Among methods to detect wine adulteration, profiling volatiles is one with a great potential regarding robustness, analysis time and abundance of information for subsequent data treatment. Volatile fraction fingerprinting by solid-phase microextraction with direct analysis by mass spectrometry without compounds separation (SPME-MS) was used for differentiation of white as well as red wines. The aim was to differentiate between varieties used for wine production and to also differentiate wines by country of origin. The results obtained were compared to SPME-GC/MS analysis in which compounds were resolved by gas chromatography. For both approaches the same type of statistical procedure was used to compare samples: principal component analysis (PCA) followed by linear discriminant analysis (LDA). White wines (38) and red wines (41) representing different grape varieties and various regions of origin were analysed. SPME-MS proved to be advantageous in use due to better discrimination and higher sample throughput.

Oxidative changes of phytosterols were recently studied in vegetable oils and some food products. Cholesterol-lowering properties of phytosterols and phytostanols are the main driver for formulating functional foods containing these compounds. Margarines enriched in plant stanols were stored at two typical temperatures for up to 18 weeks. Analysed margarines contained four phytosterols: brassicasterol, campesterol, sitosterol, avenasterol and two phytostanols: sitostanol, campestanol. The content of phytosterols and phytostanols in margarines changed from 79 mg/g in a control sample to 63 mg/g and 55 mg/g in samples stored for 18 weeks at 4 °C and 20 °C, respectively. At the end of storage, contents of sitostanol decreased by 23% and 30%, while the amounts of oxidised sterols increased by 35% and 100%, respectively, for both temperatures. 7-Hydroxy derivatives dominated among all oxidised phytosterols and their content increased threefold at the end of storage. Epoxy derivatives exhibited a maximum after 6 weeks of storage at 20 °C and thereafter decreased constantly.

Jutrzenka is a sweet liquer wine produced in Poland from the grape variety of the same name, developed in Poland to withstand the harsh climate of winery regions. Jutrzenka wine has a characteristic aroma with strong fruity and flowery notes, which make it unique among other liquer wines as demonstrated in sensory profile analysis. The work was aimed at characterization of volatile compounds in this wine, with the emphasis on characterization of compounds responsible for its unique aroma. Gas chromatography–olfactometry (GC–O) was applied to identify the key odorants using aroma extract dilution analysis (AEDA) approach. To facilitate free and bound terpenes and C13-norisoprenoids identification solid phase extraction (SPE) was used followed by GC/MS. Among identified key odorants β-damascenone was the compound having the highest FD (4096), followed by isoamyl alcohol, 4-mercapto-4-methyl-2-pentanone (FD=2048), methional, linalool, ethyl decanoate (FD=1024) and ethyl hexanoate, furaneol (FD=512). Other significant compounds were ethyl 2-methyl propanoate, ethyl 2-methylbutanoate and phenyl ethyl alcohol. Determination of odor activity values (OAV) showed the highest values for β-damascenone (566), 4-mercapto-4-methyl-2-pentanone (288) ethyl hexanoate (32) and linalool (7). Jutrzenka exhibited also a rich profile of free, and to lesser extent bound terpenes.

Within this study, main odorants of marjoram and thyme (linalool and thymol) were determined in spices and microencapsulated powders using solid-phase microextraction (SPME). Analyses were conducted on selected batches of spices before and after decontamination and on microencapsulated powders prepared for technological purposes (improvement of aroma in decontaminated spices). Conditions of SPME analyses were determined for individual compounds and matrices. Determination of total and surface contents of compounds and the percentage dependencies between encapsulated and surface aroma made it possible to identify the best powders in terms of their quality.

The aroma of several strains of Pleurotus ostreatus, Pleurotus citrinopileatus and Pleurotus djamor was studied by GC/MS. Three main mushrooms aroma constituents: 3-octanol, 3-octanone and 1-octen-3-ol were taken into account for quantitative measurements. The highest amount of 1-octen-3-ol was recorded in P. ostreatus, while considerably lower amounts in P. citrinopileatus. Sensory profile analysis as well as the electronic nose also varied between the three species of Pleurotus. Chiral gas chromatography showed the high optical purity of (R)-(-)-1-octen-3-ol in P. ostreatus and P. djamor (the highest one) in contrast to P. citrinopileatus. Carpophores of P. djamor was characterized relatively high dry matter and protein contents.

Oxidative degradation of cholesterol has been extensively researched, however, not all products formed have been established. When a phytosterols standard was heated at 60, 120 and 180 °C for different period of time the following groups of components were detected: oxidized phytosterols, fragmented phytosterol molecules, volatile compounds and oligomers. Taking into account all the components formed, we were able to balance the amounts of disappearing sterols with components formed. We established that the amount and type of products formed during thermo-oxidative degradation is affected by temperature and time. The amount of intact phytosterols decreased when temperature and time increase. The amount of oxidized phytosterols was at the highest level when a temperature of 120 °C was applied, whereas the lowest amounts were observed when a temperature of 60 °C was used. At a temperature of 180 °C the amount of oxidized sterols was lower than at 120 °C and it decreased when the heating time was increased. This indicates that oxidized sterols were the main precursors involved in the formation of other components during thermo-oxidative degradation. The amount and type of volatile compounds formed increased when time and temperature increased. We observed diversified groups of volatile compounds formed and most of them are defined as off-flavor compounds for rancid oils.

The rosemary aroma composition and the enanatiomeric ratio of chiral compounds were examined by GC (FID), GC/MS and chiral GC. Solid-phase microextraction (SPME) was examined for its suitability for isolation of volatiles from the leaves of five samples of rosemary in comparison with the traditional steam distillation procedure. Mostly five rosemary aroma components were taken into consideration: 1,8-cineole, camphor, borneol, alpha-terpineol and verbenone. Eight pairs of enantiomers were separated in all of the analyzed samples: alpha-pinene, camphene, beta-pinene, limonene, linalool, camphor, borneol and alpha-terpineol. But only one compound - borneol was detected in all the samples, with the same enantiomeric ratio and high optical purity of the minus form, over 85% of total. SPME may he used as a fast and precise tool for measuring the enantiomeric ratio of this compound when authenticity of rosemary aroma is controlled.

An application of comprehensive two-dimensional gas chromatography–time-of-flight mass spectrometry (GC×GC–ToF MS) use for the analysis of trichothecene mycotoxins is described. Trichothecenes belonging to group A (scirpentriol, HT-2, T-2, 15-monoacetoxyscirpenol (15-MAS), 4,15-diacetylscirpenol (DAS), triacetoxyscirpenol (TAS)) and those belonging to group B (deoxynivalenol (DON), 3-acetyldeoxynivalenol, fusarenone-X, nivalenol) were analyzed and quantified as trifluoroacetic acid anhydride (TFAA) and trimethylsilyl (TMS) derivatives, respectively. The application has been developed for the determination of trichothecenes in wheat grain, after extraction, without any cleanup step. The separation of trichothecenes from matrix constituents was possible due to the vast peak capacity of comprehensive two-dimensional gas chromatography. Despite the presence of uncleaned matrix constituents signal-to-noise ratios for 25pg of injected trichothecenes ranged from 11:1 to 78:1. Identification of compounds was based on their full spectra. The linearity in a range of 25–2500pg was generally 0.999 except for 3-acetyldeoxynivalenol deoxynivalenol and fusarenone-X. RSD for peak areas was <9% for all analyzed toxins.

The effect of acid (CAH) and enzymatic (CEH) hydrolysates prepared from pork cracklings on the oxidative stability of frozen pork meatballs was investigated. Meatballs were stored at −18 °C for 180, 270 and 360 days during which time peroxide value (PV), TBARS, profiling sensory analysis and cholesterol oxidation products (COPs) were determined. The oxidation products of cholesterol, such as epimers 7-hydroxy, 5,6-epoxy, 7-keto, triol and 25-hydroxy, after transesterification and SPE fractionation, were detected by capillary gas chromatography. CAH and CEH possessed similar antioxidant efficacy. Inhibition activity of cracklings hydrolysates against PV was 38–45%, and against TBARS was 30–39%. The antioxidant properties of CAH and CEH against the oxidation of lipids were poorer than that of BHT. The addition of hydrolysates changed sensory profiles and had a significant (P<0.05) effect on the taste and odour of meatballs. The total COPs in all meatballs increased during storage. 7-Keto-cholesterol was the dominant oxysterol in fresh samples. After 360 days of storage, levels of oxysterols in samples treated with hydrolysates were about 20% lower than that of the control sample. The most toxic derivative, triol-cholesterol, was detected at the lowest level in samples treated with hydrolysates. The protection of BHT against cholesterol oxidation was poorer than that of CEH.

The aim of this work was to determine the effect of cracklings hydrolysates addition on the oxidative stability of fat and cholesterol in meatballs during 7 days of refrigerated storage.Changes in peroxide value (PV), anisidine value (AV), thiobarbituric acid reactive substances (TBARS) and cholesterol oxidation products (COPs) were determined. Cholesterol and oxysterols were analyzed as trimethylsilyl derivatives (TMS) by gas chromatography. Stability properties of antioxidants so employed were characterized by their inhibition activity.Analyzed enzymatic and acid hydrolysates of cracklings (EHC and AHC) obtained from meat industry by-product showed stability properties against fat and cholesterol. AHC exhibited a superior inhibition activity against fat oxidation than that of EHC because of smaller PV, AV and TBARS values. EHC showed a better inhibition activity against the formation of COPs in stored meatballs. After 7 days of storage, inhibition of formation of the oxysterols in samples with added hydrolysates was 29–54%. The antioxidative properties of EHC and AHC based on PV, AV and TBARS values were weaker than that of BHT. On the other hand, BHT was a poorer antioxidant than the hydrolysates against cholesterol oxidation in stored meatballs.

The goal of this study was to monitor changes in the composition of phytosterols and oxyphytosterols in rapeseed oil and French fries during multiple (14 times) deep-frying. Phytosterols (brassicasterol, campesterol, stigmasterol, β-sitosterol and avenasterol), after saponification, were separated by capillary GC. The oxidation products of campesterol, stigmasterol and sitosterol, such as: epimers of 7-hydroxy, 5,6-epoxy, 7-keto and triols, after transesterification and SPE fractionation, were identified by GC/MS and quantified by capillary GC. Results of this research indicate that the content of phytosterols significantly decreased during deep frying of French fries in rapeseed oil (ca. 60%). In addition, the content of oxyphytosterols, particularly triol derivatives, significantly increased. The content of total phytosterols in fresh, good quality rapeseed oil was 5.4 mg/g and decreased after the 14 th frying to 2.0 mg/g. French fries prepared in the first frying oil contained 2.9 mg of phytosterols in 1 g of extracted lipids, but after the 14 th frying they had only 1.1 mg of phytosterols in 1 g of extracted lipids. The level of total oxyphytosterols in fresh good quality rapeseed oil used for frying was 25.1 μg/g. After the 14 th frying it increased to 197.1 μg/g. The content of oxyphytosterols in French fries during frying ranged from 16.8 to 147.6 μg/g of lipids extracted from the products. The dominating oxyphytosterols were epoxy- and 7-hydroxyphytosterols.

Phytosterols are one class of food constituent with serum cholesterol-lowering properties by inhibiting cholesterol absorption. These reasons led to an increasing avail- ability of phytosterol-enriched foods. The content of phytosterols in rapeseeds ranged from 4.7 mg/g to 6.3 mg/g of seeds depends on variety. After pressed in industrial condi- tions their content in the oil was 8.7 mg/g. In extracted oil the level of phytosterols was 25% higher then in pressed oil. During refined process, especially neutralization, the de- crease of phytosterols content was 20%. Using the rapeseed oil to multiple deep frying of French fries generated next 64% losses. The most important reasons for phytosterols con- tent decrease are their autoxidation processes. Autoxidation of sterols is theorized to be a free radical process. Some processes, such as refining plant oils and deep frying or stor- age, intentionally induce oxidation to produce phytosterol oxidation products (oxyphytos- terols). They were determined in rapeseeds on the level 10-15 µg/g of seeds. During in- dustrial production of rapeseed oil the content of oxyphytosterols systematically increased and after refining it was 100-110 µg/g. During multiple deep-frying of French fries in rapeseed oil oxyphytosterols content increased and after 14 th frying their content was 200 µg/g in used oil and 150 µg/g in French fries. Oxyphytosterols are absorbed by humans and their subsequent metabolic conversions may be of toxicological significance.