Portal de Periódicos da CAPES

Scanning electron microscopic and texture studies on characteristic consistency of Nordic ropy sour milk

1990; Elsevier BV; Volume: 11; Issue: 3-4 Linguagem: Inglês

10.1016/0168-1605(90)90024-y

1879-3460

Takahiro Toba, Hajime Nakajima, Atsumi Tobitani, Susumu Adachi,

Protein Hydrolysis and Bioactive Peptides

The characteristic consistency of Nordic ropy sour milk was studied. Skin milk, reconstituted from non-fat dry milk, was fermented at 20°C for 24 h by addition of 5% (v/v) inoculum of slime-producing (ropy) strain of Lactococcus lactis ssp. cremoris SBT 0495, isolated from Finnish ropy sour milk 'viili' starter culture, and its non-ropy variant SBT 1275. Measurements of texture showed that milk gel prepared by the ropy strain exhibited remarkably increased adhesiveness as compared to that by the non-ropy variant. Milk gel prepared by the ropy strain also exhibited decreased syneresis (wheying-off) as compared to that by the non-ropy variant. Scanning electron micrographs of milk gel prepared by the ropy strain showed that slime was in the form of a network attaching the bacterial cells to the protein matrix. A thick network of slime attached the casein micelle clusters to each other to make casein conglomerates, which is likely to result in the characteristic consistency of 'viili'.