The rise in volumes and prices of grapes and wine has encouraged fraud and adulteration in the oenological field. One of the most common forms of adulteration, is the addition of sugar to grape must using cane, beet sugar, or syrups coming from vegetable sources like cereals or fruits. The OIV (International Organisation of Vine and Wine) has issued specific official isotopic methods to determine sugar adulteration, but they are not always effective. In this study by Italian researchers, they compared the δ13C value of sugars extracted from grape must analysed by EA-IRMS (elemental analysis - IRMS) with the δ13C value of proline analysed by GC-c-IRMS, after extraction and derivatization. δ13C and δ15N of proline have also been used as potential geographical markers. Also, the δ13C values of two characteristic grapes must sugars (myo and scyllo – inositol) was measured by GC-c-IRMS after derivatization. The results indicated that the compound specific isotope analysis represents a novel analytical tool to support and improve certification and control procedures of wine making.
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