Full-fat Cheddar Cheese Research Articles

Manufacturing Low-Fat Processed Cheese Using Chickpea Proteins as a Fat Substitute and Studying Its Physicochemical, Rheological, and Sensory Quality Characteristics

Background: Manufacturing processed cheese has many advantages compared to natural cheese because the cost of refrigeration is lower during storage and transportation, and maintaining improved quality with minimal changes in the characteristics of the cheese during storage. It is possible to produce cheese with different intensity in flavor, functionality, and characteristics for different applications. Methods: This study was carried out in the laboratories of the College of Food Sciences, department of dairy science and technology at Al-Qasim green university, where full-fat cheddar cheese was mixed with full-fat soft cheese and used in the manufacture of cooked cheese treated with positive control + C, as well as mixing full-fat cheddar cheese with low-fat soft cheese to manufacture low-fat processed cheese, the negative control treatment was treated C-. Full-fat cheddar cheese was mixed with soft, low-fat cheese, with the addition of chickpea proteins as a fat replacers, with addition rates of 1.5, 3, and 4.5%, represented by treatments T3, T2, and T1, respectively. Results: The chemical tests included estimating the percentage of moisture, protein, fat, ash, carbohydrates, and total acidity, in addition to estimating the pH, while the rheological tests included hardness, adhesion, and springiness. A sensory evaluation of processed cheese parameters was also conducted. The results showed that the replacement treatments were characterized by a lower moisture content and protein percentage than the negative control treatment and close to the positive control treatment. The percentages of carbohydrates, ash, and acidity also increased in the replacement treatments, but the percentage of fats and pH decreased.

Role of food matrix in modulating dairy fat induced changes in lipoprotein particle size distribution in a human intervention

BackgroundIntake of dairy fat within the matrix of cheese lowered circulating LDL cholesterol concentration to a greater extent than the same components consumed separately as butter, protein, and calcium. However, circulating LDL cholesterol is not indicative of concentration or size of LDL particles (LDL-P), which are recognized as more sensitive risk markers of CVD. ObjectivesThis was an exploratory analysis to investigate the role of the food matrix on lipoprotein particle size distribution, after a dairy fat intervention, in overweight adults aged ≥50 y. MethodsLipoprotein particle size distribution was measured in fasting EDTA blood samples taken at week 0 (baseline) and at week 6, using NMR. In total, 127 participants (BMI ≥ 25 kg/m2, aged ≥50 y) received ∼42 g dairy fat in 1 of 4 treatments: group A, 120 g full-fat cheddar cheese (FFCC); group B, reduced-fat cheese plus butter (RFC+B); group C, butter, calcium caseinate powder, and calcium supplement (CaCO3) (BCC); or group D, 120 g FFCC (as per group A) but after a 6-wk washout period during which they excluded cheese before intervention. ResultsTotal VLDL and chylomicron particles (VLDL/CM-P) decreased after intervention. There was a strong correlation between reduced VLDL/CM-P and a reduction in small proatherogenic VLDL-P (r = 0.888, P < 0.001). Reductions in total LDL-P were associated with a reduction in small LDL-P and, to a lesser extent, with large LDL-P. There was a significant main effect of treatment for change in intermediate-density lipoprotein particles (IDL-P) after the intervention (P = 0.023) between groups B and D (−46.86 ± 30.38 and 40.69 ± 32.72 nmol/L, respectively). HDL particle (HDL-P) parameters (diameter, concentration, or size distribution) were not affected by diet. ConclusionsOur findings indicate that reductions in LDL cholesterol observed with dairy fat consumption are driven by reductions in LDL-P concentration. A trend toward a less atherogenic profile was observed, but there was no clear effect of the individual food matrices.This trial was registered at ISRCTN as ISRCTN86731958.

Lipoprotein Particle Size Distributions in Response to a 6-Week Dietary Intervention Using Different Dairy Food Matrices Including Cheese and Butter

Abstract Objectives Most dietary guidelines recommend saturated fat (SFA) intakes to be &amp;lt; 10% of total energy intake, since SFA increase low-density lipoprotein cholesterol (LDL-c) levels, a known risk factor for cardiovascular disease (CVD). However, within LDL-c, small, dense LDL particles are more strongly related to CVD risk than large buoyant particles, and response to SFA vary for different foods. Dairy fat, when eaten as cheese, significantly lowers total cholesterol compared to butter. Here, we aimed to test the effect of the cheese matrix on lipoprotein particle size distribution response in overweight adults aged ≥ 50 years. Methods In this secondary analysis of a 6-week randomised parallel intervention(1); participants received ∼40g dairy fat in 1 of 4 treatments: (A) 120 g of full-fat cheddar cheese (FFCC); (B) reduced-fat cheese plus butter (RFC + B); (C) butter, calcium caseinate powder, and calcium supplement (CaCO3) (BCC); or (D) 120 g FFCC as per (A). Fasting EDTA blood samples at wk. 0 (baseline) and wk. 6 were analysed for lipoprotein particle size distribution via nuclear magnetic resonance (NMR) spectroscopy. To examine extremes in response, those with greatest reduction in LDL-c (n = 15, ‘positive’ responders) were compared to those with the greatest increase in LDL-c (n = 15, ‘negative’ responders). Results Correlation analyses between the change in cholesterol levels and change in particle size distribution suggest a relationship between change in LDL-c, HDL-c, and corresponding particle sizes, which differs dependent on the dairy fat matrix. The correlation of LDL-c and LDL particle (LDL-p) concentration weakened as less fat was present within a cheese matrix, as LDL-c decreased so did total LDL-p, due to larger LDL particles. The positive responders displayed a stronger relationship between change in cholesterol and lipoprotein levels, with the changes in cholesterol driven by the large LDL-p and large HDL-p. Conclusions Lipoprotein particle distribution is correlated with change in cholesterol levels after a 6-week intervention of dairy fat. The changes in LDL-c and HDL-c were driven by the less atherogenic, large LDL-p and large HDL-p which are inversely associated with CVD risk. The overall response in LDL-p to SFA appears to vary, dependent on the dairy food matrix in which the fat was eaten. Funding Sources Food for Health Ireland (FHI). Enterprise Ireland.

Effect of anthocyanin-absorbed whey protein microgels on physicochemical and textural properties of reduced-fat Cheddar cheese

Reduced-fat foods have become more popular due to their health benefits; however, reducing the fat content of food affects the sensory experience. Therefore, it is necessary to improve the sensory acceptance of reduced-fat foods to that of full-fat equivalents. The aim of this study was to evaluate the effect of adding whey protein microgels (WPM) with an average diameter of 4 μm, or WPM with adsorbed anthocyanins [WPM (Ant)] on the textural and sensory properties of reduced-fat Cheddar cheese (RFC). Reduced-fat Cheddar cheese was prepared in 2 ways: (1) by adding WPM, designated as RFC+M, or (2) by adding WPM (Ant), designated as RFC+M (Ant). For comparison, RFC without fat substitutes and full-fat Cheddar cheese were also prepared. We discovered that the addition of WPM and WPM (Ant) increased the moisture content, fluidity, and meltability of RFC, and reduced its hardness, springiness, and chewiness. The textural and sensory characteristics of RFC were markedly inferior to those of full-fat Cheddar cheese, whereas addition of WPM and WPM (Ant) significantly improved the sensory characteristics of RFC. The WPM and WPM (Ant) showed a high potential as fat substitutes and anthocyanin carriers to effectively improve the acceptance of reduced-fat foods.

Discriminating aging and protein-to-fat ratio in Cheddar cheese using sensory analysis and a potentiometric electronic tongue

The objectives of this study were to evaluate the flavor and taste attributes of full-fat Cheddar cheeses with different protein-to-fat ratios (PFR) over aging time using a descriptive sensory analysis panel and a consumer panel, and to correlate these attributes with instrumental parameters obtained by the potentiometric electronic tongue. Three Cheddar cheese formulations (PFR of 0.74, 0.85, and 1.01) were produced in triplicate and composition was verified. Cheese was aged at 7.2°C and evaluated at 2, 5, 8, 10, 11, and 12 mo by a trained panel (n = 10) for 8 flavor and 5 taste attributes and using an electronic tongue for 7 nonvolatile taste attributes. Cheese aged for 12 mo was also evaluated by a consumer sensory panel for liking and intensity attributes. Principal component analysis was performed to discriminate cheese based on aging time and PFR, whereas correlation between sensory and instrumental attributes was assessed using partial least squares regression. Descriptive sensory analysis of flavor and taste attributes differentiated Cheddar cheeses over aging time, but not among PFR formulations. The electronic tongue distinguished changes among cheese samples due to PFR formulation and aging time. The electronic tongue proved successful in characterizing the nonvolatile flavor components in Cheddar cheese and correlated with taste perceptions measured by descriptive sensory analysis. Consumer evaluations showed distinctive attribute profiles for the 3 PFR Cheddar cheese formulations. Overall, higher fat content was associated with increased flavor intensities in Cheddar cheese and drove consumer acceptability and purchase intent ratings. The electronic tongue detected smaller changes in tastes (bitter, metallic, salty, sour, spicy, sweet, and umami) of the 3 PFR formulations over time when compared with the trained panelists, who detected no differences, suggesting that the electronic tongue may be more sensitive to tastants than humans and may have the capability for early detection or identification of problems in a batch of cheese during aging. Results suggest taste quality of cheese may be monitored using the electronic tongue with greater sensitivity than a trained panel, and may be more objective, rapid, and cost effective than human panelists.

Effect of pasture versus indoor feeding systems on quality characteristics, nutritional composition, and sensory and volatile properties of full-fat Cheddar cheese.

The purpose of this study was to investigate the effects of pasture-based versus indoor total mixed ration (TMR) feeding systems on the chemical composition, quality characteristics, and sensory properties of full-fat Cheddar cheeses. Fifty-four multiparous and primiparous Friesian cows were divided into 3 groups (n = 18) for an entire lactation. Group 1 was housed indoors and fed a TMR diet of grass silage, maize silage, and concentrates; group 2 was maintained outdoors on perennial ryegrass only pasture (GRS); and group 3 was maintained outdoors on perennial ryegrass/white clover pasture (CLV). Full-fat Cheddar cheeses were manufactured in triplicate at pilot scale from each feeding system in September 2015 and were examined over a 270-d ripening period at 8°C. Pasture-derived feeding systems were shown to produce Cheddar cheeses yellower in color than that of TMR, which was positively correlated with increased cheese β-carotene content. Feeding system had a significant effect on the fatty acid composition of the cheeses. The nutritional composition of Cheddar cheese was improved through pasture-based feeding systems, with significantly lower thrombogenicity index scores and a greater than 2-fold increase in the concentration of vaccenic acid and the bioactive conjugated linoleic acid C18:2 cis-9,trans-11, whereas TMR-derived cheeses had significantly higher palmitic acid content. Fatty acid profiling of cheeses coupled with multivariate analysis showed clear separation of Cheddar cheeses derived from pasture-based diets (GRS or CLV) from that of a TMR system. Such alterations in the fatty acid profile resulted in pasture-derived cheeses having reduced hardness scores at room temperature. Feeding system and ripening time had a significant effect on the volatile profile of the Cheddar cheeses. Pasture-derived Cheddar cheeses had significantly higher concentrations of the hydrocarbon toluene, whereas TMR-derived cheese had significantly higher concentration of 2,3-butanediol. Ripening period resulted in significant alterations to cheese volatile profiles, with increases in acid-, alcohol-, aldehyde-, ester-, and terpene-based volatile compounds. This study has demonstrated the benefits of pasture-derived feeding systems for production of Cheddar cheeses with enhanced nutritional and rheological quality compared with a TMR feeding system.

Effect of elevated temperature on the microstructure of full fat Cheddar cheese during ripening

Elevated temperatures have been widely studied as a route to accelerate cheese ripening and decrease energy and storage requirements but the impact of temperature on the underlying microstructure of the cheese during prolonged periods of ripening is poorly understood. In this study, Cheddar cheese was matured at four different ripening temperatures (8 °C, 15 °C, 20 °C or a combination of 8 °C and 15 °C) and the impact on cheese microstructure assessed using confocal laser scanning microscopy, cryo scanning electron microscopy and quantitative image analysis of 3D images. An increase in ripening temperature was shown to alter the microstructure of the cheese protein network after only a few weeks of ripening. Incubation at 20 °C significantly reduced branching within the protein network, leading to thicker protein strands and larger pores after 33 days. These structural changes coincided with increased proteolysis, consistent with solubilisation of the protein network; they also led to a softer, less chewy and less cohesive cheese. While the concentration of biogenic amines tryptamine and tyramine were observed to increase with ripening temperature, the concentrations were generally low, confirming that biogenic amines do not represent a health concern under the conditions examined. This study illustrates how 3D image analysis can be used to observe and quantify the effect of process changes on cheese structure, assisting our understanding of the link between structure and function in Cheddar cheese.

Effect of calcium chloride addition and draining pH on the microstructure and texture of full fat Cheddar cheese during ripening

Calcium chloride is commonly added to cheese–milk to improve coagulum formation and to increase cheese yield but high concentrations of calcium ions can have adverse effects. In this study, confocal laser scanning microscopy and cryo-scanning electron microscopy were coupled with textural and chemical analyses to observe microstructural and biochemical changes that occur in cheese during ripening when calcium chloride is added or the draining pH altered. For the cheese prepared with no additional calcium at a draining pH of 6.0, the cheese porosity increased with ripening time and the number of protein vertices in the microscopy images declined, indicative of protein solubilisation. As the amount of CaCl2 added was increased, however, these changes became less significant. Our findings show that calcium chloride addition can be used, together with a lower draining pH, to alter the manufacturing process without significantly impacting on the quality of the mature cheese.

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.

Short communication: Norbixin and bixin partitioning in Cheddar cheese and whey

The Cheddar cheese colorant annatto is present in whey and must be removed by bleaching. Chemical bleaching negatively affects the flavor of dried whey ingredients, which has established a need for a better understanding of the primary colorant in annatto, norbixin, along with cheese color alternatives. The objective of this study was to determine norbixin partitioning in cheese and whey from full-fat and fat-free Cheddar cheese and to determine the viability of bixin, the nonpolar form of norbixin, as an alternative Cheddar cheese colorant. Full-fat and fat-free Cheddar cheeses and wheys were manufactured from colored pasteurized milk. Three norbixin (4% wt/vol) levels (7.5, 15, and 30mL of annatto/454kg of milk) were used for full-fat Cheddar cheese manufacture, and 1 norbixin level was evaluated in fat-free Cheddar cheese (15mL of annatto/454kg of milk). For bixin incorporation, pasteurized whole milk was cooled to 55°C, and then 60mL of bixin/454kg of milk (3.8% wt/vol bixin) was added and the milk homogenized (single stage, 8MPa). Milk with no colorant and milk with norbixin at 15mL/454kg of milk were processed analogously as controls. No difference was found between the norbixin partition levels of full-fat and fat-free cheese and whey (cheese mean: 79%, whey: 11.2%). In contrast to norbixin recovery (9.3% in whey, 80% in cheese), 1.3% of added bixin to cheese milk was recovered in the homogenized, unseparated cheese whey, concurrent with higher recoveries of bixin in cheese (94.5%). These results indicate that fat content has no effect on norbixin binding or entrapment in Cheddar cheese and that bixin may be a viable alternative colorant to norbixin in the dairy industry.

Effect of curd washing on cheese proteolysis, texture, volatile compounds, and sensory grading in full fat Cheddar cheese

Curd was washed to varying degrees during Cheddar cheese manufacture, by partial replacement of whey with water at the early stages of cooking, to give target levels of lactose plus lactic acid in cheese moisture of 5.3 (control), 4.5, 4.3 and 3.9% (w/w). The cheeses were matured at 8 °C for 270 days. While curd washing had little effect on composition or the mean levels of proteolysis (as measured by pH 4.6 soluble nitrogen and levels of free amino acids), it led to cheeses that were, overall, firmer and less brittle. Curd washing resulted in cheeses having lower levels of some volatile compounds, and being less acid, more buttery, sweeter, saltier and creamier than non-washed cheeses that had more 'sweaty', pungent and farmyard-like sensory notes. The results suggest that curd washing during Cheddar manufacture may be used as a means of creating variants with distinctive flavour profiles.

Microstructure and Composition of Full Fat Cheddar Cheese Made with Ultrafiltered Milk Retentate.

Milk protein is often standardised prior to cheese-making using low concentration factor ultrafiltration retentate (LCUFR) but the effect of LCUFR addition on the microstructure of full fat gel, curd and Cheddar cheese is not known. In this work, Cheddar cheeses were made from cheese-milk with or without LCUFR addition using a protein concentration of 3.7%–5.8% w/w. The fat lost to sweet whey was higher in cheese made from cheese-milk without LCUFR or from cheese-milk with 5.8% w/w protein. At 5.8% w/w protein concentration, the porosity of the gel increased significantly and the fat globules within the gel and curd tended to pool together, which possibly contributed to the higher fat loss in the sweet whey. The microstructure of cheese from cheese-milk with a higher protein concentration was more compact, consistent with the increased hardness, although the cohesiveness was lower. These results highlight the potential use of LCUFR for the standardization of protein concentration in cheese-milk to 4%–5% w/w (equivalent to a casein to total protein ratio of 77%–79% w/w) to increase yield. Beyond this concentration, significant changes in the gel microstructure, cheese texture and fat loss were observed.

A new method for the production of low-fat Cheddar cheese

Our objective was to develop an alternative process to produce low-fat Cheddar cheese (LFCC) by combining reduced-fat Cheddar cheese (RFCC) made by a fat-removal process with micellar casein concentrate (MCC) to try to achieve the texture and flavor characteristics of full-fat Cheddar cheese (FFCC). The production of LFCC was replicated 3 times. The MCC was produced by ultrafiltration of skim milk, followed by 3 stages of microfiltration, and the final MCC was spray dried. The LFCC was formulated to achieve 6% fat, 28% protein, and 1.2% salt by a combination of RFCC, MCC powder, salt, and water. The 6% fat target was selected to comply with the FDA standard for a low-fat label claim. The pH of the LFCC mixture was adjusted to 5.3 by lactic acid. Rennet was added to the LFCC mixture, followed by pressing and packaging. Chemical and sensory data were analyzed by ANOVA using the Proc GLM of SAS to determine if any differences in chemical composition and sensory properties were present among different cheeses. Descriptive sensory scores were used to construct a principal component analysis biplot to visualize flavor profile differences among cheeses. The LFCC had 83% less fat, 32% less sodium, and higher protein and moisture content than FFCC. When the cheese texture was evaluated in the context of a filled-gel model consisting of matrix and filler (100% minus percentage of matrix) the LFCC had lower filler volume than FFCC, yet the LFCC had a softer texture than FFCC. The LFCC contained some of the original FFCC cheese matrix that had been disrupted by the fat-removal process, and this original FFCC matrix was embedded in the new LFCC matrix formed by the action of rennet on casein from the continuous phase of hydrated MCC. Thus, the texture of the LFCC was desirable and was softer than the FFCC it was made from, whereas commercial RFCC (50 and 75% fat reduction) were firmer than the FFCC. The sulfur flavor in LFCC was closer to FFCC than commercial RFCC. The LFCC had bitter and grape-tortilla off-flavors that came from the dried MCC ingredient. The commercial RFCC and LFCC made in this study were missing the typical aged Cheddar character (catty, nutty, fruity, brothy, milk fat flavors) found in aged FFCC. Future work to improve the flavor of LFCC made by the process described in this study should include the addition of a flavoring ingredient (e.g., enzyme-modified cheese) to enhance the aged Cheddar flavors and mask undesirable flavors.

Effect of gum tragacanth on the rheological and functional properties of full-fat and half-fat Cheddar cheese

Fat replacers can be used to improve the sensory and functional properties of reduced-fat cheeses. The effect of gum tragacanth (GT) on the rheological, functional and sensory properties of half-fat and full-fat Cheddar cheese during ripening was investigated. Four Cheddar-style cheeses were made in triplicate: full-fat control (FFC), half-fat control (HFC), full fat + GT (FFGum) and half fat + GT (HFGum). Cheesemilk for the latter two cheeses was supplemented with GT at a level of 0.05% (w/v); all cheeses were ripened at 8 °C for 10 months. Moisture and moisture-to-protein ratio were increased by GT addition. GT addition resulted in decreased pH in both FFGum and HFGum cheeses during ripening, especially the FFGum cheese. GT appeared to affect proteolysis only in the FF cheeses. GT was successful in decreasing hardness and springiness values during ripening. GT increased meltability in the FFGum cheese and to a lesser extent in the HFGum cheese in late ripening. An increase in opaqueness was also observed due to GT addition regardless of fat level. Dynamic small amplitude oscillatory rheology showed a depression in LTmax and an increase in G′ at 75 °C caused by GT at 7 months of ripening. GT did not appear to have any impact on starter bacteria and NSLAB counts. Results from a consumer ranking preference test showed that the GT was not successful in fully mimicking the sensory properties of the FFC cheese. These results suggest that GT appears more suited to enhancing the textural and functional properties of half-fat Cheddar cheese than its sensory properties.

Fortification of cheese with vitamin D3 using dairy protein emulsions as delivery systems

Vitamin D is an essential vitamin that is synthesized when the body is exposed to sunlight or after the consumption of fortified foods and supplements. The purpose of this research was to increase the retention of vitamin D3 in Cheddar cheese by incorporating it as part of an oil-in-water emulsion using a milk protein emulsifier to obtain a fortification level of 280 IU/serving. Four oil-in-water vitamin D emulsions were made using sodium caseinate, calcium caseinate, nonfat dry milk (NDM), or whey protein. These emulsions were used to fortify milk, and the retention of vitamin D3 in cheese curd in a model cheesemaking system was calculated. A nonemulsified vitamin D3 oil was used as a control to fortify milk. Significantly more vitamin D3 was retained in the curd when using the emulsified vitamin D3 than the nonemulsified vitamin D3 oil (control). No significant differences were observed in the retention of vitamin D3 when emulsions were formulated with different emulsifiers. Mean vitamin D3 retention in the model system cheese curd was 96% when the emulsions were added to either whole or skim milk compared with using the nonemulsified oil, which gave mean retentions of only 71% and 64% when added to whole and skim milk, respectively. A similar improvement in retention was achieved when cheese was made from whole and reduced-fat milk using standard manufacturing procedures on a small scale. When sufficient vitamin D3 was added to produce cheese containing a target level of approximately 280 IU per 28-g serving, retention was greater when the vitamin D3 was emulsified with NDM than when using nonemulsified vitamin D3 oil. Only 58±3% of the nonemulsified vitamin D3 oil was retained in full-fat Cheddar cheese, whereas 78±8% and 74±1% were retained when using the vitamin D3 emulsion in full-fat and reduced-fat Cheddar cheese, respectively.

Color of low-fat cheese influences flavor perception and consumer liking

The present study examines the effect of color on low-fat cheese flavor perception and consumer acceptability. To understand the flavor preferences of the consumer population participating in the sensory testing, 4 brands of retail full-fat Cheddar cheeses labeled as mild, medium, or sharp were obtained. These cheeses were evaluated by a trained descriptive panel to generate a flavor profile for each cheese and then by consumer sensory panels. Overall and color liking were measured using a 9-point hedonic scale, and flavor, chewiness, level of sharpness measured using a 5-point just-about-right (JAR) scale (with 1 being not enough, 3 being just about right, and 5 being too much of the attribute). Subsequently, 9 low-fat Cheddar cheeses were manufactured using 3 levels of annatto (0, 7.34, and 22g/100kg) and 3 levels of titanium dioxide (0, 7.67, and 40g/100kg) using a randomized block design in duplicate. Cheeses were then evaluated by descriptive and consumer sensory panels. Each consumer testing consisted of 120 panelists who were mainly 18 to 35 yr of age (>90% of total populace) with >60% being frequent cheese consumers. Overall liking preference of the consumer group was for mild to medium cheese. Using the JAR scale, the medium cheeses were considered closest to JAR with a mean score of 3.0, compared with 2.4 for mild cheese and 3.6 for sharp cheese. Among low-fat cheeses, color was shown to be important with consumer liking being negatively influenced when the cheese appearance was too translucent (especially when normal levels of annatto were used) or too white. Matching the level of titanium dioxide with the annatto level gave the highest liking scores and flavor perception closest to JAR. This study established a significant effect of color on overall liking of low-fat versions of Cheddar cheese.

Effect of curd washing on composition, lactose metabolism, pH, and the growth of non-starter lactic acid bacteria in full-fat Cheddar cheese

Cheddar cheese was manufactured in triplicate from mid-lactation milk and analysed over a 270-day ripening period. The curd was washed in the cheese vat to give target levels of lactose plus lactic acid in cheese moisture (LLAMc) in the final cheese of 5.3 (control), 4.5, 4.3 and 3.9% (w/w); these values correspond to the expected LLAMc levels in non-washed cheeses made from milk with lactose levels of 4.8 (control), 4.6, 4.3 and 3.8% (w/w), respectively. Increasing curd washing from 0 to 33% of milk volume significantly reduced mean levels of total lactate and LLAMc over the ripening period. Conversely, it increased the mean cheese pH by ∼0.3–0.4 at times≥90 days. The LLAMc was ∼1.0–1.6 units lower than predicted based on levels of milk lactose and curd washing. Otherwise, alteration of curd washing generally did not affect gross composition or microbiology of the cheese.

Coagulation temperature affects the microstructure and composition of full fat Cheddar cheese

An understanding of coagulation and factors that affect cheese microstructure is important, as this microstructure influences cheese texture and flavour. Of particular importance to many producers is the loss of milk fat during the cheese-making process, which reduces the inherent value of the product. The aim of this study was to investigate the effect of coagulation temperature on the microstructure of gel, curd and cheese samples during the manufacture of full fat Cheddar cheese. The microstructure of the gel formed at 27 °C consisted of a fine interconnected protein network as compared to a coarse, irregular and more discontinuous protein network in gel formed at 36 °C. At a higher coagulation temperature (36 °C), the size of the casein micelle aggregates in the protein strands increased when observed using confocal laser scanning microscopy possibly due to increased hydrophobic and ionic interactions and the rearrangement of casein micelles. This characteristic microstructure observed in the gel was retained in the curd collected prior to whey draining and may be responsible for the increased loss of fat in the whey. The concentration of fat in dry matter in cheese prepared from cheese-milk coagulated at 27 °C and 30 °C was significantly (P < 0.05) higher than in cheese made from milk coagulated at 33 °C and 36 °C possibly due to the observed differences in microstructure and the direct effect of coagulation temperature on physical properties of the fat and the casein micelles. Our results suggest the need to control milk coagulation temperature, as this parameter may affect product microstructure and fat retention.

EVALUATION OF KEY FLAVOR COMPOUNDS IN REDUCED- AND FULL-FAT CHEDDAR CHEESES USING SENSORY STUDIES ON MODEL SYSTEMS

Recent flavor chemistry studies have identified flavor compounds at different concentrations in full- and low-fat Cheddar cheeses. The specific flavor contributions of these compounds in full- and low-fat cheese matrices have not been established. The purpose of this study was to evaluate the sensory response of Cheddar flavor compounds in model full-fat and 75% reduced-fat cheeses. Odor activity values (OAVs) for each compound in full- and reduced-fat cheeses were calculated. Each compound was then added to model cheeses created from 3-week-old full- and reduced-fat Cheddar cheeses. A trained sensory panel (n = 8) evaluated the sensory properties of the cheese models. The final combination of compounds was incorporated into reduced-fat cheese models, and consumers (n = 85) evaluated perceived-aged Cheddar cheese aroma. Based on OAVs and perception of the individual compounds in cheese models, 12 key flavor compounds were identified. Target ideal concentrations of specific cheese flavor compounds in 75% reduced-fat cheese were determined. According to consumers, the perceived aged Cheddar cheese aroma intensity of reduced-fat model cheese with these added compounds was not different (P > 0.05) from the perceived Cheddar cheese aroma intensity of commercial aged full-fat Cheddar cheeses. PRACTICAL APPLICATION The market for reduced-fat Cheddar cheese is increasing as consumers become more health conscious. The structure and biochemistry of reduced-fat Cheddar cheeses are altered, and flavor and texture remain a challenge. This study established the role of 23 volatile compounds using descriptive analysis of cheese model systems. The impact of key compound concentration differences and how these differences affect sensory perception of cheese flavor in full- and 75% reduced-fat Cheddar cheeses were determined. These results provide guidance for mimicking aged Cheddar cheese flavor in reduced-fat cheese.

Protein interactions in reduced-fat and full-fat Cheddar cheeses during melting

Changes in physicochemical properties of 12-wk-old, half-fat (50 g/100 g reduced-fat) and full-fat Cheddar cheeses on heating at 180 °C for 25 min were investigated. The loss of moisture and fat in both cheeses were proportional to their initial amounts present; both protein:fat ratio and protein:moisture ratio were higher in half-fat cheese than in full-fat cheese. Various types of protein interactions during melting were measured by dispersing cheeses in different dissociating agents (SDS, EDTA, mercaptoethanol, and urea). Protein interactions which were expressed by dissolving heated cheese in urea appeared to contribute the most; this was followed by those expressed by dissolving in SDS. In interaction with temperature, dissociating agents appeared to have the greatest effect on the undissociated proteins still present. The protein–protein interactions during melting of cheeses, which form the hard surface skin in reduced-fat cheeses, were shown to involve disulfide bonds and hydrophobic interactions and to some extent ionic bonds with calcium.