In our investigations the membrane filtration of quality wines (Tokaji Hárslevelű and Egri Bikavér) — based on diafiltration principles, applying nanofiltration membranes — has been studied. For the diafiltration experiments a relatively dense nanofiltration membrane NF 45 has been used, while for simple wine concentrations a membrane developed for organic components rejection NF200 has been investigated. The mixture of the retarded wine compounds was considered the main product of the process. The permeate that crossed the membrane was handled as the by product. Separated wine samples and the original wines have been subjected to gas chromatographic analysis: according to the results the partition of the main components and aroma compounds of the samples was approximately equal between the main and by-product. Membrane separation has been applied in accordance with a “prelaborated” experimental plan, when completing it the effect of operational parameters on the effectiveness of the process has been evaluated and analysed. By mathematical modelling of the phenomenon empirical and quasiempirical relations were set up, and solutions for the practical realization of the procedure were searched for. Our new model describes the filtration efficiency with our new index in the function of the operational parameters’ influence. The significance of the relation is, that the knowledge of the wine-constants might promote the expedient choice of the membrane, which is a primary aspect in planning and creating the process optimal.
The lack of interpretation methods capable of examining the aroma-profiles of spicy and medicinal plants and other samples of food origin (wines, honeys, fruits, fruit-distillates) makes necessary a thorough investigation of the relating evaluation procedures. By adding three appropriate hydrocarbon standards to all sample extracts, and measuring the programmed temperature retention indices of the components and normalizing the peak areas to that of the compound corresponding to the most intense chromatographic peak, a visualization of the aroma characteristics could be achieved. The relationship or identity of aroma patterns could be deduced from the presence or absence of similar polygons in the ihconstellation-mapsl. of the components.
Volatile constituents of four red pepper (called paprika in Hungarian) cultivars of the famous Szeged paprika growing region were analysed by GC-MS measurements subsequent to Likens-Nickerson simultaneous distillation extraction (LN-SDE) sample preparation. Of the compounds, 107 common constituents were managed to be identified. The examination detected the presence of terpenes, esters, hydrocarbons, acids, alcohols, aldehydes, and ketones. Several sulphur, cyclic nitrogen, and oxygen containing compounds were found as well, which usually present fairly high odour activities. The most abundant components in the examined cultivars were the hexadecanoic acid, tetradecanoic acid, dodecanoic acid, 4-vinyl-2-methoxy-phenol (4-vinyl guaiacol), and a compound of unknown structure. Though many pyrazines and relative substances occurred in the samples, 2-methoxy-3-isobutylpyrazine, responsible for the fresh red bell pepper note, could not be detected.
The effect of the drying dehydration process on the characteristic aroma structure of apricot samples has been studied. A close mass spectrometric examination of the relating gas chromatograms revealed the fundamental differences between the fresh and parched fruits. The comparability of the records has been created by the normalisation of both chromatographic axes. The procedure is called aroma spectrum method. The measurements prove that the drying process destroys the fine scent structure to a surprisingly high extent. The two most important constituents responsible for the apricot character disappear, as well.
Comparison of Hungarianground red paprika volatiles of known origin (identical to cultivated varietiesgrown in Kalocsa, Hungary) and provenance has been performed following simultaneous distillation-extraction sample preparation. After polar phase capillary gas-chromatography, mass spectrometric identification of as many compounds as possible was carried out to precisely describe the aroma profile of the cultivars. For conceptualizing the results a data evaluation and interpretation method has been elaborated considering the component ratios that are much more characteristic of the cultivars than the absolute amounts themselves. Relative intensity interpretation of the peak areas (y-axis) and Programmed Temperature Retention Index (x-axis) measurement resulted in aromagrams individually characteristic of the cultivated varieties. In an identification experiment the cultivars have been recognized successfully by the graphic visualization of the results called aroma-spectra (by analogy to mass spectrometry) method.