Salt In Cheese Research Articles

PRODUCTION OF LOW CALORIES AND SODIUM CAST FETA CHEESE

The aim is to investigate the production of cast Feta cheese low in energy by partial or full replacement of milk fat and NaCl using, in order maltodextrin as a fat replacer and KCL as a salting substitute. Cast Feta cheese was made using skimmed milk powder which was arithmetically mixed with dried milk protein concentrate and reconstituted to form total solids of 21% and12% protein. In the base of full cream cheese, the fat was adjusted to 16% using butter oil (the control). For other treatments, butter oil was replaced with maltodextrin at the level of nil, 25, 50, 75 or 100%. All formulas were heat treated and homogenized then cooled to the suitable renneting temperature. Salted to 2.5% NaCl, whether alone or replaced with KCl at the level of nil, 25, 50 or 75%. Glucono delta lactone was added at the level of 2.5% then rennet solution was added at the rate of 2 ml /10 Kg pre-cheese, which was packaged into plastic containers and incubated at 40o C for the complete coagulation. All cheese containers were cold stored at 5o C for 3 months. The proportional fat replacement with maltodextrin led to gradual reduction in the dry matter (DM) and ash contents of resultant cheese. The repining indices; titratable acidity, water soluble nitrogen (WSN) on total nitrogen (TN) and non-protein nitrogen / TN contents were increased as the fat replacement increased. Hardness, chewiness and gumminess of cheese increased while cohesiveness decreased. Total bacterial count (TBC) increased while, yeasts and molds (Y&M) count decreased. All judging scores of cheese sensory attributes, The substitution of NaCl with KCl in cheese salting heightened the DM and protein contents. Cheese hardness was weakened while gumminess was strengthened while, decreased in TBC and Y&M count. Nevertheless, scores of sensory properties were declined by NaCl substitution by more than 50%. During cheese cold storage period (CSP) TA, WSNTN and NPNTN contents as well as Y&M count were increased while pH value lowered. All texture parameters and organoleptic attributes, scores of cheeses decreased by prolonging the CSP but still keeping their acceptable quality until the end of experimental CSP.

Effect of sodium chloride reduction or partial substitution with potassium chloride on the microbiological, biochemical and sensory characteristics of semi-hard and soft cheeses.

Sodium reduction in the human diet is currently one of the main concerns for public health agencies and, consequently, has become a challenge for the food industries. In this study, the impact of reduced sodium chloride content (20%) or its partial substitution with potassium chloride in soft ("Camembert"-type) and semi-hard ("Reblochon"-type) cheeses was evaluated. Analyses included physicochemical and biochemical composition, microbial counts, 16S rRNA gene metabarcoding and metatranscriptomic analysis, volatile aroma compounds and sensory analysis. Regarding soft cheeses, the salt content of cheeses affected proteolysis at 21 days of ripening. RNA sequencing revealed that the relative activity of G. candidum increased, whereas that of P. camemberti decreased in reduced salt cheeses in comparison to the controls. Higher global intensity of odor and taste was observed in cheeses with reduced salt content, consistent with higher levels of alcohol and ester components. Regarding semi-hard cheeses, modifications of salt content did not significantly affect either their biochemical parameters and sensory characteristics or their technological microbial composition at day 21 of ripening. Finally, no impact of salt content was observed on the growth of the spoiler Yarrowia lipolytica in soft cheeses. In contrast, reducing salt content increased spoiler growth in semi-hard cheeses, as highlighted by a greater development of Pseudomonas that led to an increase in cheese proteolysis and lipolysis. In conclusion, the effect of reducing salt content is highly dependent on the cheese type. This factor should thus be taken into account by the dairy industry when the reduction of salt content is being considered. Moreover, the quality of raw products, in particular, the level of spoiler microorganisms, must be controlled before use during dairy processes.

Conductimetry: a rapid alternative technique for chlorides determination in cheese

The correlation of two instrumental techniques for chlorides determination in Colombian cheese, Queso Molido Nariñense (a type of white cheese), was analyzed. Potentiometry of chloride precipitation is the standard technique to determined salt in cheese. Conductimetry is an alternative technique. Samples of Queso Molido Nariñense were made. In the processed cheeses the salt concentration (NaCl: 0.5 %, 0.8 %, 1.0 %, 2.0 %, 3.0% and 6.0 %) was varied. Chlorides were determined by titration with silver nitrate in the potentiometric technique. In the conductimetric technique, each sample was analyzed by direct measuring its conductivity at room temperature. It was found that there is an adequate correlation between potentiometry and conductimetry. A maximum concentration of 2% NaCl in cheese is equivalent to 2.9 S/cm for conductivity readings. Additionally, it was verified that the conductimetry constitutes an analytically reliable technique for the determination of chlorides in cheese, it is friendlier to the environment, cheaper and faster.

The Determination of Some Microbiological and Chemical Features in Herby Cheese.

The objective of this study is to measure the amounts of biogenic amines, microbial counts, values of pH, titratable acidity, dry matter, and salt (%) in herby cheese, a very popular staple in the Turkish diet, and to evaluate the concentration of biogenic amines in terms of public health risks. A high-performance liquid chromatography (HPLC) method was used for the determination of eight biogenic amines in 100 herby cheeses sold in the local markets of Van. The bacterial load of the herby cheeses ranged between 4.0 and 8.90 log CFU/g for viable total aerobic mesophilic bacteria (TAMB), <1 and 7.0 log CFU/g for lactic bacteria (LAB), <1 and 6.08 log CFU/g for coliform bacteria, <1 and 5.81 log CFU/g for Enterobacteriaceae, <1 and 2.60 log CFU/g for Staphylococcus aureus, and 3.70 and 8.05 log CFU/g for yeasts and molds. The results obtained suggested significant changes in the pH, titratable acidity, dry matter, and salt contents of the examined herby cheese samples. The detection levels of biogenic amines in the samples ranged from <0.025 to 33.36 mg/kg for tryptamine, from <0.038 to 404.57 mg/kg for β-phenylethylamine, from 0.03 to 426.35 mg/kg for putrescine, from <0.039 to 1438.22 mg/kg for cadaverine, from <0.033 to 469 mg/kg for histamine, from <0.309 to 725.21 mg/kg for tyramine, from <0.114 to 1.70 mg/kg for spermidine, and from <0.109 to 1.88 mg/kg for spermine. As a result, these cheeses are fit for consumption in terms of the amounts of biogenic amines they contain.

Effect of Salting Technique on Shreddability, Texture Profile and Microstructure of the Pre-Acidified Cowâ??s Mozzarella Cheese

The aim is to investigate the effect of salting technique together with type of pre-acidification used acid on shreddability, texture profile and microstructure of the full fat cow’s Mozzarella cheese. Mozzarella cheeses were made conventionally from standardized full fat cow’s milk; pre-acidified with either citric, lactic or acetic acid drop-wise to pH of 6.3, using 2.5% activated Yoghurt starter culture and rennet (1.5 g/100 Kg). The milled curds were salted either by the brining technique or by dry salting. The obtained results indicated that, the brine salted cheeses were associated with significant increments in the values of dry matter, protein, fat, calcium, cohesiveness, springiness and adhesiveness. While the application of dry salting led to increase the values of ash, lactose, salt, sodium, hardness, cohesiveness, gumminess and shredding efficiency. Moreover, the microstructure of the brine salted cheeses was more porous, whereas the dry salted cheeses appeared with more homogeneous and continuous protein matrix as well as less pockets. The lactic pre-acidified cheeses were the most shreddable cheeses and distinguished with the highest dry matter, protein, ash, sodium, pH, hardness and cohesiveness, as well as reflected the densest protein network with narrow fat voids. The application of acetic acid was associated with significant increments in the values of fat, lactose, springiness and adhesiveness. Moreover, the citric pre-acidified cheese showed a combination of many larger channels and smaller pores giving an increased porous structure with more sharpened protein fibers.

Calcium lactate as an attractive compound to partly replace salt in blue-veined cheese

In addition to their high sodium content, cheeses are thought to induce an acid load to the body, which is associated with deleterious effects on consumers' health. Our objective was to explore the use of alkalinizing salts in partial substitution of NaCl to reduce both the sodium content and the acid-forming potential of cheese, without altering its sensory properties. Blue-veined cheeses were produced under industrial conditions, using brine salting followed by dry salting with a 4:1 (wt/wt) mixture of calcium lactate:NaCl or calcium citrate:NaCl. Sodium chloride was used in 2 granulometries: coarse (control treatment) and fine, to obtain homogeneous mixtures with the organic salts. Cheeses were then ripened for 56 d. No major appearance defects were observed during ripening. Calcium lactate substitution decreased the Na content of the cheese core by 33%, and calcium citrate substitution increased the citrate content of the cheese core by 410%, respectively, compared with fine NaCl. This study highlighted the substantial role of salt granulometry in sodium content, with the use of the coarse salt reducing the sodium content by 21% compared with fine salt. Sensory profiles showed nonsignificant differences in bitter and salty perceptions of salt-substituted cheeses with calcium lactate and calcium citrate compared with control cheeses. The use of calcium lactate should be considered to reduce the sodium content and improve the nutritional quality of cheeses while maintaining the sensory quality of the products. Alkalinizing organic salts could replace the acidifying salts KCl or CaCl2, which are currently used in salt replacement and are not recommended for consumers with renal disease. The method described here should be considered by cheese-making producers to improve the nutritional quality of cheese. Additional nutritional optimization strategies are suggested.

Study of the cheese salting process by dielectric properties at microwave frequencies

The salting process involves complex phenomena that affect the overall quality of cheese due to its effect on water activity and induced biochemical changes. The permittivity of cheese was analysed throughout the cheese salting treatment in order to relate it to water and salt transport. The salting treatment was carried out using 25% (w/w) sodium chloride brine at 4 °C. The samples were immersed in a vessel containing the osmotic solution with continuous stirring, for 0, 10, 20, 30, 40, 50, 60, 90, 120, 180, 240, 360, 480, 720, 900 and 1440 min. Samples were subsequently equilibrated in an isothermal chamber at 4 °C for 24 h. Mass, volume, surface water activity, moisture, ion content and permittivity were determined in fresh and salted samples. Permittivity was measured from 500 MHz to 20 GHz, using an open-ended coaxial probe connected to a Vector Network Analyser. The results showed that measurements at 20 GHz explain the water loss and water flux in the overall product. The state of the electrolytes in cheese can be followed using the ionic conductivity at 500 MHz. A coupled measurement of permittivity at 20 GHz and 500 MHz can predict the chemical species involved in the cheese salting process, and its structural changes. In conclusion, the measurement of permittivity in the microwave range can be used to monitor the salting cheese process.

Redefining the effect of salt on thermophilic starter cell viability, culturability and metabolic activity in cheese

This study investigated the differential effect of salt concentration in the outside and inside layers of brine salted cheeses on viability, culturability and enzyme activity of starter bacteria. The high-salt environment of the outside layer caused a sharp decrease in L. helveticus viability as measured by traditional plate counts. Remarkably, this was associated with lower release of intracellular enzymes (LDH), reduced levels of proteolysis and larger membrane integrity as measured by flow cytometry (FC) following classical Live/Dead staining. FC analysis of light scattering properties highlighted a significant reduction in size and granularity of the microbiota located in the cheese surface, suggestive of cell shrinkage and condensation of internal macromolecules probably due to hyperosmotic stress. The microbiota of the cheese surface were found to experience greater oxidative stress, as measured by FC analysis of the total levels of reactive oxygen species, compared to that of the interior layer. These results lead us to postulate that the physiology and health status of the microbiota were significantly different in the outer and inner layers of the cheese. The hyperosmotic environment of the outer layer resulted in reduced cell lysis, as measurable by assays based upon membrane integrity, but rather triggered cell death via mechanisms involving cell shrinkage and ROS-mediated damage of vital intracellular components. This study challenges the current thinking on how salt controls microbial activity in ripening cheese, especially in cheeses which are brine salted as local variations in biochemical ripening indices can differ significantly from the outside to the inside of a ripening cheese.

The potential use of probiotic strains Lactobacillus acidophilus NRRL B 4495, Bifidobacterium bifidum NRRL B41410 in ?Lor Whey Cheese? and the effects on sensory properties [pdf

BACKGROUND In recent years, probiotic bacteria have increasingly been incorporated into various foods as dietary adjuncts. The viability of the probiotic bacteria Lactobacillus acidophilus NRRL B 4495 and Bifido- bacterium bifidum NRRL B41410 in salted (1% w/w) and unsalted lor whey cheese during storage (21 days) at a refrigerated temperature (4°C) was evaluated. METHODS As well as the survival of the probiotic bacteria, total mesophilic bacteria, total lactic acid bacteria, Pseudomonas spp., yeast-mould counts and sensory characteristics were examined in the lor samples. RESULTS The Bf. bifidum remained in large numbers, at 7.30 and 7.11 log cfu/g, and Lb. acidophilus also survived well, with counts of 7.60 and 7.47 log cfu/g, for unsalted and salted cheeses respectively. Salted lor cheeses with added Lb. acidophilus have the highest sensory scores in the groups. CONCLUSIONS “Lor” whey cheese showed good probiotic properties.

The potential use of probiotic strains Lactobacillus acidophilus NRRL B 4495, Bifidobacterium bifidum NRRL B41410 in &ldquo;Lor Whey Cheese&rdquo; and the effects on sensory properties.

In recent years, probiotic bacteria have increasingly been incorporated into various foods as dietary adjuncts. The viability of the probiotic bacteria Lactobacillus acidophilus NRRL B 4495 and Bifido- bacterium bifidum NRRL B41410 in salted (1% w/w) and unsalted lor whey cheese during storage (21 days) at a refrigerated temperature (4&deg;C) was evaluated. As well as the survival of the probiotic bacteria, total mesophilic bacteria, total lactic acid bacteria, Pseudomonas spp., yeast-mould counts and sensory characteristics were examined in the lor samples. The Bf. bifidum remained in large numbers, at 7.30 and 7.11 log cfu/g, and Lb. acidophilus also survived well, with counts of 7.60 and 7.47 log cfu/g, for unsalted and salted cheeses respectively. Salted lor cheeses with added Lb. acidophilus have the highest sensory scores in the groups. &ldquo;Lor&rdquo; whey cheese showed good probiotic properties.

Influence of process temperature and salting methods on starter and NSLAB growth and enzymatic activity during the ripening of cheeses produced with Streptococcus thermophilus and Lactobacillus helveticus

The effect of varying cook temperature (40 or 50 °C) and salting method (dry or brine salting) on bacterial viability, enzymatic activity and chemical composition in cheeses made using Streptococcus thermophilus and Lactobacillus helveticus were investigated. Dry salting resulted in decreased cell viability of L. helveticus, increased lactate dehydrogenase activity and increased free amino acid levels, compared with brine salted cheeses, irrespective of cook temperature. A cook temperature of 50 °C resulted in reduced primary proteolysis and increased pH in comparison with that in cheeses cooked to 40 °C. Salting method influenced moisture content with higher levels in brine salted cheeses; cook temperature was also influential with higher cook temperature resulting in lower moisture within each salting method. Variations in manufacture procedure can allow for the development of cheese varieties with novel flavour and texture profiles using existing Cheddar or Swiss-style manufacturing facilities.

THE ELABORATION OF CHEESE MASSES OF THERAPEUTIC AND PROPHYLACTIC DIRECTION WITH CRYOADDITIVE “PUMPKIN”

There was grounded the expedience of using cryopowder “Pumpkin” in the technology of sweet and salt cheese masses. The possibility of using cryopowder “Pumpkin” as a component of therapeutic and prophylactic cheeses masses was studied. The main factors of introduction of cryoadditive “Pumpkin” are: normative organoleptic properties of product and its daily norm. The production of cheese masses with cryoadditive “Pumpkin” provides their combination with sugar or salt. The use of cryoadditive “Pumpkin” needs preliminary comminution and mixing them with sugar-sand or salt. The receipts of 4 types of cheese masses with cryoadditive “Pumpkin” (two fatless and two semi-fat ones) were elaborated. At introduction of cryoadditive “Pumpkin” in cheese masses their food value increased. The organoleptic, technological and commodity characteristics of these cheese masses were studied. It was established, that the color of sweet cheese masses was cream with separate yellow dots of comminuted powder-like cryoadditive and the color of salt cheese masses was, correspondingly, yellow. In sweet cheese masses the distinct smell of cryoadditive was perceptible, whereas in salt cheese masses it was fresh, sour-milk. The flavor of studied samples was more expressed in sweet cheese masses. The offered cheese masses had pleasant, original commodity look, normative physical-chemical characteristics. The titrated acidity of studied samples of salt cheese masses was 124–130 °Т, moisture ms - 62–60 % and dry substances – 40–38 %, and titrated acidity of studied samples of sweet cheese masses was126–134 °Т, moisture ms 63–66 % and dry substances – 34–37 %. The offered production widens the assortment of milk products of therapeutic and prophylactic direction.

Effect of tetrasodium pyrophosphate concentration and cooking time on the physicochemical properties of process cheese

Tetrasodium pyrophosphate (TSPP) is widely used as an emulsifying salt (ES) in process cheese. Previous reports have indicated that TSPP exhibits some unusual properties, including the gelation of milk proteins at specific ES concentrations. We studied the effect of various concentrations (0.25–2.75%) of TSPP and cooking times (0–20min) on the rheological, textural, and physical properties of pasteurized process Cheddar cheese using a central composite rotatable experimental design. Cheeses were made with a constant pH value to avoid pH as a confounding factor. Modeling of the textural properties of process cheese made with TSPP exhibited complex behavior, with polynomial models (cubic) giving better predictions (higher coefficient of determination values) than simpler quadratic models. Meltability indices (degree of flow from the UW MeltProfiler (University of Wisconsin–Madison), loss tangent value at 60°C from rheological testing, and Schreiber melt area) initially decreased with increasing TSPP concentrations, but above a critical ES concentration (~1.0%) meltability increased at higher TSPP concentrations. The storage modulus values measured at 70°C for process cheese initially increased with increasing TSPP concentration, but above a concentration of 1% ES, the storage modulus values decreased. Cooking time had little effect on the various melting or rheological properties. With an increase in TSPP concentration, the insoluble Ca and P contents increased, suggesting that TSPP addition resulted in the formation of insoluble calcium pyrophosphate complexes; some of which were likely associated with caseins. A portion of the added TSPP remained in the soluble phase. The acid-base buffering profiles also indicated that calcium pyrophosphate complexes were formed in cheese made with TSPP. In milk systems, low levels of TSPP have been shown to induce protein crosslinking and gelation, whereas at higher TSPP concentrations milk gelation was inhibited due to excessive charge repulsion from these calcium pyrophosphate complexes. We hypothesized that a similar phenomenon was occurring in our process cheese, resulting in the initial reduction in meltability with TSPP addition due to protein crosslinking, but at higher TSPP levels meltability increased due to excessive charge repulsion.

Optimising Cheese Brining Times

In this article we detail the work conducted during MISG2014 on the brining of Gouda cheese for the Fonterra Cooperative Group. We consider three different mathematical models that aim to predict the salt content of cheese post-brining. The first is a diffusion model that accounts for the interstitial volume that is available for salt and water transport within the cheese. It predicts moisture content that agrees closely with data provided by Fonterra, and we show how modifications to the salt diffusivity and partial molar volume can improve the accuracy of the salt content predictions. The second model considers the moisture in the cheese to be in two phases---free moisture that contributes to the porosity of the cheese and is accessible to salt diffusion, and water that is bound by the cheese protein. The third model, referred to here as the salt-uptake model, is a reaction-diffusion model that considers salt being bound to the cheese matrix as it diffuses through the cheese. More work is required on this model to be able to draw conclusions regarding the cheese brining process. References P. W. Atkins. Physical Chemistry . Oxford University Press, 4th edition, 1990. G. Aylward and T. Findlay. SI Chemical data . John Wiley and Sons, 1974. D. A. G. Bruggeman. Calculation of the various physical constants of heterogeneous substances. I: Dielectric constants and conductivities of mixtures of isotropic substances. Annalen der Physik , 25:636–664, 1935. doi:10.1002/andp.19354160705 . G. Carey, N. Fowkes, A. Staelens, , and A. Pardhanani. A class of coupled nonlinear reaction diffusion models exhibiting fingering. Journal of Computational and Applied Mathematics , 166(1), 2004. doi:10.1016/j.cam.2003.09.037 . R. Datta and S. A. Vilekar. The continuum mechanical theory of multicomponent diffusion in fluid mixtures. Chemical Engineering Science , 65:5976–5989, 2010. doi:10.1016/j.ces.2010.08.022 . C. J. D. Fell and H. Hutchison. Diffusion coefficients for sodium and potassium chlorides in water at elevated temperatures. Journal of Chemical and Engineering Data , 16:427–429, 1971. doi:10.1021/je60051a005 . Fonterra Co-Operative Group. Personal communication. 2014. T. J. Geurts, P. Walstra, , and H. Mulder. Transport of salt and water during salting of cheese. 1: Analysis of the processes involved. Netherlands Milk and Dairy Journal , 28:102–129, 1974. T. P. Guinee. Salting and the role of salt in cheese. International Journal of Dairy Technology , 57(2):99–109, 2004. doi:10.1017/S0022112003005512 . T. P. Guinee and P. Fox. Sodium chloride and moisture changes in romano–type cheese during salting. Journal of Dairy Research , 50:511–518, 1983. doi:10.1017/S002202990003274X . J. A. Luna and M. S. Chavez. Mathematical model for water diffusion during brining of hard and semi–hard cheese. Journal of Food Science , 57:55–58, 1992. doi:10.1111/j.1365-2621.1992.tb05423.x . K. Mandl, R. W. Hartel, and W. Wendorff. Effects of moisture and salt migration on cheese firmness in cheese–in–sausage products. Journal of Food Engineering , 91:164–172, 2009. doi:10.1016/j.jfoodeng.2008.08.022 . MATLAB. version 8.1 (R2013a) . The MathWorks Inc., Natick, Massachusetts, 2013. W. Messens, K. Dewettinck, and A. Huyghebaert. Transport of sodium chloride and water in gouda cheese as affected by high–pressure brining. International Dairy Journal , 9:569–576, 1999. doi:10.1016/S0958-6946(99)00126-0 . M. R. Payne and K. R. Morison. A multi–component approach to salt and water diffusion in cheese. International Dairy Journal , 9:887–894, 1999. doi:10.1016/S0958-6946(99)00157-0 . M. Turhan and G. Kaletunc. Modeling of salt diffusion in white cheese during long–term brining. Journal of Food Science , 57:1082–1085, 1992. doi:10.1111/j.1365-2621.1992.tb11269.x . H. Weingartner. Self–diffusion in liquid water. A reassessment. Zeitschrift fur Physikalische Chemie , 132:129–149, 1982. doi:10.1524/zpch.1982.132.2.129 .

Consumers’ attitude and opinion towards different types of fresh cheese: an exploratory study

Fresh cheese stands out for its tradition and widespread consumption in Brazil. However, there is a lack of information on motivation towards the consumption of available fresh cheeses in the Brazilian market. Focus group sessions were used to explore consumers’ attitude and opinion about fresh cheese. Products with different characteristics were used to stimulate discussion among participants including cheese with “no added salt”, the claim “contains probiotic microorganisms” and products processed with goat milk. The salt content played an important role on the consumer intention to purchase of fresh cheese. Participants stated that they would consume cheese without salt only by following a medical prescription. However, the subjects declared that they would buy reduced salt cheese if such reduction would not compromise the flavor. The meaning of the claim “contains probiotic microorganisms” was often declared as unknown during the discussion. However, they would buy a probiotic product. In addition, it was mentioned that a premium price would be paid for such functional cheese. Participants declared that would buy goat cheese. Nevertheless, to pay a higher price over the conventional one was a controversial and debatable issue among consumers. Results revealed important implications for the development of marketing strategies for fresh cheese.

IMPROVEMENT THE KEEPING QUALITY AND EXTENSION OF SHELF LIFE OF LOW SALT WHITE SOFT CHEESE USING TREATED MILK WITH NISIN

White soft cheese was made from reconstituted partially skim milk powder (2% fat) with two salt concentrations (2% and 4%) and then (50, 100, 200 IU/ml) nisin were added. Control groups of both salted white soft cheeses were manufactured without addition of nisin. Furthermore, the two types of white soft cheese samples were kept in their whey at refrigerator temperature (2-4°C) till signs of spoilage were observed. Periodically, the control and preserved samples were examined chemically (pH and titratable acidity) and bacteriologically (aerobic plate, psychrotrophic, coliform and aerobic sporeformer counts) to determine the influence of nisin on prolongation of their shelf life. Nisin extended the shelflife of low salt cheese (2% salt) up to 9 days at concentration 100 IU/ml and up to 11 days for 200 IU/ml, while, nisin-free cheese samples were spoiled after the 5th day of refrigeration storage. On the other hand, the shelf life of 4% salt cheese was extended up to 21 days of cold storage by addition of nisin at conc. 100 and 200 IU/ml. In contrast, the cheese samples of control group were deteriorated after the 9th day of refrigerated storage. There were significant differences (p < 0.05) between the chemical and bacteriological profiles of low salt soft cheese as a result of storage time. Actually, the nisin had a significant destructive action on contaminating coliforms and aerobic spore forming bacteria of white soft cheese and lead to increase its validity period.

Consumers' willingness to pay for nutritional claims fighting the obesity epidemic: the case of reduced-fat and low salt cheese in Spain

ObjectivesThe aim of this study was to investigate consumers' willingness to pay (WTP) for cheeses bearing reduced-fat and low salt claims in Spain. Study designAn experiment with 219 cheese consumers was conducted in the period March–May 2015. We used different versions of cheese bearing reduced-fat and low salt claims. MethodsA choice experiment was used to estimate WTP for reduced-fat and/or low salt cheeses. Participants faced eight choice sets, each consisting of two packages of cheese with different combinations of two claims. Individuals chose one of the two packages of cheese in each choice set, or decided not to choose either. Moreover, to consider possible heterogeneity in WTP across consumers, a random parameters logit model (RPL), a Chi-squared test, and analysis of variance tests were used. ResultsSpanish cheese consumers were willing to pay a positive premium for packages of cheese with reduced-fat claims (€0.538/100 g), and for cheese with reduced-fat and low salt claims (€1.15/100 g). Conversely, consumers valued low-salt content claims negatively. They preferred to pay €0.38/100 g for a conventional cheese rather than one low in salt content. As there was heterogeneity in consumers' WTP, two different consumer segments were identified. Segment 1 consisted of normal weight and younger consumers with higher incomes and levels of education, who valued low salt cheese more negatively than those individuals in Segment 2, predominantly comprising overweight and older consumers with low income and educational level. This means that individuals in Segment 1 would pay more for conventional cheese (€1/100 g) than those in Segment 2 (€0.50/100 g). However, no difference between the two segments was found in WTP for reduced-fat cheese. ConclusionsThe findings suggest that consumers are willing to pay a price premium for a package of cheese with a reduced-fat claim or cheese with reduced-fat and low salt claims appearing together; however, they are not willing to pay for a package of cheese with only a low salt claim. In comparison with overweight people, normal weight consumers would prefer to pay more for conventional cheese than low salt cheese. Finally, the results of this study contribute to insights in the promotion of healthier food choices among consumers. In this regard, outreach activities promoted by food companies could drive consumers to increase their knowledge of the benefits of eating reduced-fat and low salt food products in relation to their health status.

DISTRIBUIÇÃO DE NaCl NO QUEIJO REINO AO LONGO DA MATURAÇÃO

O objetivo foi determinar o tempo mínimo necessário para a distribuição igualitária do sal em todas as partes do queijo Reino, ou seja, desde a superfície até o centro, e verificar se houve diferença significativa nessa distribuição em diferentes condições de maturação. Os queijos de um mesmo lote foram submetidos a dois tratamentos, com diferentes temperaturas, umidade relativa do ar e também com e sem embalagem. No primeiro tratamento o queijo foi maturado sem embalagem termoencolhível, à temperatura de 18 °C a 22 °C, com 55% - 65% de URA. Já no segundo tratamento, o queijo inicialmente foi maturado sem embalagem (apenas nos cinco primeiros dias) e nas mesmas condições do primeiro tratamento e, após este período, foi embalado em película termoencolhível e maturado a 5 °C - 10 °C, com 70% - 80% de URA, até completar o tempo de maturação total estipulado. A caracterização do perfil de distribuição de sal nos queijos Reino foi conduzida por meio da determinação do teor percentual de cloreto de sódio (m/m) nas porções centrais, intermediárias e superficiais. A análise de variância indicou que não houve diferença entre os tratamentos na distribuição de sal no queijo Reino, porém, houve diferença entre a porção de queijo analisada e o tempo de maturação, o que demonstrou a dependência da distribuição do sal em função destas variáveis. Conclui-se que a partir do 27º dia após a fabricação, o sal se distribui homogeneamente em todas as partes do queijo Reino, independentemente das diferentes condições empregadas na maturação.

Effect of brine concentration on the ripening of an Argentinean sheep’s milk cheese

In the present work, it was studied the influence of brine concentration on the ripening of an Argentinean sheep cheese. The aim was to establish the conditions of the salting process for it to lead to a product with good quality and acceptability by consumers. Sheep cheeses were manufactured using a direct-vat-set culture of Streptococcus thermophilus as starter and chymosin as coagulant. The salting was carried out using brine with the following concentrations: 20, 15, 10 and 5% (w/v). The cheeses were vacuum packed on the fourth day and ripened for 60 days. In order to evaluate the influence of salt content in brine on cheese quality, there were analyzed gross composition, pH, microbial counts, proteolysis, sodium and calcium concentration, melting capacity and sensory characteristics. The increase of salt concentration in brine corresponded with a decrease in moisture as proteolysis advanced. This suggests some inhibition of proteolytic and peptidolytic enzymes involved in ripening due to these adverse environmental conditions. In the descriptive sensory analysis, differences were only found for bitter taste, which was significantly higher for the less salted cheeses. This was attributable and correlated with an increase in concentration of hybrophobic peptides due to an imbalance in proteolysis/peptidolysis during ripening. The melting capacity of the cheese was not affected by the level of salt used. Therefore, it is proposed that the salting process for an Argentinean sheep cheese should be with a 15% brine.

Effect of sodium, potassium, magnesium, and calcium salt cations on pH, proteolysis, organic acids, and microbial populations during storage of full-fat Cheddar cheese

Sodium reduction in cheese can assist in reducing overall dietary Na intake, yet saltiness is an important aspect of cheese flavor. Our objective was to evaluate the effect of partial substitution of Na with K on survival of lactic acid bacteria (LAB) and nonstarter LAB (NSLAB), pH, organic acid production, and extent of proteolysis as water-soluble nitrogen (WSN) and protein profiles using urea-PAGE, in Cheddar cheese during 9mo of storage. Seven Cheddar cheeses with molar salt contents equivalent to 1.7% salt but with different ratios of Na, K, Ca, and Mg cations were manufactured as well as a low-salt cheese with 0.7% salt. The 1.7% salt cheeses had a mean composition of 352g of moisture/kg, 259g of protein/kg and 50% fat-on-dry-basis, and 17.5g of salt/kg (measured as Cl−). After salting, a faster initial decrease in cheese pH occurred with low salt or K substitution and it remained lower throughout storage. No difference in intact casein levels or percentage WSN levels between the various cheeses was observed, with the percentage WSN increasing from 5% at d 1 to 25% at 9mo. A greater decrease in intact αs1-casein than β-casein was detected, and the ratio of αs1-casein (f121–199) to αs1-casein could be used as an index of ripening. Typical changes in bacteria microflora occurred during storage, with lactococci decreasing gradually and NSLAB increasing. Lowering the Na content, even with K replacement, extended the crossover time when NSLAB became dominant. The crossover time was 4.5mo for the control cheese and was delayed to 5.2, 6.0, 6.1, and 6.2mo for cheeses with 10, 25, 50, and 75% K substitution. Including 10% Mg or Ca, along with 40% K, further increased crossover time, whereas the longest crossover time (7.3mo) was for low-salt cheese. By 9mo, NSLAB levels in all cheeses had increased from initial levels of ≤102 to approximately 106cfu/g. Lactococci remained at 106 cfu/g in the low-salt cheese even after 9mo of storage. The propionic acid concentration in the cheese increased when NSLAB numbers were high. Few other trends in organic acid concentration were observed as a function of Na content.