The unique flavor of high quality Swiss cheese is difficult to reproduce in commercial market cheese. Swiss cheese flavor has never been duplicated or thoroughly understood. New techniques and advances in flavor research have enabled better definition and understanding of food flavors. Therefore, it was desirable to make a detailed investigation of Swiss cheese flavor. Neutral volatile flavor compounds were isolated from Swiss cheese fat by low-temperature low-pressure distillation. The compounds were separated by temperature programmed gas chromatography. Direct analysis of cheese fat and whole cheese from four domestic and two imported good flavored cheeses by gas entrainment and on-column trapping provided a further means of isolation of volatile flavor compounds in Swiss cheese. Gas chromatography in conjunction with rapid scan mass spectrometry and relative retention time data were used to identify compounds. Compounds positively identified by the distillation and on-column trapping techniques were as follows: methanol, ethanol, 1-propanol, 1-butanol, 2-pentanol, trans-2-hexene-1-ol, 2-phenylethanol, acetaldehyde, 2-methyl propanal, 2-methyl butyraldehyde, benzaldehyde, phenylacetaldehyde, acetone, butanone, 2-pentanone, 2-hexanone, 2-heptanone, 2-nonanone, 2-undecanone, 2-tridecanone, 2-pentadecanone, hexane, octane, 1-octene, nonane, 1-nonene, dodecane, pentadecane, toluene, α-pinene, methyl acetate, methyl hexanoate, methyl octanoate, methyl decanoate, ethyl propionate, ethyl butanoate, ethyl hexanoate, ethyl octanoate, ethyl decanoate, ethyl dodecanoate, butyl acetate, 3-methyl butyl acetate, γ-valerolactone, γ-dodecalactone, δ-octalactone, δ-decalactone, δ-dodecalactone, dimethyl sulfide, diacetyl, benzothiazole, o-dichlorobenzene, 1, 2, 4-trichlorobenzene, di-isobutyl adipate, and chloroform. Compounds tentatively identified include an aromatic hydrocarbon, pinane, α-fenchene, ethyl benzene, a di-methyl benzene, methyl benzoate, 2-phenyl-2-methyl butane, 5-methyl-5-ethyl decane, 3-methyl butyl octanoate, 2, 5-dimethyl tetra decane, methyl vinyl ether and 2-methyl propenal. The concentration of selected volatile compounds identified by the on-column trapping technique were determined by relating their peak heights to known quantities of compound. Average concentrations calculated from the mean values for all the six cheeses and expressed in parts per million were as follows: dimethyl sulfide. 0.107; diacetyl, 0.8; acetaldehyde, 1.4; acetone, 1.6; butanone, 0.3; 2-methyl butyraldehyde, 0.42; 2-pentanone, 0.98; 2-heptanone, 0.45; ethanol, 16.3; 2-butanol, 0.3; 1-propanol, 2.9; 1-butanol, 0.7; methyl hexanoate, 1.5; and ethyl butanoate, 0.6. Liquid-liquid partition chromatography and gas chromatography were utilized to determine quantitatively the major free, fatty acids in the six Swiss cheeses. 2-Methyl butyric acid was detected in all cheeses and varied from 9.0 to 100.0 mg/kg cheese. The other isomeric acid, 3-methyl butyric, was detected in only two cheeses. Formic acid was detected in only one cheese. No n-valeric or 2-methyl propionic acids were detected. A synthetic Swiss cheese flavor was prepared utilizing the data obtained in this investigation and that available in the literature for free amino acids. A satisfactory reproduction of Swiss cheese flavor could be achieved only if the mixture contained free fatty acids, volatile constituents, and free amino acids and was adjusted to the pH of natural cheese. / Graduation date: 1966

From Cache Valley Dairy Association in Smithfield, Utah, milk from two to three cheese vats plus the corresponding Swiss cheese trimmings, salted cheese, and whey were sampled each week from October 1981 to October 1982. The weights of the Swiss Cheese were recorded. Milk samples were analyzed for fat and protein; cheese samples were analyzed for fat, protein, and moisture; whey samples were analyzed for fat. By using Gauss-Newton nonlinear Least Squares method of iteration, the data was analyzed. Two formulas for predicting Swiss cheese yield were derived. A good relationship was found to exist between Swiss cheese yield and fat and protein. In this study it was found that the season affected the percentage of fat and protein in the milk and thereby the cheese yield. The highest cheese yields corresponded with the months with highest protein and fat percentage in the milk.

Eighty-five samples of milk and Swiss cheese made from the same milk were collected at Cache Valley Dairy Association, Smithfield, Utah, between August, 1979, and July, 1980. The weights of the milk, Swiss cheese and the trim were carefully recorded. The milk samples were analyzed for fat and protein, and the cheese samples were analyzed for fat, protein and moisture. An attempt was made to predict Swiss cheese yields from the fat and protein content of the milk and the moisture content of the cheese. The data were analyzed statistically by Gauss-Newton non-linear least squares method of iteration. Three formulas for predicting Swiss cheese yield were derived. The differences among the three formulas in predicting actual yield were insignificant. A good comparison was demonstrated between Swiss cheese yield and fat and protein in milk. The effect of season on cheese yield was also evaluated. The highest yield of Swiss cheese was in December and the lowest yield was in July. This corresponded with high and low levels of fat and protein in the milk.

Swiss cheese has been rightly called "king of the cheeses." It has been prized the world over for its stately appearance and sweet "hazelnut" flavor. In grading Swiss cheese, these two things,appearance and flavor, are important considerations in determining the cheese score. Appearance is judges according to the number, type, and size of eyes present in the cheese, with color and body and texture also considered. Flavor is judges according to the degree of sweetness and the amount and kinds of off flavors present. In the past, there has been considerable variation in the quality of the Swiss cheese produces. Causes of this variation were little understood, since wide ranges in grades of cheese were obtained from seemingly similar milk and manufacturing precedures. Technique has been greatly improved by research conducted in both private industry and experiment stations. Much has been done to produce beneficial effects in the cheese, and to reduce detrimental effects. One question, still debated, is the amount of eye forming bacteria necessary to produce the best eye formation. Propionibacterium shermanii, by its production of carbon dioxide, is thought to be the most important bacteria in producing the eyes. Some Swiss cheese makers see no necessity in adding prepared culture of E. shermanii to their milk. They allow the milk to become "seeded" from organisms already present in the vets and on the equipment. Other cheese makers add small amounts of prepared cultures of T. shermanii, whil still others add rather large quantities. Procedure varies from plant to plant. Propionic acid and acetic acid are also produced in the life processes of P. shermanii. These two acids are important factors in the development of flavor in Swiss cheese. Therefore, a change in the amount of P. shermanii in the Swiss cheese, and the subsequent effect on eye formation and flavor. It is the purpose of this experiment to determine the general effects that variations in the size of the inoculation of P. shermanii will produce on eye formation and flavor development. The effects, if any, of the three milk treatments mentioned above will also be noted.

Importance of project: A sweet hazelnut flavor, a pliant texture, and large, evenly distributed "eyes" characterize high quality Swiss of Emmenthaler cheese. The typical sweet flavor is chiefly due to bacteria which produce propionic acid, acetic acid, and carbon dioxide. The eyes are formed from the gas, mainly carbon dioxide, produced by these and other bacteria. Krett and Stine (20) have found that the lower fatty acid content of a Swiss cheese generally indicates its quality. A study of factors which may influence the amount and ratios of the volatile acids should be helpful in determining manufacturing and curing procedures which will give a fine flavored product. Purpose of investigation Commercially, Swiss cheese is usually made from raw or heat-treated milk. Experimentally, hydrogen peroxide treated milk has shown some promise. A comparison of these three milk treatments was made to determine the effect they have on the volatile fatty acid content and cheese quality. Some successful cheesemakers add no prepared cultures of propionic acid bacteria (Propionibacterium shermanii); some add small amounts, while others advocate larger inoculums. Cheese in this experiment was made with varying amounts of added Propionibacterium shermanii culture to study the relationship to the lower fatty acid content, eye formation, and quality. This experiment is a study of the butyric, propionic, and acetic acid content of 4-month old cheese as affected by the above mentioned milk treatments and Propionibacterium shermanii culture variations.

Cette thèse présente des travaux de deux natures différentes ; (1) l'étude approfondie des travaux de James Reason (Swiss cheese model) et (2) l'activité d'ingénierie d'un modèle (ECHO) pour l'étude des facteurs organisationnels et humains dans l'exploitation des barrages d'EDF. Ces travaux sont articulés autour de la question du rôle, de la valeur et de la place des modèles d'erreur humaine dans la gestion de la sécurité industrielle.Une revue de littérature montre que les dispositions de sécurité dans les barrages sont essentiellement techniques. Les considérations relatives au facteur humain, bien que prégnantes dans l'accidentologie, semblent faire défaut dans les pratiques. Constatant sa très large utilisation, nous présentons en détail le modèle de Reason. Nous mettons en lumière une « double » collaboration (peu documentée) entre recherche et industrie d'une part, sciences humaines et sciences de l'ingénieur d'autre part. Partant de cette double collaboration comme une condition de réussite à des évolutions culturelles de sécurité, nous présentons le processus d'ingénierie qui a permis la conception puis la mise en place d'un modèle facteur humain dans les études de dangers de barrages d'EDF. Nous tentons enfin de mesurer et de présenter les effets produits par ECHO sur les représentations et les pratiques. La discussion porte sur l'intérêt et les modalités de double collaboration dans la sécurité industrielle et espère contribuer à un recadrage du débat sur la nature et la valeur des modèles. / This thesis presents two different works: (1) an in-depth study of James Reason's work (Swiss cheese model) and (2) the engineering activity of a model (ECHO) of organizational and human factors in operation of EDF's dams. These works are articulated regarding the role, value and place of human error models in industrial safety management.A literature review shows that dams' safety is mainly based on technical issues. The considerations relating to human factors, although pervasively present in the accidents, seem to be lacking in practice. After its wide use, we present in detail the Reason's model. We highlight a double collaboration (poorly documented) between research and industry on the one hand, Humanities and engineering Sciences on the second hand. Based on this dual partnership as a success condition for efficient safety culture developments, we present the engineering process associated with the design and the implementation of a human factor model in EDF dams' hazards study. Finally, we try to measure and report the effects produced by ECHO on the representations and practices.The discussion focuses on the interest and modalities for double collaboration in industrial safety and, therefore hopes to contribute to reframe the debate on model's nature and value.

Danish type swiss cheese has the characteristic "eye" of a regular swiss cheese and is similar in texture. The flavor is milder and has a softer body. Because of its milder flavor and softer body it is of interest for consumption. Because it cures faster than swiss cheese it has the added advantage of cutting down curing cost and thus requires a shorter time to reach the consumers. Another advantage is that it is made in small loaves or wheels which make for better handling, for it can be sold in both wholes ale and retail establishments without cutting before wrapping. Still another advantage of Danish type swiss cheese is that small equipment needed which is also adapted to manufacturing of cheddar cheese. The problem was to make better Danish type swiss cheese by applying different types and amounts of starters using Streptococcus lactis with a mixture of (1) Streptococcus thermophilus and (2) Lactobacillus bulgaricus and also to find the best combination of these bacilli and cocci. The influence of warm room temperature upon the eye formation and body and texture was studied. The Cheese was held in brine solution for different lengths of time to find the most effective salt concentration. Different temperatures were maintained in a warm room to find out which temperature was best for a higher quality of cheese. A pancreatic enzyme was added in different amounts to a few lots of milk before pasteurization, to find out whether it affects the body and texture and reduce the curing time. Pure trypsin was used in one lot to determine its influence on the quality of cheese.

The size, shape, and handling of the large swiss cheese wheels have given rise to problems of labor, marketing, and waste in cutting. At the present time, there is a trend to produce a smaller swiss cheese which will enable the manufacturer and marketing agencies to overcome the difficulties in handling the large wheels.

One of the least controlled defects in Swiss cheese is development of splits. Split defect is characterized by fissures or cracks in the body of the cheese that can be as short as 1 cm in length or long enough to span a 90-kg block. This defect appears during refrigerated storage after the cheese is removed from the warm room. Swiss cheese with splits is downgraded because it is unsuitable for use on high-speed slicing equipment (up to 1,000 slices per minute). A 2x2x2 factorial experiment was used to determine the effect of different commercial Lactobacillus helveticus starters combined with commercial gas-forming strains of Propionibacterium freudenreichii ssp. shermanii on the occurrence of split defect in Swiss cheese. Two strains of L. helveticus recommended for Swiss cheese manufacture were used along with two strains of P. freudenreichii ssp. shermanii. The same strain of Streptococcus thermophilus was used in all treatments. To investigate the influence of seasonal variations in milk supply, eight vats were made in the summer and eight vats were made in the winter, each producing five 90-kg blocks of cheese. Each 90-kg block of cheese was cut into twenty-four 4-kg blocks, and each 4-kg block was graded based on the presence of splits. If splits were present, the cheese was downgraded from A to C grade. Only small variations were found in the composition of cheeses made during the same season. There were no correlations between cheese moisture, pH, fat, protein, calcium, lactose contents, D/L lactate ratio, or protein degradation that could be used to predict the amount of splits present after 90 d of storage. The extent of split formation was influenced by both the L. helveticus and P. freudenreichii ssp. shermanii cultures used. In this study, we were able to show a fivefold reduction in downgraded cheese through proper culture selection from 90% to 14% in the summer cheese. Even though less than 6% of the cheese split in the winter, the culture effect was nonetheless repeatable with a similar reduction through culture selection from 6% to 1% in winter cheese. Split formation also increases with storage time. If a cheese has a tendency to split, there will be a higher percentage of downgraded cheese the longer it is kept in storage.

Le modèle standard de la cosmologie est fondé sur les hypothèses d'homogénéité et d'isotropie de l'Univers. Pour interpréter la plupart des observations, ces deux hypothèses sont appliquées de façon stricte ; l’objectif principal de cette thèse a été d'évaluer leur pertinence, en particulier lorsque de très petites échelles sont mises en jeu. Après une revue détaillée des lois de l'optique géométrique en espace-temps courbe, on propose une analyse exhaustive de la propagation de la lumière à travers des modèles cosmologiques « en gruyère », modélisant le caractère grumeleux de l'Univers. L'impact sur l'interprétation du diagramme de Hubble s'avère être faible, en particulier grâce à la constante cosmologique. Lorsqu'appliquées aux données actuelles issues de l'observation de supernovae, les corrections associées tendent à améliorer l'accord entre les paramètre cosmologiques mesurés à partir du diagramme de Hubble et du fond diffus cosmologique. Ceci suggère que la précision des observations cosmologiques atteinte aujourd'hui ne permet plus de négliger l'effet des petites structures sur la propagation de lumière à travers le cosmos. Un tel constat a motivé le développement d'un nouveau cadre théorique, inspiré de la physique statistique, visant à décrire ces effets avec précision. Quant à l'hypothèse d'isotropie, cette thèse aborde d'une part les conséquences potentielles d'une anisotropie cosmique sur la propagation de la lumière, en résolvant les équation de l'optique géométrique dans l'espace-temps de Bianchi I. D'autre part, on y analyse une classe de sources d'anisotropie, à savoir les modèles scalaire-vecteur. / The standard model of cosmology is based on the hypothesis that the Universe is spatially homogeneous and isotropic. When interpreting most observations, this cosmological principle is applied stricto sensu ; the main goal of the present thesis was to evaluate how reliable this assumption is, especially when small scales are at stake. After having reviewed the laws of geometric optics in curved spacetime, and the standard interpretation of cosmological observables, the dissertation reports a comprehensive analysis of light propagation in Swiss-cheese models, designed to capture the clumpy character of the Universe. The resulting impact on the interpretation of the Hubble diagram is quantified, and shown to be relatively small, thanks to the cosmological constant. When applied to current supernova data, the associated corrections tend to improve the agreement between the cosmological parameters inferred from the Hubble diagram and from the cosmic microwave background. This is a hint that the effect of small-scale structures on light propagation may become non-negligible in the era of precision cosmology. This motivated the development of a new theoretical framework, based on stochastic processes, which aims at describing small-scale lensing with a better accuracy. Regarding the isotropy side of the cosmological principle, this dissertation addresses, on the one hand, the potential effect of a large-scale anisotropy on light propagation, by solving the equations of geometric optics in the Bianchi I spacetime. On the other hand, possible sources of such an anisotropy, namely scalar-vector models for inflation or dark energy, are analysed.