Strains of molds Aspergillus niger, A. ochraceus, A. oryzae, A. parasiticus, Penicillium chrysogenum, P. citrinum, P. funiculosum, P. raistrickii, P. viridicatum, Alternaria, Cephalosporium, and Fusarium sp. were grown on sterile coarse wheat meal at 26 to 28 C for 120 h. The volatiles from mature cultures were distilled at low temperature under reduced pressure. The distillates from traps-40 and-78 C were extracted with methylene chloride and subsequently concentrated. All the concentrates thus obtained were analyzed by gas-liquid chromatography, mass spectrometry, chemical reactions of functional groups, and olfactory evaluation. Six components detected in the culture distillates were identified positively: 3-methylbutanol, 3-octanone, 3-octanol, 1-octen-3-ol, 1octanol, and 2-octen-1-ol. They represented 67 to 97% of all the volatiles occurring in the concentrated distillate. The following 14 components were identified tentatively: octane, isobutyl alcohol, butyl alcohol, butyl acetate, amyl acetate, octyl acetate, pyridine, hexanol, nonanone, dimethylpyrazine, tetramethylpyrazine, benzaldehyde, propylbenzene, and phenethyl alcohol. Among the volatiles produced by molds, 1-octen-3-ol yielding a characteristic fungal odor was found predominant.

Strains of molds Aspergillus niger, A. ochraceus, A. oryzae, A. parasiticus, Penicillium chrysogenum, P. citrinum, P. funiculosum, P. raistrickii, P. viridicatum, Alternaria, Cephalosporium , and Fusarium sp. were grown on sterile coarse wheat meal at 26 to 28 C for 120 h. The volatiles from mature cultures were distilled at low temperature under reduced pressure. The distillates from traps -40 and -78 C were extracted with methylene chloride and subsequently concentrated. All the concentrates thus obtained were analyzed by gas-liquid chromatography, mass spectrometry, chemical reactions of functional groups, and olfactory evaluation. Six components detected in the culture distillates were identified positively: 3-methylbutanol, 3-octanone, 3-octanol, 1-octen-3-ol, 1-octanol, and 2-octen-1-ol. They represented 67 to 97% of all the volatiles occurring in the concentrated distillate. The following 14 components were identified tentatively: octane, isobutyl alcohol, butyl alcohol, butyl acetate, amyl acetate, octyl acetate, pyridine, hexanol, nonanone, dimethylpyrazine, tetramethylpyrazine, benzaldehyde, propylbenzene, and phenethyl alcohol. Among the volatiles produced by molds, 1-octen-3-ol yielding a characteristic fungal odor was found predominant.

A culture of Aspergillus flavus grown on moistened wheat meal was homogenized with a blendor, and the resulting slurry was vacuum-distilled at 5 mm of Hg and 35 C. The aqueous distillate was collected in traps cooled to -10 to -80 C. The culture volatiles were extracted from the distillate with CH 2 Cl 2 , and, after removal of the bulk of the solvent, the concentrated volatiles were examined by packed-column gas chromatography. Nineteen peaks were observed, and coupled gas chromatography-mass spectrometry was employed to identify the larger components. The compounds identified were: 3-methyl-butanol, 3-octanone, 3-octanol, 1-octen-3-ol, 1-octanol, and cis -2-octen-1-ol. The two octenols were the predominant compounds, and sufficient sample was trapped from the gas chromatograph for infrared analyses; this confirmed the mass spectral identifications and permitted the assignment of the cis designation to 2-octen-1-ol. Both oct-1-en-3-ol and cis -2-octen-1-ol are thought to be responsible for the characteristic musty-fungal odor of certain fungi; the latter compound may be a useful chemical index of fungal growth.

Literature indicates a broad contribution of microorganisms to the odours occurring in foods, Own research on volatile odour compounds produced by moulds, bacteria and yeasts growing on cereal grains hase been concentrated to I-octen-3-01, especially, which was found to be produced in great amounts by certain moulds as well as by mushrooms both growing wild and cultivated. In the bacteria strains studied about 50 volatile compounds have been identified. In most of the bacterial cultures developed on cereal grain acetoin was the predominant substance.Practical applications are proposed and discussed. On one side a flavour concentrate may be produced from mould cultures yielding fungal odour. Otherwise the main microbial metabolites could be used as indices of the growth rate of individual groups of the microflora on cereal grains and other foodstuffs.Strains capable of producing odour substances have been detected in all classes of microorganisms. As a matter of fact certain microorganisms produce the base for various foods while others have been p r w d 10 be the source of off-flavours. The contribution of microflora to the development of odour and taste of such foods as baked products, fermented beverages, dairy products, pickles, oriental foods has been reviewed by MAR-GALITH et al. [26]. As early as in 1923 OMELIANSKI gave a review of aroma-producing microorganisms. The author described the microorganisms producing a series of odours from sweetish resembling limetree flower. produced by Pseudomonus pyocyanea to acrid yielded by the cultures of Bucilfusfitzianus [33]. As stated by MANN [25] Pseudomonus ueroginose produces 2-aminoacetophenone yielding a grape-like or sweety-aromatic odour. Scientists from the University of Connecticut [3,4, 14-161 studied the applicability of fungi as agents for the production of new flavour compounds. They proved the fungus Cerutocysiis variusporu to be capable of producing a series of monoterpenes including linalool, neral, geranial, citronellol and geraniol [3]. The fungus Trumetes odorutu was stated to produce not only monoterpenes but also considerable amounts of methyl-p-methoxyphenyl-acetate yielding a pleasant anise-like odour [ 141. As stated by COLLINS et al. [4] Trichodermu viride can produce 6-pentyl-2-pyrone yielding a coconut-like aroma. According to HALM et al.[16] Penicillium decumbens cultures yield a distinctive odour suggestive of soap perfume, the main odour compounds being thujopsene, 3-octanone, nerolidol, I-octen-3-01 and phenylethyl alcohol. As shown by HALIM et al. [15] the fungus Myouciu udu produces a pleasant fruity aroma. The compounds contributing to the latter aroma were p-tolualdehyde yielding an almond-like odour, p-methylacetophenone giving a sweet fruity odour and 2-4-methykyclo-hex-3-ene ethyl alcohol -a distinctive fruity odour.In Japan TAHARA et al. [41,42] carried out a study on the volatile compounds produced by the yeast Sporobolomyces odorus. The identified compounds included alcohols, esters, carbonyls and the following lactones: y-dec...