Effects of dietary supplementation with extruded linseed and oregano in autochthonous goat breeds on the fatty acid profile of milk and quality of Padraccio cheese

The study aimed to evaluate the effects of linseed and oregano supplementation to the diet of goats on fatty acid profile and sensory properties of Padraccio, a typical cheese produced during spring through summer in the Basilicata region (southern Italy). Extruded linseed and dried oregano inflorescences were integrated in the pelleted concentrate supplementation (500 g/head per day) in 21 grazing goats that were randomly assigned, 7 per group, to the following experimental treatments: concentrate, concentrate with addition of linseed, and concentrate with addition of linseed and oregano. Pooled milk from each group was used in cheesemaking. From a nutritional perspective, integration of extruded linseed in the goat diet improved the fatty acid profile of Padraccio cheese. Moreover, the cheese from this group evidenced the highest scoring on color, flavor, texture, and overall liking.     

The effect of substituting NaCl with KCl on Nabulsi cheese: chemical composition, total viable count, and texture profile

The effect of substituting NaCl with KCl on Nabulsi cheese characteristics was investigated. Nabulsi cheese was made and stored in 4 different brine solutions at 18%, including NaCl only (A; control); 3NaCl:1KCl (wt/wt; B); 1NaCl:1KCl (wt/wt; C); and 1NaCl:3KCl (wt/wt; D). Chemical composition, proteolysis, total viable count, and texture profile analysis were assessed at monthly intervals for 5 mo. No significant effect was found among experimental cheeses in terms of chemical composition or texture profile. Proteolytic activities were higher in cheeses kept in brine solutions that contained higher KCl (B, C, and D) compared with the control. At the end of the storage period, water-soluble nitrogen in Nabulsi cheeses stored in B, C, and D was higher than that in the control cheese (A). In addition, total viable count increased significantly after 1 mo of storage for all salt treatments. Hardness and gumminess generally decreased significantly during storage within the same salt treatment.     

Texture and colour characteristics,and optimisation of sodium chloride,potassium chloride and glycine of reduced-sodium frankfurter

The three-components mixture design was applied to optimise a ratio of NaCl (0%–65%), KCl (35%–100%) and glycine (0%–20%) in reduced-sodium frankfurters. Fourteen frankfurters were analysed for texture and colour, and consumer (n = 100) acceptability. Results indicated that NaCl levels affected consumer acceptability of reduced-sodium frankfurters. Increasing NaCl generally increased texture hardness. Optimisation of a salt mixture was performed by superimposing contour plots of predicted acceptability scores (≥5.5 on a 9-points hedonic scale) of all sensory attributes and revealed the optimal salt mixture: 40.03%–63.66% NaCl, 35.00%–55.90% KCl and 0.00%–20.00% glycine. The optimal salt mixture contained 220–340 mg Na/100g frankfurter compared with 540 mg Na/100 g of the control formulation (100% NaCl). The mean overall liking score (5.9 vs. 5.9) of the optimal reduced-sodium frankfurter was not different from the control (100% NaCl). This optimal formulation had >25% sodium reduction and could be claimed as ‘reduced-sodium’ according to US Food and Drugs Administration regulation.     

Salt Reduction in a Model High‐Salt Akawi Cheese: Effects on Bacterial Activity,pH, Moisture,Potential Bioactive Peptides,Amino Acids,and Growth of Human Colon Cells

This study evaluated the effects of sodium chloride reduction and its substitution with potassium chloride on Akawi cheese during storage for 30 d at 4 °C. Survival of probiotic bacteria (Lactobacillus acidophilus, Lactobacillus casei, and Bifidobacterium longum) and starter bacteria (Streptococcus thermophilus and Lactobacillus delbrueckii ssp. bulgaricus), angiotensin‐converting enzyme‐inhibitory and antioxidant activities, and concentrations of standard amino acids as affected by storage in different brine solutions (10% NaCl, 7.5% NaCl, 7.5% NaCl+KCl [1:1], 5% NaCl, and 5% NaCl+KCl [1:1]) were investigated. Furthermore, viability of human colon cells and human colon cancer cells as affected by the extract showing improved peptide profiles, highest release of amino acids and antioxidant activity (that is, from cheese brined in 7.5% NaCl+KCl) was evaluated. Significant increase was observed in survival of probiotic bacteria in cheeses with low salt after 30 d. Calcium content decreased slightly during storage in all cheeses brined in various solutions. Further, no significant changes were observed in ACE‐inhibitory activity and antioxidant activity of cheeses during storage. Interestingly, concentrations of 4 essential amino acids (phenylalanine, tryptophan, valine, and leucine) increased significantly during storage in brine solutions containing 7.5% total salt. Low concentration of cheese extract (100 μg/mL) significantly improved the growth of normal human colon cells, and reduced the growth of human colon cancer cells. Overall, the study revealed that cheese extracts from reduced‐NaCl brine improved the growth of human colon cells, and the release of essential amino acids, but did not affect the activities of potential bioactive peptides.     

Characterization of starter-free Queso Fresco made with sodium-potassium salt blends over 12 weeks of 4°C storage

Development of reduced-sodium cheese to meet the demands of consumers concerned about sodium levels in their diet is challenging when a high-moisture, higher pH, fresh cheese, such as Queso Fresco (QF), depends on its NaCl salt content to obtain its signature flavor and quality traits. This study evaluated the effects of different Na-K salt blends on the compositional, sensorial, microbial, functional, and rheological properties of QF stored for up to 12 wk at 4°C. Queso Fresco curd from each vat was divided into 6 portions and salted with different blends of NaCl-KCl (Na-K, %): 0.75-0.75, 1.0-0.5, 1.0-1.0, 1.0-1.3, 1.0-1.5, and 2.0-0 (control). Within this narrow salt range (1.5 to 2.5% total salt), the moisture, protein, fat, and lactose levels; water activity; pH; and the textural and rheological properties were not affected by salt treatment or aging. The total salt, sodium, potassium, and ash contents reflected the different Na-K ratios added to the QF. Total aerobic microbial count, overall proteolysis, the release of casein phosphopeptides, and the level of volatile compounds were affected by aging but not by the salt treatment. Only the 1.0-1.3 and 1.0-1.5 Na-K cheeses had sensory saltiness scores similar to that of the 2.0-0 Na-K control QF. Loss of free serum from the cheese matrix increased steadily over the 12 wk, with higher losses found in QF containing 1.5% total salt compared with the higher Na-K blends. In conclusion, KCl substitution is a viable means for reduction of sodium in QF resulting in only minor differences in the quality traits, and levels of 1.0-1.3 and 1.0-1.5 Na-K are recommended to match the saltiness intensity of the 2.0-0 Na-K control. The findings from this study will aid cheese producers in creating reduced-sodium QF for health-conscious consumers.     

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.     

The effect of sodium chloride substitution with potassium chloride on texture profile and microstructure of Halloumi cheese

The effect of partial substitution of NaCl with KCl on texture profile and microstructure of Halloumi cheese was investigated. Four batches of Halloumi cheese were made and kept in 4 different brine solutions (18%, wt/wt), including A) NaCl only, B) 3NaCl:1KCl, C) 1NaCl:1KCl, and D) 1NaCl:3KCl and then stored at 4°C for 56 d. The texture profile was analyzed using an Instron universal machine, whereas an environmental scanning electron microscope was used to investigate the effect of NaCl substitution on the microstructure of cheeses. No significant difference was found in hardness, cohesiveness, adhesiveness, and gumminess among experimental cheeses at the same storage day. Hardness, cohesiveness, and gumminess decreased significantly during storage period with the same salt treatment, whereas adhesiveness significantly increased. Environmental scanning electron microscope micrographs showed a compact and closed texture for cheeses at the same storage period. The microstructure of all cheeses became more closed and compact with storage period. Calcium content negatively correlated with hardness and Na and K contents during storage with the same salt treatment.     

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.     

Review Article: Sensory Characteristics of Probiotic Cheese

Abstract: Cheese has a good potential for delivery of probiotic microorganisms into the human intestine. In addition, the very wide variety of cheese types all over the world, consumption of cheese by almost everybody, as well as the high nutritional value of cheese constitute growing market for probiotic cheese. Probiotic microorganisms must survive in food products above a standard level until the time of consumption without adversely changing their sensory attributes. Since probiotic microorganisms could affect the flavor, texture, and appearance of dairy products, the sensory attributes of these products have been the subject of numerous studies. This article reviews the sensory characteristics of cheese as affected by probiotic microorganisms.     

The effect of sodium reduction with and without potassium chloride on the survival of Listeria monocytogenes in Cheddar cheese

Sodium chloride (NaCl) in cheese contributes to flavor and texture directly and by its effect on microbial and enzymatic activity. The salt-to-moisture ratio (S/M) is used to gauge if conditions for producing good-quality cheese have been met. Reductions in salt that deviate from the ideal S/M range could result in changing culture acidification profiles during cheese making. Lactococcus lactis ssp. lactis or Lc. lactis ssp. cremoris are both used as cultures in Cheddar cheese manufacture, but Lc. lactis ssp. lactis has a higher salt and pH tolerance than Lc. lactis ssp. cremoris. Both salt and pH are used to control growth and survival of Listeria monocytogenes and salts such as KCl are commonly used to replace the effects of NaCl in food when NaCl is reduced. The objectives of this project were to determine the effects of sodium reduction, KCl use, and the subspecies of Lc. lactis used on L. monocytogenes survival in stirred-curd Cheddar cheese. Cheese was manufactured with either Lc. lactis ssp. lactis or Lc. lactis ssp. cremoris. At the salting step, curd was divided and salted with a concentration targeted to produce a final cheese with 600 mg of sodium/100 g (control), 25% reduced sodium (450 mg of sodium/100 g; both with and without KCl), and low sodium (53% sodium reduction or 280 mg of sodium/100 g; both with and without KCl). Potassium chloride was added on a molar equivalent to the NaCl it replaced to maintain an equivalent S/M. Cheese was inoculated with a 5-strain cocktail of L. monocytogenes at different times during aging to simulate postprocessing contamination, and counts were monitored over 27 or 50 d, depending on incubation temperature (12 or 5°C, respectively). In cheese inoculated with 4 log₁₀ cfu of L. monocytogenes/g 2 wk after manufacture, viable counts declined by more than 3 log₁₀ cfu/g in all treatments over 60 d. When inoculated with 5 log₁₀ cfu/g at 3 mo of cheese age, L. monocytogenes counts in Cheddar cheese were also reduced during storage, but by less than 1.5 log₁₀ cfu/g after 50 d. However, cheese with a 50% reduction in sodium without KCl had higher counts than full-sodium cheese at the end of 50 d of incubation at 4°C when inoculated at 3 mo. When inoculated at 8 mo postmanufacture, this trend was only observed in 50% reduced sodium with KCl, for cheese manufactured with both cultures. This enhanced survival for 50% reduced-sodium cheese was not seen when a higher incubation temperature (12°C) was used when cheese was inoculated at 3 mo of age and monitored for 27 d (no difference in treatments was observed at this incubation temperature). In the event of postprocessing contamination during later stages of ripening, L. monocytogenes was capable of survival in Cheddar cheese regardless of which culture was used, whether or not sodium had been reduced by as much as 50% from standard concentrations, or if KCl had been added to maintain the effective S/M of full-sodium Cheddar cheese.     

Reducing salt in imitation cheese: Effects on manufacture and functional properties

Imitation cheeses (48% moisture, 0-1.5% NaCl) were manufactured using a Farinograph or Blentech cooker. The effects of NaCl reduction on cheese manufacture, functionality (assessed by texture profile analysis, flowability, dynamic rheology and microscopy), microbiological stability and sensory attributes were investigated. Reducing NaCl concentration decreased processing times and mixing energy required during manufacture and, post-manufacture, decreased cheese hardness, G′ values at 25 °C and crossover temperature and increased fat globule size. Cheeses from both cookers showed the same trend in functionality. Microbial stability was reduced at 0% NaCl, and the sensory panellists preferred the 50% reduced NaCl cheese to the standard.     

Effect of KCl substitution on bacterial viability of Escherichia coli (ATCC 25922) and selected probiotics

Excessive intake of NaCl has been associated with the increased risk of several diseases, particularly hypertension. Strategies to reduce sodium intake include substitution of NaCl with other salts, such as KCl. In this study, the effects of NaCl reduction and its substitution with KCl on cell membranes of a cheese starter bacterium (Lactococcus lactis ssp. lactis), probiotic bacteria (Bifidobacterium longum, Lactobacillus acidophilus, and Lactobacillus casei), and a pathogenic bacterium (Escherichia coli) were investigated using Fourier-transform infrared (FTIR) spectroscopy. A critical NaCl concentration that inhibited the viability of E. coli without affecting the viability of probiotic bacteria significantly was determined. To find the critical NaCl concentration, de Man, Rogosa, and Sharpe (MRS) broth was supplemented with a range of NaCl concentrations [0 (control), 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, and 5.0%], and the effect on cell viability and FTIR spectra was monitored for all bacteria. A NaCl concentration of 2.5% was found to be the critical level of NaCl to inhibit E. coli without significantly affecting the viability of most of the probiotic bacteria and the cheese starter bacterium. The FTIR spectral analysis also highlighted the changes that occurred mainly in the amide regions upon increasing the NaCl concentration from 2.5 to 3.0% in most of the bacteria. Escherichia coli and B. longum were more sensitive to substitution of NaCl with KCl, compared with Lb. acidophilus, Lb. casei, and Lc. lactis ssp. lactis. To evaluate the effect of substitution of NaCl with KCl, substitution was carried out at the critical total salt concentration (2.5%, wt/vol) at varying concentrations (0, 25, 50, 75, and 100% KCl). The findings suggest that 50% substitution of NaCl with KCl, at 2.5% total salt, could inhibit E. coli without affecting the probiotic bacteria.     

The effect of substitution of NaCl with KCl on chemical composition and functional properties of low-moisture Mozzarella cheese

The effect of NaCl substitution with KCl on chemical composition, organic acids profile, soluble calcium, and functionality of low-moisture Mozzarella cheese (LMMC) was investigated. Functionality (meltability and browning), organic acids profile, and chemical composition were determined. Chemical composition showed no significant difference between experimental cheeses at same storage period, and same salt treatment. Meltability of LMMC salted with 3NaCl:1KCl, 1NaCl:1KCl, and 1NaCl:3KCl was higher compared with only NaCl (control). The amount of soluble Ca and P increased significantly during storage, with no significant difference between salt treatments. Organic acids profile did not differ between salt treatments at the same storage time.     

The effect of yeast extract addition on quality of fermented sausages at low NaCl content

Fermented sausages with 25% or 50% of their NaCl replaced by KCl and supplemented with 1% or 2% concentrations of yeast extract were produced. The sausage production process was monitored with physical, chemical and microbiological analyses. After production, the sausage samples were submitted to a consumer study and their volatile compounds were extracted by solid-phase microextraction and analyzed by GC-MS. The replacement of NaCl by KCl did not significantly influence the physical, chemical or microbiological characteristics. The sensory quality of the fermented sausages with a 50% replacement was poor compared with the full-salt control samples. The use of yeast extract at a 2% concentration increased volatile compounds that arose from amino acids and carbohydrate catabolism. These compounds contributed to the suppression of the sensory-quality defects caused by the KCl introduction, thus enabling the production of safe fermented sausages that have acceptable sensory qualities with half as much sodium content.     

Utilization of temporal dominance of sensations and time intensity methodology for development of low-sodium Mozzarella cheese using a mixture of salts

Evidence has linked excessive salt consumption to the development of chronic degenerative diseases. Therefore, special attention has been given to the consumption of healthier products with reduced sodium contents. This study aimed to develop a Mozzarella cheese with a reduced sodium content using a mixture of salts through acceptance testing and temporal sensory evaluation. The following 3 formulations of Mozzarella cheese were prepared: formulation A (control), which was produced only with NaCl (0% sodium reduction), formulation B (30% sodium reduction), and formulation C (54% sodium reduction). Every formulation was produced using a mixture of salts consisting of NaCl, KCl, and monosodium glutamate at different concentrations. The products underwent sensory acceptance tests, and the time intensity and temporal dominance of sensations were evaluated. The proportions of salts used did not cause strange or bad tastes but did result in lower intensities of saltiness. Mozzarella with low sodium content (B and C) had a sensory acceptance similar to that of traditional Mozzarella (A). Therefore, the use of a mixture of salts consisting of NaCl, KCl, and monosodium glutamate is a viable alternative for the production of Mozzarella, with up to a 54% reduction in the sodium content while still maintaining acceptable sensory quality.     

钾盐替代和附属发酵剂对切达干酪品质的影响

为明确降低钠含量和添加在脱脂乳中表现出具有较高血管紧张素转换酶（angiotensin-converting enzyme,ACE）抑制率的Lactobacillus paracasei M3作为附属发酵剂对切达干酪理化性质和体外抗高血压潜力的影响,将部分钾盐替代和L. paracasei M3单独和混合加入到干酪与空白组作对照,以主要成分、微生物、蛋白水解度、质构和风味为理化指标和以ACE抑制率为体外抗高血压潜力指标。结果表明,4 组干酪的主要成分差异不大（P＞0.05）,钾盐替代组、L. paracasei M3组、钾盐替代和L. paracasei M3混合组干酪在乳酸菌总数、pH 4.6可溶性氮、总游离氨基酸上显著高于空白组干酪（P＜0.05）,但是降低了干酪的硬度、pH值和有明显的苦味（P＜0.05）,而在体外抗高血压潜力方面,3 组干酪在成熟6 个月之后ACE抑制率达65.2%、74.3%和78.7%,比空白组分别高19.6%、36.2%和44.4%,由此可知,在切达干酪中钾盐替代和添加L. paracasei M3有助于具有抗高血压潜力的ACE抑制肽的产生,但是后续需要对风味进行补偿性研究。     

Reduction in sodium content of fresh,semihard Tzfat cheese using salt replacer mixtures: taste,texture and shelf life evaluation

Tzfat cheese is a semihard, fresh cheese commonly produced in Israel, with an average sodium content of 1000 mg/100 g cheese. Reduction in sodium levels by 30% and 50% (w/w) with and without salt replacer mixtures was assessed in terms of cheese physicochemical, microbiological and sensory properties. Cheese, containing 30% KCl and 70% NaCl had the closest taste profile to the control cheese, according to electronic tongue analysis. All cheeses underwent a similar increase in extent of proteolysis and microbial growth during shelf life. This study demonstrates the possibility of reducing the sodium content in fresh, semihard cheeses like Tzfat cheese by more than 30% using salt replacer mixtures, without significantly affecting quality.     

混菌发酵刺梨果渣风味组分及香气特征的变化分析与评价

采用嗜酸乳杆菌（Lactobacillus acidophilus）GIM.1.208、戊糖乳杆菌（Lactobacillus pentosus）CICC.22210和生香酵母混菌发酵刺梨果渣,通过定量描述性分析（QDA）法对发酵前后刺梨果渣进行感官评定,并利用顶空固相微萃取-气质联用（HS-SPME-GC-MS）技术、相对气味活度值（ROAV）对其风味组分及香气特征成分进行检测分析。结果表明,混菌发酵后,刺梨果渣的风味轮廓发生明显变化,产生酵母味,果香增强,刺激性涩味减弱;醇类、酯类、酸类物质相对含量均增加,烃类、醛类、酮类物质均减少;刺梨果渣保留了原果渣松木树脂样香及麦芽香等特征风味物质,且风味更加协调、柔和。     

Effect of Partial Substitution of NaCl with KCl on Halloumi Cheese during Storage: Chemical Composition,Lactic Bacterial Count,and Organic Acids Production

Abstract: The effect of partial substitution of NaCl with KCl on chemical composition, lactic bacterial count, and organic acids profile of Halloumi cheese was investigated. Halloumi cheeses were made and kept in 4 different brine solutions at 18% including NaCl only (HA), 3NaCl : 1KCl (HB), 1NaCl : 1KCl (HC), and 1NaCl : 3KCl (HD) and then stored at 4 °C for 56 d. No significant effect was observed between control and experimental cheeses in terms of moisture, fat, protein, lactic bacterial count, and pH values at the same storage period. There was a significant difference in ash, sodium, and potassium contents among experimental cheeses at the same storage period. Ash, sodium, and potassium contents increased significantly during storage at same salt treatment. There was no significant difference in lactic and citric acid contents among experimental cheeses and that of the control. In contrary, there was a significant difference in acetic acid among experimental cheeses. A strong positive correlation was observed between ash, Na, and K contents. An inverse correlation between organic acids and both Na and K contents was also observed.