190 research outputs found
From Cocoa to Chocolate: The Impact of Processing on In Vitro Antioxidant Activity and the Effects of Chocolate on Antioxidant Markers In Vivo
No full textChocolate is a product processed from cocoa rich in flavonoids, antioxidant compounds, and bioactive ingredients that have been associated with both its healthy and sensory properties. Chocolate production consists of a multistep process which, starting from cocoa beans, involves fermentation, drying, roasting, nib grinding and refining, conching, and tempering. During cocoa processing, the naturally occurring antioxidants (flavonoids) are lost, while others, such as Maillard reaction products, are formed. The final content of antioxidant compounds and the antioxidant activity of chocolate is a function of several variables, some related to the raw material and others related to processing and formulation. The aim of this mini-review is to revise the literature on the impact of full processing on the in vitro antioxidant activity of chocolate, providing a critical analysis of the implications of processing on the evaluation of the antioxidant effect of chocolate in in vivo studies in humans
Sensory evaluation and quality indices of three authochtonous apple cultivars fom Abruzzo
No full textThe valorisation of marginal varieties, belonging to different vegetables species can allow to recover genetic resources with a positive impact on the preservation of biodiversity. This aspect is of considerable importance in the case of species rich in nutrients, vitamins or antioxidant. To this aim, three autochthonous apple cultivars from Abruzzo (Limoncella, Mela Gelata and Mela Rosa) were evaluated for chemical, physical and sensory quality. The latter grants the appreciation of these products in the local market where they are commonly commercialized. A sensory profile was created by Quantitative Descriptive Analysis (QDA) for the autochthonous apple cultivars and compared to that of the Golden Delicious apples that were used as reference. A panel of 11 trained judges was used to evaluate the sensory profile. Significant relations were found between instrumental measurements and sensory attributes. QDA results were processed by Analysis of Variance and Principal Component Analysis. The cultivar Mela Gelata was characterized by low acidity and sourness, the cultivar Limoncella by high acidity and sourness whilst the cultivar Mela Rosa showed a strong flowery flavour. Fifty untrained consumer were asked to express their visual and overall preference using a 9 point hedonic scale. Autochthonous apples having small size and being not uniform in shape were characterized by low visual preference scores. Among the autochthonous cultivars Mela Rosa showed the highest mean overall preference score, which resulted not significantly different from that of Golden Delicious.[...
Application of a radical scavenging activity test to measure the total antioxidant activity of poultry meat
No full textThe antioxidant activity of the hydrophilic and lipophilic fraction of poultry meat was determined in terms
of ‘radical scavenging activity’ (RSA) using a modified ABTS radical cation decolorization method.
The method uses the extraction of hydrophilic and lipophilic fractions in water and methanol–chloroform,
respectively. The determination of the RSA of the lipophilic fraction was conducted using a chloroform
extract and maintaining a constant chloroform:ethanol ratio in the solution of analysis. The method
was tested on nine samples of poultry breasts and thigh meats and permitted to quantify the RSA in terms
of lmol Trolox equivalent antioxidant capacity (TEAC) with a mean relative standard deviation of less than
5%.
The contribution of the hydrophilic fraction to the total RSA was much higher than that of the lipid soluble
fraction. Breast showed a higher RSA than thigh meat due to its lower total lipids content. The total RSA
value (TEAC = 2.4 lmol g1) suggests that poultry meat could significantly contribute to the antioxidant
activity of the diet
Effect of phenolic antioxidant on the dispersion state and chemical stability of olive oil O/W emulsions
No full textThe effect of gallic acid, catechin and quercetin on physical and chemical stability of olive oil-in-wateremulsions was investigated. These molecules, characterised by different polarity and antioxidant activity,showed different interface activity and efficiency in delaying lipid oxidation. Gallic acid contributed positivelyto stabilise the colloidal properties of the systems toward physical instability whilst showed a lowactivity towards secondary oxidation. Catechin showed an interfacial localisation which was reflected inthe enhancement of primary oxidation and in the inhibition of secondary oxidation. Quercetin poorlypartitioned in the aqueous phase and was proven not to slow down the bimolecular phase of auto-oxidation.Results confirmed that polarity is not the only parameter to determine efficiency of antioxidants inemulsions but other variables, such as its antioxidant activity in terms of capacity and rapidity in donatingan hydrogen atom, can affect its protective role towards lipids auto-oxidation in emulsions.[...
Role of olive oil phenolics in physical properties and stability of mayonnaise-like emulsions
No full textThe effect of olive oil phenolic content and pattern on the physical properties and stability of olive oil mayonnaise-like emulsions has been investigated. Mayonnaises were formulated with either naturally phenolic-rich extra virgin olive oils or purified olive oil artificially enriched with a phenolic-rich olive extract and pure oleuropein. Mayonnaises were characterized by droplet size distribution, microstructure, textural properties and flow behaviour. The addition of phenolic extracts significantly affected the dispersion degree of the corresponding mayonnaise-like emulsions, their microstructure and physical stability especially in the systems prepared with purified olive oil treated with pure oleuropein and the highest olive phenolic extract concentration. The viscosity and back-extrusion analyses evidenced that the systems characterized by a relatively high content of phenolics, either natural or by addition, presented lower yield stress and viscosity indices and were easier to deform and to break. This study confirms the main role of olive phenolic compounds, and in particular that of oleuropein, in the dispersion state, and physical properties of emulsions with main effects on their quality and stability
Mirror Acts: Dramatic Form in Pirandello’s Six Characters in Search of an Author and Beckett’s Waiting for Godot
No full textPirandello is among the first playwrights to reshape the very notion of theatre and pave the way for a postmodern understanding of the human. By fixing one of drama’s cardinal axes—space—and making it simultaneously literal and inherently static—Pirandello frees the other—time—thereby undoing the core of the dramatic arc. This simple shift repositions both plot and characters, placing them in a cosmology which tauntingly ignores them. Their experience—and by extension the human experience—becomes inherently aimless. In this latter light, Pirandello’s characters are an anticipation of Beckett’s. While this is indubitably an important point of contact between the two, it is the similarity in their structural redefinition of spacetime, that allows both to pave the way for a pivotal revolution of form that will bloom in the works of their heirs—Pinter and Stoppard, primarily—and anticipate postdramatic theatre. In this light, Six Characters in Search of an Author, first staged in Rome and Paris in 1921 a time when Beckett would have been exposed to a response to it, plants a lasting seed
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