Ropy milk

Hammer, B. W. and Hussong, R. V. 1931. Observations on the heat resistance of some ropy milk organisms. J. Dairy Sci. 14, 27-39. 

Macura, D. and Townsley, P. M. 1984. Scandinavian ropy milk—Identification and characterization of endogenous ropy lactic streptococci and their extracellular excretion. 

Fig. 2B. Decrease of lactose and increase of galactose during fermentation and storage. D = ropy milk E = acidophilus milk ...

Ropy and Slimy Milk. Ropy or slimy milk of bacterial origin becomes apparent only after milk has been stored and is therefore distinguishable from the stringy milk associated with mastitis (Harding and Pru-cha 1920). Ropiness may be evident only as a slightly abnormal viscosity, or it may be so pronounced that the affected milk can be drawn out in fine threads a yard long and in some instances may assume a gel-like consistency. Thickening may be confined to the top layer of the milk. 

Sullivan, J. J., Mou, L., Rood, J. I. and Jago, G. R. 1973. The enzymic degradation of bitter peptides by starter streptococci. Aust. J. Dairy Technol. 28, 20-26. Sundman, V. 1953. On the microbiology of Finnish ropy sour milk. 13th Int. Dairy Congr. 3, 1420-1427. 

Schellhaass, S. M., and Morris, H. A. (1985). Rheological and scanning electron microscopic examination of skim milk gels obtained by fermenting with ropy and non-ropy strains of lactic acid bacteria. Food Microstruct. 4, 279-287. 

Lactococcus lactis subsp. cremoris is a lactic acid bacterium commonly associated with some cheeses and buttermilk (Leroy De Vuyst, 2004). L. lactis subsp. cremoris (strain KVS20) isolated from a starter culture of Scandinavian ropy sour milk (viili), previously shown to elicit an inunune response in mice, produces a phosphopolysac-charide (molecular mass of 1.884 x 10 Da) comprising the sugars rhamnose, glucose and galactose. This polysaccharide was shown to induce IFN-1 and IL-la production... 

Kitazawa, H., Toba, T., Itoh, T., Kumano, N., Adachi, S., Yamaguchi, T. (1991). Antitumoral activity of shme-foiming, encapsulated Lactococcus lactis subsp. cremoris isolated from Scandinavian ropy sour milk. Animal Science and Technology, 62, 277-283. 

Nakajima, H., Suzuki, Y, Hirota, T. (1992). Cholesterol lowering activity of ropy fermented milk. Journal of Food Science, 57(6), 1327-1329. 

Exocellular polysaccharides are of interest to the milk industry and for indnstrial and medical applications, bnt mnch less so in enology. They give rise to ropiness and the graisse disease, studied by Pasteur. A lot less rare than tourne and amertume, this spoilage has incited new research. 

Laws, A., Marshall, V. M. (2001). The relevance of exopolysaccharides to the rheological properties in milk fermented with ropy strains of lactic acid bacteria. International... 

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