Production of methanethiol in milk fat-coated microcapsules containingBrevibacterium linensand methionine

Abstract

SummaryMilk fat-coated microcapsules containingBrevibacterium linensand methionine were used to produce methanethiol, one of the volatile sulphur compounds implicated in Cheddar cheese flavour. Production of methanethiol from methionine occurred aerobically and anaerobically, but the production was 3- to 4-fold greater aerobically with most of the methanethiol being oxidized to dimethyl disulphide. About 35% of the total methanethiol was absorbed by the milk fat capsules and about 65% detected in the headspace. Levels of methanethiol began to decline at 26 °C after 24 h in milk fat-coated microcapsules. However, low temperature, such as 4–12 °C, stabilized levels of methanethiol in microcapsules over an 8-d analysis period. Optimum pH and temperature for methanethiol production were 8 and 26 °C respectively. The antioxidants butylated hydroxytoluene, butylated hydroxyanisole and ascorbic acid had negligible effects on methanethiol production.

Biotechnological Methods to Accelerate Cheddar Cheese Ripening

“…High concentrations of 3-methylbutanal and 3-methylbutanol and a strong malty flavor were produced in cheeses treated with capsules containing a complete cell-free extract mixture (Braun and Olson, 1986a). Kim and Olson (1989) studied aerobic and anaerobic production of methanethiol by milkfat-coated microcapsules containing Brevibacterium linens and methionine. The production of methanethiol was three-to four-fold greater under aerobic conditions, with most of the methanethiol being oxidized to dimethyl disulfide.…”

Identification and characterization of a cystathionine β/γ-lyase from Lactococcus lactis ssp. cremoris MG1363

“…Sulfur compounds (particularly methanethiol and hydrogen sul¢de) are components of cheddar cheese £avor [6,8,9], and enzymes involved in the metabolism of sulfur containing amino acids may therefore have a major role in the formation of £avor compounds during cheese ripening [10,11]. Cystathionine lyase, which is involved in methionine biosynthesis [12], has been puri¢ed from a number of organisms, including Lactococcus lactis ssp.…”

Production of Sulfur Flavors by Ten Strains of Geotrichum candidum

“…The origin of many sulfur flavors in cheese is associated with the production of methanethiol (MTL) by bacterial cultures which are used in the preparation of cheese (20,23,30,43). Numerous bacteria, such as lactobacilli, lactococci (11), and Brevibacterium linens in particular (6,10,11,15), produce useful quantities of this compound.…”