Extra virgin olive oil bitterness evaluation by sensory and chemical analysis

An experimental investigation was performed on blend extra virgin olive oils (EVOO) from different cultivars and EVOO from different olive monovarieties (Coratina, Leccino, Maiatica, Ogliarola) with the aim to evaluate the possibility of estimating the perceived bitterness intensity by using chemical indexes, such as the total phenol content and the compounds responsible of oil bitterness measured spectrophotometrically at 225 nm (K225 value) as bitterness predictors in different EVOO. Therefore, a bitterness predictive model, based on the relationship between the perceived bitterness intensity of the selected stimuli and the chosen chemicals parameters has been built and validated. The results indicated that the oil bitterness intensity could be satisfactorily predicted by using the K225 values of oil samples

HPLC determination of agmatine and other amines in wine.

An optimised HPLC analysis is described for the determination by dansylation of the following 11 biogenic amines in wine: agmatine, cadaverine, ethanolamine, histamine, methylamine, 2-phenylethylamine, spermine, spermidine, putrescine, tryptamine and tyramine. Seven amines were found in red and white wines produced in Southern Italy, being present at levels ranging from not detectable to 10.97 mg/L. The most abundant amine resulted ethanolamine, while the polyamine present at the highest concentration was agmatine with maximum levels of 9.92 mg/L. Total biogenic amines content was higher in the red wines

Improvement of Analytical Methods for the Determination of Polyphenolic Bioactive Compounds in Berry Fruits

Berry fruits contain high levels of different phytochemicals, most of which are phenolic molecules. Fruits of the same cultivar from different locations and different harvest years have different chemical compositions, particularly related to polyphenols. The difference may be due to specific climatic conditions, the type of soil in which the plants grow, and the stresses to which the plants were subjected because these phytochemicals are produced as a defense mechanism through a secondary metabolic process. For this reason, it is important to establish simple and reliable procedure to determine polyphenolic compounds in berry fruits considering the increasing attention on these compounds for different potential uses. In order to choose and to improve the most adequate analytical procedure for the determination of the polyphenolic substances in berry fruits, different methods were applied and compared on samples of elderberry and blackberry

Conventional and organic foods: A comparison focused on animal products

AbstractThe term "organic" denotes a product of a food production system that is socially, ecologically, and economically sustainable. The organic food market is growing in response to an ever increasing demand for organic products. They are often considered more nutritious, healthier, and free from pesticides than conventional foods. However, the results of scientific studies do not show that organic products are more nutritious and safer than conventional foods. In this work a comparison between conventional and organic foods is made, the focus is on animal products. The data available in the existing literature is often conflicting, even if the differences are often associated with breeds suited to organic vs. conventional production systems. In order to have a clear understanding of the role that "organic effect" plays on animal foods, further research is necessary

HPLC determination of agmatine and other amines in wine.

An optimised HPLC analysis is described for the determination by dansylation of the following 11 biogenic amines in wine: agmatine, cadaverine, ethanolamine, histamine, methylamine, 2-phenylethylamine, spermine, spermidine, putrescine, tryptamine and tyramine. Seven amines were found in red and white wines produced in Southern Italy, being present at levels ranging from not detectable to 10.97 mg/L. The most abundant amine resulted ethanolamine, while the polyamine present at the highest concentration was agmatine with maximum levels of 9.92 mg/L. Total biogenic amines content was higher in the red wines

A green process for nutraceuticals recovery from grape seeds using SC-CO2 and Subcritical Water

The objective of this research was to evaluate the feasibility of utilising a combined SCCO2/Subcritical Water process for oil and phenols recovery from grape seeds, with the aim to set up an integrated extraction process in which environmental friendly and no harmful solvents could be utilised, allowing to produce extracts having high commercial value and similar or better composition and characteristics of those obtained by classical extraction techniques. In particular, after the delipidization step with SC-CO2, that allowed over 99% of oil removal, the research was aimed to study the recovery of the polyphenol moieties from the fat depleted seed matrix, by using subcritical water. The study was conducted and optimised by using Central Composite Design and Response Surface Methodology with respect to specific parameters such as operating temperature and water pH

Extra virgin olive oil bitterness evaluation by sensory and chemical analyses

An experimental investigation was performed on blend extra virgin olive oils (EVOOs) from different cultivars and EVOO from different olive monovarieties (Coratina, Leccino, Maiatica, Ogliarola) with the aim to evaluate the possibility of estimating the perceived bitterness intensity by using chemical indices, such as the total phenol content and the compounds responsible for oil bitterness measured spectrophotometrically at 225 nm (K225 value), as bitterness predictors in different EVOO. Therefore, a bitterness predictive model, based on the relationship between the perceived bitterness intensity of the selected stimuli andthe chosen chemicals parameters has been built and validated. The results indicated that the oil bitternessintensity could be satisfactorily predicted by using the K225 values of oil samples

METODI FOTOMETRICI PER LA DETERMINAZIONE DI PARAMETRI QUALITATIVI DELL’OLIO EXTRAVERGINE DI OLIVA

The quality of extra virgin olive oils is determined by physico-chemical and sensory parameters well-defined and established by Reg. 1989/2003/EC. Among the factors affecting the quality characteristics and the stability of this category of oils, it is important to consider the degree of acidity, the oxidative state and the antioxidant content. The official methods described in the rule consider the determination of oil acidity by an acid-base titration and the determination of the peroxide value, which represents an index of oxidative state, by a redox titration. An official method for the determination of the oxidative stability of oils is not available, but a wide bibliography relates this property with the content of polyphenolic substances. In the present work has been evaluated the possibility of using an apparatus based on photometric methods (Oxitester) for the determination of acidity, peroxide value and index of polyphenols as an alternative to the official methods of analysis or those commonlyused. A total of 113 extra virgin olive oils produced in the Basilicata region by using a twophase centrifugal extraction and obtained from various cultivars were analysed