STUDY OF BIOLOGICALLY FRACTIONATED STABLE OXYGEN ISOTOPES 18O AND 16O IN POMEGRANATE FRUITS FROM THE CASPIAN REGION
The IRMS/SIRA technique with isotopic equilibration method for measuring of 18O/16O isotope ratios was first applied for the analysis of superfruits with health benefits pomegranate fruits from Azerbaijan (the Caspian region). Authentic fruit samples were selected from the crop of 2011 at the processing plant Aznar (Goychay/Göyçay area) from a total amount of 4880 t of processed fruits of seven cultivars. The oxygen isotopes were measured in an aqueous phase of fresh juices, which were expressed under laboratory conditions from fresh ripe pomegranate fruits. The method applied revealed high sensitivity towards juice origin and quality. Oxygen isotope ratios expressed as δ18О in analyzed fresh ripe pomegranates from Azerbaijan vary from -4.50 to -0.43‰. Soluble solids of fresh pressed juices vary from 14.40 to 20.00°Brix, weight of fruits from 87 to 560 g, seeds weight from 47 to 302 g, and fruits size from 59 to 110 mm. To evaluate the extent of biological fractionation the 18O/16O ratio were measured in ground water from this area. Compared to ground water (δ18О=-9.69 -8.93‰), the intracellular water of fruits is found to be enriched with 18О isotope. These results are of practical importance for determination of origin, quality, and detection of adulteration of commercial products from pomegranates (e.g., adulterated juice extended with water; added flavorings). Thus, the results of the study can be used as additional criterion in the International Multidimensional Authenticity Specification Algorithm for Detection of Commercial Pomegranate Juice Adulteration (IMAS) and Code of Practice AIJN for the evaluation of pomegranate juices represented on national and international juice markets.
Kolesnov, A., Filippova, R., Filatova, I., Zadorozhnyaya, D. and Maloshitskaya, O. 2014. STUDY OF BIOLOGICALLY FRACTIONATED STABLE OXYGEN ISOTOPES 18O AND 16O IN POMEGRANATE FRUITS FROM THE CASPIAN REGION. Acta Hort. (ISHS) 1017:119-126
Punica granatum L., δ18О, IRMS/SIRA, mass spectrometry, isotopic equilibration, pomegranate direct juice, authenticity, detection of adulteration