Swiss-type cheese

Lactic acid-producing bacteria associated with fermented dairy products have been found to produce antibiotic-like compounds caUed bacteriocins. Concentrations of these natural antibiotics can be added to refrigerated foods in the form of an extract of the fermentation process to help prevent microbial spoilage. Other natural antibiotics are produced by Penicillium wqueforti the mold associated with Roquefort and blue cheese, and by Propionibacterium sp., which produce propionic acid and are associated with Swiss-type cheeses (3). 

Swiss-type cheeses are ripened at about 22°C for a period to encourage the growth of Propionibacterium spp. which use lactic acid as an energy... 

Mitchell, G. E. 1981. The production of selected compounds in a Swiss-type cheese and their contribution to cheese and flavor. Aust. J. Dairy Technol 36, 21-25. 

Fermentation of lactic acid to yield propionic acid, carbon dioxide, acetic acid, and succinic acid is important for proper eye formation and flavor development in Emmental, Gruyere, and Swiss-type cheese varieties. This fermentation is associated with Propionibacterium spp. subspecies of Propionibacterium freudenreichii are of greatest significance. These organisms can also be used for industrial production of vitamin Bi2 and propionic acid. 

Hirsch, A., Grinsted, E., Chapman, H. R. and Mattick, A. T. R. 1951. A note on the inhibition of an anaerobic sporeformer in Swiss-type cheese by a nisin-producing streptococcus. J. Dairy Res. 18 205-206. 

Pinheiro, A.J.R., Liska, B.J., Parmelee, C.E. 1965. Heat stability of lipases of selected psychro-philic bacteria in milk and Purdue Swiss-type cheese. J. Dairy Sci. 48, 983-984. 

In general, milk and dairy products (particularly Swiss-type cheeses), certain fruits (kiwi, oranges) and vegetables (broccoli, dried beans) as well as processed food such as chocolate exceed others such as meat, poultry or pasta in their relevance for optimal calcium nutrition (Tables 2.3-2 and 2.3-3). Since consumption of mineral water, which can contain relatively high amounts of calcium (Table 2.3-2), is increasing in industrialized countries, it becomes more and more important as a calcium source. 

Lactate serves as substrate for the production of propionic acid, acetic acid, and CO2 during the ripening of Swiss-type cheeses. 

The metabolism of lactose and lactate in Swiss-type cheeses was described comprehensively by Turner et al. (1983). Typically, Emmental cheese contains 1.7% lactose 30 min after moulding, which is rapidly metabolized by 5. thermophilus with the production of L-lactate. Only the glucose moiety of lactose is metabolized by S. thermophilus and consequently galactose accumulates to a maximum of —0.7% at —10 hr, when the lactobacilli begin to multiply. These metabolize galactose to a mixture of d- and L-lactate, which reach —0.35 and 1.2%, respectively, at 14 days, when the galactose is metabolized completely. 

Lipolysis is considered to be undesirable in most cheese varieties. Cheddar, Gouda, and Swiss-type cheeses containing even a moderate level of free fatty acids would be considered rancid however, certain cheese varieties are characterized by extensive lipolysis (e.g., Romano, Parmesan, and Blue cheeses). Bills and Day (1964) quantified FFA ( 2 0 to Cj8 3) in 14 Cheddar cheeses with wide variations in flavor but found only small differences, qualitatively or quantitatively, between cheeses of different flavor. The... 

As mentioned in Section IV El, the extent of proteolysis varies from very limited, e.g.. Mozzarella, to very extensive, e.g., blue-mould varieties. The use of PAGE showed that the proteolytic pattern, as well as its extent, exhibit marked intervarietal differences (Ledford et al., 1966 Marcos et al., 1979). The PAGE patterns of both the water-insoluble and water-soluble fractions are, in fact, quite characteristic of the variety, as shown in Figs. 11 and 12 for a number of Cheddar, Dutch, and Swiss-type cheeses. RP-HPLC of the water-soluble fraction or subfractions thereof also shows varietal characteristics (Fig. 13). Both the PAGE and HPLC patterns vary and become more complex as the cheese matures and are in fact very useful indices of cheese maturity and to a lesser extent of its quality (O Shea, 1993). Therefore, they have potential in the objective assessment of cheese quality. 

Consumer resistance to the use of synthetic additives in foods has stimulated interest in natural additives and preservatives. The principal natural additive used in cheese is the bacteriocin, nisin. Bacteriocins are peptides which inhibit a limited range of bacteria, usually closely related to the producer organism. The potential of nisin, produced by Lactococcus lactis, as a food preservative was first demonstrated using nisin-producing cultures in the manufacturer of Swiss-type cheese to prevent spoilage by Clostridia (Hirsch et ai, 1951). To date, nisin is the only purified bacteriocin commercially exploited as a food preservative. It can be added to processed cheese products to prevent late blowing by Clostridia, the spores of which, if present in the natural cheese, survive pasteurization (Barnby-Smith, 1992). 

Bican, P., and Spahni, A. (1993). Proteolysis in Swiss-type cheeses A high-performance liquid chromatography study. Int. Dairy J. 3, 73-84. 

Ollikainen, P., and Nyberg, K. (1988). A study of plasmin activity during ripening of Swiss-type cheese. Milchwissenschaft 43, 497-499. 

Starter cultures used in the production of dairy products comprise a great variety of lactic acid bacteria. Most common are species within the genera Lactococcus, Streptococcus, Lactobacillus and Leuconostoc. Non-lactic acid bacteria of the genera Bifidobacterium and Propionibacterium are commonly used in Swiss-type cheeses and so-called health cultures . 

The growth, acid production and lactate utilization by propionibacteria (especially P. freudenreichii and P. shermanii) are inhibited by long-chain fatty acids (10-100 mg/1 each) lauric (C o), myristic (C o), oleic (Cis i) and linoleic (Ci8 2) acids (Boyaval et al, 1995), present in milk lipids. However, the inhibitory effects of these acids were only observed in lactate-yeast extract medium (YEL), but not in milk or curd. The work was undertaken in connection with the often poor eyes formation in Swiss-type cheese. 

The classical manufacturing process of the Swiss-type cheese did not rely on special introduction of propionibacteria (as the starter), but sufficient numbers of propionic acid bacteria were present naturally in raw milk and rennet extract. At present, pasteurized milk is used in cheese making, and during heating at 71 C for 15 s most of the propionibacteria are killed (Alekseeva et al, 1983). A standard requirement for the content of propionibacteria is 2T0 -4T0 per g Soviet cheese, that is why it is necessary to add propionic acid bacteria with high acid-, gas- and lipolytic... 

Under normal processing conditions, the vitamin content in milk does not change too much. The loss caused by pasteurisation is up to 10% and about 10-20% in UHT milk. In the manufacture of hard cheeses, the vitamin retention is about 60-90% of the original content. Dairy products fermented using Propionibaaerium sher-manii (such as Swiss-type cheeses), have increased vitamin content in comparison with the original milk (up to 30 times). 

P. freudenreichii subsp. freudenreichii Used in Swiss-type cheese... 

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