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Major Volatile Compounds (major + volatile_compound)
Selected AbstractsA comparison of the physicochemical, microbiological and aromatic composition of Traditional and Industrial Leben in TunisiaINTERNATIONAL JOURNAL OF DAIRY TECHNOLOGY, Issue 1 2010OLFA SAMET-BALI Traditional Tunisian Leben (TL) was produced according to the traditional method. Physicochemical and microbiological characteristics and major aromatic compounds were studied and compared to industrial Leben (IL) and experimental Leben (EL). The results show a decrease in lactose content and pH value and an increase in lactic acid during spontaneous fermentation. TL and EL were characterised by higher protein, lactose and ash contents but were less fatty and acidic than IL. Lactic acid bacteria (LAB) and yeasts present in TL were responsible for lactic acid fermentation and aroma development. The LAB and yeast counts in TL were higher than that in EL and IL. Dynamic headspace extraction procedure shows the existence of four major volatile compounds: acetaldehyde, ethanol, diacetyl and acetoin in TL, IL and EL. However, TL has the most important quantity of aroma. [source] Characterization of the Enterobacteriaceae isolated from an artisanal Italian ewe's cheese (Pecorino Abruzzese)JOURNAL OF APPLIED MICROBIOLOGY, Issue 2 2006C. Chaves-López Abstract Aims:, To evaluate some physiological characteristics of the Enterobacteriaceae isolated from Pecorino cheese. Methods and Results:, The production of organic acids, secondary volatile compounds, biogenic amines (BA) and the lipolytic and proteolytic activities of Citrobacter braakii, Enterobacter sakazakii, Escherichia coli, Kluyvera spp., Salmonella enterica ssp. arizonae and Serratia odorifera strains were determined in skim milk after 48 h of fermentation at 30°C. The proteolytic activity observed only in Ser. odorifera and Kluyvera spp. was confirmed by the peptide profiles of the pH 4·6-insoluble fraction using RP-HPLC; however, the lipase activity was evidenced in all the isolates of E. coli, Kluyvera spp. and Salm. enterica ssp. arizonae. During fermentation, all the strains utilized citric acid and produced significant quantities of putrescine followed by histamine, spermine and spermidine as well as acetic and lactic acid. Moreover, the major volatile compounds produced were ethanol, 2,3-butanedione, 3-hydroxy-2-butanone, 2-heptanone and acetone. Conclusions:, The Enterobacteriaceae of dairy origin possess many metabolic activities that could affect the sensory quality of the cheese in which they grow during ripening. Significance and Impact of the Study:, The important physiological characteristics possessed by Enterobacteriaceae confirm the complexity of the microbiota of Pecorino Abruzzese cheese, which influences the typical sensory properties of this product. [source] Effect of cutting and storage on sensory traits of cantaloupe melon cultivars with extended postharvest shelf lifeJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 7 2003Olusola Lamikanra Abstract Fresh cut cantaloupe melons (Cucumis melo L var reticulatus) from fruits with extended postharvest shelf life were analysed for changes in their volatile aroma compounds and polygalacturonase activity during storage. The total volatile aroma contents and the number of volatile compounds in fruits with extended shelf life were significantly less than those present in the traditional shelf life cultivar Mission. Esters were the major volatile compounds present in the fruits, and their concentrations decreased considerably with storage of the cut fruit for 24,h at 4,°C. Polygalacturonase activity was detected from measurements of the hydrolytic release of reducing groups after storage of the cut fruit for 3 days. Enzymatic activity decreased thereafter in all fruits. The results indicate a lack of correlation between the postharvest shelf life of whole cantaloupe and that of fresh cut fruit. © 2003 Society of Chemical Industry [source] Quantitative analysis of the volatile aroma components of pepino fruit by purge-and-trap and gas chromatographyJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 10 2002Francisco Ruiz-Beviá Abstract A system specifically designed for the analysis of volatile organic compounds in water, called the purge-and-trap sample concentrator, has been set up to quantify the volatile aroma constituents of fruits. The technique shows some advantages over other conventional and new methods. The quantification of the major volatile compounds (3-methyl-2-buten-1-ol, 3-methyl-3-buten-1-ol and their acetates) of different pepino fruit samples has been performed using the purge-and-trap method. Relationships between the volatile content and the characteristics of fruits have been established. © 2002 Society of Chemical Industry [source] | ||||||||||