RESUMO
The aim of this study was to examine olive oils purchased in Poland for their compliance with label declarations and EEC criteria. Statistical analysis was used to compare the olive oils in terms of their content and composition of essential constituents and color parameters. Fifty olive oils (extra virgin, bioextra virgin, cold-pressed, refined, and pomace) from different countries (Spain, Italy, Greece, Portugal, Germany, France, Israel, and the European Union), were purchased commercially in Poland. The contents of triacylglycerols, sterols, and tocopherols, the fatty acid composition, and the color parameters were determined using chromatographic and spectrophotometric methods. Statistical methods were used to divide the olive oils into clusters. Our results show that the composition and color parameters of olive oils available commercially in Poland, excluding pomace olive oils, are similar. It can thus be concluded that, irrespective of the type of olive oil stated on the label, their quality is the same or very similar.
Assuntos
Cor , Ácidos Graxos/análise , Análise de Alimentos/métodos , Rotulagem de Alimentos , Qualidade dos Alimentos , Azeite de Oliva/análise , Azeite de Oliva/química , Fitosteróis/análise , Tocoferóis/análise , Triglicerídeos/análise , PolôniaRESUMO
This study compared the mineral content and bioactive properties of flowers and fruit coming from wild elderberry plants with those of flowers and fruit harvested from elderberry cultivars grown in an orchard. Elderberry fruit and flowers were analyzed for the content of selected minerals, phenolic compounds, and anthocyanins, as well as for antioxidant activity. Mineral content was determined by the atomic absorption spectrometry method, while antioxidant activity and the content of polyphenols and anthocyanins were determined by spectrophotometric methods. Flowers were found to contain more total ash and much higher content of most of minerals, except magnesium which was present in high concentrations in fruit. Fruit showed significantly higher antioxidant activity than flowers, whereas the total phenolic content varied depending on the growing location or cultivar. The material obtained from selected cultivars growing in an orchard had higher antioxidant activity and polyphenol and anthocyanin content than the material obtained from wild plants. Fruit of the "Haschberg" cultivar and flowers of the "Sampo" cultivar had the best bioactive properties of the studied samples.
Assuntos
Antioxidantes/análise , Flores/química , Frutas/química , Minerais/análise , Sambucus nigra/química , Antocianinas/análise , Análise por Conglomerados , Genótipo , Fenóis/análise , Filogenia , Extratos Vegetais/química , Sambucus nigra/genéticaRESUMO
European black elderberry naturally occurs in most of Europe and has been introduced into various parts of the world for fruit and flower production. Elderberry is rich in nutrients, such as carbohydrates, proteins, fats, fatty acids, organic acids, minerals, vitamins and essential oils. Elderberry also contains cyanogenic glycosides which are potentially toxic. Polyphenols, known for their free radical scavenging (antioxidant) activity, are the most important group of bioactive compounds present in elderberry in relatively high concentration. The high antioxidant activity of elderberry fruit and flowers is associated with their therapeutic properties. Elderberry has for a long time been used in folk medicine as a diaphoretic, antipyretic and diuretic agent. In recent years it was also found to have antibacterial, antiviral antidepressant and antitumour and hypoglycemic properties, and to reduce body fat and lipid concentration. Due to its health-promoting and sensory properties, elderberry is used primarily in food and pharmaceutical industry.
RESUMO
BACKGROUND: Elderberries are a source of dietary supplements and bioactive compounds, such as anthocyanins. These dyes are used in food technology. The aim of the study was to assess the changes in colour parameters, anthocyanin contents and sensory attributes in solutions of elderberry juice concentrates during storage in a model system and to determine predictability of sensory attributes of colour in solutions based on regression equations using the response surface methodology. METHODS: The experiment was carried out according to the 3-level factorial design for three factors. Independent variables included pH, storage time and temperature. Dependent variables were assumed to be the components and colour parameters in the CIE L*a*b* system, pigment contents and sensory attributes. RESULTS: Changes in colour components X, Y, Z and colour parameters L*, a*, b*, C* and h* were most dependent on pH values. Colour lightness L* and tone h* increased with an increase in experimental factors, while the share of the red colour a* and colour saturation C* decreased. The greatest effect on the anthocyanin concentration was recorded for storage time. Sensory attributes deteriorated during storage. The highest correlation coefficients were found between the value of colour tone h* and anthocyanin contents in relation to the assessment of the naturalness and desirability of colour. A high goodness-of-fit of the model to data and high values of R2 for regression equations were obtained for all responses. CONCLUSIONS: The response surface method facilitates optimization of experimental factor values in order to obtain a specific attribute of the product, but not in all cases of the experiment. Within the tested range of factors, it is possible to predict changes in anthocyanin content and the sensory attributes of elderberry juice concentrate solutions as food dye, on the basis of the lack of a fit test. The highest stability of dyes and colour of elderberry solutions was found in the samples at pH 3.0, which confirms the advisability of using an anthocyanin preparation to shape the colour of high-acidity food products, such as fruit fillings, beverages,desserts.