abstract: kefir is fermented milk that has a unique flavor because of acetaldehyde, diacetyl, acetoin and ethanol. the aim of this study was to evaluate flavor and aroma compounds present in kefir. two types of starter (christian hansen and sacco) and three levels of temperatures (30, 33 and 35oc) were used for the preparation of kefir samples. the samples were analyzed for acetaldehyde, diacet...

A highly regio-, chemo-, diastereo- and enantioselective organocatalytic [4 + 1] annulation of 2-halo-1,3-dicarbonyl compounds with Morita-Baylis-Hillman adducts catalyzed by commercially available, low cost quinidine for the preparation of synthetically unique and medicinally multi-functionalized isoxazoline N-oxides with three stereogenic centers including adjacent quaternary and tertiary ste...

Patients suffering from pulmonary tuberculosis were investigated for the levels of isoniazid (INH) and its metabolites viz. acetyl-INH, mono and diacetyl hydrazines and ammonia. It was observed that 50% of the patients are slow inactivators of INH and almost all show an increase in circulating levels of NH3 at 6 hrs. Mono and diacetyl hydrazine levels in blood and urine were detectable in all t...

Reaction of meso-tetraphenylsecochlorin bisaldehyde with hydroxylamine results in the formation of the known meso-tetraphenyl-2-nitroporphyrin and the novel meso-tetraphenylimidazolophorphyrin. The products are the result of two diverging pathways of the presumed intermediate monooxime monoaldehyde that are unusual and surprising, but fully rationalized. The structures of both products were con...

The dissociation of diacetyl dilute in krypton has been studied in a shock tube using laser schlieren densitometry, LS, at 1200-1800 K and at two reaction pressures, 55±2 Torr and 120±3 Torr. The experimentally determined rate coefficients show falloff. An ab-initio/Master Equation/VRC-TST analysis was used to determine pressure dependent rate coefficient expressions that are in good agreement ...

Six microorganisms that produced acetoin or diacetyl or both from glucose were tested for the production of 2,3-butylene glycol from lactose. Bacillus polymyxa and Streptococcus faecalis gave positive results and were tested in unmodified wheys. Cottage cheese whey was unsatisfactory, but B. polymyxa produced large amounts of the glycol in sweet whey, about 60 mmol of glycol per 100 mmol of lac...

[61Cu]diacetyl-bis(N4-methylthiosemicarbazone) ([61Cu] ATSM) was prepared using in house-made diacetyl-bis(N4-methylthiosemicarbazone) (ATSM) ligand and [61Cu]CuCl2 produced via the natZn(p, x)61Cu (180 muA proton irradiation, 22 MeV, 3.2 h) and purified by a ion chromatography method. [61Cu]ATSM radiochemical purity was >98 %, as shown by HPLC and RTLC methods. [61Cu]ATSM was administered into...

Diacetyl long-chain 1(3)- and 2-acyl-sn-glycerols containing either [9,10-3H]oleic acid or [1-14C]palmitic acid were synthesized by partial hydrolysis of the corresponding labelled triacylglycerols and acetylation. They were obtained in a high degree of stereochemical purity by preparative h.p.l.c. on a column containing a diol bonded phase. Each compound was rapidly metabolized by adipocyte pr...