Influence of fat replacers on chemical composition, proteolysis, texture profiles, meltability and sensory properties of low-fat Kashar cheese

Changes in chemical composition, proteolysis, lipolysis, texture, melting and sensory properties of low-fat Kashar cheese made with three different fat replacers (Simplesse D-100, Avicel Plus CM 2159 or beta-glucan) were investigated throughout ripening. The low-fat cheeses made with fat replacers were compared with full- and low-fat counterparts as controls. Reduction of fat caused increases in moisture and protein contents and decreases in moisture-in-non fat substance and yield values in low-fat cheeses. The use of fat replacers in the manufacture of low-fat Kashar cheese increased water binding capacity and improved overall quality of the cheeses. Use of fat replacer in low-fat cheese making has enhanced cheese proteolysis. All samples underwent lipolysis during ripening and low-fat cheeses with fat replacers had higher level of total free fatty acid than full- or low-fat control cheeses. Texture attributes and meltability significantly increased with addition of fat replacers. Sensory scores showed that the full-fat cheese was awarded best in all stages of ripening and low-fat variant of Kashar cheeses have inferior quality. However, fat replacers except beta-glucan improved the appearance, texture and flavour attributes of low-fat cheeses. When the fat replacers are compared, the low-fat cheese with Avicel Plus CM 2159 was highly acceptable and had sensory attributes closest to full-fat Kashar cheese.     

Application of exopolysaccharide-producing cultures in reduced-fat Cheddar cheese: texture and melting properties

Textural, melting, and sensory characteristics of reduced-fat Cheddar cheeses made with exopolysaccharide (EPS)-producing and nonproducing cultures were monitored during ripening. Hardness, gumminess, springiness, and chewiness significantly increased in the cheeses as fat content decreased. Cheese made with EPS-producing cultures was the least affected by fat reduction. No differences in hardness, springiness, and chewiness were found between young reduced fat cheese made with a ropy Lactococcus lactis ssp. cremoris [JFR1; the culture that produced reduced-fat cheese with moisture in the nonfat substance (MNFS) similar to that in its full-fat counterpart] and its full-fat counterpart. Whereas hardness of full-fat cheese and reduced-fat cheese made with JFR1 increased during ripening, a significant decrease in its value was observed in all other cheeses. After 6 mo of ripening, reduced fat cheeses made with all EPS-producing cultures maintained lower values of all texture profile analysis parameters than did those made with no EPS. Fat reduction decreased cheese meltability. However, no differences in meltability were found between the young full-fat cheese and the reduced-fat cheese made with the ropy culture JFR1. Both the aged full- and reduced-fat cheeses made with JFR1 had similar melting patterns. When heated, they both became soft and creamy without losing shape, whereas reduced-fat cheese made with no EPS ran and separated into greasy solids and liquid. No differences were detected by panelists between the textures of the full-fat cheese and reduced-fat cheese made with JFR1, both of which were less rubbery or firm, curdy, and crumbly than all other reduced-fat cheeses.     

Influence of composition on the biochemical and sensory characteristics of commercial Cheddar cheese of variable quality and fat content

Ten commercial Cheddar cheeses of variable quality differing in fat content and age were subjected to compositional, proteolytic, lipolytic and sensory analyses. The compositional parameters of the full-fat cheeses were predominantly outside those typically associated with good-quality cheese. Sensory analysis discriminated the full-fat cheeses predominantly by age, with the longer ripened cheeses associated with more negative attributes, some which appeared to be due to excessive lipolysis and/or β-casein breakdown. Both proteolysis and lipolysis appear to be age dependent. The two reduced-fat cheeses were clearly discriminated from the eight full-fat cheeses by sensory analysis that appeared to be due to differences in composition and the extent of lipolysis.     

Effects of genetic type,stage of lactation,and ripening time on Caciocavallo cheese proteolysis

The objective of this experiment was to evaluate the effects of genetic type, stage of lactation, and ripening time on proteolysis in Caciocavallo cheese. One hundred twenty Caciocavallo cheeses made from the milk of 2 breeds, Italian Brown and Italian Holstein and characterized by different stages of lactation were obtained and ripened for 1, 30, 60, 90, and 150 d. Cheese proteolysis was investigated by ripening index (ratio of water-soluble N at pH 4.6 to total protein, %) and by the study of degradation of the protein fractions (α_S1-, β-, and para-κ-casein), which was determined by densitometric analysis of isoelectric focusing results. The statistical analysis showed a significant effect of the studied factors. Ripening index was higher in Italian Brown Caciocavallo cheese and in cheeses made with early lactation milk, whereas casein solubilization was greater in the first 2 mo of ripening. Isoelectric focusing analysis of cheese samples during ripening showed extensive hydrolysis of caseins. In particular, the protein fraction that underwent major degradation by proteolytic enzymes was α_S1-casein, followed by β-casein, whereas para-κ-casein was less degraded. Italian Brown cheese showed a lower residual quantity of β- and para-κ-casein, whereas Italian Holstein cheese showed a lower residual quantity of α_S1-casein. In addition, significant interactions of both first and second order were found on both ripening index and degradation of protein fractions. This study demonstrated that the analyzed factors influenced proteolysis of Caciocavallo cheese, which forms the basis of new knowledge that could lead to the production of a pasta filata cheese with specific characteristics.     

SDS-PAGE of Proteins in Goat Milk Cheeses Ripened under Different Conditions

Proteolytic characteristics of five varieties of commercial goat milk cheeses and a cow milk Cheddar aged under different conditions were evaluated by SDS-PAGE and an advanced densitometry system. All fresh goat cheeses had distinctively lower intensities of α_S1-casein (CN) bands than those of cow milk Cheddar, whereas intensities of β-CN were much greater in the goat cheeses. The PAGE patterns clearly displayed α_S2-CN in all goat cheese, but it was negligible in cow milk Cheddar. The greater protein degradation in hard goat cheeses than cow milk Cheddar at 4°C and 22°C strongly correlated with water-soluble nitrogen compound concentrations and densitometric values of corresponding cheeses.     

Effects of exopolysaccharide-producing cultures on the viscoelastic properties of reduced-fat Cheddar cheese

The objective was to study the influence of different exopolysaccharide (EPS)-producing and nonproducing lactic cultures on the viscoelastic properties of reduced-fat Cheddar cheese. Changes in the viscoelastic properties were followed over a ripening period of 6 mo. Results showed that the elastic, viscous, and complex moduli were higher in reduced-fat cheeses made with EPS-nonproducing cultures than in full-fat cheese. No differences in the viscoelastic properties were found between young reduced-fat cheese made with a ropy strain of Lactococcus lactis ssp. cremoris (JFR1) and its full-fat counterpart. Interestingly, the changes in viscoelastic moduli in both full-fat cheese and reduced-fat cheese made with JFR1 during ripening followed the same pattern. Whereas the moduli increased during the first month of ripening in those 2 cheeses, a dramatic decrease was observed in all other cheeses. Slopes of the viscoelastic moduli as a function of frequency were lower in the full-fat than in reduced-fat cheeses. The creep test showed that fresh reduced-fat cheese made with JFR1 was less rigid and more deformable than that made with EPS-nonproducing cultures. The creep and recovery properties of young reduced-fat cheese made with JFR1 and the full-fat type were similar. No differences were found in the viscoelastic properties between reduced-fat cheese made with no EPS and those made with EPS-producing adjunct cultures of Streptococcus thermophilus. After 6 mo of ripening, cheeses made with EPS-producing cultures maintained lower elastic and viscous moduli than did those made with no EPS.     

Impact of fat reduction on flavor and flavor chemistry of Cheddar cheeses

A current industry goal is to produce a 75 to 80% fat-reduced Cheddar cheese that is tasty and appealing to consumers. Despite previous studies on reduced-fat cheese, information is critically lacking in understanding the flavor and flavor chemistry of reduced-fat and nonfat Cheddar cheeses and how it differs from its full-fat counterpart. The objective of this study was to document and compare flavor development in cheeses with different fat contents so as to quantitatively characterize how flavor and flavor development in Cheddar cheese are altered with fat reduction. Cheddar cheeses with 50% reduced-fat cheese (RFC) and low-fat cheese containing 6% fat (LFC) along with 2 full-fat cheeses (FFC) were manufactured in duplicate. Cheeses were ripened at 8°C and samples were taken following 2 wk and 3, 6, and 9 mo for sensory and instrumental volatile analyses. A trained sensory panel (n = 10 panelists) documented flavor attributes of cheeses. Volatile compounds were extracted by solid-phase microextraction or solvent-assisted flavor evaporation followed by separation and identification using gas chromatography-mass spectrometry and gas chromatography-olfactometry. Selected compounds were quantified using external standard curves. Sensory properties of cheeses were distinct initially but more differences were documented as cheeses aged. By 9 mo, LFC and RFC displayed distinct burnt/rosy flavors that were not present in FFC. Sulfur flavor was also lower in LFC compared with other cheeses. Forty aroma-active compounds were characterized in the cheeses by headspace or solvent extraction followed by gas chromatography-olfactometry. Compounds were largely not distinct between the cheeses at each time point, but concentration differences were evident. Higher concentrations of furanones (furaneol, homofuraneol, sotolon), phenylethanal, 1-octen-3-one, and free fatty acids, and lower concentrations of lactones were present in LFC compared with FFC after 9 mo of ripening. These results confirm that flavor differences documented between full-fat and reduced-fat cheeses are not due solely to differences in matrix and flavor release but also to distinct differences in ripening biochemistry, which leads to an imbalance of many flavor-contributing compounds.     

Effect of β-casein concentration in cheese milk on rennet coagulation properties,cheese composition and cheese ripening

Effects of the use of a β-casein powder to enrich cheese milk on rennet coagulation properties of milk, cheese composition and cheese ripening were investigated. Casein content of control milk was 2.5%, whereas that for the three enriched milks was adjusted with β-casein powder at 2.7%, 2.9% and 3.1%. The β-casein to α-casein ratio of these cheese milks was, respectively, 0.70, 0.79, 0.89 and 0.99. Rennet coagulation properties were related not only to casein concentration but also to the proportion of β-casein and α_s-casein presents in milks. Milk with higher concentration of β-casein had poorer coagulation properties. Cheeses could be produced by using a miniature cheese making process. Moisture, ash and calcium contents decreased, while protein content and β-casein increased in cheese as casein and β-casein concentration increased in milk. As a result, hardness was higher in enriched cheeses than in control cheese. During cheese ripening, α-casein was hydrolyzed, but the rate of degradation of α-casein decreased as protein and β-casein concentration increased in cheese. β-Casein seemed to be not hydrolyzed. The rate of decrease of hardness was also slower for enriched cheeses.     

Flavour-enhancement of low-fat Kashkaval cheese using heat-or freeze-shocked Lactobacillus delbrueckii var. helveticus cultures

Kashkaval cheese of different fat contents was manufactured using heat- or freeze-shocked cultures of Lactobacillus delbrueckii var. helveticus added at a level of 2% to cheese milk prior to renneting. Levels of moisture, total N, salt or titratable acidity of cheeses with different fat levels were different. Proteolysis and lipolysis in low-fat Kashkaval cheese without additives were lower than those found in full-fat cheese. Incorporation of heat- or freeze-shocked L. delbrueckii var. helveticus cultures into milk of low-fat cheese greatly enhanced proteolysis and increased slightly the levels of free fatty acids. Regular low fat cheese did not develop adequate Kashkaval cheese flavour and the cheese was firm. However, addition of heat- or freeze-shocked cultures increased the flavour intensity and improved body and texture of the resultant cheese, yielding low-fat cheese with flavour intensity and body characteristics similar to those of standard fat cheese at each stage of ripening.     

Kinetics of Casein Degradation during Ripening of Fynbo Cheese Salted with NaCl/KCl Brine

First-order kinetics with respect to the α_s1-casein concentration was used to study casein degradation during low-fat Fynbo cheese ripening. Effects of partial NaCl replacement by KCI during cheese salting were studied by statistical treatment of the casein degradation results. Four zones from cheeses at 1, 5, 10, 20, and 30 ripening days were analyzed by a polyacrylamide gel electrophoresis method. Similar kinetic parameters were obtained for a cheese salted with a NaCl/KCl brine and for a control cheese during ripening. Results were more affected by salt concentration than by salt substitution. KCl did not strongly influence kinetics of Fynbo cheese proteolysis.     

Study of the biochemical changes during ripening of Ahumado de Áliva cheese: a Spanish traditional variety

The changes in chemical composition, main physico-chemical parameters, classical nitrogen fractions, caseins and their degradation products, and some fat characteristics were studied during the ripening of ten batches of Ahumado de Áliva cheese, a traditional variety made in the north of Spain. The values of the different compositional and physico-chemical parameters at the end of the ripening did not differ significantly from those found in other cows' milk cheeses elaborated by similar technology. The low pH values are outstanding. The presence of residual lactose at the end of ripening is also relevant. Total soluble nitrogen and non-protein nitrogen increased very little during ripening. The evolution of the values of the different nitrogen fractions show that this cheese undergoes very little proteolysis and that the rennet is the main proteolytic agent. Using PAGE, it was possible to show that, throughout ripening, only 22% of α_s-casein and 9% of β-casein were degraded. The TBA value indicated that the fat of Ahumado de Áliva cheese does not undergo noticeable autooxidation during ripening. The acidity index of the fat also indicated that this cheese underwent little lipolysis during ripening.     

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.     

Rheology of Full-fat and Low-fat Cheddar Cheeses as Related to Type of Fat Mimetic

Cheeses with 60% reduced fat were prepared with three fat mimetics and viscoelasticity was studied. Storage and loss moduli of low-fat cheeses made with a carbohydrate-based fat mimetic were greater (p < 0.05) than those of low-fat cheeses made with two protein-based fat mimetics or low-fat control cheese, but smaller (p < 0.05) than the storage and loss moduli of full-fat cheese. A six-element Kelvin model properly predicted the creep compliance for the full-fat cheese and the low-fat cheeses made with or without fat mimetics. Low-fat cheese made with a carbohydrate-based fat mimetic had a network structure more similar to full-fat cheese than the low-fat control or samples made with protein-based fat mimetics.     

Application of exopolysaccharide-producing cultures in reduced-fat Cheddar cheese: composition and proteolysis

Proteolysis during ripening of reduced fat Cheddar cheeses made with different exopolysaccharide (EPS)-producing and nonproducing cultures was studied. A ropy strain of Lactococcus lactis ssp. cremoris (JFR1) and capsule-forming nonropy and moderately ropy strains of Streptococcus thermophilus were used in making reduced-fat Cheddar cheese. Commercial Cheddar starter was used in making full-fat cheese. Results showed that the actual yield of cheese made with JFR1 was higher than that of all other reduced-fat cheeses. Cheese made with JFR1 contained higher moisture, moisture in the nonfat substance, and residual coagulant activity than all other reduced-fat cheeses. Proteolysis, as determined by PAGE and the level of water-soluble nitrogen, was also higher in cheese made with JFR1 than in all other cheeses. The HPLC analysis showed a significant increase in hydrophobic peptides (causing bitterness) during storage of cheese made with JFR1. Cheese made with the capsule-forming nonropy adjunct of S. thermophilus, which contained lower moisture and moisture in the nonfat substance levels and lower chymosin activity than did cheese made with JFR1, accumulated less hydrophobic peptides. In conclusion, some EPS-producing cultures produced reduced-fat Cheddar cheese with moisture in the nonfat substance similar to that in its full-fat counterpart without the need for modifying the standard cheese-making protocol. Such cultures might accumulate hydrophobic (bitter) peptides if they do not contain the system able to hydrolyze them. For making high quality reduced-fat Cheddar cheese, EPS-producing cultures should be used in conjunction with debittering strains.     

Evolution of chemico-physical characteristics during manufacture and ripening of Castelmagno PDO cheese in wintertime

Biochemical, volatile and textural profiles during manufacture and ripening were determined in samples of Castelmagno PDO cheese obtained from three different batches in the main artisan cheese plant of Castelmagno PDO production area. At the end of manufacture, samples were characterised by a pH of 6.57% and 52.4% moisture content. The HPLC analysis of organic acids and sugars showed the exhaustion of lactose content, while Urea-PAGE indicated extensive primary proteolysis of both β-casein and α_s1-casein. During ripening, cheeses were characterised by high degradation of β-casein and α_s1-casein, due to bacterial action. RP-HPLC profiles showed a high production of peptides eluted between 20 and 30 min. In total, 92 volatile compounds were identified in cheese headspace. Texture profiles showed an increase in hardness, gumminess, chewiness and adhesiveness values, as well as a decrease in cohesiveness during ripening.     

Effects of variousMicrococcus strains on the ripening and organoleptic characteristics of Arzúa cow's-milk cheese

Ten batches of Arzúa, a soft cow's-milk cheese produced in northwest Spain, were prepared from pasteurized milk. Two (control) batches (CB) were made with a commercial starter containingLactococcus lactis subspecieslactis andcremoris. Another eight batches (MB) were made with the commercial starter plus one of eightMicrococcus spp. strains previously isolated from raw-milk Arzúa cheeses. In all MB, β-casein degradation over the 30-day ripening period was more pronounced (mean 31%) than in the CB (mean 12%). α_S1-Casein degradation was highly variable in the MB, though mean degradation over the ripening period (75%) was similar to that observed in the CB (73%). Similarly, volatile fatty acid (VFA) content was highly variable in the MB, with the mean content at 30 days (3.8 mEq per 100 g) being higher than in the CB (1.6 mEq per 100 g). Rheological characterization of the cheeses (by uniaxial compression) revealed significant differences between batches, with some samples fracturing under the compression pressure applied and others not. Sensory evaluation also revealed significant differences. “Non-milk” aromas were more frequently detected in batches made with lipolytic micrococcal strains. Betweenbatch differences in tastes and texture were also detected. Multiple correlation analysis of the data obtained at day 15 of ripening revealed statistically significant positive correlations (r>0.70) between α_S1-casein content and dry matter content, between α_S1-casein content and sensorially evaluated firmness, and between VFA content and sensorially evaluated rancidity. Statistically significant negative correlations between sensorially evaluated firmness and the ratio of α_S1-I content to α_S1-casein content were detected. The results of this study suggest a need for further studies aimed at selecting those strains which could be most suitable for the production of Arzüa cheeses; due to their effects on texture, α_S1-caseinolytic strains seem to be more appropriate than β-caseinolytic ones.     

Reduced-fat cheddar cheese manufactured using a novel fat removal process

Normally, reduced-fat Cheddar cheese is made by removal of fat from milk prior to cheese making. Typical aged flavor may not develop when 50% reduced-fat Cheddar cheese is produced by this approach. Moreover, the texture of the reduced-fat cheeses produced by the current method may often be hard and rubbery. Previous researchers have demonstrated that aged Cheddar cheese flavor intensity resides in the water-soluble fraction. Therefore, we investigated the feasibility of fat removal after the aging of Cheddar cheese. We hypothesized the typical aged cheese flavor would remain with the cheese following fat removal. A physical process for the removal of fat from full-fat aged Cheddar cheese was developed. The efficiency of fat removal at various temperatures, gravitational forces, and for various durations of applied forces was determined. Temperature had the greatest effect on the removal of fat. Gravitational force and the duration of applied force were less important at higher temperatures. A positive linear relationship between temperature and fat removal was observed from 20 to 33 degrees C. Conditions of 30 degrees C and 23,500 x g for 5 min removed 50% of the fat. The removed fat had some aroma but little or no taste. The fatty acid composition, triglyceride molecular weight distribution, and melting profile of the fat retained in the reduced-fat cheeses were all consistent with a slight increase in the proportion of saturated fat relative to the full-fat cheeses. The process of fat removal decreased the grams of saturated fat per serving of cheese from 6.30 to 3.11 g. The flavor intensity of the reduced-fat cheeses were at least as intense as the full-fat cheeses.     

Application of exopolysaccharide-producing cultures in reduced-fat Cheddar cheese: cryo-scanning electron microscopy observations

The microstructure of reduced- and full-fat Cheddar cheeses made with exopolysaccharide (EPS)-producing and nonproducing cultures was observed using cryo-scanning electron microscopy. Fully hydrated cheese samples were rapidly frozen in liquid nitrogen slush (−207°C) and observed in their frozen hydrated state without the need for fat extraction. Different EPS-producing cultures were used in making reduced-fat Cheddar cheese. Full-fat cheese was made with a commercial EPS-nonproducing starter culture. The cryo-scanning electron micrographs showed that fat globules in the fully hydrated cheese were surrounded by cavities. Serum channels and pores in the protein network were clearly observed. Young (1-wk-old) full-fat cheese contained wide and long fat serum channels, which were formed because of fat coalescence. Such channels were not observed in the reduced-fat cheese. Young reduced-fat cheese made with EPS-nonproducing cultures contained fewer and larger pores than did reduced-fat cheese made with a ropy strain of Lactococcus lactis ssp. cremoris (JFR1), which had higher moisture levels. A 3-dimensional network of EPS was observed in large pores in cheese made with JFR1. Major changes in the size and distribution of pores within the structure of the protein network were observed in all reduced-fat cheeses, except that made with JFR1, as they aged. Changes in porosity were less pronounced in both the full-fat and the reduced-fat cheeses made with JFR1.     

Physicochemical analysis of full-fat, reduced-fat, and low-fat artisan-style goat cheese

The objective of this study was to examine the physicochemical properties of cheese elaborated via traditional artisan methods using goat milk containing 5, 1.5, or 0.4% fat and ripened for 1, 7, 14, or 28 d. Seventy-two cheeses were produced (2 batches × 3 fat levels × 4 ripening times × triplicate). Proximal composition, pH, texture analysis, and color were recorded in each cheese. Protein and moisture were increased in cheese, and fat and fat in DM were decreased with decreasing fat in milk. Internal and external pH was higher in low-fat and reduced-fat cheese, and pH values decreased during the first 2 wk of ripening but increased slightly on d 28. Cheese fracturability, cohesiveness, masticability, and hardness increased with decreasing fat, whereas elasticity and adhesiveness decreased. Cheese lightness and red and yellow indexes decreased with decreasing fat content; during ripening, lightness decreased further but yellow index increased.