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Among the Moscato grapes, Moscato Giallo is a winegrape variety characterised by a high content of free and glycosylated monoterpenoids, which gives wines very intense notes of ripe fruit and flowers. The aromatic bouquet of Moscato Giallo is strongly influenced by the high concentration of linalool, geraniol, linalool oxides, limonene, α-terpineol, citronellol, hotrienol, diendiols, trans/cis-8-hydroxy linalool, geranic acid and myrcene, that give citrus, rose, and peach notes. Except for quali-quantitative analysis, no investigations regarding the isotopic values of the target volatile compounds in grapes and wines are documented in the literature. Nevertheless, the analysis of the stable isotope ratio represents a modern and powerful tool used by the laboratories responsible for official consumer protection, for food quality and genuineness assessment. To this aim, the aromatic compounds extracted from grapes and wine were analysed both by GC-MS/MS, to define the aroma profiles, and by GC-C/Py-IRMS, for a preliminary isotope compound-specific investigation. Seventeen samples of Moscato Giallo grapes were collected during the harvest season in 2021 from two Italian regions renowned for the cultivation of this aromatic variety, Trentino Alto Adige and Veneto, and the corresponding wines were produced at micro-winery scale. The GC-MS/MS analysis confirmed the presence of the typical terpenoids both in glycosylated and free forms, responsible for the characteristic aroma of the Moscato Giallo variety, while the compound-specific isotope ratio analysis allowed us to determine the carbon (δ13C) and hydrogen (δ2H) isotopic signatures of the major volatile compounds for the first time. [ABSTRACT FROM AUTHOR]

Rationale: Typical storage in oak barrels releases in distillates different degradation products such as vanillin, which play an important role in flavour and aroma. The addition of vanillin, as well as other aroma compounds, of different origin is prohibited by European laws. As vanillin samples from different sources have different δ13C values, the δ13C value could be used to determine whether the vanillin is authentic (lignin‐derived), or if it has been added from another source (e.g. synthetic). Methods: The δ13C values for vanillin derived from different sources, including natural, synthetic and tannins, were measured by gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS), after diethyl ether addition and/or ethanol dilution. A method for analysing vanillin in distillates after dichloromethane extraction was developed. Tests were undertaken to prove the reliability, reproducibility and accuracy of the method with standards and samples. Distillate samples were run to measure the δ13C values of vanillin and to compare them with values for other sources of vanillin. Results: δ13C values were determined for: natural vanillin extracts (−21.0 to −19.3‰, 16 samples); vanillin ex‐lignin (−28.2‰, 1 sample); and synthetic vanillin (−32.6 to −29.3‰, 7 samples). Seventeen tannin samples were found to have δ13C values of −29.5 to −26.7‰, which were significantly different (p < 0.05) from those of the natural and synthetic vanillins. The vanillin δ13C values measured in distillates (−28.9 to −25.7‰) were mainly in the tannin range, although one spirit (−32.5‰) was found to contain synthetic vanillin. Conclusions: The results show that synthetic vanillin added to a distillate could be differentiated from vanillin derived from oak barrels by their respective δ13C values. The GC/C/IRMS method could be a useful tool in the determination of adulteration of distillates. [ABSTRACT FROM AUTHOR]

Only scarce information is available on how organic C is incorporated into the soil during the decay and how (micro) climate influences this process. Therefore, we investigated the effect of exposure and elevation on the organic litter decomposition and C-stabilisation in acidic soils of an Alpine environment. An experiment with artificially C labelled Norway spruce needles was carried out at north- and south-exposed sites between 1200 and 2400 m a.s.l. in the Italian Alps using mesocosms. After 1 year, the C recoveries of the bulk soil were 18.6% at the north-facing slopes and 31.5% at the south-facing slopes. A density fractionation into a light (LF; ≤1.6 g cm) and a heavy fraction (HF; >1.6 g cm) of the soil helped to identify how the applied substrate was stabilised. At the northern slope, 10.5% of the substrate was recovered in the LF and 8.1% in the HF and at the south-facing slope 22.8% in the LF and 8.1% in the HF. The overall C recovery was higher at the south-facing sites due to restricted water availability. Although the climate is humid in the whole area, soil moisture availability becomes more important at south-facing sites due to higher evapotranspiration. However, at sites >1700 m a.s.l, the situation changed, as the northern slope had higher recovery rates. At such altitudes, temperature effects are more dominant. This highlights the importance of locally strongly varying edaphic factors when investigating the carbon cycle. [ABSTRACT FROM AUTHOR]

The feasibility of using δ15N as an additional isotopic marker able to link wine to its area of origin was investigated. The whole production chain (soil-leaves-grape-wine) was considered. Moreover, the research included evaluation of the effect of the fermentation process, the use of different types of yeast and white and red vinification, the addition of nitrogen adjuvants and ultrasound lysis simulating wine ageing. The δ15N of grapes and wine was measured in bulk samples and compounds, specifically in proline, for the first time. Despite isotopic fractionation from soil to wine, the δ15N values of leaves, grapes, wine and particularly must and wine proline conserved the variability of δ15N in the growing soil. Fermentation and ultrasound treatment did not affect the δ15N values of grape must, which was therefore conserved in wine. The addition of inorganic or organic adjuvants was able to influence the δ15N of bulk wine, depending on the amount and the difference between the δ15N of must and that of the adjuvant. The δ15N of wine proline was not influenced by adjuvant addition and is therefore the best marker for tracing the geographical origin of wine. [ABSTRACT FROM AUTHOR]

RATIONALE The essential oil of Rosa damascena Mill. is known for its fine perfumery application, use in cosmetic preparations and for several pharmacological activities. Due to its high value, it can be easily adulterated with flavors or cheaper oils. This study is aimed at a detailed phytochemical characterization of commercial samples of R. damascena essential oil and at their authenticity assessment. METHODS Nineteen commercial samples of R. damascena essential oil of different geographic origin and an additional authentic one, directly extracted by hydro-distillation from fresh flowers, were considered. GC/MS and GC/FID techniques were applied for the phytochemical analysis of the samples. EA/IRMS (Elemental Analyzer/Isotope Ratio Mass Spectrometry) and GC/C (Combustion)/IRMS were used to determine the δ13C composition of bulk samples and of some specific components. RESULTS Citronellol (28.7-55.3%), geraniol (13.5-27.3%) and nonadecane (2.6-18.9%) were the main constituents of Bulgarian and Turkish essential oils, while those from Iran were characterized by a high level of aliphatic hydrocarbons (nonadecane: 3.7-23.2%). The δ13C values of bulk samples were between −28.1 and −26.9‰, typical for C3 plants. The δ13C values of specific components were in the usual range for natural aromatic substances from C3 plants, except for geranyl acetate, which displayed higher values (up to −18‰). These unusual δ13C values were explained by the addition of a natural cheaper oil from a C4 plant ( Cymbopogon martinii, palmarosa), which was found to occur in most of the essential oils. CONCLUSION GC/C/IRMS, in combination with GC/MS and GC/FID, can be considered as an effective and reliable tool for the authenticity control of R. damascena essential oil. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Bacteria can play different roles affecting flavors and food characteristics. Few studies have described the bacterial microbiota of butter. In the present paper, next-generation sequencing was used to determine bacterial diversity, together with aromatic characteristics, in raw cow milk butter processed by traditional fermentation, in fourteen small farms called "Malga", located in the Trentino province (Alpine region, North-East of Italy). The physicochemical and aromatic characterization of traditional mountain butter (TMB) showed a low moisture level depending on the Malga producing the butter. Counts of lactic acid bacteria, Staphylococci, and coliforms, as well as diacetyl/acetoin concentrations exhibited changes according to the geographical origin of Malga and the residual humidity of butter. MiSeq Illumina data analysis revealed that the relative abundance of Lactococcus was higher in TMB samples with the highest values of acetoin (acetoin higher than 10 mg/kg). The traditional mountain butter bacterial community was characterized by a "core dominance" of psychrotrophic genera, mainly Acinetobacter and Pseudomonas, but according to ANCOM analysis, a complex bacterial population emerged and specific bacterial genera were able to characterize the TMB bacteria community, with their high abundance, based on the Malga producing the butter. [ABSTRACT FROM AUTHOR]

Rationale: Typical storage in oak barrels releases in distillates different degradation products such as vanillin, which play an important role in flavour and aroma. The addition of vanillin, as well as other aroma compounds, of different origin is prohibited by European laws. As vanillin samples from different sources have different δ 13 C values, the δ 13 C value could be used to determine whether the vanillin is authentic (lignin-derived), or if it has been added from another source (e.g. synthetic)., Methods: The δ 13 C values for vanillin derived from different sources, including natural, synthetic and tannins, were measured by gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS), after diethyl ether addition and/or ethanol dilution. A method for analysing vanillin in distillates after dichloromethane extraction was developed. Tests were undertaken to prove the reliability, reproducibility and accuracy of the method with standards and samples. Distillate samples were run to measure the δ 13 C values of vanillin and to compare them with values for other sources of vanillin., Results: δ 13 C values were determined for: natural vanillin extracts (-21.0 to -19.3‰, 16 samples); vanillin ex-lignin (-28.2‰, 1 sample); and synthetic vanillin (-32.6 to -29.3‰, 7 samples). Seventeen tannin samples were found to have δ 13 C values of -29.5 to -26.7‰, which were significantly different (p < 0.05) from those of the natural and synthetic vanillins. The vanillin δ 13 C values measured in distillates (-28.9 to -25.7‰) were mainly in the tannin range, although one spirit (-32.5‰) was found to contain synthetic vanillin., Conclusions: The results show that synthetic vanillin added to a distillate could be differentiated from vanillin derived from oak barrels by their respective δ 13 C values. The GC/C/IRMS method could be a useful tool in the determination of adulteration of distillates., (Copyright © 2017 John Wiley & Sons, Ltd.)

The feasibility of using δ(15) N as an additional isotopic marker able to link wine to its area of origin was investigated. The whole production chain (soil-leaves-grape-wine) was considered. Moreover, the research included evaluation of the effect of the fermentation process, the use of different types of yeast and white and red vinification, the addition of nitrogen adjuvants and ultrasound lysis simulating wine ageing. The δ(15) N of grapes and wine was measured in bulk samples and compounds, specifically in proline, for the first time. Despite isotopic fractionation from soil to wine, the δ(15) N values of leaves, grapes, wine and particularly must and wine proline conserved the variability of δ(15) N in the growing soil. Fermentation and ultrasound treatment did not affect the δ(15) N values of grape must, which was therefore conserved in wine. The addition of inorganic or organic adjuvants was able to influence the δ(15) N of bulk wine, depending on the amount and the difference between the δ(15) N of must and that of the adjuvant. The δ(15) N of wine proline was not influenced by adjuvant addition and is therefore the best marker for tracing the geographical origin of wine. Copyright © 2016 John Wiley & Sons, Ltd., (Copyright © 2016 John Wiley & Sons, Ltd.)