title: Diacetyl, acetoin, and acetaldehyde production by mixed-species lactic starter cultures.
abstract: Citrate utilization and acetoin, diacetyl, acetaldehyde, and lactic acid production in milk at 21 C by five different mixed-strain starters, containing Streptococcus diacetilactis (D type), Leuconostoc (B type), and S. diacetilactis and Leuconostoc (BD type), were measured. BD and D cultures utilized citrate more rapidly and produced more diacetyl, acetoin, and acetaldehyde than B types. All cultures produced much more acetoin than diacetyl, with the BD and D cultures producing four to five times larger amounts of acetoin than the B cultures. Reduction of diacetyl and acetoin toward the end of the normal incubation period was characteristic of BD and D cultures, whereas a similar reduction of acetaldehyde was characteristic of BD and especially of B cultures. Continued incubation of B cultures beyond 17 h also resulted in reduction of diacetyl and acetoin. Addition of citrate to the milk retarded diacetyl and acetoin reduction. Mn(2+) had no effect on diacetyl production by a BD culture but increased citrate utilization and, as a consequence, caused greater diacetyl destruction in one of the B cultures.
mesh_terms: D000079:Acetaldehyde / Q000096:biosynthesis*; D000440:Butanols / Q000096:biosynthesis*; D002074:Butanones / Q000096:biosynthesis*; D002951:Citrates / Q000378:metabolism; D003470:Culture Media; D007773:Lactates / Q000096:biosynthesis*; D007934:Leuconostoc / Q000187:drug effects / Q000378:metabolism*; D008345:Manganese / Q000494:pharmacology; D013291:Streptococcus / Q000187:drug effects / Q000378:metabolism*; D013997:Time Factors
chemical_list: D000440:Butanols; D002074:Butanones; D002951:Citrates; D003470:Culture Media; D007773:Lactates; D008345:Manganese; D000079:Acetaldehyde