The influence of the addition of two sugars (trehalose and sucrose) on the retention of volatiles responsible for the characteristic aroma in dehydrated apricot puree was studied. Aroma compounds of fresh and both freeze-dried and foam-mat-dried apricot puree were analysed by manual headspace solid-phase microextraction coupled with gas chromatography (GC-FID and GC-MS). The best retention of aroma compounds in dehydrated apricot puree was obtained when trehalose was added, regardless of the dehydration process used (freeze drying or foam-mat drying), although, generally, a much higher retention of flavour volatiles was obtained in freeze-dried purees. Principal Component Analysis and Cluster Analysis were applied to all the apricot purees studied to obtain a simplified view of the relationship among the aroma compounds in dehydrated apricot purees. This study gives further insights into the mechanisms that occur when trehalose is applied as an additive and will enable the development of new processes to maximize this effect and to produce superior dried products.

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To investigate the varietal aroma compound composition of monovarietal grape marc distillates made from six different varieties (Vitis vinifera L.) in the region of Istria (Croatia), 30 samples were subjected to GC/MS and GC/FID analysis. A total of 73 compounds were identified: 45 monoterpenes, 20 sesquiterpenes, 3 diterpenes, and 5 C(13)-norisoprenoids. The largest number and the highest concentration of monoterpenes were found in Muscat Blanc, followed by Rose Muscat of Porec (Muskat ruza porecki) distillates, which were both characterized as highly aromatic. Lower, but still significant monoterpenol content was determined in distillates made from Istrian Malvasia (Malvazija istarska) grape marc. Chardonnay, Cabernet Sauvignon, and Teran distillates exhibited poorer monoterpene profiles, while Teran distillates contained elevated sesquiterpene concentrations. It was concluded that investigated monovarietal grape marc distillates significantly differ in varietal aroma compound composition. Stepwise linear discriminant analysis provided efficient discrimination models, and extracted various monoterpenes, sesquiterpenes and C(13)-norisoprenoids as important differentiators of distillates according to varietal origin.

Solid-phase microextraction (SPME) was examined to investigate volatiles in tomatoes and tomato products. Aroma volatiles and differences in volatile composition of different varieties of fresh tomatoes and several commercial tomato products, such as tomato juice, tomato puree, tomato paste and canned diced tomatoes, were analysed by a manual headspace SPME technique coupled with gas chromatography (GC-FID and GC-MS). Fresh and processed tomato aroma was composed of terpenes and lactones, esters, carbonyls and alcohols, sulphur compounds, free acids and oxygencontaining heterocyclic compounds. In most samples of processed tomatoes, lower relative concentrations of volatiles than in fresh tomato samples were determined, but in some cases (especially in samples of tomato juice) higher concentrations were observed. The most important difference between fresh tomato and processed tomato aroma was the almost complete loss of cis-3-hexenal and the presence of furfural in tomato products. On the basis of the aromatic profiles obtained by GC analysis, relationships between fresh and processed tomato samples were obtained, using multivariate PCA statistical analysis.

Knowledge of the content of heavy metals is important because of their impact on the wine stability or on the health of the consumers. The presence of heavy metals in wines is a consequence of an action of various factors such as conditions of the cultivation and processing of grapes and production, stabilisation or storage of wine. In this work determination of heavy metals (Cu, Fe, Zn and Pb) content in red wines was carried out. Selected wine was Plavac mali, Croatian autochthonous sort, produced by various producers during the three consecutive vintages. The aim of this work was to examine whether the wines produced in different vintage, and by various producers, vary according to the content of heavy metals. For the determination of heavy metals content, the atomic absorption spectrometry (AAS) was used. Content of heavy metals ranged between 0.235-1.122 mg Cu/l, 0.809-6.202 mg Fe/l, 0.266-2.434 mg Zn/l and 0.107-0.3355 mg Pb/l. Data analysis showed statistically significant differences only between producers for iron and copper content.