Manufacture of Low-Na White Soft Brined Cheese: Effect of NaCl Substitution with a Combination of Na-K Salts on Proximate Composition, Mineral Content, Microstructure, and Sensory Acceptance

All over the world, especially in Western societies, table salt intake that is inordinately higher than the acceptable level has been observed. An excess of Na in the human diet, mostly from processed foods, is becoming the "number one killer", leading to increased blood pressure. Therefore, the food industry is faced with a need to reduce Na in human nutrition in an effort to raise public health protection to a higher level. In this study, a commercially available combination of Na/K salts (COMB) at different concentrations was used as a NaCl substitute in the production of a modified, healthier, Na-reduced cheese. Samples of the modified low-Na white soft-brined cheese (WSBC) were produced by adding four different concentrations of COMB to production lots PL-1 to PL-4, and the control (CON) samples were prepared by salting with the usual, non-reduced concentration of NaCl. The effects of NaCl replacement on the physical-chemical parameters, major- and micro-elements, and microstructural and sensory properties of the WSBC were investigated. The obtained results indicated that there was no significant influence on the ash content, pH, and aw. The Na and K levels differed among treatments (p < 0.001). The lowest Na level in this study was recorded in PL-4 (only COMB was added) and was 334.80 ± 24.60 mg/100 g. According to the Na content, WSBC PL4 can be labeled with the nutrient claim "reduced amount of Na". A significant difference (p < 0.05) was noticed in overall acceptance between the CON and PL-4, with no statistically significant difference found amongst other WSBC production lots. The replacement of NaCl resulted in a slightly greater firmness of the WSBC. The results confirm the possibility of producing low-Na WSBC when optimal amounts of a suitable mineral salt are used as a substitute for NaCl, thus reducing the risk of high Na intake in the human body through the consumption of evaluated cheese.

The effect of solution plasma treatment on the microbial safety and quality characteristics of albumen

The aim of this study was to make eggs microbially safe and increase their durability without damaging the functional properties of the albumen and preserving the solubility of its proteins as much as possible by the solution plasma technique. The pH, Brix, density, and viscosity values of samples decreased during treatment (p < .05 except pH). Although the L* and a* values of both the albumen and egg foam decreased, the b*, hue angle, and chroma values of both increased during treatment. The L* and a* values of the albumen decreased by 7.01 and 1.89 units, and the values of the egg foam decreased by 10.93 and 1.03 units, respectively. At the end of the treatment, foaming capacity and foam stability were decreased by 25% and 21.42%, respectively. Foaming capacity values obtained as a result of this treatment were higher and foam stability values were lower compared to the values obtained in pasteurization of eggs by heat treatment. The count of the two pathogenic bacteria inoculated into the albumen decreased during the treatment (p < .05), the count of Salmonella Enteritidis decreased to 0, and the count of Staphylococcus aureus decreased by 1.09 log cfu/g at the end of the treatment. Compared to current heat treatments, solution plasma treatment caused significantly less adverse effects on albumen quality characteristics. In particular, the foaming properties of the albumen were much less affected by this method and remained at higher values compared to the values achieved by other methods. The treatment also produced a microbiologically safer product.

Influence of Sodium and Potassium Chloride on Rennet Coagulation and Curd Firmness in Bovine Milk

One of the salting methods in cheese production implies salting the milk before coagulation used in making Domiati-type cheeses and a variety of autochthonous "Lički Škripavac" cheese. The most used sodium replacer is potassium. This study investigated the influence of different added salt concentrations (1%, 1.5%, and 2%) and NaCl to KCl ratios (100%, 50:50%, 25:75%) on the rennet coagulation and curd firmness in bovine milk. The milk coagulation parameters were determined with a computerized renneting meter, Lactodinamograph. The results showed significant interactions between the salt concentrations and NaCl to KCl ratios (p < 0.0001, α = 0.05) by prolonging the beginning of coagulation (10-20 min) and curd firming rate (1-5 min) by an increase in salt concentration for all treatments. The 50:50 treatment values (RCT, k₂₀, a₃₀, a₆₀, a_max) were closest to the control (without salt) and had the best results among all treatments in the lower (1%) and medium (1.5%) salt concentration (p > 0.0001, α = 0.05) while in the highest salt concentration (2%) the treatment effect was nonsignificant (p > 0.05). These results should help future studies make a lower sodium product appealing to consumers without losing quality.

Low-moisture part-skim mozzarella cheese made from blends of camel and bovine milk: Gross composition, proteolysis, functionality, microstructure, and rheological properties

Camel (CM) milk is used in variety of ways; however, it has inferior gelling properties compared with bovine milk (BM). In this study, we aimed to investigate the physicochemical, functional, microstructural, and rheological properties of low-moisture part-skim (LMPS) mozzarella cheese, made from BM, or BM mixed with 15% CM (CM15%) or 30% CM (CM30%), at various time points (up to 60 d) of storage at 4°C after manufacture. Low-moisture part-skim mozzarella cheeses using CM15% and CM30% had high moisture and total Ca contents, but lower soluble Ca content. Compared with BM cheese, CM15% and CM30% LMPS mozzarella cheese exhibited higher proteolysis rates during storage. Adding CM affected the color properties of LMPS mozzarella cheese manufactured from mixed milk. Scanning electron microscopy images showed that the microstructure of CM15% and CM30% cheeses had smooth surfaces, whereas the BM cheese microstructures were rough with granulated surfaces. Low-moisture part-skim mozzarella cheeses using CM15% and CM30% showed significantly lower hardness and chewiness, but higher stringiness than BM cheese. Compared with BM cheese, CM15% and CM30% cheeses showed lower tan δ levels during temperature surges, suggesting that the addition of CM increased the meltability of LMPS mozzarella cheese during temperature increases. Camel milk addition affected the physicochemical, microstructural, and rheological properties of LMPS mozzarella cheese.

The Effect of Salt Reduction and Partial Substitution of NaCl by KCl on Physicochemical, Microbiological, and Sensorial Characteristics and Consumers' Acceptability of Semi-Hard and Hard Lactose-Free Cow's Milk Cheeses

Increasing consumer demand for healthier foods prompts the development of cheeses reduced in salt. The aim of his study was to assess the effect of reducing the level of sodium chloride (NaCl) and their partial substitution by potassium chloride (KCl) on the biochemical, microbiological, and sensorial characteristics and consumer's acceptability of semi-hard and hard lactose-free cow's milk cheeses. To improve the possible lower salty taste or the development of bitter taste, the addition to yeast extract, as a flavor enhancer, was also checked. Different brining times and brine conditions were tested to obtain a reduction of >25% of salt with respect to conventional cheese. Reduced-salt cheeses were elaborated by reducing half the salting time used in conventional cheeses, and a ratio of 60 Na⁺:40 K⁺ was used to reduce Na concentration in substituted cheeses. The results obtained in this study show that the reduction of salt by both methods in semi-hard and hard lactose-free cheeses could be an alternative for the production of healthier and sensorial acceptable cheeses, without significantly affecting their physicochemical characteristics. The addition of yeast extract, as a flavor enhancer, increased the free amino acids (FAAs) levels but decreased the acceptability of cheeses.

Isolation of enterotoxigenic Staphylococcus aureus harboring seb gene and enteropathogenic Escherichia coli (serogroups O18, O114, and O125) from soft and hard artisanal cheeses in Egypt

Background:

Soft and hard artisanal cheeses are regularly consumed in Egypt. These products are usually processed from raw milk which may harbor many pathogenic and spoilage microorganisms.

Aim:

To evaluate the safety of some artisanal cheeses in Egypt, such as Ras, Domiati, and Mish, through chemical and microbiological examination.

Methods:

One hundred and fifty random samples of traditional Ras, Domiati, and Mish cheeses (50 each) were microbiologically and chemically analyzed. Counts of total bacteria, presumptive coliform, staphylococci, yeast, and mold were estimated. Furthermore, isolation of Escherichia coli and Staphylococcus aureus was performed, followed by PCR confirmation; isolates of E. coli were examined for the presence of virulence genes; on the other hand, the detection of the five classical enterotoxin genes of S. aureus was performed using multiplex PCR. Regarding chemical analysis, moisture, salt, and acidity content were measured. Correlations between chemical and microbial findings were investigated.

Results:

Mean counts of total bacteria, presumptive coliform, staphylococci, yeast, and mold were (2 × 10⁸, 3 × 10⁶ and 1 × 10⁷ ), (3 × 10⁵, 5 × 10 and 5 × 10²), (1 × 10⁶, 4 × 10⁵and 1 × 10⁵), (3 × 10⁵, 1 × 10⁵ and 5 × 10⁵), and (7 × 10³, 4 × 10³ and 3 × 10⁴) for Ras, Domiati and Mish cheeses, respectively. Serological identification of suspected E. coli revealed that E. coli O125 was isolated from Ras and Domiati samples, E. coli O18 was recovered from Ras samples, while E. coli O114 was isolated from Mish samples. PCR results revealed that all detected isolates of E. coli were positive for both iss (increased serum survival) and fimH (type 1 fimbriae) genes. Concerning isolated S. aureus, all examined products were harboring S. aureus enterotoxigenic strains, with seb and sed genes being the most common. The mean values of moisture, salt, and acidity were (30.03, 56.44, and 58.70), (3.30, 6.63, and 7.56) and (0.65, 0.68, and 0.50) for Ras, Domiati, and Mish cheeses, respectively.

Conclusion:

Enterotoxigenic S. aureus harboring seb gene and enteropathogenic E. coli (serogroups O18, O114, and O125) were frequently isolated from soft and hard artisanal cheeses in Egypt. Therefore, strict hygienic measures should be applied during their manufacture, handing, and distribution.

Psychrotrophs in raw milk: effect on texture, proteolysis index, and sensory evaluation of smoked provolone cheese

BACKGROUND

Provolone can be fresh or ripened, with its taste varying from sweet to spicy. The high psychrotrophic density of raw milk is associated with thermoresistant enzymes that can change cheese characteristics such as texture, promote sensory defects and decrease industrial yield. Two batches of provolone-type smoked cheese were produced from chilled raw milk with 3 log cfu mL^-1 (Treatment 1) and 7 log cfu mL^-1 (Treatment 2) of psychrotrophs. The psychrotrophic (21 °C for 25 h) and physical-chemical profile of the raw milk were determined. Cheeses were evaluated by fat level, primary and secondary proteolysis index, yield, protein profile (Urea-polyacrylamide gel electrophoresis), and texture (hardness, cohesiveness, elasticity, and chewiness) at 14, 30, and 60 days of storage time. Sensorially, the cheeses were evaluated (100 tasters/period) using the triangular test.

RESULTS

The treatments did not influence proteolysis index, although maturation influenced the proteolytic depth index after 60 days. The psychrotrophic population influenced α_s 1- and β-casein fractions, while maturation time influenced α_s 1- and γ-casein fractions. Treatment 2 induced a 3% reduction in cheese yield. Hardness and chewiness showed a linear and positive relationship with the milk's psychrotrophic load. There was a significant difference in the fat content of the cheeses, with Treatment 2 having a lower level. The triangular test showed no difference between the cheeses.

CONCLUSION

Although the larger psychrotrophic population in raw milk was associated with superior values of hardness and chewiness, as well as an increase in protein fractions indicating that proteolysis was observed, the tasters did not identify sensorial differences between the cheeses. © 2020 Society of Chemical Industry.

Reduced-sodium cheeses: Implications of reducing sodium chloride on cheese quality and safety

Sodium chloride (NaCl) universally well-known as table salt is an ancient food additive, which is broadly used to increase the storage stability and the palatability of foods. Though, in recent decades, use of table salt in foods is a major concern among the health agencies of the world owing to ill effects of sodium (Na) that are mostly linked to hypertension and cardiovascular diseases. As a result, food scientists are working to decrease the sodium content in food either by decreasing the rate of NaCl addition or by partial or full replacement of NaCl with other suitable salts like potassium chloride (KCl), calcium chloride (CaCl₂ ), or magnesium chloride (MgCl₂ ). However, in cheese, salt reduction is difficult to accomplish owing to its multifaceted role in cheese making. Considering the significant contribution in dietary salt intake (DSI) from cheese, researchers across the globe are exploring various technical interventions to develop reduced-sodium cheeses (RSCs) without jeopardizing the quality and safety of cheeses. Thus, the purpose of this study is to provide an insight of NaCl reduction on sensory, physicochemical, and technofunctional attributes of RSCs with an aim to explore various strategies for salt reduction without affecting the cheese quality and safety. The relationship between salt reduction and survival of pathogenic and spoilage-causing microorganisms and growth of RSCs microflora is also discussed. Based on the understanding of conceptual and applied information on the complex changes that occur in the development of RSCs, the quality and safety of RSCs can be accomplished effectively in order to reduce the DSI from cheese.

Efficacy of sodium alginate as fat replacer on the processing and storage quality of buffalo mozzarella cheese

Purpose

The sensory quality and yield of mozzarella cheese deteriorate as the fat content in milk is reduced. This study aims to evaluate the efficacy of sodium alginate as a fat replacer in low-fat buffalo mozzarella cheese on the basis of processing and storage (4 ± 1°C) quality.

Design/methodology/approach

Five treatments of buffalo mozzarella cheese, viz., control full-fat cheese (6.0 per cent milk fat; CFFC), control low-fat cheese (<0.5 per cent milk fat) without sodium alginate (CLFC), low-fat cheese with 0.1 per cent sodium alginate (LFC-1), 0.2 per cent sodium alginate (LFC-2) and 0.3 per cent sodium alginate (LFC-3), were comparatively evaluated.

Findings

Increase in the level of sodium alginate increased the percent yield of treated low-fat cheese than CLFC. Addition of sodium alginate to low-fat cheese resulted in decrease in hardness (p = 0.023) and chewiness than CLFC. Meltability was significantly decreased (p = 0.03) in low-fat cheese than CFFC. It was recorded as 1.5 ± 0.14 cm for CFFC to 0.2 ± 0.08 cm in LFC-3. Sensory panellists awarded LFC-3 highest and lowest to LFC-1; however, treated products at all selected levels were superior to CLFC. Oxidative stability and microbial stability were improved in LFC-3 than CFFC during storage.

Practical implications

Results concluded that 0.3 per cent sodium alginate is optimum for the development of extended shelf-life functional/low-fat/low-calorie buffalo mozzarella cheese.

Originality/value

Processing interventions can be successfully used to develop low-fat/low-calorie mozzarella cheese with acceptable sensory attributes and longer storage life.

The effect of partial substitution of NaCl with KCl on the physicochemical, microbiological and sensory properties of Akkawi cheese

BACKGROUND

Studies have shown a direct relationship between increased dietary sodium intake and chronic diseases such as hypertension, cardiovascular disease and osteoporosis. Potassium chloride is the most widely used salt substitute for sodium chloride in different processed foods. Akkawi cheese, commonly consumed as fresh cheese, has a semi-hard curd, chalky color, firm texture and salty flavor. The effect of partial replacement of NaCl with KCl on the chemical, textural, microbiological and sensory characteristics of fresh and mature Akkawi cheese was investigated.

RESULTS

Salt treatment (NaCl reduction) had a significant effect on pH, lactic acid, sodium and potassium contents of cheeses. Texture profile analysis revealed a significant effect of salt treatment on adhesiveness, chewiness and hardness of cheese. All tested microorganisms increased with storage but in general did not differ between salt treatments, specifically between control (100% NaCl) and (70% NaCl, 30% KCl) samples. Descriptive analysis showed that salt treatment had a significant effect on bitterness, crumbliness and hardness, whereas the age of cheese was significant for color and fermented flavor. Salt treatment had no effect on acceptability variables for all experimental 2-week Akkawi samples.

CONCLUSION

The above results suggest that a 30% substitution of NaCl by KCl (70% NaCl, 30% KCl brine) is acceptable.

Cross-sectional survey of salt content in cheese: a major contributor to salt intake in the UK

OBJECTIVE

To investigate the salt (sodium chloride) content in cheese sold in UK supermarkets.

STUDY DESIGN

We carried out a cross-sectional survey in 2012, including 612 cheeses available in UK supermarkets.

METHODS

The salt content (g/100 g) was collected from product packaging and nutrient information panels of cheeses available in the top seven retailers.

RESULTS

Salt content in cheese was high with a mean (±SD) of 1.7±0.58 g/100 g. There was a large variation in salt content between different types of cheeses and within the same type of cheese. On average, halloumi (2.71±0.34 g/100 g) and imported blue cheese (2.71±0.83 g/100 g) contained the highest amounts of salt and cottage cheese (0.55±0.14 g/100 g) contained the lowest amount of salt. Overall, among the 394 cheeses that had salt reduction targets, 84.5% have already met their respective Department of Health 2012 salt targets. Cheddar and cheddar-style cheese is the most popular/biggest selling cheese in the UK and has the highest number of products in the analysis (N=250). On average, salt level was higher in branded compared with supermarket own brand cheddar and cheddar-style products (1.78±0.13 vs 1.72±0.14 g/100 g, p<0.01). Ninety per cent of supermarket own brand products met the 2012 target for cheddar and cheddar-style cheese compared with 73% of branded products (p=0.001).

CONCLUSIONS

Salt content in cheese in the UK is high. There is a wide variation in the salt content of different types of cheeses and even within the same type of cheese. Despite this, 84.5% of cheeses have already met their respective 2012 targets. These findings demonstrate that much larger reductions in the amount of salt added to cheese could be made and more challenging targets need to be set, so that the UK can continue to lead the world in salt reduction.

The effect of NaCl substitution with KCl on Akawi cheese: chemical composition, proteolysis, angiotensin-converting enzyme-inhibitory activity, probiotic survival, texture profile, and sensory properties

The effect of partial substitution of NaCl with KCl on Akawi cheese with probiotic bacteria was investigated during 30 d of storage at 4 °C. Chemical composition, the survival of probiotic and lactic acid bacteria, proteolytic activity, and texture profile analysis were analyzed and sensory analysis was carried out to determine the effects of substitution. No significant differences were observed in moisture, protein, fat, and ash contents among the experimental Akawi cheeses at the same storage period. Significant differences were observed in water-soluble nitrogen and phosphotungstic-soluble nitrogen between experimental cheeses at the same of storage period. No significant difference was observed in the growth of Lactobacillus delbrueckii ssp. bulgaricus between experimental cheeses at the same storage period. However, the growth of Streptococcus thermophilus, Lactobacillus casei, and Lactobacillus acidophilus was significantly affected among experimental cheeses. A significant difference was observed in soluble Ca among experimental cheeses at the same storage period. In general, no significant differences existed in hardness and adhesiveness among experimental cheeses at the same storage period. No significant differences existed in sensory attributes, including creaminess, bitterness, saltiness, sour-acid, and vinegar taste among experimental Akawi cheeses at the same storage period.

Effect of partial NaCl substitution with KCl on the texture profile, microstructure, and sensory properties of low-moisture mozzarella cheese

The effect of partial substitution of NaCl with KCl on texture profile, soluble Ca, K, Na, and P, and microstructure of low-moisture mozzarella cheese (LMMC) was investigated. LMMC batches were prepared using four combinations of NaCl and KCl salt viz., NaCl only, NaCl:KCl, 3:1, 1:1 and 1:3 (w/w); all used at of 46 g/kg curd and plasticised in 4% brine containing the above salt mixtures. Texture profile, microstructure, and percentages of soluble Ca, K, Na, and P were determined. There were no significant differences in hardness, cohesiveness, adhesiveness, and gumminess among the experimental LMMC batches. Environmental scanning electron microscopy images showed compact and homogeneous structure of LMMC at day 27 of storage; however, no significant difference was observed among the experimental LMMC batches. Hardness increased significantly in all experimental LMMC during storage. LMMC salted with NaCl/KCl mixtures had almost similar sensory properties compared with the control. There was no significant difference in creaminess, bitterness, saltiness, sour-acid, and vinegary taste among the experimental LMMC at the same storage period.

The impact of NaCl substitution with KCl on proteinase activities cell-free extract and cell-free supernatant at different pH levels and salt concentrations: Lactobacillus delbrueckii ssp. bulgaricus and Streptococcus thermophilus

The effect of NaCl substitution with KCl at different pH levels (6.0, 5.5, and 5.0) and salt concentrations on proteinase activities of cell-free and supernatant of Lactobacillus delbrueckii ssp. bulgaricus 11824 (L. bulgaricus) and Streptococcus thermophilus MS (ST) was investigated. MRS broths were separately mixed with 4 salt treatments (NaCl only, 1NaCl:1KCl, 1NaCl:3KCl, and KCl only) at 2 different concentrations (5% and 10%) and incubated at 37 °C for 22 h. The cell pellets were used to prepare proteinase of cell-free extract and the cell-free supernatants were used as source of extracellular proteinases. The proteolytic activities and protein contents of both fractions were determined. The supernatants after incubation of both fractions with 3 milk caseins (α-, β-, κ-casein) were subjected to angiotensin-converting-enzyme inhibitory (ACE-inhibitory) activity and proteolytic activity by ortho-phthalaldehyde (OPA) method. Significant differences were observed in ACE-inhibitory activities and proteolytic (OPA) between salt treatments of cell-free extract and cell-free supernatant of L. bulgaricus and S. thermophilus at same salt concentration and same pH level. There was a significant effect of pH level and salt treatments interaction on ACE-inhibitory activity, OPA activity and azocasein activity.

PRACTICAL APPLICATION

To reduce sodium concentration in cheese by substituting of NaCl with KCl, it was important to study the effect on starter culture proteinases which play a vital role in ripening and texture profile of cheese.