Some factors affecting the production of volatile sulfhydryl compounds in Cheddar cheese slurries

Abstract

Gas chromatographic headspace analysis was used to monitor the production of hydrogen sulfide, methanethiol, carbonyl sulfide, and dimethyl sulfide in Cheddar cheese slurries. The production patterns of the four compounds were similar to published production patterns of normally aged Cheddar cheese. The addition of reduced glutathione to the slurries did not significantly alter the oxidation-reduction potential of the system, but it did enhance hydrogen sulfide and methanethiol production, and, to a limited extent, the production of carbonyl sulfide and dimethyl sulfide. The effects of glutathione were reduced when azaserine was added to the slurry to inhibit-[gamma]-glutamyl transpeptidase. When cysteine was added to the slurries, it promoted the production of hydrogen sulfide and methanethiol to the same degree as glutathione. Milk heat treatment had a significant effect on hydrogen sulfide and methanethiol production. Slurries made from milk heated at 75 °C for 15 min failed to produce hydrogen sulfide. Neither cysteine nor glutathione could enhance hydrogen sulfide production in slurries prepared from high heat treatment milk. With the exception of the addition of glutathione, none of the treatments produced significant changes in carbonyl sulfide and dimethyl sulfide. The addition of methionine to the slurries did not significantly alter production of the volatile sulfhydryl compounds. Slurries that contained additional rennet showed only a slight increase in hydrogen sulfide production.