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The encapsulation is a process by which small particles of core products are packaged within a wall material to form microcapsules. One of the most useful processes for drying thermosensitive substances that are unstable in aqueous solutions is the freeze-drying technique (lyophilization), which involves conversion of liquid oils in the form of an emulsion into dry powders. In this paper, the chemical composition of walnut oil and microencapsulation conditions (microcapsule wall material composition) have been evaluated in order to assess the influence of the microencapsulation process on the quality and shelf-life of microencapsulated walnut oil. Highest encapsulation yield was achieved when maltodextrin, carboxymethylcellulose, and lecithin were used as encapsulation agents and the ratio of oil-wall material was 1:1.5. Under these conditions all the oil was encapsulated. The presence of protein constituents in the microcapsule wall material extended the shelf-life of the microencapsulated walnut oil regardless of the use of antioxidant additives.

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Mixtures of bovine serum albumin (BSA) and several low molecular weight phenolics were incubated and fractionated using G-50 Sephadex chromatography. Fractions corresponding to the protein and the possible phenolic-protein complexes and fractions corresponding to the free phenolics were collected, and their phenolic content was determined. Among the selected commercial phenolic standards tested (p-coumaric acid, phydroxybenzoic acid, protocatechuic acid, caffeic acid and (+)-catechin), the strongest BSA-binding affinity was demonstrated by 3,4-dihydroxy benzoic and cinnamic acids (protocatechuic acid and caffeic acid), whereas phydroxybenzoic acid did not interact with BSA. The methodology was also applied to a phenolic extract obtained from lentils containing p-coumaric acid, a p-coumaric acid derivative, (+)-catechin and procyanidins B 3 [(+)-catechin-(4␣Õ8)-(+)-catechin] and B 1 [(-)-epicatechin-(4␣Õ8)-(+)-catechin].Interactions observed among the lentil phenolics and BSA were comparable to those observed among the commercial phenolic standards and BSA.

The phenolic composition of heartwood extracts from Fraxinus excelsior L. and F. americana L., both before and after toasting in cooperage, was studied using LC-DAD/ESI-MS/MS. Low-molecular weight (LMW) phenolic compounds, secoiridoids, phenylethanoid glycosides, dilignols and oligolignols compounds were detected, and 48 were identified, or tentatively characterized, on the basis of their retention time, UV/Vis and MS spectra, and MS fragmentation patterns. Some LMW phenolic compounds like protocatechuic acid and aldehyde, hydroxytyrosol and tyrosol, were unlike to those for oak wood, while ellagic and gallic acid were not found. The toasting of wood resulted in a progressive increase in lignin degradation products with regard to toasting intensity. The levels of some of these compounds in medium-toasted ash woods were much higher than those normally detected in toasted oak, highlighting vanillin levels, thus a more pronounced vanilla character can be expected when using toasted ash wood in the aging wines. Moreover, in seasoned wood, we found a great variety of phenolic compounds which had not been found in oak wood, especially oleuropein, ligstroside and olivil, along with verbascoside and isoverbascoside in F. excelsior, and oleoside in F. americana. Toasting mainly provoked their degradation, thus in medium-toasted wood, only four of them were detected. This resulted in a minor differentiation between toasted ash and oak woods. The absence of tannins in ash wood, which are very important in oak wood, is another peculiar characteristic that should be taken into account when considering its use in cooperage.

Thirty-two phenolic compounds of low molecular weight were identified in 36 white, blanc de noir, and rosé sparkling wines by using HPLC with photodiode array and mass spectrometry detection. Some of the identified compounds, such as cis- and trans-ethylcaftaric, cis- and trans-ethylcaffeic, and cis- or trans-ethyl-p-coumaric acids, 2R,3R-dihydroquercetin, 2R,3R-dihydrokaempferol 3-O-beta-d-glucoside, and a lignan derivative are described for the first time in sparkling wines manufactured with grapes of red varieties. This is also the first time that cis- or trans-diethylfertaric acids have been identified in wines. When cluster analysis was applied to the data of 19 of the 32 identified compounds, the greatest differences found in the low molecular weight phenolic compounds in sparkling wines were due to the grape variety from which they were manufactured, whereas aging time did not significantly influence phenolic composition. Nine phenolic compounds, that is, trans-p-coumaric and trans-caftaric acids, trans-resveratrol glucoside, cis-coutaric, trans-coutaric, cis-p-coumaric, and cis-caftaric acids, tryptophol, and syringic acid, permit the wines to be classified correctly in accordance with the grape variety from which they were manufactured.

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