Adamopoulou, E., Leloudi, M. C., Hatzidimitriou, E.
Xinomavro Naousa red wines typicality; linking sensory and physicochemical data

Typicality rating of 10 red wine samples, using a non-structured scale, at left “very bad example”, at right “very good example” of what a panel of wine experts, professionals, initiated assessors and consumers, considered to be a typical Xinomavro Naoussa wine, was combined to physicochemical analysis (color characteristics, phenolic content) and GC analysis of volatile profile. Assessors were able to successfully identify the Xinomavro Naoussa samples and rate them as the most typical. Based on both physicochemical and sensory data, wines were successfully grouped according to composition and origin (monovarietal or blended, Naoussa or other PDO’s).

Ritzoulis, C., Margelou, I., Rousi, R., Karayannakidis, P., Papageorgiou, M.
Development of in vitro digestion models for food colloids

This is a discussion on the staged development of an in vitro model as constructed during the course of five years at the Department of Food Technology, ATEI Thessaloniki. In its initial form, a direct probe of the interactions between mucin (the principal gastrointestinal mucus component) and sodium caseinate (a model food protein) studied the pH-dependence of the two components' interactions, which can be key to the protein's digestion and eventually its bioavailability. A further refinement includes linking up in vitro mouth and stomach components, aimed in studying the stability and flocculation of protein-stabilized oil- in-water emulsions moving from the model mouth to the stomach. A more recent development includes a set-up including a model mouth, followed by in vitro stomach and duodenum. This model has been used in order to study the kinetics of starch and gluten release from bread during a simulated digestion process.

Sotiroglou, M., Nenadis, N., Xatzidimitriou, E., Blekas, G.
Influence of sulfur dioxide and/or ascorbic acid on the antioxidant activity of resinated wine models and their oxidative stability under accelerated conditions

The impact of sulphur dioxide and/or ascorbic acid on the antioxidant activity of resinated wine models containing (+)-catechin and chlorogenic acid was examined using models containing different levels of the above constituents as well as constituents extracted from the Pinus Halepensis resin. The composition was selected in terms of an experimental design approach (Taguchi method). The antioxidant activity of the prepared models was examined employing the Folin-Ciocalteu assay and the scavenging of the DPPH radical. Selected models were stored under accelerated oxidation conditions (11 days, dark, 55 °C, 33 % headspace) and evaluated for the changes in antioxidant activity and the possible formation of brown pigments (A₄₂₀). The results indicated that the resin’s constituents did not contribute to the antioxidant activity of the models. Antagonistic phenomena among the constituents were observed which were more pronounced in the case of the DPPH assay. Models using a single typical sulfur dioxide concentration (35 mg/L) with (100, 150 and 200 mg/L) or without ascorbic acid were stored under accelerated oxidation conditions. On the basis of Folin-Ciocalteu assay after the end of the storage the activity was always higher than that of the control (1.08-1.4 fold). Examination with the DPPH assay showed that the activity after storage was higher than that of the control only when ascorbic acid was added at 200 mg/L. Under the experimental conditions employed formation of brown pigments remained low.

Leyva-Jiménez, F. J., Lozano-Sánchez, J., Arráez-Román, D., Segura-Carretero, A.
Encapsulation and controlled release of bioactive phenolic compounds: phenolic acids, flavonoids and phenylpropanoids

In this work the effectiveness of spray drying encapsulation as a new strategy to increase bioavailability of bioactive compounds has been evaluated. Thus, an experimental design based on a central composite 2² model was carried out to encapsulate different phenolic compounds from vegetable sources. Inlet air temperature and ratio sample/encapsulation agent (inuline) were selected as independent variable. The results pointed out a great yield was obtained under all experimental conditions. Encapsulation efficiency presented variability depending on the chemical group studied.

de la Luz Cádiz-Gurrea, M., Fernández-Arroyo, S., Segura-Carretero, A.
Extensive characterization of phenolic composition from Pine Bark concentrated extract as a food supplement by HPLC-ESI/DAD-QTOF-MS

Pine bark is used as a dietary supplement and phytochemical remedy for several diseases. A comprehensive characterization of the bioactive compounds using advanced and powerful techniques as HPLC-ESI-QTOF-MS and their antioxidant capacity are crucial in food supplement studies. A total of 37 compounds were identified belonging to various structural classes being the most representative ones flavan-3-ols (oligomeric forms). Moreover, the extract showed antioxidant activity decreasing the generation of ROS and high values were obtained by TPC and flavan-3-ol content assays.