Cheese Structure Research Articles

Changes in textural, microstructural, and colour characteristics during ripening of cheeses made from raw, pasteurized or high-pressure-treated goats’ milk

Abstract Goats’ milk cheeses were made from raw (RA), pasteurized (PA; 72°C, 15 s) or pressure-treated (PR; 500 MPa, 15 min, 20°C) milk to compare textural, microstructural, and colour characteristics in relation to ripening time. Texture, microstructure and colour were evaluated by uniaxial compression and stress relaxation tests, confocal laser scanning microscopy and Hunter colorimetry, respectively. Raw and PR cheeses were firmer and less fracturable than PA cheese, but differences became less notable toward the end of ripening. PA and PR cheeses were less cohesive than RA cheese. Although cheeses exhibited a loss of elastic characteristics with ageing, PR cheese showed the most elastic behaviour initially. Confocal laser scanning micrographs displayed PR cheese with a regular and compact protein matrix, with small and uniform fat globules resembling the structure of RA cheese. Finally, colour evaluation demonstrated significant differences between cheeses due to milk treatments and ripening time.

Caracterização química, reológica e aceitação sensorial do queijo petit suisse brasileiro

The chemical composition, water holding capacity, rheological properties and sensory acceptability of six commercial brands of Brazilian petit suisse cheeses collected from local markets, where analyzed after 20 days of storage at temperatures between 8 and 12°C. The commercial products differed mainly with respect to the type of hydrocolloid added and protein/fat ratio. Product B showed more than two times the water holding capacity as compared to the other samples presenting an intermediate protein/fat ratio and whey protein concentrate and pectin added. The highest apparent viscosity, complex viscosity, G’ and G’’ where presented by product E which also showed the highest protein/fat ratio, suggesting that there was a good correlation between these rheological parameters and protein/fat ratio. The protein/fat ratio significantly influenced (p<0,05) G’, G’’ and the complex viscosity, showing the impact of product composition on the petit suisse cheese structure and elasticity. All the samples showed viscoelastic behavior but G’ was higher than G’’ for all studied frequencies, The G’/G’’ ratio was between 3 and 4, characteristic of weak gel for this type of cheese. Sensory scores for taste, global appearance, texture and global terms where significantly different among the samples. Products E and F received the highest acceptability scores and the product B, the lowest. Product A received the highest acceptability scores for taste and texture, but also presented the lowest acceptance in global appearance, due to its high syneresis. In general, the samples were well accepted by adult consumers indicating a good potential in this segment to be explored by national processors of petit suisse cheese.

Nota. Estudio de algunos quesos típicos españoles por microscopía electrónica de barrido. Principales modificaciones microestructurales causadas por la congelación / Note. Study of some typical Spanish cheeses by scanning electron microscopy. Main microstructural modifications caused by freezing

The microstructure of some Spanish cheeses and the main microstructural modifications caused by freezing are studied by scanning electron microscopy (SEM). In cured and pressed cheeses such as Manchego and Mahón cheeses, the protein matrix constitutes a compact network in which fat glob ules, uniformly distributed, are immersed; frequently, these spherical globules are limited by an ap parent protein membrane. In the protein matrix, micellar bodies are identified in different aggrega tion grades; this is a characteristic of the enzymatic coagulation. In non-cured Herreño cheese (pressed paste) the compaction grade of the casein micelles is less than in cured and pressed cheeses. In fresh cheese, which is a fresh and non-cured cheese, proteins are distributed as micelle clusters more or less loose. Large fissures and small spherical voids, which would probably contain whey, air or fat, are observed. Cottage cheese, a non-pressed paste, is obtained fundamentally from whey protein coagulation; the protein bodies are distributed loose or in the form of clusters, and large voids are formed. Freezing at -25 °C affected the pressed and cured cheeses ( Manchgeo and Mahón) and non- cured cheeses ( Herreño); the spherical voids containing fat are deformed, the protector membranes are broken, and reticular structures and micellar bridges are found inside the protein matrix. In non- cured and soft paste cheeses such as fresh cheese, the protein matrix becomes hard with fissures, and the spherical voids appear destroyed and deformed. Freezing produces total destruction of the cot tage cheese structure. Texture studies of the cheeses (shear strength) agreed with microscopy results by SEM.

Structure, physico-chemical and sensory properties of feta cheese made with tapioca starch and lecithin as fat mimetics

Abstract Functionality of modified tapioca starch and lecithin as fat mimetics in Feta cheese was studied. Cheeses were made with no fat mimetics, 1% modified tapioca starch, 0.2% lecithin, and a combination of 0.5% tapioca starch and 0.1% lecithin. Low-fat Feta cheeses (9–16% fat) were prepared from bovine 1.6–2.2% fat milk. Cheeses were ripened for 45 d before chemical, sensory, SEM, and textural evaluation. Levels of fat and fat mimetics significantly affected moisture, protein, yield, and hardness. Reduced-fat cheeses with modified tapioca starch had the highest moisture (67.6%) and lowest protein (13.5%) content and their hardness was higher. SEM micrographs revealed that the size of protein aggregates increased as the fat content of the cheese decreased. The combination of modified tapioca starch and lecithin improved flavor, texture and overall acceptability of reduced-fat and low-fat Feta cheeses.

Soft goat cheeses at different ripening stages: cheese structure, composition and non solvent water

Soft goat cheeses of the Sainte-Maure variety were studied at different ripening stages to characterise their microstructure in relation to their composition and water content. The intemalliq- uid phase of the cheeses was extracted by hydraulic pressure and analysed. Non solvent water (NSW) in cheese was calculated according to the method of van Boekel and Walstra from the concentration of sorne completely dissolved components such as potassium (K), sodium (Na) or 13-lactoglobulin (I3-Lg) in the liquid fraction compared to that in the whole cheese. The values obtained for NSW in the 7-d-old cheeses were 1.1, 0.8, 2.1 ss:' casein (CN) for K, Na and I3-Lg, respectively. A reduc- tion in NSW values was observed during ripening, down to 0.6 gg CN for K and Na and 1.3 ss:' CN for I3-Lg in the 58-d-old cheese. Total water content of cheese decreased during ripening from 4.7 to 1.9 g.g-I CN, so that the relative proportion of NSW to total water increased during ripening. Very different cheese microstructures were observed at the beginning and end of the ripening period. In the early stage of ripening the structure of cheese was loose, characterised by accelerated enzymatic reactions which developed in the aqueous phase as a result of proteolysis. A rapid decrease in the water content occurred due to evaporation at the cheese surface, facilitated by the easy movement of water from the inner part of cheese to the surface through the open and porous structure. During these early stages of ripening, pressing of the cheese led to high flow rates of Iiquid. When cheese total solids reached 600-650 g·kg-1, which occurred after -43 d of ripening, the cheese microstructure became more compact. The residual water had a slower diffusion rate in the structure, as indicated by the lower variation in the cheese water content with time. Residual water was mainly non solvent. The prote- olytic rate in the cheeses decreased, probably due to the lower content in solvent water. The kinetics of the pressing at this stage was characterised by a low flow rate. © InraJElsevier, Paris. goat cheese 1non solvent water 1hydraulic pressing 1desorption 1structure

Use of Fat Replacers in Low Fat Mozzarella Cheese

Low fat Mozzarella cheeses with <6% fat were made using fat replacers to increase the moisture content and to improve the functional properties of the cheese. We used two protein-based fat replacers (Simplesse® D100 and Dairy-Lo®) and two carbohydrate-based fat replacers (Stellar™ 100X and Novagel™ RCN-15). Moisture contents of the cheeses were 53.0, 54.3, 55.2, 55.3, and 57.3% for the control, Stellar™, Dairy-Lo®, Simplesse®, and Novagel™ cheeses, respectively. Apparent viscosity of the cheese at 80°C was not significantly affected by addition of fat replacers, but there was a significant effect on meltability. Cheeses made with Stellar™ and Simplesse® had greater overall meltability than cheese made with Dairy-Lo® or the control. The cheese made with Novagel™ contained the most moisture but, from d 1 to d 14, melted to the least extent. By d 21, all cheeses melted to the same extent.The location of the fat replacers in the cheese structure was examined using scanning electron microscopy. Distribution of the fat replacers within the cheese was influenced by the extent of microparticulation of the fat replacer, size of the fat replacer particles, and processing steps that caused an interaction between the fat replacer and the caseins in milk. Novagel™ was present as the largest particles (up to 80 μm), and their incorporation into the cheese curd resulted in increased openness in the cheese, and large serum channels (up to 300 μm) were formed. None of the other fat replacers increased the openness of the cheese structure. Cheese sample preparation for the electron microscopy caused the Novagel™ particles to shrink and to appear artifactually as solid particles rather than as fibrous particles as shown by freeze-drying. Stellar™ was observed as spheroid particles (0.5 to 1μm in diameter) embedded within the protein matrix of the cheese as well as being present in the serum channels. No discrete Dairy-Lo® particles were observed in the protein matrix, indicating a low level of microparticulation (particles<0.2μm) of the proteins in Dairy-Lo®.

Rheological and microstructural characterization of double cream cheese

AbstractFirmness at 5 °C, dynamic viscoelastic moduli (G' G) and capillary extrusion profiles at 20 °C, were obtained on double cream cheese after the different steps of processing (curd obtention, mixing at 70 °C and 500 r.p.m. with heat‐denatured WPC, heating at 85 °C, homogenizing at 20 MPa (1st stage) and 5 MPa (2nd stage) and cooling to 20 °C and 13 °C) and storage 7–9 days at 5 °C. It was found that double cream cheese became firmer and more elastic after heating and homogenization, although it became softer and more viscous after mixing and cooling. Transmission Electron Microscopy (TEM) and cryo‐Scanning Electron Microscopy (SEM) micrographs showed that rheology results could be related to aggregation (during heating and homogenization) and disruption (during cooling) of milk fat globule/casein complexes. Dispersion of homogenization clusters after cooling, and aggregation of milk fat globules during storage caused double cream cheese structural instability to appear. It was suggested that the heterogeneity of capillary extrusion profiles could be quantified through application of fractal concepts and Fourier analysis and related to structure and texture of double cream cheese.

Effects of processing on rheology and structure of double cream cheese

Double cream cheese curd was industrially made and post-treated in a pilot scale plant. After storage at 5 °C for 7–9 days, rheological properties of the intermediate and final products were measured using penetrometry, flow curves recording and dynamic testing. Results showed that the curds exhibited timedependent hysteresis of the flow properties and polymer-like dynamic viscoelastic behaviour, independently of the manufacturing stage. Curd mixing at 70 °C and 500 r.p.m. with salt and predenatured whey protein concentrate and dynamic cooling at 20 or 13 °C decreased firmness and dynamic viscoelastic parameters G′ and G″, while tan δ ( G″ G′ ) increased. There was a breakdown of the curd with a decrease in elastic deformation, typical of a solid material and a corresponding increase in viscous flow, characteristic of a liquid. On the other hand, evolution of the rheological parameters was the reverse after heat treatment at 85 °C and homogenization at 20 MPa (first stage) + 5 MPa (second stage). The curd structure was developed with a transition of behaviour to that typical of an elastic solid. Curd cooled dynamically to 13 °C became unstable during subsequent storage. This phenomenon was thought to result from an important breakdown of the curd during dynamic cooling and from aggregation of the milk fat globules during storage.

Rheological and textural behaviour of double cream cheese. Part I: Effect of curd homogenization

Double cream cheese was made by classical cheesemaking and different products were obtained by varying the curd homogenization pressure (0, 5, 10, 20, 30 and 50 MPa). Rheological and textural behaviour of cheeses were estimated by determining flow curves, viscoelastic parameters G′ and G″ (dynamic testing) and extrusion shear stress (capillary extrusion). Flow curve results were not reliable because the majority of cheese were ‘brittle’ and product destructuration was observed during sampling. Extrusion shear stress increased with the homogenization pressure, and a pressure of around 20 MPa seems to be a value which determines the borderline between two cheese structures. Storage modulus (G′) increased and loss modulus (G″) decreased with the pressure. This, with extrusion results, indicates that fat re-emulsification leads to a product better organized and thus more elastic because of more interactions between particles. Emphasis was placed on the importance of the upstream steps in the manufacturing process, especially on the fat phase destabilization.

Women's Work in Agriculture: Divergent Trends in England and America, 1800 to 1930

English cheeses—Cheddar, Gloucester single or double, Cheshire, Stilton, and others—are familiar throughout the Anglo-American world, whether consumed after dinner in English homes or as key ingredients of American tex-mex or vegetarian cuisine. These famous cheeses originated long ago but in most cases reached a zenith in quantity and in reputation during the last century. Little is known about the history of English cheese dairying, despite its fame and its importance to agriculture past and present. Its economic background has received only slight attention, and its social history is almost entirely unexplored; yet clearly the social structure of English cheese dairying has historically exerted a major influence on the industry, because it traditionally depended upon a distinctive sexual division of labor. The history of women's work in English cheese dairying has implications for a broader historiographical question: When and why did women gradually disappear from many kinds of agricultural work in Western societies?

繊維構造チーズ製造工程の機械化 （第４報） 繊維構造チーズの繊維性におよぼすセミミクロ構造の影響

繊維構造チーズの品質は,これを引き裂いた時に観察される糸状物の多さで評価しており,この品質特性を繊維性と呼んでいる。繊維性は生成した糸状物の面積に対応し,糸状物の太さと数とで決定される。加熱処理した試料と保存した試料とを用い,繊維構造チーズの繊維性におよぼすセミミクロ構造の影響を,レオロジー的性質とあわせて考察した。セミミクロ構造を定量的に考察する指標として,脂肪球の円形度を測定した。加熱処理の温度が高く,または保存期間が長くなるにしたがって,繊維性は低下し,力学的な異方性は消滅し,細長く伸びていた脂肪は球形に近づいていった。これらを再度延伸した結果,加熱処理試料では繊維性,異方性および円形度が回復したのに対し,保存試料ではまったく回復しなかった。このことは,加熱処理試料のタンパク質の凝集状態は,加熱処理と再延伸を行う過程で変化しないのに対し,保存試料ではタンパク質が酵素によって分解されたことを反映していると推測した。繊維構造チーズの繊維性の発現には,レオロジー的性質に加え,方向性を持ったセミミクロ構造の形成が必要であると考えた。

Contribution of the cryo-SEM to the cheese technology. Development of the structure of Saint-Paulin cheese during ripening

Biology of the CellVolume 63, Issue S1 p. 9-9a Contribution of the cryo-SEM to the cheese technology. Development of the structure of Saint-Paulin cheese during ripening Micheline Rousseau, Micheline Rousseau Station de Recherches laitéres, INRA, Centre de Recherch'es de Jouy-en-Josas, 78350 Jouy-en-Josas (France)Search for more papers by this authorMichel Desmazeaud, Michel Desmazeaud Station de Recherches laitéres, INRA, Centre de Recherch'es de Jouy-en-Josas, 78350 Jouy-en-Josas (France)Search for more papers by this authorDehli Guillaumin, Dehli Guillaumin Microscopie a balayage, CNRS, Université P.M. Curie, 105 Boulevard Raspail, 75005 Paris (France)Search for more papers by this author Micheline Rousseau, Micheline Rousseau Station de Recherches laitéres, INRA, Centre de Recherch'es de Jouy-en-Josas, 78350 Jouy-en-Josas (France)Search for more papers by this authorMichel Desmazeaud, Michel Desmazeaud Station de Recherches laitéres, INRA, Centre de Recherch'es de Jouy-en-Josas, 78350 Jouy-en-Josas (France)Search for more papers by this authorDehli Guillaumin, Dehli Guillaumin Microscopie a balayage, CNRS, Université P.M. Curie, 105 Boulevard Raspail, 75005 Paris (France)Search for more papers by this author First published: 1988 https://doi.org/10.1016/0248-4900(88)90152-9AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume63, IssueS11988Pages 9-9a RelatedInformation

Microstructural change of Al on H implantation

Abstract Modifications to the subsurface layer of Al on 25 keV H2 + ion implantation to fluences of 4 × 1017 to 2 × 1018 H+/cm2 at room temperature were investigated by transmission electron microscopy (TEM) and elastic recoil detection (ERD) with 1.5 MeV He+. Numerous bubbles ranging in diameter from 50 to 1000 A were observed with a sharp peak at 120 A irrespective of the ion fluence. Stereomicroscopic observations revealed the depth distribution of the bubbles. At fluences greater than 6 × 1017 H+/cm2, a lateral layer of lower density compared with matrix was observed and named “Swiss cheese structure” since its estimated structure is similar to Emmental cheese containing many holes. This Swiss cheese structure causes the formation of new layers on a free surface, and plays a precursor role for blistering. Hydrogen depth profiling with ERD was performed on every specimen revealing the collapse of the implanted hydrogen profile due to the formation of the Swiss cheese structure.

Effect of milk pretreatment and making conditions on the properties of Cheddar cheese from milk concentrated by ultrafiltration

SUMMARYCheddar cheeses were made from milks concentrated 3- to 6-fold by ultrafiltration. Modifications to the conventional cheesemaking process were designed to obtain the correct composition and pH value in the final curd, improve the fat and moisture retention and cheese texture, and increase the ripening rate. The compositions of all cheeses were similar to those of controls made with unconcentrated pasteurized milk. The curd and cheese structures and the textural properties of the cheeses were closer to those of the controls when made from milk concentrated 5-fold than when made from milk concentrated 3-fold. Light homogenization of the milk before concentration led to improved fat recovery and decreased graininess and crumbliness in the cheese. Lowering the coagulation temperature of concentrated milks gave improved curd structure and less grainy and more sticky cheeses. Addition of the bacterial proteinase, Neutrase, with the salt, stimulated proteolysis and flavour production in the cheeses and made them more sticky. Neither reduction of the mineral levels in the milk by acidification before concentration nor reduction of the lactose concentration by diafiltration had any significant effect on the composition or textural properties of the cheeses.

Effect of variation in the composition of milk supply on the composition and quality of farmhouse Cheshire cheese

SUMMARYThe composition of the diet fed to cows, the composition and coagulating properties of the milk produced by them and used for cheesemaking, the cheesemaking methods and the chemical composition, texture and grade of Cheshire cheese obtained from four farmhouse producers during the period December to June 1982–83 were investigated. The presence of pockets of loose fat in the cheese structure, which can lead to downgrading in the late winter and spring, was not related to the chemical composition of the milk and may arise from the handling of the milk before cheesemaking. Generally the composition of the forage and the milk varied with date, but not between the different farms, whereas the composition and properties of the cheese were dependent on the manufacturers but were fairly constant during the period of study.

Surface Hydrophobicity of αs1 -I, αs1 -Casein A and B and Its Implications in Cheese Structure

The first major proteolytic cleavage during Cheddar cheese maturation is the scission of αs1-casein to give a small peptide and αs1-I. Previously this proteolytic step was correlated with changes in the rheological properties of cheese, notably a lower elasticity and a decrease in the force required to fracture the cheese. Using cis-parinaric acid and 1,8-anilinonaphthalene sulfonate, we showed that αs1-I and αs1-casein A have lower surface hydrophobicities than αs1-casein B. The peptide segment involving residues 14 to 24 of the αs1-casein B sequence must be important in the formation of a hydrophobic interaction site, and an extensive network of hydrophobically bonded αs1-casein molecules is probably important in young cheese as well as in concentrated casein solutions.

An electron-microscope study of the structure of Domiati cheese

SummaryA technique is described for preparing ultrathin sections from cheese for electron-microscopic examination. The internal structure of fresh Domiati cheese was found to be composed of a framework of large, spherical casein aggregates held by bridges and enclosing fat.After pickling, the casein aggregates were partly disintegrated into small spherical particles forming a loose structure.

The distribution of bacteria in New Zealand Cheddar cheese

SummaryThe distribution and development of bacteria during the maturing of New Zealand Cheddar cheese have been studied using stained sections of cheese. The starter streptococci usually occur singly and in small groups throughout the mass of the cheese, their distribution on a microscopic scale being very irregular. In contrast, the bacteria developing later form discrete microcolonies, most of which are associated with the curd junctions. Instead of adding lactobacilli to milk, smaller numbers may be added to the dry curd before cheddaring or after milling. Some observations on the physical structure of cheese are made.

Electronic Microscopic Observations of the Structure of Cheese

Summary This study was initiated to develop a method for the examination of the ultra-fine structure of cheese with the electron microscope. It was used to study the structure of Cheddar cheese made from variously treated milk. Freshly broken surfaces of chilled Cheddar cheese were covered with a parlodion film. Next, the film was stripped and the replica side covered with a formvar film. After dissolving the parlodion portion, the formvar film was shadow-cast with gold and examined under the electron microscope. Observations made on replica films showed specific surface patterns for cheese made from raw, pasteurized, and pasteurized homogenized milk.