Lipolysis in reduced sodium Kefalograviera cheese made by partial replacement of NaCl with KCl

Kefalograviera cheeses (five trials) of different sodium contents were made from split lots of curd by varying the salting processes, i.e. brine- and dry-salting with NaC1 (control) or a mixture of NaClJ/Cl (3:1 or 1:1, w/w basis). Lipolysis in cheeses was monitored during aging by the acid degree value (ADV) method and gas chromatography (GC). It was found that the ADV of control and experimental cheeses were similar (P>0.05) at all sampling ages (5, 25, 60, 90 and 180 days). Moreover, the results of GC showed that there were neither qualitative nor significant (P>0.05) quantitative differences in the levels of individual free fatty acids of the control and experimental cheeses at the age of 90 and 180 days. These findings indicated that the partial replacement of NaCl with KCl in the manufacture of Kefalograviera cheese did not significantly influence the lipolysis during cheese aging.     

Proteolysis in reduced sodium Feta cheese made by partial substitution of NaCl by KCl

Feta cheeses (five trials) of different sodium content were made, using ewes’ milk, from split lots of curd by varying the salting procedure, i.e. dry salting with NaCl (control) or mixtures of NaCl/KCl (3:1 or 1:1, w/w basis) and filling the cans with brine made with NaCl or the above NaCl/KCl mixtures, respectively, in order to study the influence of the partial substitution of NaCl by KCl on the proteolysis during cheese ripening. The extent and characteristics of proteolysis in the cheeses were monitored during aging by using Kjeldahl determination of soluble nitrogen fractions (water-soluble nitrogen, trichloroacetic acid-soluble nitrogen, phosphotungstic acid-soluble nitrogen), the cadmium–ninhydrin method for the determination of total free amino acids (FAA), urea–polyacrylamide gel electrophoresis of cheese proteins followed by densitometric analysis of the α_s1- and β-casein fractions, reverse-phase HPLC analysis of the water-soluble extracts of cheeses, and ion-exchange HPLC analysis of FAA. The results showed that proteolysis was similar in control and experimental cheeses at all sampling ages, indicating that the partial substitution of NaCl by KCl in the manufacture of Feta cheese had no significant effect on the extent and characteristics of proteolysis during cheese aging.     

Lipolysis in reduced sodium Feta cheese made by partial substitution of NaCl by KCl

Feta cheese (five trials) of different sodium content was made from split lots of curd by varying the salting procedure, i.e. dry salting with NaCl (control) or mixtures of NaCl/KCl (3 : 1 or 1 : 1, w/w basis) and filling the cans with brine made with NaCl or the above NaCl/KCl mixtures, respectively. Lipolysis in cheese was monitored during aging by using the acid degree value (ADV) method and gas chromatography (GC). It was found that the ADVs of control and experimental cheeses were similar (P>0.05) at all sampling ages (3, 20, 40, 60, 120 and 240 d). Moreover, the results of GC showed that there were neither qualitative nor significant (P>0.05) quantitative differences in the individual free fatty acids (FFA) of the control and experimental cheeses at the ages of 40 and 120 d. These findings indicated that the partial substitution of NaCl by KCl in the manufacture of Feta cheese had no effect on lipolysis during cheese aging.     

Incorporation of Lactobacillus casei in Iranian ultrafiltered Feta cheese made by partial replacement of NaCl with KCl

Probiotic Iranian ultrafiltered Feta cheese was produced from ultrafiltration of milk with a volumetric concentration factor of 4.5:1. The heat-treated retentates were inoculated with 10(7) cfu of Lactobacillus casei LAFTI L26/mL. A mesophilic-thermophilic mixed culture of Lactococcus lactis ssp. lactis, Lactococcus lactis ssp. cremoris, and Streptococcus thermophilus was also used. Three percent (wt/wt) salt with different ratios of NaCl:KCl (100% NaCl, 50% NaCl:50% KCl, 75% NaCl:25% KCl, and 25% NaCl:75% KCl) were used in cheese formulation. The viability of L. casei was determined in treatments during the ripening period (90d at 5°C) within 15-d intervals. The pH, titratable acidity, and redox potential changes were monitored throughout the mentioned period. The mean pH drop rate, mean acidity increase rate, and mean redox potential increase rate were calculated at the end of the storage period. Also, total nitrogen, water-soluble nitrogen, lactic acid, and acetic acid concentrations, and syneresis and sensory characteristics of the product were measured during the mentioned period every 30d. The maximum viability of L. casei was observed within d 15 to 30 of the ripening period in the treatment containing the lowest amount of sodium. Addition of KCl enhanced syneresis. Cheeses with NaCl alone and with only 25% replacement by KCl have the highest sensory acceptability.     

Proteolysis of low-moisture Mozzarella cheese as affected by substitution of NaCl with KCl

The proteolytic and ACE inhibitory activities of low-moisture Mozzarella cheese (LMMC) as affected by partial substitution of NaCl with KCl were investigated. Experimental LMMC were made and salted with 4 salt mixtures: NaCl only (control), 3NaCl:1KCl, 1NaCl:1KCl, and 1NaCl:3KCl, and then proteolytic activity and angiotensin-converting enzyme inhibitory activity were determined. Salt treatment significantly affected angiotensin-converting enzyme inhibitory activity and phosphotungstic acid-soluble N of LMMC during storage. Water-soluble N, trichloroacetic acid-soluble N, lactic acid bacteria population, and total free amino acids were unaffected during storage. Nonetheless, water-soluble N and trichloroacetic acid-soluble N increased significantly during storage within a salt treatment. Peptide profiles and urea-PAGE gels did not differ between experimental cheeses at the same storage time.     

Effect of partial substitution of NaCl with KCl on proteolysis of halloumi cheese

The effect of substitution of NaCl with Potassium chloride (KCl) in brine solution on proteolysis of halloumi cheese was investigated. Halloumi cheeses were made and kept in 4 different brine solutions (18% w/w), including only NaCl (HA; control); 3NaCl:1KCl (w/w) (HB); 1NaCl:1KCl (w/w) (HC); 1NaCl:3KCl (w/w) (HD); and stored for 56 d at 4 °C. Proteolysis was assessed using water-soluble nitrogen (WSN), trichloroacetic acid-soluble nitrogen (TCA-SN), phosphotungstic-soluble nitrogen (PTA-SN), urea polyacrylamide gel electrophoresis (urea-PAGE), and peptide patterns. WSN and TCA-SN contents were similar in all experimental cheeses. Peptide patterns of the pH 4.6 N fraction and urea-PAGE showed no significant difference between halloumi cheeses kept in various NaCl/KCl mixtures (HB, HC, HD) and control (HA). Sodium and potassium contents showed positive correlations with WSN and PTA-SN. There was an inverse correlation between calcium (Ca) contents and WSN and PTA-SN. Correlations between Ca and Na or K were negative at the same salt treatment.     

KCl部分替代NaCl对干腌火腿工艺过程中蛋白质水解的影响

为了降低干腌火腿钠含量,应用40%KCl替代Na Cl对火腿原料进行腌制,采用强化高温成熟现代工艺制备干腌火腿,分析加工过程中火腿股二头肌盐分含量、水分含量、p H、蛋白水解指数、肽氮和氨态氮含量,研究KCl替代对火腿加工过程中组织蛋白酶B和L潜在酶活力变化的影响。结果表明:40%KCl替代Na Cl对火腿中组织蛋白酶B和L潜在酶活力变化无显著影响(p>0.05),风干成熟产品理化指标、蛋白水解指数、肽氮和氨态氮含量等无显著差异(p>0.05),说明采用40%KCl替代Na Cl对干腌火腿的蛋白质降解过程无显著影响(p>0.05)。      

Biochemical changes in dry-cured loins salted with partial replacements of NaCl by KCl

The effect of partial replacement of NaCl by KCl in the dry-curing of loins has been evaluated by biochemical and sensory analysis of the final products. Endoproteolytic enzymes like cathpesins B and B + L appeared to be more active when more KCl and less NaCl were present in the curing salt while cathepsin H remained unaffected. Proteolysis was reflected by SDS–PAGE in the higher density of the sarcoplasmic proteins bands within the range 55.0–28.0 kDa. Alanyl aminopeptidase (AAP) was unaffected while arginyl and leucyl aminopeptidases were more activated by KCl. On the other hand, methionyl aminopeptidase and dipeptidylpeptidase I and III were more inhibited as KCl increased in the curing salt blends. The sensory analysis revealed no significant differences between control loins with 100% NaCl and those with up to 50% of KCl substitution. Furthermore, loins elaborated with 50% of each salt obtained the highest scores.     

Comparing the antimicrobial effectiveness of NaCl and KCl with a view to salt/sodium replacement

A study using a small range of pathogenic bacterial species (Aeromonas hydrophila, Enterobacter sakazakii, Shigella flexneri, Yersinia enterocolitica and 3 strains of Staphylococcus aureus) has shown that potassium chloride has an equivalent antimicrobial effect on these organisms when calculated on a molar basis. Combined NaCl and KCl experiments were carried out and data was analysed using a modification to the Lambert and Lambert [Lambert, R.J.W., and Lambert, R., 2003. A model for the efficacy of combined inhibitors. Journal of Applied Microbiology 95, 734–743.] model for combined inhibitors and showed that in combination KCl is a direct 1:1 molar replacement for the antimicrobial effect of common salt. If this is a general finding then, where salt is used to help preserve a product, partial or complete replacement by KCl is possible.     

Production of brine-salted Mozzarella cheese with different ratios of NaCl/KCl

Mineral and moisture concentrations, proteolysis, bacterial counts and hardness were assessed in the centre and edge portions of unmelted and melted pizza cheeses, brine-salted with four mixtures of NaCl/KCl. Bacterial counts and proteolysis were not affected by brine solutions. Moisture and Ca were lower at the edge than in centre, whereas an opposite trend was observed for Na and K. This gradient between edge and centre was different for brine solutions with KCl. After 28 d, equilibrium between the edge and the centre was obtained for moisture only. The evolution of hardness between the edge and the centre of the unmelted cheeses could mainly be attributed to the lower moisture in the edge, whereas that of the melted cheeses could be attributed to the K concentration. Further investigation is needed to understand the role that K plays in regard to all functional properties of pizza cheese brine-salted with NaCl/KCl mixtures.     

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.     

Proteolysis of Fynbo Cheese Salted with NaCl/KCl and Ripened at Two Temperatures

Cheeses salted in solutions of 100g NaCl/L and 100g KCl/L and ripened for 90 days at 12°C and 16°C were compared with cheeses salted in brine of 190g NaCl/L and ripened at the same temperatures. Peptides of the water-soluble nitrogen (WSN) fraction were quantified by the Kjeldahl method and analyzed by reverse-phase HPLC. There were no differences (P>0.05) attributable to salt treatments; and the cheeses stored at 16°C showed higher levels of WSN/Total Nitrogen (TN) than cheeses ripened at 12°C. HPLC profiles of WSN extracts showed differences in the hydrophilic zone for cheeses ripened at different temperatures, but profiles were similar for cheeses salted with NaCl and with NaCl/KCl.     

Influence of partial replacement of NaCl with KCl and CaCl2on microbiological evolution of dry fermented sausages

The survival of lactic acid bacteria, Micrococcaceae, and pathogens in dry fermented sausages produced with a mixture of 1·0% NaCl, 0·55% KCl and 0·74% CaCl₂compared to a control product (2·6%NaCl) was studied. Hygienic quality was guaranteed in the modified products by an adequate process of desiccation and acidification. These products showed a higher acidification than the control during the entire ripening process.Lactobacillus and Micrococcaceae counts were not affected by the NaCl reduction. Enterobacteriaceae disappeared by the fifteenth day in both types of products. Escherichia coli, Staphylococcus aureus, Salmonella and sulfite-reducing clostridia counts in final products were acceptable in both types of products. These results indicated that the applied mixture of salts did not affect the development of the starter culture and guaranteed the hygienic quality of the products.     

盐替代和复合抗氧化剂对培根风味物质形成的影响

采用固相微萃取-气质联用结合电子鼻技术研究了盐替代和抗氧化剂处理对培根风味形成的影响。结果显示:在培根中共检测到60种挥发性风味物质,其中醛16种、醇18种、酮9种、酸3种、酯5种和烃9种。电子鼻可以很好地区分不同加工阶段的样品,随着培根风干成熟的进行,挥发性风味物质含量不断增加。风干结束时,与对照组相比,40%KCl替代Na Cl处理组能显著提高直链烃和总酯含量(P0.05);抗氧化剂处理组除了降低醛类物质外,对其他物质的影响与对照组相比无显著差异。     

Proteolysis in goat cheese made from raw,pasteurized or pressure-treated milk

Primary and secondary proteolysis of goat cheese made from raw (RA), pasteurized (PA; 72 °C, 15 s) and pressure-treated milk (PR; 500 MPa, 15 min, 20 °C) were examined by capillary electrophoresis, nitrogen fractionation and HPLC peptide profiles. PA milk cheese showed a more important hydrolysis (P<0.05) of α_s1-casein than RA milk cheese at the first stages of ripening (15 days), while PR milk cheese had a level between those seen in PA and RA milk cheeses. Degradation of β-casein was more important (P<0.05) in PA and PR than in RA milk cheeses at 15 days of ripening. However, from thereon β-casein in PR and RA milk cheeses was hydrolyzed at essentially similar rates, but at lower rates (P<0.05) than in PA milk cheeses. Pressure treatment could induce proteolysis of β-casein in a way, which is different from that produced by heat treatment. There was an increase in 4.6-soluble nitrogen (WSN) and in trichloroacetic acid (TCASN) throughout ripening in cheeses, but higher contents (P<0.05) in PA and PR milk cheeses at the end of ripening were observed. PR milk cheeses contained considerably higher content (P<0.05) of free amino acids than RA or PA milk cheeses. In general, heat and pressure treatments had no significant effect on the levels of hydrophobic and hydrophilic peptides.     

Proteolysis and microstructure of Piacentinu Ennese cheese made using different farm technologies

The aim of this study was to provide the biochemical and structural characterization of Piacentinu Ennese cheese and to evaluate the impact of different farm technologies on cheese proteolysis and microstructure. Fifteen cheeses were manufactured according to traditional technology, i.e., from raw milk and farmhouse rennet in the absence of starter culture. Pasteurized milk, commercial rennet, and starter were used for production of 20 nontraditional cheeses. Proteolysis in Piacentinu Ennese cheese was monitored during a 2- to 10-mo ripening time. Low rates of overall proteolysis were observed in cheese, as percentages of total N soluble at pH 4.6 and in 12% trichloroacetic acid were about 11.40 and 8.10%, respectively, after 10 mo of age. Patterns of primary proteolysis by urea-PAGE showed that alpha(s)-caseins were degraded to a larger extent than were beta-caseins, although a considerable amount of both caseins was still intact after 10 mo. Reversed phase-HPLC analysis of the cheese peptide fractions showed a slow decrease in the levels of hydrophobic peptides coupled to increasing levels of hydrophilic compounds as the cheese aged. The structural characteristics of Piacentinu Ennese cheese were evaluated by scanning electron microscopy after 2, 4, and 6 mo of age. The micrographs showed a sponge-like structural network with a well-distributed system of empty spaces, originally occupied by whey and fat. The microstructure changed during cheese ripening to become more compact with cavities of smaller size. Farm technology significantly affected cheese proteolysis and microstructure. Nontraditional cheeses had higher levels of pH 4.6-soluble N and showed a larger hydrolysis of alpha(s)-casein fractions by urea-PAGE analysis than did traditional cheeses. Large differences between cheese-types also concerned the patterns of secondary proteolysis. Nontraditional cheeses had higher levels of 12% trichloroacetic acid-soluble N and showed larger proportions of free amino acids and hydrophilic peptides in the HPLC profiles of the corresponding 70% ethanol-soluble N fraction than traditional cheeses. Nontraditional cheeses also had a more open structure with a coarser and less continuous appearance than did traditional cheeses. A large amount of variability in cheese proteolysis and structure within nontraditional treatment reflected farm-dependent changes in manufacturing conditions related to the use of various types of rennet and starter.     

Reduced fat process cheese made from young reduced fat Cheddar cheese manufactured with exopolysaccharide-producing cultures

In a previous study, exopolysaccharide (EPS)-producing cultures improved textural and functional properties of reduced fat Cheddar cheese. Because base cheese has an impact on the characteristics of process cheese, we hypothesized that the use of EPS-producing cultures in making base reduced fat Cheddar cheese (BRFCC) would allow utilization of more young cheeses in making reduced fat process cheese. The objective of this study was to evaluate characteristics of reduced fat process cheese made from young BRFCC containing EPS as compared with those in cheese made from a 50/50 blend of young and aged EPS-negative cheeses. Reduced fat process cheeses were manufactured using young (2 d) or 1-mo-old EPS-positive or negative BRFCC. Moisture and fat of reduced fat process cheese were standardized to 49 and 21%, respectively. Enzyme modified cheese was incorporated to provide flavor of aged cheese. Exopolysaccharide-positive reduced fat process cheese was softer, less chewy and gummy, and exhibited lower viscoelastic moduli than the EPS-negative cheeses. The hardness, chewiness, and viscoelastic moduli were lower in reduced fat process cheeses made from 1-mo-old BRFCC than in the corresponding cheeses made from 2-d-old BRFCC. This could be because of more extensive proteolysis and lower pH in the former cheeses. Sensory scores for texture of EPS-positive reduced fat process cheeses were higher than those of the EPS-negative cheeses. Panelists did not detect differences in flavor between cheeses made with enzyme modified cheese and aged cheese. No correlations were found between the physical and melting properties of base cheese and process cheese.     

Influence of partial replacement of NaCl with KCl, CaCl2 and MgCl2 on lipolysis and lipid oxidation in dry-cured ham

Sodium intake above nutritional recommendations may involve harmful consequences to health such as the increased risk of cardiovascular diseases. Dry-cured ham constitutes a product with a relatively large amount of sodium. Thus, to obtain a healthier product for consumers with reduced sodium content, two formulations containing KCl alone (formulation II) or mixed with CaCl2 and MgCl2 (formulation III) have been proposed to partially replace NaCl. Lipolysis and lipid oxidation occurring in hams processed with these formulations have been studied since they have direct influence on the final flavor. No significant differences in acid lipase activity or lipid oxidation were found at the end of the process between the alternative formulations and formulation I (control with 100% NaCl). Differences in some free fatty acids, generated along the processing, were detected among treatments and at the end of dry-curing. Data suggests a slight trend towards a major lipolysis during treatment III.