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Several nut oil varieties mainly used as culinary and overall healthy food ingredients were subject of the present study. Headspace solid-phase microextraction combined with gas chromatography-mass spectrometry was employed in order to determine the qualitative composition of volatile compounds. Furthermore, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry was used in order to assess the profiles and relative composition of the prevalent triacylglycerols (TAG) within the oils. The headspace of the majority of oil samples was dominated by high contents of acetic acid (up to 42%) and hexanal (up to 32%). As nut oils are typically gained by cold-pressing from previously roasted nuts, characteristic pyrazine derivatives as well as degradation products of long-chain fatty acids were detected. TAG analysis of these oils revealed a quite homogeneous composition dominated by components of the C 52 and C 54 group composed mainly of oleic (18:1), linoleic (18:2), stearic (18:0) and palmitic (16:0) acid residues representing together between 65 and 95% of the investigated nut oils. The TAG profiles showed characteristic patterns which can be used as 'fingerprints' of the genuine oils. Nut oils exhibiting quite similar fatty acid composition (e.g. hazelnut, pistachio and beech oil) could be clearly discriminated based on TAG showing significant differences between the oils.

In this study the antimicrobial activities of five volatiles, which represent main compounds of several essential oils, were tested. Terpineol, (R)-(–)-linalool, carvacrol, (S)-(–)-perillaldehyde and 1,8-cineole were evaluated for their influence on airborne microbes when vaporized with a room diffuser. In the present investigation terpineol and (S)-(–)-perillaldehyde showed the highest antimicrobial activities. The average reduction of the germ count was 59.4% and 42.3%, respectively, after 5 h of spreading in a testing room. Carvacrol (average germ reduction 37.5%) and (R)-(–)-linalool (29.7%) showed lower results. For 1,8-cineole only, no unambiguous antimicrobial effect was detectable. It has to be considered that the amounts of vapour spread during 5 h of testing time were different, depending on the volatility of the scent used. Nevertheless, four of the investigated volatiles showed satisfying antimicrobial action against airborne microbes. Copyright © 2008 John Wiley & Sons, Ltd.

Some typical original Indian edible and non-edible fatty plant oils were subject of our investigations. Fundamental research was done on analyzing volatile compounds using HS-SPME-GC-MS. In addition, a sensorial evaluation was applied to receive data on the smell of the samples. Furthermore, the typical and prevailing triacylglycerols (TAG) were investigated by MALDI-TOF-MS. Mass spectra reflect the TAG profiles of the whole oil samples based on the detection of [M+Na] + ions. Oil samples exhibit quite unique TAG profiles, which are suitable for rapid characterization of the original plant oils. The fatty acid composition of the corresponding TAG structures was calculated using lipid analysis software based on the known fatty acid composition. Relative quantification of TAG components was in good agreement with the literature, in case appropriate data are available so far.

Shea butter is used as an edible vegetable fat in many African countries. It can be utilized as a substitute or complete replacement for cocoa butter in various applications and plays an important role in traditional African medicinal practice. Although detection of volatile compounds by solid-phase micro-extraction gas-chromatography mass-spectroscopy (SPME-GC-MS) is a very reliable and reproducible technique, which can be used as an important part of authenticity checking, production monitoring and contamination detection, no published data about volatile compounds of shea butter are available so far. In this investigation, the characteristic volatiles in the headspace of original African shea butter samples were identified by using SPME-capillary-GC coupled to a mass selective detector. Almost 100 different volatile components were identified, e.g. fatty acids, saturated and unsaturated aldehydes and ketones, terpenes, and typical Maillard reaction products such as methylfuranes and pyrazines. Furthermore, the samples have been olfactorily evaluated by a panel of professional flavorists and trained analytical chemists. It can be stated that variations in processing conditions of shea butter result in considerable differences in the composition of headspace volatiles, detected by SPME-GC-MS and human olfaction.

Linseed (Linum usitatissimum, L.) and camelina (Camelina sativa, L.) are ancient crops containing seed oils with a high potential for nutritional, medicinal, pharmaceutical and technical applications. In the present study, linseed and camelina oils of plant varieties grown under Central European climate conditions were examined with respect to their volatile and triacylglycerol (TAG) components. Solid-phase microextraction was applied to the study of volatile compounds of several linseed and camelina oils, which have not been described prior to this publication. Hexanol (6.5-20.3% related to the total level of volatiles), trans-2-butenal (1.3-5.0%) and acetic acid (3.6-3.8%) could be identified as the main volatile compounds in the linseed oil samples. Trans-2-butenal (9.8%) and acetic acid (9.3%), accompanied by trans,trans-3,5-octadiene-2-one (3.8%) and trans,trans-2,4-heptadienal (3.6%), dominated the headspace of the examined camelina oil samples. TAG were analysed by MALDI-RTOF-MS and ESI-IT-MS, providing information about the total TAG composition of the oils as well as the fatty acid composition of the individual components. More than 20 TAG could be identified directly from whole linseed oil samples, mainly composed of linolenic (18:3), linoleic (18:2) and oleic (18:1) acid, and to a lesser degree of stearic (18:0) and palmitic (16:0) acid. While in linseed these TAG comprise more than 60% of the oils, Camelina sativa exhibited a wider range of more than 50 constituents, with a considerable amount (>35%) of TAG containing gadoleic (20:1) and eicosadienoic (20:2) acid.

Four aroma chemicals, thymol, eugenol, trans-cinnamaldehyde and linalool, were tested for their influence on total microbial count (bacteria, yeasts and moulds) in air. After determining both the total microbial count (TC) and the total count of yeasts and moulds (YM) of airborne microbes in a selected testing room, using a RCS Air Sampler, each of the aroma chemicals was vapourized in four different concentrations, 5, 2.5, 1.5 and 0.5 mg/m3. After a residence time of 15 min, the germ count in the testing room was measured again, using the air sampler. Each tested substance in any concentration showed a reduction of total microbial count as well as a reduction of total count of yeasts and moulds in the air and thus contributes to abating infection hazard for humans. The most effective concentrations for each substance were as follows. For total microbial count reduction: thymol, 1.5 mg/m3 (69.50% reduction); eugenol, 1.5 mg/m3 (69.40% reduction); trans-cinnamaldehyde, 1.5 mg/m3 (65.93% reduction); and linalool, 2.5 mg/m3 (69.92% reduction). For total count reduction of yeasts and moulds: thymol, 0.5 mg/m3 (50.60%); eugenol, 1.5 mg/m3 (58.31%); trans-cinnamaldehyde, 2.5 mg/m3 (46.19%); and linalool, 1.5 mg/m3 (50.25%). Copyright © 2006 John Wiley & Sons, Ltd.

Five selected compounds, geraniol, (R)-(-)-linalool, terpineol, γ-terpinene and 1,8-cineole, were tested for their influence on airborne microbes when vaporized with an air washer. Terpineol and 1,8-cineole showed the highest antimicrobial activities. The average reduction of germ count was 68% and 64%, respectively. Although γ-terpinene gave the lowest result among the compounds investigated, the average reduction of germ count was still 40%. When water without volatile compounds was sprayed, the colony forming units increased. These results show the positive effect of selected aroma compounds on the reduction of microbes in the room.