Aged Cheddar Research Articles

English

Restaurants and pizza makers in Pakistan demand a cheese that has ability to melt, stretch with a characteristics flavor and less free oil formation while applied on pizza dough. The desired characteristics can be obtained with proper amalgamation of fresh and ripened cheeses. Therefore, the present research was planned to prepare Pizza cheese blends (PCB) from fresh Mozzarella and ripened (2 and 4 months) Cheddar cheese. Seven Pizza cheese blends were prepared with fresh Mozzarella and ripened (2 and 4 months) Cheddar cheese. The quality of Pizza cheese blends were evaluated by measuring chemical composition, proteolysis, intact casein and organic acids contents. The rate of proteolysis (pH 4.6-soluble and TCA-soluble nitrogen) was rapid in PCB made with higher level of four months ripened Cheddar cheese. Electrophoresis (Urea PAGE) and High Performance Liquid Chromatography (HPLC) analysis indicated reduced intact casein in PCB that has higher level of aged (4 months) Cheddar cheese. Mean abundances indicated significant change in organic acid contents of PCB. In conclusion, significant variation was observed for proteolysis, intact casein and organic acids production with the difference in percentages and ages of cheeses. The prevalence of a comparatively large amount of variability in technological properties of Pizza cheese was confirmed. This blending of cheeses provides new insight to cheese industries which directs new strategies to improve the characteristics of Pizza cheese.

Identification of texture parameters influencing commercial cheese matrix disintegration and lipid digestion using an in vitro static digestion model.

Cheese characteristics, such as composition or textural properties, can impact the matrix degradation rate which could modulate the bioaccessibility of fatty acids during digestion. The aim of this study was to identify texture parameters influencing cheese degradation in a gastrointestinal environment. A static in vitro digestion model has been used on nine commercial cheeses: young and aged cheddar, regular and light cream cheese, parmesan, feta, camembert, mozzarella, and sliced processed cheese. At the end of gastric digestion, camembert and mozzarella presented the lowest matrix disintegration whereas aged cheddar, regular and light cream cheeses showed the highest. For all cheeses, the fatty acid release was fast during the first 30 min of duodenal digestion and slowed down afterwards. A partial least square regression revealed that springiness, cohesiveness, and hardness were negatively correlated to the rate of cheese disintegration during gastric digestion. In addition, textural parameters were not correlated with free fatty acid release. By modulating cheese texture, it could be possible to influence matrix disintegration during gastrointestinal digestion which could have an impact on lipids release.

Hot topic: Geographical distribution and strain diversity of Lactobacillus wasatchensis isolated from cheese with unwanted gas formation

Lactobacillus wasatchensis, an obligate heterofermentative nonstarter lactic acid bacteria (NSLAB) implicated in causing gas defects in aged cheeses, was originally isolated from an aged Cheddar produced in Logan, Utah. To determine the geographical distribution of this organism, we isolated slow-growing NSLAB from cheeses collected in different regions of the United States, Australia, New Zealand, and Ireland. Seven of the cheeses showed significant gas defects and 12 did not. Nonstarter lactic acid bacteria were isolated from these cheeses on de Man, Rogosa, and Sharpe medium supplemented with ribose, a preferred substrate for Lb. wasatchensis. Identification was confirmed with 16S rRNA gene sequencing and the API50CH (bioMérieux, Marcy l'Etoile, France) carbohydrate panel. Isolates were also compared with one another by using repetitive element sequence-based PCR (rep-PCR). Lactobacillus wasatchensis was isolated only from cheeses demonstrating late-gas development and was found in samples from 6 of the 7 cheeses. This supports laboratory evidence that this organism is a causative agent of late gas production defects. The rep-PCR analysis produced distinct genetic fingerprints for isolates from each cheese, indicating that Lb. wasatchensis is found in several regions across the United States and is not a local phenomenon.

Commercial cheeses with different texture have different disintegration and protein/peptide release rates during simulated in vitro digestion

Solid food disintegration in the stomach has recently been linked to food texture, which changes during digestion. This phenomenon is likely to affect the kinetics of protein digestion and therefore associated postprandial metabolic responses. Depending upon the variety, the cheese protein and lipid content as well as the texture can be modulated, illustrating complexity. Five commercial cheeses, covering a range of textural properties, were selected and characterised. Cheese particles were submitted to an in vitro digestion model to study cheese disintegration and protein/peptide release. Cheese disintegration was affected by cheese texture and composition. At the end of gastric digestion, elastic cheeses (mozzarella) were less disintegrated when compared with ripened and soft cheeses with high fat content (Camembert, aged Cheddar). The protein digestion was different amongst cheeses according to different disintegration rates. Cheese structural and textural properties, attributed to processing parameters, can be used to modulate gastro-intestinal digestion of cheese proteins.

Assessment of the changes in the structure and component mobility of Mozzarella and Cheddar cheese during heating

During heating the structure of cheese changes which impacts on the functional properties. This research compares the rheological and structural changes during heating of three types of cheese: Mozzarella, medium Cheddar, and aged Cheddar. We use small amplitude oscillation rheology and a variety of magnetic resonance techniques to study these changes. The complex viscosity of Mozzarella and the two Cheddar samples varied with temperature. A number of structural changes were identified as being responsible for variations in the rate of change in viscosity. Magnetic resonance indicated that as cheese is heated there is a progressive increase in the quantity of free water present in the cheese structure. The diffusion properties of water within the structure allowed information relating to the tortuosity and the surface to volume ratio of pores to be calculated, and subsequent analysis indicated that these properties are temperature dependent. These results indicate that significant information regarding the structural dynamics of various constituents of cheese can be monitored during heating using rheology and magnetic resonance. In particular the MR data include the first application of time dependent diffusion measurements to characterize the molecular dynamics associated with structural changes in cheese.

Evaluation of commercial enzyme systems to accelerate Cheddar cheese ripening

This study was undertaken to independently evaluate three commercial enzyme preparations: Accelase AM317, Accelase AHC50, Accelerzyme CPG used to accelerate Cheddar cheese ripening. Cheese trials were carried out in triplicate under identical conditions and compared with a control without an added enzyme preparation. All enzyme preparations were incorporated according to manufacturers' guidelines. The flavour of the Cheddar cheese was accelerated by the inclusion of each enzyme preparation, evident by more complex volatile profiles and the development of sensory attributes associated with aged Cheddar. Compositional parameters were not adversely impacted. Instrumental and descriptive textural analyses indicated some adverse rheological effects in cheeses produced by both Accelase blends, attributed to excessive primary proteolysis, and higher levels of moisture. The study has highlighted the potential of commercial accelerating ripening systems, but also identified that compositional and proteolytic indices need to be optimised to maximise their potential.

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.

Cloning and characterization of debittering peptidases, PepE, PepO, PepO2, PepO3, and PepN, of Lactobacillus helveticus WSU19

Peptidases of Lactobacillus helveticus WSU19 are important for debittering aged Cheddar–type cheese. Our objective was to determine specificities of aminopeptidase N (PepN) and endopeptidases E, O, O2, and O3 (PepE, PepO, PepO2, and PepO3) of Lb. helveticus WSU19 on the bitter peptide, β–CN f193–209. Aminopeptidase and endopeptidase genes of Lb. helveticus WSU19 were cloned in Escherichia coli DH5 α. The β–CN f193–209 peptide was digested by cell–free extracts from peptidase–positive clones under cheese ripening conditions. The degradation pattern was analyzed qualitatively using matrix–assisted laser desorption/ionization time–of–flight mass spectrometry. Proline residues precluded PepN activity on β–CN f193–209. Complete degradation of β–CN f193–209 by PepN required post–proline endopeptidases, particularly PepO and PepO3. PepO–like endopeptidase activities on Pro 206–Ile 207 prevented formation of bitter peptides from the C–terminus of β–CN f193–209. PepE cleaved β–CN f193–209 only when combined with PepN or PepO–like endopeptidases. Aminopeptidase and post–proline endopeptidase activities contributed to the initial degradation of β–CN f193–209.

Flavor Profiles of Full-Fat and Reduced-Fat Cheese and Cheese Fat Made from Aged Cheddar with the Fat Removed Using a Novel Process

Many consumers are concerned with fat intake. However, many reduced-fat foods, including reduced-fat cheese, lack robust flavors. The objectives of this study were to characterize the flavors found in full-fat cheese, cheese fat, and reduced-fat cheese made from aged Cheddar using a novel process to remove the fat (Nelson and Barbano, 2004). Two full-fat, aged cheeses (9 and 39 mo) were selected, and the fat was removed using the novel fat removal process. Full-fat cheeses, shredded and reformed full-fat cheeses, corresponding reduced-fat cheeses, and cheese fats were then analyzed using descriptive sensory and instrumental analysis followed by consumer acceptance testing. Cheeses were extracted with diethyl ether followed by isolation of volatile material by high vacuum distillation. Volatile extracts were analyzed using gas chromatography/ olfactometry with aroma extract dilution analysis. Selected compounds were quantified. The 39-mo cheese was characterized by fruity and sulfur notes, and the 9-mo-old cheese was characterized by a spicy/brothy flavor. Reduced-fat cheeses had similar flavor profiles with no difference in most sensory attributes to corresponding full-fat cheeses. Sensory profiles of the cheese fats were characterized by low intensities of the prominent flavors found in the full-fat cheeses. Instrumental analysis revealed similar trends. Consistent with sensory analysis, there were lower concentrations and log3 flavor dilution factors for most compounds in the cheese fats compared with both the reduced- and full-fat cheeses, regardless of compound polarity. Consumers found the intensity of flavor in the reduced-fat cheese to be equal to the full-fat cheeses. This study demonstrated that when fat was removed from aged full-fat Cheddar cheese, most of the flavor and flavor compounds remained in the cheese and were not removed with the fat.

Optimization of Cheddar Cheese Taste in Model Cheese Systems

ABSTRACT: To construct a Cheddar taste in media similar to Cheddar cheese, we developed dairy, nondairy, and mozzarella model systems. We trained a descriptive analysis panel to evaluate real and model cheeses for a variety of taste attributes and for Cheddar‐like taste. We added sodium chloride, lactic acid, citric acid, and monosodium glutamate to the model systems using mixture designs and used response surface methodology to determine optimum levels of these 3 components. Less sodium chloride and acids were needed to simulate the taste of mild Cheddar compared with aged Cheddar. None of the model cheeses closely mimicked the texture of real Cheddar. We approximated, but did not match, the taste of aged cheddar using our mozzarella base. Panelists generally rated the optimized tastes in the dairy model system as more Cheddar‐like than the optimized tastes in the nondairy model.

Characterization of nutty flavor in cheddar cheese.

The objectives of this study were to determine the volatile components responsible for the sensory perception of nutty flavor in Cheddar cheese. Cheddar cheeses with and without nutty flavors were selected by descriptive sensory analysis. Volatile aroma components from Cheddar cheeses with and without nutty flavors were isolated and characterized using solvent extraction with high vacuum distillation, dynamic headspace analysis, gas chromatography-olfactometry, and gas chromatography-mass spectrometry. More than 50 aroma-active compounds were detected in Cheddar cheeses. Consistent differences were observed between nutty and not nutty Cheddar cheeses. Strecker aldehydes were detected in higher amounts in Cheddar cheeses with nutty flavors compared with Cheddar cheeses without nutty flavors. Strecker aldehydes, dimethyl sulfide, and propionic acid were evaluated in young and aged Cheddar cheese models for nutty flavor by descriptive sensory analysis. Dimethyl sulfide and propionic acid did not contribute to nutty flavor in Cheddar cheese. The addition of Strecker aldehydes to young (<4 mo old) Cheddar cheese models resulted in nutty/malty flavor perceived by sensory analysis. When Strecker aldehydes were incorporated into aged (>9 mo old) Cheddar cheese models, nutty flavor perception increased. Strecker aldehydes contribute to nutty flavor in aged Cheddar cheese.

Quantitation of Growth of Mold on Cheese

Earlier work by others indicated that a mold colony grows radially at a constant rate on solid media. This concept was used in our study to develop a method for quantifying growth of mold on cheese. The ability of molds to grow on cheeses or pasteurized process cheese made with or without addition of sorbate was compared. Cheeses tested were mild Cheddar, aged Cheddar, aged-smoked Cheddar, brick and pasteurized process cheese. Pasteurized process cheeses were made from the natural cheeses by addition of water and a phosphate salt, then the mixture was heated. Some pasteurized process cheese from mild Cheddar was made to contain 0–500 ppm sorbic acid. Natural cheeses were sliced under aseptic conditions and were placed in sterile petri-plates. The hot and molten pasteurized process cheeses were poured into petri-plates. A spore suspension of Aspergillus parasiticus or Penicillium camemberti was inoculated onto the center of the cheese slice or pasteurized process cheese, and plates were covered and incubated at 22°C. The radius of mold colonies was measured at 24-h intervals. Data were analyzed by linear regression and lag period and rate of radial growth were calculated. Mold colonies grew radially at constant rates on cheeses and pasteurized process cheese. Lag in growth of each mold was longest on aged Cheddar cheese and pasteurized process cheese made from it, whereas it was shortest on mild Cheddar, brick and pasteurized process cheeses made therefrom. A. parasiticus grew faster on all cheeses and pasteurized process cheeses than did P. camemberti. Aged Cheddar cheese and pasteurized process cheese made from it effectively slowed the growth of both molds that were studied. Pasteurized process cheese containing sorbic acid inhibited growth of both molds. Generally, the higher the concentration of sorbic acid in the pasteurized process cheese, the slower was mold growth and the longer was the lag period.

Determination of free amino acids by capillary gas liquid chromatography in aged and late gasing cheddar cheese

Determination of free amino acids by capillary gas liquid chromatography in aged and late gasing cheddar cheese

A Comparison of Available Methods for Determining Salt Levels in Cheese

Comparative salt analyses were run on seven different types of cheese using each of four methods: Mohr, Volhard, ion selective electrode, and chloride analyzer. The results of Volhard, Mohr, and chloride analyzer methods were similar for unaged cheese varieties, i.e., Mozzarella, Cheddar, Ricotta, Romano, and Provolone, but concentrations detected with the ion selective electrode were lower than the other three methods. Results were similar with aged Cheddar and process cheeses except the Mohr procedure proved unreliable. A constant correction factor could be used to make the ion selective electrode results similar to that obtained with the Volhard procedure.

Evaluation of the Bacteriological Health Risk of 60-Day Aged Raw Milk Cheddar Cheese

One hundred twenty-seven 60-d aged Cheddar cheese samples produced by 21 provincially inspected cheese plants were analyzed by 8 regional laboratories of the Ontario Ministry of Health. Coliforms were detected in 37 (31.2%) and fecal coliforms confirmed in 22 (18.3%) samples, with geometric mean counts per g of 92.5 and 79.3, respectively. Staphylococcus aureus was found in only two products at a level of >1000 per g. Salmonella spp. and Campylobacter jejuni were not isolated from any of the samples tested. Yersinia enterocolitica was isolated from one product; however, the isolate was bile esculin-and salicin-positive, and considered a non-pathogenic biotype. The pH of these aged Cheddars ranged between 4.98 and 5.50, with a mean of 5.26. Alkaline phosphatase activity was detected in 94 (79.7%) of the 118 samples tested. These results suggest that 60-d aged raw milk Cheddar cheese produced in Ontario does not pose a significant bacteriological health risk.

A STUDY OF CLEAN MILK FOR AGED CHEDDAR CHEESE

A STUDY OF CLEAN MILK FOR AGED CHEDDAR CHEESE