ENANTIOMERIC DISTRIBUTION AND C-13/C-12 ISOTOPE RATIO DETERMINATION OF GAMMA-LACTONES - APPROPRIATE METHODS FOR THE DIFFERENTIATION BETWEEN NATURAL AND NONNATURAL FLAVORS

The quantitative and enantiomeric distribution of gamma-lactones in certain fruits (strawberry, raspberry, pineapple, passion fruit, plum and coconut) compared with corresponding fruit concentrates and beverages was determined by multi-dimensional gas chromatography-mass spectrometry with an achiral-chiral column combination. It was found that significant variations in enantiomeric excess values of gamma-lactones due to varieties and processing influences can occur. On-line multi-dimensional gas chromatographic-isotope ratio mass spectrometric C-13/C-12 isotope ratio measurements of gamma-decalactone in vinous beverages and references (synthetic and microbial) were performed, in order to establish how far enantiomeric data in combination with additional delta-C-13 values can serve as a basis for the validation of the genuineness of flavours and flavoured products.