Low-fat Cheddar Cheese Research Articles

Effect of Transglutaminase on Yield, Compositional and Functional Properties of Low-fat Cheddar Cheese

Effect of Transglutaminase on Yield, Compositional and Functional Properties of Low-fat Cheddar Cheese

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.

The influence of fat globule membrane material on the microstructure of low-fat Cheddar cheese

Microstructural characteristics of low-fat Cheddar cheese differing in the content of milk fat globule membrane (MFGM) material achieved by addition of either buttermilk powder (BMP) or skim milk powder (SMP) to the cheese milk were investigated. Scanning electron microscopy and confocal scanning laser microscopy were used to study the cheese structure and the distribution of the starter culture and fat globules. Variations in the microstructure were observed relating to the MFGM content. The structure of the control cheese (made with the addition of SMP) was more irregular with inhomogeneous large voids. In contrast, cheese made with BMP addition had a homogeneous protein network with small voids, showing a smoother, more compact and less coarse structure accompanied by more pronounced fat globules that were uniformly scattered throughout the protein matrix. The starter bacteria were located within the protein networks in clusters that were distributed homogeneously throughout the cheese matrix regardless of treatment.

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.

Survival of probiotic adjunct cultures in cheese and challenges in their enumeration using selective media

Various selective media for enumerating probiotic and cheese cultures were screened, with 6 media then used to study survival of probiotic bacteria in full-fat and low-fat Cheddar cheese. Commercial strains of Lactobacillus acidophilus, Lactobacillus casei, Lactobacillus paracasei, or Bifidobacterium lactis were added as probiotic adjuncts. The selective media, designed to promote growth of certain lactic acid bacteria (LAB) over others or to differentiate between LAB, were used to detect individual LAB types during cheese storage. Commercial strains of Lactococcus, Lactobacillus, and Bifidobacterium spp. were initially screened on the 6 selective media along with nonstarter LAB (NSLAB) isolates. The microbial flora of the cheeses was analyzed during 9 mo of storage at 6°C. Many NSLAB were able to grow on media presumed selective for Lactococcus, Bifidobacterium spp., or Lb. acidophilus, which became apparent after 90 d of cheese storage, Between 90 and 120 d of storage, bacterial counts changed on media selective for Bifidobacterium spp., suggesting growth of NSLAB. Appearance of NSLAB on Lb. casei selective media [de man, Rogosa, and Sharpe (MRS)+vancomycin] occurred sooner (30 d) in low-fat cheese than in full-fat control cheeses. Differentiation between NSLAB and Lactococcus was achieved by counting after 18 to 24h when the NSLAB colonies were only pinpoint in size. Growth of NSLAB on the various selective media during aging means that probiotic adjunct cultures added during cheesemaking can only be enumerated with confidence on selective media for up to 3 or 4 mo. After this time, growth of NSLAB obfuscates enumeration of probiotic adjuncts. When adjunct Lb. casei or Lb. paracasei cultures are added during cheesemaking, they appear to remain at high numbers for a long time (9 mo) when counted on MRS+vancomycin medium, but a reasonable probability exists that they have been overtaken by NSLAB, which also grow readily on this medium. Enumeration using multiple selective media can provide insight into whether it is the actual adjunct culture or a NSLAB strain that is being enumerated.

Rheological properties and microstructure of Cheddar cheese made with different fat contents

Reduced- and low-fat cheeses are desired based on composition but often fall short on overall quality. One of the major problems with fat reduction in cheese is the development of a firm texture that does not break down during mastication, unlike that observed in full-fat cheeses. The objective of this investigation was to determine how the amount of fat affects the structure of Cheddar cheese from initial formation (2 wk) through 24 wk of aging. Cheeses were made with target fat contents of 3 to 33% (wt/wt) and moisture to protein ratios of 1.5:1. This allowed for comparisons based on relative amounts of fat and protein gel phases. Cheese microstructure was determined by confocal scanning laser microscopy combined with quantitative image analysis. Rheological analysis was used to determine changes in mechanical properties. Increasing fat content caused an increase in size of fat globules and a higher percentage of nonspherical globules. However, no changes in fat globules were observed with aging. Cheese rigidity (storage modulus) increased with fat content at 10°C, but differences attributable to fat were not apparent at 25°C. This was attributable to the storage modulus of fat approaching that of the protein gel; therefore, the amount of fat or gel phase did not have an effect on the cheese storage modulus. The rigidity of cheese decreased with storage and, because changes in the fat phase were not detected, it appeared to be attributable to changes in the gel network. It appeared that the diminished textural quality in low-fat Cheddar cheese is attributed to changes in the breakdown pattern during chewing, as altered by fat disrupting the cheese network.

Comparative Evaluation of Yogurt and Low‐Fat Cheddar Cheese as Delivery Media for Probiotic Lactobacillus casei

This study used Lactobacillus casei 334e, an erythromycin-resistant derivative of ATCC 334, as a model to evaluate viability and acid resistance of probiotic L. casei in low-fat Cheddar cheese and yogurt. Cheese and yogurt were made by standard methods and the probiotic L. casei adjunct was added at approximately 10(7) CFU/g with the starter cultures. Low-fat cheese and yogurt samples were stored at 8 and 2 degrees C, respectively, and numbers of the L. casei adjunct were periodically determined by plating on MRS agar that contained 5 microg/mL of erythromycin. L. casei 334e counts in cheese and yogurt remained at 10(7) CFU/g over 3 mo and 3 wk, respectively, indicating good survival in both products. Acid challenge studies in 8.7 mM phosphoric acid (pH 2) at 37 degrees C showed numbers of L. casei 334e in yogurt dropped from 10(7) CFU/g to less than 10(1) CFU/g after 30 min, while counts in cheese samples dropped from 10(7) CFU/g to about 10(5) after 30 min, and remained near 10(4) CFU/g after 120 min. As a whole, these data showed that low-fat Cheddar cheese is a viable delivery food for probiotic L. casei because it allowed for good survival during storage and helped protect cells against the very low pH that will be encountered during stomach transit.

Influence of Fat-Replacing Ingredients on Process and Age Induced Soluble Nitrogen Content and Ultrastructure of Lowfat Cheddar Cheese

Influence of fat-replacers on process and age (up to 6 months at 5°C ) induced water soluble nitrogen generation in lowfat (5%, w/w) Cheddar cheese was investigated. Treatments with cellulose plus guar gum based Novagel NC200 (NOV), starch based Stellar (STEL), and protein based Dairy Lo (DL) and Simplesse (SIMP) were compared with lowfat (LFC) and fullfat (32%) controls. Nitrogen contents in aqueous extract were determined by Kjeldahl method. Process induced proteolysis followed the order DL>NOV>SIMP>STEL>LFC>FFC. Age related proteolysis, which generated hydrophobic peptides, was rapid in the first 3 months, and resulted in an increase of non-protein nitrogen compared to post-process content by 113, 50, 17 and 14%, respectively for LFC, STEL, FFC, and NOV. Protein based DL showed a reduction in this value by 22% and SIMP showed no change. The ultrastructure of the DL treated cheese matrix appeared closer to FFC compared to all other treatments and the LFC in that smaller ( 3μ) non-globular occlusions in the NOV and SIMP treatments. While the LFC showed signs of globular coalescence and enlargement, DL, and to a lesser extent STEL treatments showed markedly less. The possible reason for the treatment effect on the cheese matrix ultrastructure is discussed.

Use of a β-glucan hydrocolloidal suspension in the manufacture of low-fat Cheddar cheeses: textural properties by instrumental methods and sensory panels

The textural properties of 3-month-old low-fat Cheddar cheeses manufactured with a β-glucan hydrocolloidal composite denoted as Nutrim, a nutraceutical fat replacer, were studied via instrumental methods and sensory panels. Instrumental methods used included texture analysis, melt-flow-index meter, and shreddability analysis. The sensory attributes studied were texture and flavor. The low-fat control cheeses (11.2% fat) were compared with Nutrim-I (6.8% fat), and Nutrim-II (3.47% fat) cheeses. Although the fat levels of Nutrim cheeses were reduced significantly, the hardness, fracturability, and melt-flow index-time values were significantly lower than the low-fat control cheeses. The elasticity and the cohesiveness values were similar for all the cheeses. This was in agreement with the uniform shred sizes found for the cheeses. Most textural attributes from the sensory panel were similar, except for Nutrim-II cheeses, which were significantly more pasty. For flavor attributes, the low-fat control cheeses were significantly less bitter, more buttery, and less starchy than the Nutrim cheeses. These results may be linked to higher fat contents and lower water activity of the cheeses. Instrumental measurements significantly correlated to the sensory panel and to the proximate analysis. Significant replacement of fat with the Nutrim composites resulted in softer Cheddar cheeses with decreased melt times and decreased sensory scores.

Affinage de fromages allégés de type Cheddar fabriqués à partir de laits enrichis en phospholipides

Ripening of low fat Cheddar cheeses made from milks enriched with phospholipids. Low fat Cheddar cheeses obtained from milks rich in buttermilk phospholipids (PPL) were analysed during 12 weeks of ripening. The evolution of proteolysis, texture and bacterial flora, and the sensory properties were determined. The texture profile was affected by the presence of PPL. Low fat cheeses rich in PPL were softer and their microstructure was granular. The evolution of lactococci and non- starter lactic acid bacteria was similar in all cheeses. Hence, the rate of second proteolysis (soluble ni- trogen in TCA) was similar. However, due to higher moisture content, the rate of the first proteolysis (water-soluble nitrogen) was also higher. Sensory evaluation confirmed that a low fat cheese rich in PPL is softer. However, during the first 8 weeks of maturation no difference was observed between the flavour profile of cheeses containing 0.8 or 1.0 g.kg -1 of PPL. Over this period of time, cheeses be- came bitter and rancid. Therefore, low fat cheese with a texture and flavour improvement due to PPL should be consumed within 60 days. low fat cheese ripening / buttermilk / phospholipid / ultrafiltration

Volatiles in Lowfat Cheddar Cheese Containing Commercial Fat Replacers.

Influence of protein (Dairy LoTM )(DL) and carbohydrate based (NovagelTM)(NOV) fat replacers on the flavor volatiles of low fat Cheddar cheese (5% fat), during initial stage of ripening, were determined using Gas Chromatography-Mass Spectrometry. The predominant volatiles in all cheeses were; octanoic acid> acetoin > 2,3-butanedione. Undecanoic acid, nonanoic acid, and heptanone were less dominant. Treatments apparently attenuated them differently during initial aging compared to the low fat control (LFC) based on their relative ratio to an internal standard (12 μg of 3-heptanol/250 g of grated cheese). Within one month of maturation, the ratio of acetoin increased from 12.5 to 16, decreased from 15 to 13, and 11 to 9 for NOV, DL, and LFC, respectively. Octanoic acid, the most dominant volatile, decreased markedly in all cases in the order; 29 to 18>26 to 18>26.5 to 22, for LFC, NOV, DL, respectively. 2,3-Butanedione decreased to about half the initial concentration only for NOV and remained relatively the same for DL and LFC. Other comparatively minor volatiles were also impacted differently. These preliminary data show that fat replacers attenuated initial storage related flavor volatiles of low-fat Cheddar cheese compared to control and this influence varied depending on the type of fat replacer used.

Manufacture and composition of low fat Cheddar cheese from milk enriched with different protein concentrate powders

The effects of milk enriched at 3%, 4%, 5% or 6% casein with a diafiltered microfiltered retentate (DMF) powder compared with a commercial calcium caseinate (CaCN) powder and an ultrafiltered retentate (UF) powder on the production, composition and yields of low fat Cheddar cheeses were determined. The concentration of all components of milk increased in enriched milks, in wheys and in cheeses as the casein concentration in enriched milk increased, except for mineral contents which decreased with casein concentration in whey and in cheese obtained from milk enriched with CaCN powder. By adjusting casein at the same level, dry matter, proteins, non-casein nitrogen, ash and lactose concentrations were higher in milk enriched with UF powder, but lower in milk enriched with CaCN powder than in milk enriched with DMF powder. These soluble milk components were lost in whey. Cheese production was slightly longer for milks enriched with DMF powder. Curd obtained from milk enriched with CaCN powder did not retain fat very well. As a result, the composition of low fat Cheddar cheeses made from milk enriched with UF and DMF powder were similar, whereas the moisture was higher and the fat was lower in cheeses made from milk enriched with CaCN powder. Cheese yields were higher for low fat cheeses produced form milk enriched with DMF powder, especially at 5% and 6% of casein, than for the other enriched milks.

Rheology and Microstructure of Lowfat (5%) Cheddar Cheese Containing a Fat-Like Perception Enhancer and Fat Replacers.

Rheology and Microstructure of Lowfat (5%) Cheddar Cheese Containing a Fat-Like Perception Enhancer and Fat Replacers.

Microstructure of Low-fat Cheddar Cheese Containing Varying Concentrations of Sucrose Polyesters

The effect of milkfat sucrose polyesters (SPE) on the microstructure of reduced and low fat Cheddar cheese was investigated. Sucrose polyesters, nonpolar fat substitutes, were synthesized using milkfat fatty acids. Full fat cheeses were made with milkfat SPE replacing 10, 25, 50, or 75% of the natural milkfat. Control cheese with no added SPE was also made. No significant differences in moisture, pH or whey titratable acidity were observed between the control cheese and cheeses containing milkfat SPE, or among the cheeses containing milkfat SPE. Cheeses containing milkfat SPE exhibited fat globules that were smaller and more uniform in size compared to the control cheese with no SPE.

Production of low-fat Cheddar cheese from low and high mineral retentate powders and different fractions of milkfat globules

Low-fat Cheddar cheeses were manufactured from skim milk enriched to 5% total protein with a low (LMR) or a high (HMR) mineral content UF milk retentate powder. The protein to fat ratio was adjusted to 1.9 with cream 1 1 While the CC and LFG are rich enough in milkfat to classify as cream , the SFG fraction has also been referred to as ‘cream’ for want of a better word because, except for its somewhat lower milkfat concentration, the SFG fraction behaves as a cream in all other respects, e.g. it rises on standing, and contains milkfat in its native globular form. separated either centrifugally (CC) or by a new proprietary process and containing large milkfat globules [LFG (surface-weighted diameter, D vs =2.4 μ m; standard deviation of D vs , σ=0.25 μ m)] or small milkfat globules [SFG, ( D vs =1.6 μ m , σ=0.25 μ m)]. Although the composition of creams used (CC, LFG and SFG) were different, the protein retentions were similar for all the low-fat cheeses made three times on different days. The fat loss in whey was lower when using LFG cream to make cheese, but the low-fat cheese was also influenced by type of retentate powder used besides the source of fat (CC, LFG or SFG). The low-fat cheeses made from LMR powder were higher in moisture but lower in ash and fat than the low-fat cheeses made with HMR powder. During cheese ripening (six months), pH remained higher in HMR cheeses than in LMR cheeses (5.15 versus 5.00), whereas the soluble nitrogen was similar in all low-fat cheeses. All LMR low-fat cheeses were evaluated sensorially after four months of ripening by 160 consumers. Acceptance of LFG cheese was significantly higher in texture, flavor and color (whiteness) scores than the SFG and CC cheeses. Thus, the use of LMR powder combined with LFG fraction improved the overall quality of low-fat Cheddar cheese in terms of its texture, flavor and color.

Identification and Quantification of Potent Odorants in Regular-Fat and Low-Fat Mild Cheddar Cheese

The potent odorants of regular-fat and low-fat Cheddar cheese were systematically characterized by aroma extract dilution analysis and gas chromatography/olfactometry of static headspace samples. Quantification of nine odorants using stable isotopes as the internal standards and calculation of odor activity values revealed methional, 2(5)-ethyl-5(2)-methyl-4-hydroxy-3(2H)-furanone (homofuraneol), diacetyl, acetic acid, and butyric acid as odorants with high aroma impact. Among the highly volatile compounds, the role of methanethiol and dimethyl sulfide for the nasal perception of the cheese flavor was established. The low-fat Cheddar cheese had a meaty-brothy odor defect that is believed to be caused by significantly higher amounts of 4-hydroxy-2,5-dimethyl-3(2H)-furanone (Furaneol), homofuraneol, and methional in this cheese. Keywords: Cheddar cheese; regular fat; low fat; AEDA; static headspace; odor activity value

Aging-Induced Changes in Populations of Lactococci, Lactobacilli, and Aerobic Microorganisms in Low-Fat and Full-Fat Cheddar Cheese

The objective of this study was to observe the impact of lowering fat content on the microflora of Cheddar cheese. Full-fat (32%) and low-fat (5%) Cheddar cheeses were produced and evaluated one day after manufacture and at monthly intervals for 5 months. The cheeses were aged at 4°C after being dipped in mold inhibitor and vacuum packed in high-density polythene bags. Standard plate counts and counts of lactococci and lactobacilli were performed. Transmission and scanning electron microscopy of the microflora were also conducted. The lactococci decreased gradually over the ripening period, while the lactobacilli, though not knowingly added during Cheddar cheese preparation, increased concomitantly. Transmission electron microscopic observations revealed affinity of lactococci for the fat phase in aged cheese.

Acid adaptation of Listeria monocytogenes can enhance survival in acidic foods and during milk fermentation.

We have previously shown that tolerance to severe acid stress (pH 3.5) can be induced in Listeria monocytogenes following a 1-h adaptation to mild acid (pH 5.5), a phenomenon termed the acid tolerance response (ATR) (B. O'Driscoll, C. G. M. Gahan, and C. Hill, Appl. Environ. Microbiol. 62:1693-1698, 1966). In an attempt to determine the industrial significance of the ATR, we have examined the survival of adapted and nonadapted cells in a variety of acidic foods. Acid adaptation enhanced the survival of L. monocytogenes in acidified dairy products, including cottage cheese, yogurt, and whole-fat cheddar cheese. Acid-adapted L. monocytogenes cultures also demonstrated increased survival during active milk fermentation by a lactic acid culture. Similarly, acid-adapted cells showed greatly improved survival in low-pH foods (orange juice and salad dressing) containing acids other than lactic acid. However, in foods with a marginally higher pH, such as mozzarella cheese, a commercial cottage cheese, or low-fat cheddar cheese, acid adaptation did not appear to enhance survival. We have previously isolated mutants of L. monocytogenes that are constitutively acid tolerant in the absence of an induction step (O'Driscoll et al., Appl. Environ. Microbiol. 62:1693-1698, 1996). In the present study, one such mutant, ATM56, demonstrated an increased ability to survive in low-pH foods and during milk fermentation when compared with the wild-type strain. Significant numbers of ATM56 could be recovered even after 70 days in both whole-fat and low-fat cheddar cheese. Collectively, the data suggest that ATR mechanisms, whether constitutive or induced, can greatly influence the survival of L. monocytogenes in low-pH food environments.

P02 Enfant, faishoi flaisir, dessime-moi

Low-fat Cheddar cheeses were manufactured from skim milk enriched to 5% total protein with a low (LMR) or a high (HMR) mineral content UF milk retentate powder. The protein to fat ratio was adjusted to 1.9 with cream1 separated either centrifugally (CC) or by a new proprietary process and containing large milkfat globules [LFG (surface-weighted diameter,Dvs=2.4μm; standard deviation of Dvs,σ=0.25 μm)] or small milkfat globules [SFG, (Dvs=1.6μm,σ=0.25 μm)]. Although the composition of creams used (CC, LFG and SFG) were different, the protein retentions were similar for all the low-fat cheeses made three times on different days. The fat loss in whey was lower when using LFG cream to make cheese, but the low-fat cheese was also influenced by type of retentate powder used besides the source of fat (CC, LFG or SFG). The low-fat cheeses made from LMR powder were higher in moisture but lower in ash and fat than the low-fat cheeses made with HMR powder. During cheese ripening (six months), pH remained higher in HMR cheeses than in LMR cheeses (5.15 versus 5.00), whereas the soluble nitrogen was similar in all low-fat cheeses. All LMR low-fat cheeses were evaluated sensorially after four months of ripening by 160 consumers. Acceptance of LFG cheese was significantly higher in texture, flavor and color (whiteness) scores than the SFG and CC cheeses. Thus, the use of LMR powder combined with LFG fraction improved the overall quality of low-fat Cheddar cheese in terms of its texture, flavor and color.

Sensory properties of low fat cheddar cheese:effect of salt content and adjunct culture

The influence of salt concentration and of direct‐to‐vat culture adjuncts (DVCA) on the sensory properties of low fat hard cheese of the cheddar type has been investigated. Salt content has a major influence, and, at a level of 1·8%, low fat cheese with high levels of cheddar flavour and low bitter scores was produced. In addition, further enhancement of flavour was achieved by use of DVCA. Using the methodology described in this report, low fat cheese was manufactured which corresponded in flavour level and balance to that of commercial mature full fat cheese. Nevertheless, textural differences between low fat and full fat product remain to be resolved.