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Sieber R., Collomb M.

Formation of conjugated linoleic acids through starter cultures

The conjugated linoleic acids (CLA) contained in milk fat have a high health amelioration potential. The capacity of different starter cultures to form CLA from linoleic acid could be used to increase the CLA level in fermented dairy products. In a medium supplemented with linoleic acid, some strains of lactobacilli, lactococci and streptococci as well…

Höhn E., Künsch U., Infanger E., Koch W.

Were fruits more nutritious in former times?

The headline “fruits and vegetables diminished in their nutritional quality” appeared in recent years in the media. The claimed quality loss was supposedly related to changes in agricultural practice. The comparison of contents of nine minerals and eleven vitamins of the five most important locally produced fruits as published in three different food composition databases…

Höhn E., Künsch U., Infanger E., Koch W.

Were vegetables more nutritious in former times?

The headline “fruits and vegetables diminished in their nutritional quality” appeared in recent years in the media. The claimed quality loss was supposedly related to changes in agricultural practice and depletion of the soil. The comparison of contents of nine minerals and eleven vitamins of the 7 most important vegetables as published in three different…

Casey M.G., Gruskovnjak J., Fröhlich-Wyder M.-T.

Reaction of Streptococcus thermophilus to Stress

The effect of low pH on the survival of S. thermophilus in liquid cultures was studied. Results showed that the bacteria do not live more than a week at 37°C when grown in milk. Survival can be prolonged by growing them in diluted milk or preferably in M17 containing low concentrations of lactose. It would…

Bachmann H.-P., Thomet A., Schafroth K.

Innovatives processes for cheese-making

Milk was concentrated by microfiltration. From this concentrate fresh, soft and semihard cheeses can be produced very easily. These processes are also economically very attractive: less investments in plants and infrastructure, labour saving, high-grade by-products (unacidified permeate with native whey proteins) and the option for a continuous production. On the occasion of several practical demonstrations,…

Aebi R., Mühlemann M., Bühlmann G., Schällibaum M.

Risk assessment of L. monocytogenes in Swiss Emmental raw milk cheese

About 33% of the total Swiss agricultural earnings are from the milk production which is important to the Swiss agricultural industry. Our approach follows the origin and propagation of Listeria monocytogenes-contamination using data and expert-knowledge at all involved production levels and competence areas. The result is shown in a contamination profile along the food production…

Mühlemann M., Aebi R., Schällibaum M.

An introduction to risk analysis and microbiological risk assessment

In this article, the concepts of microbiological risk analysis are presented as well as risk assessment following the Codex Alimentarius guidelines. Special attention is given firstly to the so-called infectious disease triangle between host, microorganism and foodstuff and secondly to different approaches of risk assessment in practice. The dynamic process of controlling risks is visualised…

Isolini D., Fröhlich-Wyder M.-T.

Results of screening of lipolytic activity in propionibacteria extrapolated to Emmental cheese production

The lipolytic activity of six strains of propionibacteria were differentiated in laboratory, using a simple method based on the incubation of cells in milk fat and the subsequent determination of free fatty acids. The production of cheese with the analysed strains confirmed that the propionibacteria are essentially responsible for the lipolysis in Emmental cheese and…

Collomb M., Malke P., Spahni M., Sieber R., Bütikofer U.

Different lipolysis in winter cheese compared to summer

This study shows results on the content of individual free fatty acids in six different ripened winter and summer Swiss cheeses. The sum of the content of free fatty acids formed by lipolysis was always higher in winter cheeses than in summer ones, the one in Emmental being 4 to 5 times higher than in…

Eberhard P., Bütikofer U., Sieber R.

Vitamins in stored high heated milk

Whole milk was pasteurised with a direct method at 125 °C and an indirect method at 115 °C. Immediately after heating and storage at 5 °C during 1 and 4 weeks, the vitamins B1, B6, B12 as well as folic acid were examined. No losses due to storage (storage losses) were detected with Vitamin B12…

Thomet A., Sieber R., Gugolz R., Gantenbein-Demarchi C.

Efficient conservation of microorganisms by flow bed-drying

The process of flow bed drying has been used for the conservation of several different products for some time. Preliminary experiments for the conservation of lactic acid bacteria gave positive results. Commercial use of the flow bed-drying technology for the conservation and confectioning of microorganisms used in fermentation processes seems to be realisable, however, further…

Collomb M., Eyer H., Sieber R.

Chemical structure and composition of fatty acids in milk fat

Milk fat contains approximately 400 different fatty acids. They can originate directly from the fat of the foodstuffs or the animal tissue, formed either by biohydrogenation in the rumen of the cow or synthesised in the mammary gland. At the present time, the official methods for the determination of fatty acid composition in milk fat…

Bachmann H.-P., Bobst C., Bütikofer U., DallaTorre M., Fröhlich-Wyder M.-T., Fürst M.

Development of a surface smear starter culture

The FAM has developed two new surface mixed-cultures for smear ripened cheeses. These cultures have proven to be successful in practice and can now be ordered from the FAM. Research work carried out with the objective of combating sticky smear yielded numerous data on its formation. These results were used by the FAM to develop…

Eyer H., Collomb M., Sieber R.

Precious milk fat from the high lands

High land milk fat produced on swiss alps during summer months contains significantly higher amounts of unsaturated fatty acids than common summer milk fat. Also conjugated cis/trans linoleic acids and ?-3 fatty acids contents are markedly higher. This result obtained in a single alp study a few years ago could be confirmed in a follow-up…

Sieber R., Eyer H.

Milk and dairy products – from birth to death

Depending on age, human beings have different needs for nutrients which can be supplied only through a varied diet. Milk and dairy products play a very important part in the human diet thanks to their composition in different nutritive elements. Among the most important elements are the proteins, linoleic acids, short chain fatty acids, sphingolipids…

Bogdanov S., Blumer P.

Natural antibiotic properties of honey

In honey there are different natural antibacterial substances, or so called inhibines. One of them, hydrogen peroxide, was thought to be the most important one. However, our studies show, that there are different non-peroxide antibacterial substances. Contrary to the peroxide inhibines, they are not sensitive towards heat , light and storage. The antibacterial effect of…

Bachmann H.-P., Bobst C., Bütikofer U., Casey M.G., Dalla Torre M., Fürst M., Wyder M.Th.

Cultures for reducing the stickiness of smeared cheese surfaces

“Numerous traditional Swiss cheese varieties are smear-ripened e.g. Gruyère, Raclette, Appenzeller and Tilsiter. The smear is a very complex ecosystem composed of moulds, yeasts and bacteria. It contributes to the typical flavour of these cheese varieties. In recent years, the occurence of a defect, the so-called stickiness of the smear, has increased. The smear became…