Analysis of old brandy and oak extracts by capillary electrophoresis

A Theoretical Approximation of the Accelerating Effects of Ultrasound about the Extraction of Phenolic Compounds from Wood by Wine Spirits

The acceleration on the extraction by the sonication of phenolic compounds (measured as the Total Phenolic Index) from wood chips by wine distillates is studied in the present paper. Using the Arrhenius equation, the theoretical temperature at which the kinetics obtained by these sonicated extraction processes are equal to the kinetics of non-sonicated and thermally accelerated extractions, was calculated. By applying a pseudo-second order kinetic model, it was shown that the initial rate values obtained from the sonicated extractions were as high as those obtained from the thermal extractions carried out at a temperature at least 2.5 °C higher than the real temperature at which the experiment was performed. Higher power densities lead to higher initial rates of extraction, although very high power densities decrease the amount of phenols in equilibrium, probably due to the degradation processes. Additionally, the positive synergy between the sonication and the movement of the recirculated distillate through wood chips was also stablished, obtaining a difference of temperature of at least,18.2 °C for the initial extraction rate and 7.0 °C for the equilibrium.

Discriminant ability of phenolic compounds and short chain organic acids profiles in the determination of quality parameters of Brandy de Jerez

Brandy de Jerez is the most produced spirit in Spain. The rules of its Regulatory Council require the spirit to age in American oak casks that have previously contained any kind of sherry wine. This use, called seasoning, releases wine compounds into the spirit. Because of the differences among sherries, the organoleptic features of a brandy will be significantly different from any other depending on the seasoning. In addition, its specific features make it different from any other spirit. The chromatographic profiles of Brandy de Jerez are reported to be different depending on the seasonings through their ageing process. Different types of Brandy de Jerez have been characterised, regarding their seasoning, using chromatographic techniques. Applying statistical analysis, correlations between the chromatographic profiles and the seasonings have risen up. In addition, the profiles have demonstrated to possess a high degree of correlation with the ageing time of the samples.

Grape brandy production, composition and sensory evaluation

Grape brandy is a spirit drink produced by wine distillation and is matured in wooden casks. According to legislation, it can be characterised by the geographical area where the grapes were produced, the grape variety used and the selected distillation and ageing techniques. Distillation increases ethanol concentration and aromatic constituents which are already present in grapes or are developed during fermentation and distillation. During maturation in wooden casks, compounds that contribute to the aroma and taste are extracted from the wood. Hence the spirit acquires the desired softer mouth feel, aromatic complexity and overall quality. Different methods of analysis are used in order to pursuit this process by analysing volatile and non-volatile substances and correlate composition with quality. Analysis can also be useful in identification of brandy safety, potential adulterations, provenance and differentiation from other spirits drinks.

Authenticity of the traditional cypriot spirit "zivania" on the basis of 1h NMR spectroscopy diagnostic parameters and statistical analysis

A previous publication (Kokkinofta et al. J. Agric. Food Chem. 2003, 51, 6233-6239) discussed the use of inductively coupled plasma spectroscopy to differentiate between the traditional Cypriot alcoholic beverage zivania and other spirits similar in alcoholic content collected from different countries. In the present paper (1)H NMR spectroscopy is applied to confirm the previous conclusions and to obtain additional physical-chemical characteristics that may be used to differentiate zivania from other similar beverages. NMR spectroscopy gave a satisfactory degree of prediction and classification between zivanias and other distillings. The validity of quantification of the method was tested using comparative GC data. It appears that chemical analysis can be very helpful for identifying the unique geological and climatic conditions existing in the island of Cyprus that lead to an authentic product.

Analysis of natural antioxidants by capillary electromigration methods

In this work, an exhaustive survey of capillary electromigration methods used to analyze natural antioxidants is presented together with some discussion of the use of these substances use as functional foods. This review provides an updated and exhaustive overview of the separation and identification by capillary electrophoresis of natural compounds with antioxidant activity found in natural matrices and/or foods. The compounds concerned are catechins, isoflavones, anthocyanins, phenolic acids, vitamins, as well as other less common natural substances that have shown antioxidant activity.

Capillary electrophoresis in food authenticity

Food authenticity is a term which simply refers to whether the food purchased by the consumer matches its description. False description can occur in many forms, from the undeclared addition of water or other cheaper materials, or the wrong declaration of the amount of a particular ingredient in the product, to making false statements about the source of ingredients i.e., their geographic, plant, or animal origin. The aim of this review is to summarize applications of capillary electrophoresis in food authentication.

Analytical determination of polyphenols in olive oils

The increasing popularity of olive oil is mainly attributed to its high content of oleic acid, which may affect the plasma lipid/lipoprotein profiles, and its richness in phenolic compounds, which act as natural antioxidants and may contribute to the prevention of human disease. An overview of analytical methods for the measurement of polyphenols in olive oil is presented. In principle, the analytical procedure for the determination of individual phenolic compounds in virgin olive oil involves three basic steps: extraction from the oil sample, analytical separation, and quantification. A great number of procedures for the isolation of the polar phenolic fraction of virgin olive oil, utilizing two basic extraction techniques, LLE or SPE, have been included. The reviewed techniques are those based on spectrophotometric methods, as well as analytical separation (gas chromatography (GC), high-performance liquid chromatography (HPLC), and capillary electrophoresis (CE)). Many reports in the literature determine the total amount of phenolic compounds in olive oils by spectrophometric analysis and characterize their phenolic patterns by capillary gas chromatography (CGC) and, mainly, by reverse phase high-performance liquid chromatography (RP-HPLC); however, CE has recently been applied to the analysis of phenolic compound of olive oil and has opened up great expectations, especially because of the higher resolution, reduced sample volume, and analysis duration. CE might represent a good compromise between analysis time and satisfactory characterization for some classes of phenolic compounds of virgin olive oils.

Determination of hydrolyzable tannins in the fruit of Terminalia chebula Retz. by high-performance liquid chromatography and capillary electrophoresis

A RP-HPLC method for determining fourteen components (gallic acid, chebulic acid, 1,6-di-O-galloyl-D-glucose, punicalagin, 3,4,6-tri-O-galloyl-D-glucose, casuarinin, chebulanin, corilagin, neochebulinic acid, terchebulin, ellagic acid, chebulagic acid, chebulinic acid, and 1,2,3,4,6-penta-O-galloyl-D-glucose) in the fruit of Terminalia chebula Retz. is described. The separation was achieved within 80 min using a binary gradient with mobile phases consisting of a pH 2.7 phosphoric acid solution and an 80% CH3CN solution. Capillary electrophoretic analyses were also attempted, and it was found that CZE (25 mM Na2B4O7, 5 mM NaH2PO4, pH 7.0) was an efficient method for the separation of gallotannins, while an MEKC method (25 mM Na2B4O7, 5 mM NaH2PO4, 20 mM SDS, pH 7.0, and 10% acetonitrile) provided a better separation for most of the tannins examined. The HPLC and CE methods developed were both successfully applied to the assay of tannins in commercial samples of Chebulae Fructus.

Fast separation and determination of tyrosol, hydroxytyrosol and other phenolic compounds in extra-virgin olive oil by capillary zone electrophoresis with ultraviolet-diode array detection

Olive oil is the main source of fat in the Mediterranean diet, and its consumption has been related to a low incidence of coronary heart disease and certain cancers. Recent findings demonstrate that olive oil phenolics are powerful in vitro and in vivo antioxidants and display other biological activities that could partially account for the observed healthful effects of the Mediterranean diet. A detailed method optimization plan was carried out to separate the most popular phenols in olive oil for four separation parameters: buffer concentration, buffer pH, applied voltage and temperature. Consequently, an analytical method capable of separating 21 different phenols and polyphenols by capillary zone electrophoresis was developed; the separation was performed within 10 min, using a 40 cm x 50 microm capillary, with a 45 mM sodium tetraborate buffer (pH 9.60), at 27 kV and 30 degrees C. The optimized method was applied to methanolic extracts of several Italian extra-virgin olive oils obtained by different technologies in order to characterize and to compare their antioxidant profile. Positive correlations of phenolic compounds found by capillary zone electrophoresis (CZE) and two colorimetric indexes (total polyphenols and o-diphenols) were found and discussed.

Determination of aloenin, barbaloin and isobarbaloin in aloe species by micellar electrokinetic chromatography

Aloenin, barbaloin and isobarbaloin in JP Aloe, Aloe barbadensis (Aloe vera) and Aloe arborescens Miller var. natalensis Berger (Aloe arborescens Miller) were determined by micellar electrokinetic chromatography (MEKC) with 50 mM sodium dodecyl sulfate. Aloenin, barbaloin and isobarbaloin were well separated by MEKC and as little as 5.5 pg/11 nl of the three compounds could be detected. The determination took around 14 min.

Determination of organic acids in food samples by capillary zone electrophoresis

A comprehensive survey of the use of capillary zone electrophoresis for the determination of organic acids in food and beverage samples is presented. The analytes discussed in this paper include low-molecular-mass organic acids, amino acids, vitamin related compounds and free fatty acids.

Applications of in-capillary reaction micellar electrokinetic chromatography in the food industry

This review describes the quantitative analysis of in-capillary reactions by using capillary electrophoresis (CE) in the food industry. An electrophoretic analysis of products of an enzyme reaction of a substrate by in-capillary reaction was useful for the activity measurement of glucoamylase in sake rice koji. p-Nitrophenyl-beta-D-maltoside was employed as a substrate and p-nitrophenyl-beta-D-glucopyranoside was the product of the enzyme reaction. The glucoamylase activity of sake rice koji samples gave a good linear relationship with the peak area observed in the in-capillary enzyme reaction method. Also, in-capillary micellar electrokinetic chromatography (MEKC) was used for analyzing the Monascus pigment-mediated degradation of mutagenic 3-hydroxyamino-1-methyl-5H-pyrido[4,3-b]indole. During the electrophoresis, the mutagen and the pigment, due to their different migration velocities, mix for a certain period of time to interact, and then they are separated and quantitated. The in-capillary reaction MEKC method can be applied to the routine quality control of enzyme activities in the food industry and the evaluation of mutagenic compounds in food materials.

Electrophoretic methods in the analysis of beverages

A review of the applications of electrophoresis to the determination of various compounds in beverage samples, namely beer, hard drinks, juice, milk, soft drinks, tea and wine, is presented.

The development and application of capillary electrophoresis methods for food analysis

Capillary electrophoresis (CE) offers the analyst a number of key advantages for the analysis of the components of foods. CE offers better resolution than, say, high-performance liquid chromatography (HPLC), and is more adept at the simultaneous separation of a number of components of different chemistries within a single matrix. In addition, CE requires less rigorous sample cleanup procedures than HPLC, while offering the same degree of automation. However, despite these advantages, CE remains under-utilized by food analysts. Therefore, this review consolidates and discusses the currently reported applications of CE that are relevant to the analysis of foods. Some discussion is also devoted to the development of these reported methods and to the advantages/disadvantages compared with the more usual methods for each particular analysis. It is the aim of this review to give practicing food analysts an overview of the current scope of CE.