured meat product have been tested, although the followed approaches sometimes result in undesirable characteristics concerning flavor, texture and mouthfeel. The use of halophytic plants such as glasswort (Salicornia herbacea) in food matrices has been suggested as a novel strategy to reduce sodium content, due its salty flavor. The main aim of the present study is to produce traditional dry-cured pork bellies from the Bísaro breed using glasswort as a NaCl partial replacer, and compare it with dry-cured bellies salted either with NaCl or a mix of NaCl + KCl. Control bellies (BC) were salted with 100% of NaCl, the second formulation (BK) had 50% of NaCl and 50% of KCl, and the third formulation (BG) had 90% of NaCl and 10% of glasswort powder (GP). After production, the bellies were evaluated for a_w, pH, CIELab coordinates, weight loss, proximal composition, TBARS, collagen and chloride contents, fatty acid profile and sensory attributes. The use of BG in dry-cured pork bellies did not affect processing indicators such as weight loss, a_w and pH. Concerning CIELab, only the coordinates L* and hue angle from the external surface color of BG were statistically different from BC and BK. As expected, ash and NaCl contents differed from BG to the other two formulations. SFA and indexes AI and TI were lower, whereas the MUFA and h/H ratio were higher in BG than other treatments, leading to a product with a healthier lipid profile. The sensory evaluation revealed differences in appearance, taste and flavor among treatments, but did not indicate any negative effects of BG in the product attributes. This study reinforces the potential of BG as a natural sodium reducer for the production of traditional dry-cured pork bellies.

The use of high pressure processing to compensate for the effects of salt reduction in ready-to-eat meat products

Sodium chloride is an essential ingredient in meat products, where it is not only used as a flavoring agent but also to achieve desired textural properties and as an antimicrobial to improve its safety and extend shelf-life. Although NaCl plays this multi-functional role in meat products, excessive sodium intake is linked to various negative health consequences such as cardiovascular disease and obesity. Sodium chloride added to ready-to-eat meat products is the largest contributor of sodium. Thus, there is an increased interest in the development of meat products with reduced sodium levels. Strategies to reduce sodium include identification of alternatives to sodium, considering safety and functionality, and including technological innovations and alternative food processing strategies. Several studies have shown that high pressure processing (HPP) can partially compensate for the loss in functional and sensory properties of meat products as a result of NaCl reduction. This review summarizes these studies to date and will highlight the ability of HPP to enhance the safety, shelf-life and quality of sodium-reduced meat products.

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.

The effects of curing agents on the proteolysis and lipid oxidation of pastırma produced by the traditional method

In the study, the effects of nitrate and/or nitrite (150 mg/kg KNO₃, 300 mg/kg KNO₃, 150 mg/kg NaNO₂, and 150 mg/kg KNO₃ + 150 mg/kg NaNO₂) on proteolytic changes (free amino acid composition, SDS-PAGE) in pastırma were investigated. Pastırma samples were also analyzed in terms of some qualitative (pH, a_w, TBARS, residual nitrite, salt) properties. The lowest total free amino acid content (1818.3 mg/ 100 g DM) was observed in the combination of 150 mg/kg KNO₃ + 150 mg/kg NaNO₂, while the highest content (2847.49 mg/ 100 g DM) was observed in 150 mg/kg KNO₃. Although the pastırma groups generally exhibited similar SDS-PAGE profiles, differences were detected at some band intensities. The lowest TBARS value (22.24 μmol MDA/kg) was observed in 150 mg/kg KNO₃ + 150 mg/kg NaNO₂. As a result, the use of 150 mg/kg KNO₃ in the pastırma curing process causes more intense proteolysis.

Evaluation of small molecular metabolites and sensory properties of Xuanwei ham salted with partial replacement of NaCl by KCl

The study was to understand the effect of the partial substitution of NaCl by KCl on small molecular metabolites and sensory quality of Xuanwei ham. Thirty green hams were randomly divided into five treatments, and salted with 100% NaCl (I), 70% NaCl+30% KCl (II), 60% NaCl+40% KCl (III), 50% NaCl+50% KCl (IV) and 40% NaCl+60% KCl (V), respectively. With the increase of KCl substitution, the moisture content of Xuanwei ham increased. Non-targeted ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-Q-Exactive-MS) was used to study the effect of partial substitution of NaCl by KCl, and twenty-eight metabolites were identified as markers of small molecular metabolites in the different treatments. KCl substitution promoted the release of tryptophan, histidine, citrulline, lysine, creatine and oleic acid, which contributed to improve the flavor and taste of ham. Therefore, the treatment II and III could reduce the NaCl content of Xuanwei ham by 30% and 40%, and maintained a better sensory acceptability.

Effects of partial NaCl substitution with high-temperature ripening on proteolysis and volatile compounds during process of Chinese dry-cured lamb ham

The effects of partial NaCl substitution combined with high-temperature ripening on the proteolysis and formation of volatile compounds in dry-cured lamb ham was investigated. Two salt treatments, I (0% KCl + 100% NaCl) and II (25% KCl + 75% NaCl), were considered. Although some studies have analyzed the influences of salt substitution on volatile compounds of dry-cured ham, no studies have evaluated lamb ham produced in China. Intensifying the high-temperature ripening lead to an increase in the formation of flavors generated by the Maillard reaction and Strecker degradation in both treatments, also, had a positive influence on proteolysis index and content of total free amino acids during the ripening stage. The application of 25% KCl did not influence the formation of volatiles during curing stage, however, there were more volatiles came from amino acids degradation in the final products with 25% KCl. Therefore, sodium reduction combined with high-temperature ripening may be an alternative method to manufacture Chinese dry-cured lamb hams.

Effects of partial replacement of NaCl with KCl on bacterial communities and physicochemical characteristics of typical Chinese bacon

This work aimed to determine the effects of partial substitution of NaCl with 0% (control), 30%, 50%, and 70% of KCl on the bacterial communities, proteolysis and lipid oxidation of Chinese bacon during processing. The proportion of genus Lactobacillus increased from 22.45% (fresh meat) to 72.78%, 81.64%, 76.53% and 85.63% at the end of processing for 0%, 30%, 50% and 70% KCl replacement samples, respectively. During the processing, Lactobacillus gradually became the dominant one, and higher the KCl ratio, more rapid was the process. After salting, the TBARS of control was markedly higher (P < 0.05) than that of the others, while a similar lipid oxidation level (P > 0.05) was observed at the end of processing for different groups. After salting, there was no difference in total free amino acids (TFAA) content among four treatments (P > 0.05), whereas KCl replacement samples shared significantly higher (P < 0.05) values than control at the end of processing. Redundancy analysis and Pearson correlation showed positive correlation between Lactobacillus versus TBARS and TFAA. Partial replacement of NaCl with KCl could, directly or subsequently by promoting the growth of Lactobacillus, influence proteolysis and lipid oxidation over the manufacturing process.

Challenges to reduce or replace NaCl by chloride salts in meat products made from whole pieces - a review

NaCl is fundamental for the development of the physico-chemical, sensorial and microbiological stability in meat products made from whole pieces such as dry-cured lacón, loin, ham, bacon, jerked beef, and pastirma). The substitution of NaCl by other chloride salts (KCl, CaCl₂ and MgCl₂), in order to minimize changes in the processing steps and insertion of new ingredients, is a major challenge for the elaboration of salted meat products in the context of increasing awareness among consumer about sodium consumption and health. This review aims to discuss the potential use of binary, ternary and quaternary salting mixtures in the processing of salted meat products and their effects on microbiological evolution and safety, sensory properties, oxidative reactions on proteins and lipid, and proteolysis and lipolysis reactions. More specifically, the substitution of NaCl by other chloride salts can influence the growth of microorganisms, the formation of toxic compounds, progression of enzymatic and oxidative reactions, and the sensory attributes. Scientific evidences from a food technological point of view, support the use of KCl to partially replace NaCl while major advances/more sophisticated strategies are still necessary to effectively introduce CaCl₂ and MgCl₂ as NaCl replacers. Moreover, further studies regarding the shelf-life and economic problems of the alternatively salted products are still necessary.

Effect of NaCl replacement by other chloride salts on physicochemical parameters, proteolysis and lipolysis of dry-cured foal "cecina"

This study was proposed following the strategy of the meat sector to reduce sodium intake through applying different salting processes instead of the traditional method. Therefore, the influence of two salting treatments (with 50% and 55% of NaCl replacement by other chloride salts) on the chemical, physicochemical, proteolysis and lipolysis of foal cecinas was evaluated and compared to those cecinas salted with a traditional procedure. Regarding physicochemical parameters, cecinas treated with CaCl₂ and MgCl₂ increased the lipid oxidation and luminosity, while decreased the redness. The highest contents of protein and the lowest of moisture were obtained in cecinas salted with 50% KCl, while the NaCl content was dramatically reduced by the experimental batches (4.25 and 3.40 g/100 g) in comparison with control samples (7.73 g/100 g). The values of texture (hardness) did not reflect differences among batches. The content of free amino acids increased with NaCl replacement. In fact, data suggests that NaCl had more inhibitory power on the proteolytic enzymes than the other salts. On the contrary, lipolytic phenomenon showed lower differences among treatments (mainly individual PUFA). However, these variations could be related to the higher oxidation observed in the samples with NaCl replacement. On the other hand, the substitution of NaCl by other salts had an important influence in mineral contents. The main objective, which is the reduction of sodium intake, was achieved. Nevertheless, a sensory study should carry out to observe how aforementioned changes affect the organoleptic quality of the final product and the consumer's acceptability.

Combined Effects of Sodium Substitution and Addition of Cellulose or Chitosan on Quality Properties of Pork Sausages

The aim of this study was to assess the impacts of cellulose/chitosan addition in combination with sodium substitution, including KCl and MgCl₂, on the quality and sensory properties of sausages. Sausages (control, 100% NaCl; T1, 60% NaCl, and 40% KCl; T2, 50% NaCl, 40% KCl, and 10% MgCl₂) were formulated with cellulose/chitosan at concentrations of 3% and compared to control. T1 and T2 decreased the pH values (p<0.05), while the use of cellulose increased these values. Biopolymer addition reduced lipid oxidation (p<0.05). In sausages containing cellulose, volatile basic nitrogen (VBN) in T1 was lower than that in T2 (p<0.05). The use of cellulose increased L*-, a*-, and W color values in T1 (p<0.05). Furthermore, cellulose addition was associated with lower hardness (p<0.05). Cellulose addition contributed to better overall acceptability (p<0.05). Consequently, a combined mixture containing T1 and cellulose appears to be the best combination, indicating a possible synergistic effect.

Impact of partial substitution of NaCl by KCl, and MgCl2 on physicochemical and sensory properties of cooked sausages during storage

Objective

To determine the effect of three salting treatments (control, 100% NaCl; T1, 60% NaCl and 40% KCl; T2, 50% NaCl, 40% KCl, and 10% MgCl₂) on meat quality of sausages during storage.

Methods

Various types of curing salts were used for processing of salamis. Physico-chemical and sensory evaluation of the sausages were analyzed during 4 weeks of ripening.

Results

The pH values and salinity contents were the highest in control, while they were the lowest in T2 at 4 weeks (p<0.05). Control and T1 had less thiobarbituric acid reactive substances than T2 at 2 weeks (p<0.05). The volatile basic nitrogen levels in T1 were similar to control and lower than T2 at 2 and 4 weeks (p<0.05). Moreover, T1 samples were redder and had a higher saturation index (C*) value when compared to the others. T2 showed greater hardness, gumminess and chewiness when compared with the control (p<0.05). Control was comparable to T1 for sensory attributes.

Conclusion

Sodium chloride may be partially substituted with potassium chloride without negatively influencing meat quality of sausages up to 4 weeks of storage. These results could help to develop low-sodium sausages.

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.

The changes in the proteolysis activity and the accumulation of free amino acids during chinese traditional dry-cured loins processing

Twelve pieces of longissimus dorsi were processed into Chinese traditional dry-cured loins. The changes in the proteolylic enzymes activities, myofibrillar proteins degradation, and free amino acids content were investigated during processing. Compared with fresh piece (0 day), the cathepsin B + L and calpains activities decreased after dry-curing and maintained potential activities values of 23.25 and 15.04% in the final products, respectively. The myosin heavy chain (MHC) and C protein were intensely degraded at the dry-ripened stage; the 50 kDa desmin increased at day 2 and then disappeared at day 11. The total free amino acids content increased from 333.18 mg/100 g in the raw to 1096.54 mg/100 g at the end of the dry-ripening. This work provided a mechanism for the accumulation of free amino acids and predicted the proteolysis extent of myofibrillar proteins by monitoring the changes of three marker proteins (MHC, C protein and 50 kDa desmin) during Chinese traditional dry-cured loins processing.

Effect of partial substitution of NaCl by KCl on physicochemical properties, biogenic amines and N-nitrosamines during ripening and storage of dry-cured bacon

Effects of three salting treatments (Formulation II: 80 % NaCl + 20 % KCl; Formulation III: 60 % NaCl + 40 % KCl and Formulation IV: 40 % NaCl + 60 % KCl) on physicochemical properties, residual nitrite, N-nitrosamines and biogenic amines were compared with those of control bacons (Formulation I: 100 % NaCl) during processing and storage. Results showed that there were no significant differences among treatments for moisture, pH, and total volatile basic nitrogen (TVBN) content in dry-cured bacons during processing. The replacement of 40 % or less NaCl by KCl had no negative effects on the sensory quality of bacons during processing. Formulation III significantly reduced putrescine, cadaverine and histamine contents and enhanced nitrite residues compared with the control. After 12-day ripening and during storage, the substitution of NaCl by 60 % KCl significantly increased the N-nitrosodimethylamine (NDMA) content than the control. Principal component analysis showed that there were positive correlations between TVBN, biogenic amines (putrescine, cadaverine, histamine and tyramine) and NDMA, and negative correlation between NDMA and nitrite. These findings suggested the partial substitution of NaCl by KCl could be utilized for producing reduced-sodium dry-cured bacons to improve safety of finished products.

Influence of partial replacement of NaCl with KCl on formation of volatile compounds in Jinhua ham during processing

The influence of partial replacement of NaCl with KCl on formation of volatile compounds during Jinhua ham processing was evaluated using GC/MS system. Jinhua ham was treated with either 100% NaCl (I) or 60% NaCl and 40% KCl (II). Formation of volatile compounds increased in Jinhua hams during processing for both salt formulations, particularly at the end of the salting period. There were differences in volatile compound formation between formulations I and II after 45 days of processing. Contents of lipid-derived volatiles (hexanal) and Strecker aldehydes (2-methylbutanal and 3-methylbutanal) were higher in Jinhua hams treated with formulation II after 45 days of processing. Partial salt replacement of NaCl with KCl changed formation of volatile compounds in Jinhua hams and may have affected the flavor of finished products.