Authenticity assessment

Enantiomeric purities of terpinen-4-ol are significantly different when Melaleuca and Eucalyptus oils are compared in view of authenticity assessment. The absolute configuration of terpinen-4-ol was determined by Ohloff and Uhde. ... 

Mosandl A, Juchelka D, Advances in the authenticity assessment of citrus oils. J Essent Oil Res 9 5—12, 1997. 

Mosandl A, Authenticity assessment A permanent challenge in food flavor and essential oil analysis, / Chromatogr Sci 42 440—449, 2004. 

On the authenticity assessment of the essential oil of Rosmarinus officinalis L., Pharmazie 1994. 

The odour threshold may be lower than the limit of analytical detection (e.g. sulphur compounds, pyrazines). In such cases authenticity assessment is definitely impossible. 

Trace compounds without any sensorial relevance (odour activity value much less than 1) should not be evaluated in the sense of authenticity assessment, as the fraudulent addition of a sensorially ineffective compound makes no sense. 

Certainly, most of the data given in Table 17.2 are not qualified as indicators in authenticity assessment of food flavour, owing to their low and non-characteristic enantiomeric distributions, which could be simulated easily by calculated blending of the (S)-enantiomer (from biotechnological origin) with the synthetic racemate. 

Unfortunately, enantiomeric purities and total percentages of a-pinene, ]3-pinene, limonene and a-terpineol from tea tree oils more or less overlap with those of Eucalyptus oils (Table 17.3). Only enantiomeric purities and total percentages of terpinen-4-ol and a-phellandrene are significantly different, when Melaleuca and Eucalyptus oils are compared with regard to authenticity assessment [45]. 

The highly precise measurement of isotope ratios has a long tradition in organic geochemistry. Nowadays, the elucidation of stable isotope distributions is highly desirable in view of fundamental studies in biochemistry, nutrition, drug research and also in the authenticity assessment of food ingredients. 

IRMS has become more and more important in food authenticity assessment, since cGC, coupled online via a suitable combustion/pyrolysis interface with IRMS has been realised. The substances eluted from the cGC column are converted into the corresponding gas (carbon dioxide, nitrogen, hydrogen and car-... 

A reliable authenticity assessment is concluded from the simultaneous consideration of multielement IRMS and enantioselective analysis. The differences of the stable isotope ratios of linalool and linalyl acetate are depicted as a three-dimensional plot of A values (d values of linalool minus d values of linalyl acetate for oxygen, hydrogen and carbon) (Fig. 17.15). This plot shows that the commercial samples S1-S5 are different from all the other samples investigated. Linalool and linalyl acetate of S1-S5 definitely are not genuine lavender oil compounds. 

All details about starting materials and central production features should be known, in order to define exactly the status natural of a flavouring substance. In principle, the burden of proof is the responsibility of the producer. If necessary, production documents should be disclosed, in order to get objective authenticity assessment by qualified and authorised experts. Constructive cooperation between food researchers, the food industry and authorities will be stimulating to quality assessment in the food industry and will enhance consumer confidence [83]. 

Bilke S, Mosandl A (2002) Authenticity assessment of lavender oil i ing GC-P-IRMS H/ H-ratios of linalool and linalyl acetate. Eur Food Res Technol 214 532... 

Kahle K, Preston C, Richling E, Heckel F, Schreier P (2005) On-line gas chromatography combustion/pyrolysis isotope ratio mass spectrometry (HRGC-C/P-lRMS) of major volatiles from pear fruit (Pyrus communis) and pear products. Food Chem 91 449 Tamura H, Appel M, Richling E, Schreier P (2005) Authenticity assessment of y- and 5-deca-lactone from Prunus fruits by gas chromatography combustion/pyrolysis isotope ratio mass spectrometry (GC-C/P-IRMS). J Agric Food Chem 53 5397... 

Schmidt H-L, Rossmann A, Werner RA (1998) Flavourings. Wiley-VCH, Weinheim Jung J, Sewenig S, Hener U, Mosandl A (2005) Comprehensive authenticity assessment of lavender oils using multielement/ multicomponent IRMS-analysis and enantioselective MDGC-MS. Eur Food Res Technol 220 232... 

The use of ICP-MS for elemental characterization in beverages has been covered by a recent review that emphasized the applications in the area of fingerprinting and authenticity assessment [48], The combination of (multi)elemental/ isotopic analyses with powerful multivariate statistical methods can provide a solution for the authentication of food and beverages [49] and there is an increasing awareness of the potential of ICP-MS in this respect. Foods originating from... 

Instead by solvent extraction [207], aroma compounds from aqueous media, e.g. fruit juices, can even be separated and enriched by techniques of solid phase micro extraction (SPME), preferably from the headspace [208] , corresponding devices can often be directly connected to GC systems. These techniques provide the complete spec-tmm of the individual compounds of an aroma. As it will normally not be possible and even not necessary to analyse all components of the complex mixture, the separation of its main compounds may demand a multi-dimensional (MD) gas chromatographic system [209[ as displayed in Fig. 6.14 [210[. Examples for the multi-ele-ment/multi-compound isotope analysis by such systems will be given later (6.2.2.4.4, [211[) they can even integrate the identification of the compounds by molecular mass spectrometry and a simultaneous determination of the enantiomer ratios of isomers [210, 211 [. The importance of enantiomer analysis as a tool for authenticity assessment is extensively treated in chapter 6.2.3. 

B.O. Agiular-Cisneros, M.G. Fopez, F. Richling, F. Heckel, P. Schreier (2002) Tequila authenticity assessment by headspace SPME-HRGC-IRMS analysis of C/ C and O/ O ratios of ethanol. J. Agric. Food Chem. 50, 7520-7523... 

J. Jung, S. Sewenig, U. Hener, A. Mosandl (2005) Comprehensive authenticity assessment of lavander oils using multielement/multicompound IRMS-analysis and enantioselective MDGC-MS. Eur. Food Res. Technol. 220, 232-237... 

C. Preston, E. Richling, K. Kahle, M. Kraus, W. Hummer, M. Appel, F. Heckel, P. Schreier (2005) Ester synthesis authenticity assessment by stable isotope analysis. In T. Hofmann, M. Rothe, P. Schieberle (eds.) State-of-the-Art in Flavour Chemistry and Biology. DFA, Garching, pp. 358-362... 

C. Ruff, K. Hor, B. Weckerle, T. Konig, P. Schreier (2002) Authenticity assessment of estragole and methyl eugenol by on-line gas chromatography-isotope ratio mass spectrometry. J Agric. Food Chem. 50, 1028-1031... 

A. Kaunzinger, D. Juchelka, A. Mosandl (1997) Progress in the authenticity assessment of Vanilla. 1. Initiation of authenticity profiles. J. Agric. Food Chem. 45, 1752-1757... 

S. Bilke, A. Mosandl (2002 b) Authenticity assessment of lavender oils using GC-P-IRMS H/ H isotope ratios of linalool and linalylacetate. Eur Eood Res Technol 214. 532-535... 

Consequently, high efficiency sample clean-up remains an essential condition to chirality evaluation and legally binding interpretation of authenticity assessment of flavourings [53]. 

Presently, online cGC-IRMS determination of 5 C and 5 H values of flavour compounds are established [107. 118-123] and, further on, 5 0 measurements using online cGC-IRMS procedures will be available. Finally, enantio-MDGC combined with multielement- and multicomponent IRMS methods will open the door to comprehensive authenticity assessment of natural flavour and fragrance compounds in the near future. 

---