In this work the suitability of extracting volatiles with polar, non-polar and mixed polar SPME fibers is presented. Peach aroma constituents were devided in groups consisted of components representing immature (alcohols and aldehydes) and mature (lactones and terpens) peach aroma. The content of volatiles was calculated and expressed in equivalents of internal standard (1-octanol). The fibers which propose the maximal performance were PDMS, PDMS/CAR and PDMS/CAR/DVB.
COBISS.SI-ID: 1839611
The method of monitoring volatile compounds present in peaches was successfuly applied also to wine and its off-odours. Ethyl acetate is a typical organoleptic defect detectable by the smell of acid and glue. It was efficiently measured with the SPME method and a high correlation between ethyl acetate and volatile acidity (R2 0.955) was found. In cases where the correlation is not followed and the defect is perceived, the explaination could be found in the relative proportion of ethyl acetate compared to other volatile compounds. Where the wine is rich with other volatile compounds, the effect of ethyl acetate is decreased and less organoleptically detectable.
COBISS.SI-ID: 6978425
Peaches are worldwide consumed and are meant as one of the fruit of peak demand. Compared to apricots, the volatiles defining typical peach aroma are still poorly analytically characterized. For these purpose, specific fibers, which retain the main group of volatiles present in peaches were proposed. Besides, an artisan made glassware, which enables bigger sample loads, was presented. It offered a 3-times higher extraction of aromatic compounds, in average. Significant differences were also found when the same peach pulp was analyzed fresh or frozen (liquid nitrogen and freezer at -16°C). In fresh peaches, a higher amount of some alcohols and some important esters was noticed. Liquid nitrogen had a positive impact on hexanal and (E)-2-hexenal, whereas storage of samples in the freezer had a major impact on most other aldehydes, and also on limonene. The study revealed the importance of sample preparation and storage on the overall aromatic profile of peaches.
COBISS.SI-ID: FOODCHEM-D
The aromatic constituents of four peach cultivars were studied in order to fulfill two gaps perceived by scientific literature regarding: the discrimination of cultivars by the analysis of substances present in all peaches (two-year experiment) and to study the impact of added preservatives on the final aroma of cooked peaches. The cultivars' differences and the impact of preservatives were statistically evaluated. By applying the multiple group discriminant analysis it was possible to discriminate all 4 cultivars, even very similar, by two functions - function 1 (which accounts for 56.9% of the variance explained by the model) and function 2 (31.7%). The use of preservatives had also an important impact on the aromatic profile of peaches. The statistical analysis indicated that from 57 identified volatiles, 40 volatiles showed statistically significant difference regarding the way of preservation. The main negative impact had Na-benzoate compared to control or samples preserved with citric acid.
COBISS.SI-ID: PONE-D-12-
The aromatic profile of volatiles in fresh figs (FF), fresh figs frozen in liquid nitrogen (NF) and dried figs (DF) (dark variety Petrovača Crna) were characterised by HS–SPME followed by GC–MS. Figs were dried in a pilot plant cabinet dryer using different pre-treatments to preserve the dried fruit: sulphuring, immersion in a solution of citric acid and ascorbic acid (separately). The adaptability of a thin-layer drying model to whole figs was investigated. Fresh figs and fresh figs frozen in liquid nitrogen differed mainly in the amount of aldehydes. The highest abundance of volatile compounds in dried figs was found in figs pre-treated with sulphur dioxide and the control, compared to samples immersed in the acid solutions. Preservation was most successful for the group of terpenes and terpenic compound, quite good for some esters and ketones, whereas aldehydes were not affected by the pre-treatment used.
COBISS.SI-ID: IJFST-2011