E. La Notte

Phenolic Content and Antioxidant Activity of Primitivo Wine: Comparison among Winemaking Technologies

The aim of this study was to assess the influence of 9 winemaking technologies (traditional, delestage, saignée, delayed punching-down, addition of grape seed tannins, addition of ellagic-skin-seed tannins, heating of must-wine, cryo-maceration, and prolonged maceration) on the phenolic content and antioxidant activity of Primitivo musts and wines. Three methods for the determination of the antioxidant activity were compared: DPPH, beta-carotene bleaching assay, and ABTS. Oenological parameters and composition of the phenolic fraction of 1-y-aged wines was also determined. The addition of tannins allowed the increase of the phenolic content of musts and wines in a greater amount than the other technologies. The results concerning the antioxidant activity depended on the method applied. Concerning musts, the DPPH assay did not highlight great differences among technologies, whereas the addition of tannins allowed the obtainment of the highest antioxidant activity according to beta-carotene and ABTS assays. The wine aging determined an increase of the antioxidant activity, independently on the method applied. Wine obtained through traditional technology, saignée, and addition of tannins showed the highest antioxidant activities according to DPPH and beta-carotene. The highest correlation coefficients (0.961 and 0.932) were calculated between phenolic content and ABTS values of musts whereas the lowest values (0.413 and 0.517) were calculated between phenolic content and ABTS values of wines. Wines produced through traditional technology were the richest in anthocyanins. The addition of tannins allowed to obtain high content in monomeric anthocyanins, flavonoids, flavans reactive to vanillin, and coumaroylated malvidin and a low content in acetylated malvidin. Practical Applications: It is well known that a moderate consumption (equivalent to 2 glasses per day) of red wine is actually recommended since it appears associated with a decreased incidence of cardiovascular diseases. The mechanisms involved in this protective effect are not completely understood although they appear related to the presence of phenolic compounds. To increase the intake of these compounds without increase of the wine consumption, it is necessary to improve their extraction during maceration. This study could represent a helpful tool for wineries aimed to know the way to increase the antioxidant content of their wines, thus changing them in functional beverages and prolonging their shelf life.

Influence of packaging geometry and material properties on the oxidation kinetic of bottled virgin olive oil

Abstract A two-dimensional mathematical model able to predict the time course of hydroperoxides and oxygen concentration profile inside bottled virgin olive oil during storage is presented. By simulating the behavior of the bottled virgin olive oil it was possible to assess the influence of the bottle’s shape and size on the quality decay kinetics of virgin olive oil bottled in glass and plastic containers. In particular, five geometrically different containers were used to predict the storage behavior of bottled virgin olive oil. The obtained results show that the quality decay kinetics of bottled virgin olive oil greatly depends on container geometry. However, the extent to which the container’s geometrical factors affect the quality decay kinetics depends on the material used to make the bottle, and on the initial value of the oxygen partial pressure in the bottle headspace.

Modeling the starch retrogradation kinetic of durum wheat bread

A mathematical model able to predict the starch retrogradation kinetic of durum wheat bread and its influence on the crumb firming process is presented. The proposed model consists of two equations: the first is used to predict the evolution during storage of starch crystallinity level, and the second is used to relate the starch crystallinity level to the crumb elastic modulus. To validate the proposed model accelerated tests were conducted conditioning the samples at 5 °C and at two different water activities: 1.0 and 0.877. To monitor both the starch retrogradation kinetic and the crumb firming process during storage, wide-angle X-ray diffraction and compression tests were used respectively. The experimental results were successfully fitted by means of the proposed model. The analysis of the data evidenced that by reducing the water activity from 1.0 to 0.877 the overall starch crystal growth rate increase due to the increase of starch nucleation rate.

Modeling the water transport properties of casein-based edible coating

Abstract A mathematical model able to predict the water transport properties of casein-based edible coating is presented. The model consists of two parts. The first is aimed to describe the water solubilization process into the investigated film, and it was derived taking into account the presence of both “bound water” and “free water”. The second is intended to describe the water diffusion process, and it was derived considering both the dependence of water diffusion coefficient of local water concentration and the superposition of polymer relaxation to stochastic diffusion. To validate the model both water sorption isotherm and sorption kinetics of the investigated film were determined at 25 °C. The proposed model was successfully fitted to both sorption and diffusion data, corroborating the validity of the hypothesis used to derive it.

Influence of Raw Materials and Processing Conditions on Spaghetti Hydration Kinetic During Cooking and Overcooking

ABSTRACT A study of the influence of raw materials and processing conditions on the hydration kinetic during cooking and overcooking of spaghetti is presented. Water sorption tests on commercially available spaghetti and on three different types of homemade spaghetti were run at 100°C. In particular, the weight, diameter, and length of spaghetti strands were monitored over time for ≈200 min. The spaghetti hydration process was quantitatively resolved into the controlling phenomena (i.e., water diffusion, macromolecular matrix relaxation kinetic, and residual deformation release kinetic) by fitting a novel mathematical model to the experimental data. The different behavior of spaghetti was analyzed for each of the phenomena involved during hydration. Results suggest that processing conditions highly influence the quality of spaghetti with respect to raw materials.

Polysaccharide and volatile composition of Cabernet wine affected by different over-lees ageing

The influence of different over-lees ageing conditions on the soluble polysaccharides’ glycosyl residue and volatile composition of Cabernet wine was addressed in this work. Specific operating conditions have been considered: wine ageing on fine white lees, wine ageing on fine red lees, wine ageing on fine second-passage white lees and short ageing on rough red lees, which were compared with ageing without lees. The ageing on lees led to an increase in all wine polysaccharide glycosyl residues, with the exception of glucose, xylose and myo-inositol, and to volatile profile modifications. Different behaviours could be observed between the four types of lees, giving important hints for a rational use of them in winemaking. In particular, the use of red grape-derived lees caused the major release of polysaccharides; on the other hand, white grape-derived lees were more effective in enhancing ester content. Second-passage lees did not lead to any increase in wine polysaccharides, whereas they allowed aroma changes, and short ageing on rough red lees caused the greatest adsorption of several volatiles.