Search

Several experiments were conducted to developed orange based vinegar by surface culture. The addition of sugar (sucrose and concentrated must) and the presence/absence of peel in the raw material (squeezed juice, peeled orange, non-peeled orange plus squeezed juice) have been studied during the development of the final product. Polyphenolic and volatile characterization and sensory analysis have also been carried out. The polyphenolic and volatile content of the resulting wines and vinegars showed significant differences depending upon the raw material used. In general, the complexity of the polyphenolic and volatile profiles increased for experiments in which orange peel was included in the raw material. Sensory analysis revealed significant differences between the samples in respect of both sugar addition and raw material. The vinegars using sugar, peeled orange and non-peeled orange plus squeezed juice raw materials, had more preference and keeping in view relative efficiency of the process, vinegar made from the peeled orange material was considered to be best.

Dietary fiber derived from citrus fruits was added to vinegar. Different sources and quantities of fiber and storage conditions have been scrutinized. Formulated vinegars were evaluated on the basis of their phenolic profile, volatile composition and sensory analysis. The addition of citrus fiber enhanced the phenolic and volatile profile of the resulted vinegars. Whereas lemon fiber contributed mostly to the enrichment of the polyphenolic composition, orange fiber was that which increased in a higher way the volatile composition of the vinegars. Moreover, the content of hydroxycinnamic acid derivatives and the majority of volatile compounds decreased as the dose of fiber increased. Furthermore, the judges preferred fiber-enriched vinegars, but in different quantities depending of the fiber source. This preference was mainly based on citric attribute, contributing several terpenes and ketones derived from them. The addition of citrus fiber to vinegar did not result in a marked storage-dependence.

Background Nineteen commercially available aromatised vinegars, which were representative of this type of product, were tested to ascertain their phenolic and volatile composition and antioxidant activity. The aromatised vinegars came from different raw materials such as fruits, spices, herbs and vegetables. The antioxidant activity was determined by means of photochemiluminescence, phenolic profile by using ultra performance liquid chromatography with ultraviolet detection, and the volatile composition was determined by using stir bar sorptive extraction–gas chromatography–mass spectrometry. Results Nine polyphenolic compounds and 141 volatile compounds were identified. Vinegar aromatised with black truffle and rosemary obtained the highest values of antioxidant activity, followed by those aromatised with lemon, tarragon, aromatic herbs and vegetables. Antioxidant activity was highly correlated with the presence of trans-p-coutaric acid, trans-caftaric acid, 5-hydroxy-methylfurfural and furfural. Moreover, (Z)-3-hexen-1-ol was exclusive to the vinegar aromatised with tarragon, while p-menth-1,8-ol, dimethyl styrene, 4-methyl acetophenone and nootkatone were only found in vinegar aromatised with lemon. Conclusion On the basis of the results from the cluster analysis of cases, it can be concluded that the grouping responds more to the trademark of each vinegar than to the raw material.

BACKGROUND: Despite the long history of sherry wine vinegar, new alternatives of consumption are being developed, with the aim of diversifying its market. Several new acetic-based fruit juices have been developed by optimising the amount of sherry wine vinegar added to different fruit juices: apple, peach, orange and pineapple. Once the concentrations of wine vinegar were optimised by an expert panel, the aforementioned new acetic fruit juices were tasted by 86 consumers. Three different aspects were taken into account: habits of consumption of vinegar and fruit juices, gender and age. RESULTS: Based on the sensory analysis, 50 g kg−1 of wine vinegar was the optimal and preferred amount of wine vinegar added to the apple, orange and peach juices, whereas 10 g kg−1 was the favourite for the pineapple fruit. Based on the olfactory and gustatory impression, and ‘purchase intent’, the acetic beverages made from peach and pineapple juices were the most appreciated, followed by apple juice, while those obtained from orange juice were the least preferred by consumers. CONCLUSION: New opportunities for diversification of the oenological market could be possible as a result of the development of this type of new product which can be easily developed by any vinegar or fruit juice maker company. © 2012 Society of Chemical Industry

Aroma compounds of 48 Sherry brandies have been identified and quantified by the stir bar sorptive extraction method coupled to gas chromatography-mass spectrometry (SBSE-GC/MS). Analysis of variance and multivariate analysis techniques have been used to classify these brandy samples according to the commercial category (Solera brandy, Solera Reserva brandy, and Solera Gran Reserva brandy). From an univariate point of view (analysis of variance), several of the volatile compounds considered showed significant differences. Principal component analysis, using the global data matrix, showed that only the Solera brandy samples, with the shortest aging in wood, were well-differentiated from the others. Partial least-squares discriminant analysis (PLS-DA) results provided evidence of the ability of the content of volatile compounds to discriminate among the different commercial categories. Linear discriminate analysis allowed for a 93% differentiation according to the commercial category and, thus, the length of its aging process in wood. The results obtained show that it would be possible to ensure the commercial category of a Sherry brandy using its content of volatile compounds.

Several experiments of maceration of a sherry wine vinegar with different fruits (orange, lemon, strawberry, grapefruit, and lime) have been carried out. After optimization (only peel, no heating and seven days as maximum time of maceration), parameters such as polyphenolic content, superoxide anion scavenging ability (related to antioxidant activity) and ascorbic acid content were determined in sherry wine vinegars macerated with two amounts of peel and for two maceration times (3 and 7 days). The analysis of variance pointed to a clear relationship (p

A study of accelerated aging on an industrial scale, employing both microoxygenation and oak chips, of a Sherry wine vinegar has been carried out. The effect of these two factors, microoxygenation and oak chips, on polyphenolic and volatile compounds, and sensorial parameters has been evaluated. The dose of oxygen applied to the vinegar and the use of chips provoke important changes in its content in polyphenols and volatile compounds and make it similar to the profile obtained using traditional aging. An alternative method of aging is proposed, using 5 g/L of chips and a dose of oxygen around 70 mL/L month. With the proposed method, and according to the sensorial and analytical results obtained, vinegars similar to those traditionally aged can be obtained by accelerated aging with microoxygenation and chips in shorter periods of time. In our case, a final reduction of 86% of time is achieved with the proposed method.

BACKGROUND: Due to the diversity of vinegars on the market and the increase in demand, it is considered necessary to investigate and establish criteria for classifying them in order to obtain more information concerning their real origin. New spectroscopic techniques such us mid-infrared spectroscopy with Fourier transform (FT-IR) are capable of providing information in relation to these aspects. FT-IR combined with multivariate analysis has been used to classify vinegars according to the raw materials and production processes (with or without ageing in wood). Principal component analysis (PCA), partial least-squares discriminant analysis regression (PLS-DA) and stepwise linear discriminant analysis (SLDA) were used. RESULTS: The results obtained have been compared to those achieved using different analytical parameters (polyphenolic content, organic acids and volatile compounds). SLDA and PLS-DA results show the ability of mid-FT-IR spectra to discriminate among vinegars from different raw materials and with or without ageing in wood, with correct classification percentages similar to those obtained using different analytical parameters. CONCLUSION: The discriminative ability combined with other advantages (e.g. rapid and non-destructive analysis, low cost) makes this new FT-IR method a promising tool for the classification and/or differentiation of vinegars. Copyright © 2010 Society of Chemical Industry

Stir bar sorptive extraction (SBSE) has been evaluated for analysing pesticides in vinegar. The extraction analytical conditions have been optimised using a two-level factorial design expanded further to a central composite design. After optimization, the proposed analytical conditions are: sample volume 40 mL, sampling time 150 min, and stirring speed 1000 rpm. On the basis of the results, it was decided not to add NaCl. The SBSE procedure developed shows detection limits and linear ranges adequate for analysing this type of compound, giving recoveries close to 100%. The repeatability and reproducibility values obtained were lower than 18 and 23%, respectively. The method was applied to a variety of commercial vinegars. SBSE is a very simple, solvent-free, and fast technique with high sensitivities.

Stir bar sorptive extraction (SBSE) was evaluated for analysing volatile compounds in vinegar. The extraction and desorption analytical conditions have been optimised using a two-level factorial design expanded further to a central composite design. This chemometric tool is very appropriate in screening experiments where the aim is to investigate several possibly influential and/or interacting factors. For the extraction step, the optimum analytical conditions were: sample volume 25 ml without dilution, sampling time 120 min, NaCl content 5.85 g, and stirring speed 1250 rpm. For the desorption step, the optimised analytical conditions were: desorption temperature 300 degrees C, cryofocusing temperature -140 degrees C, flow of helium 75 ml min(-1), and desorption time 10 min. The SBSE procedure developed shows detection limits, and linear ranges adequate for analysing this type of compounds. The repeatability values obtained were lower than 10%. SBSE is a very simple, solvent-free, fast technique with better sensitivities, in general, than SPME. However, a disadvantage of this technique is that, up to now, the stir bar offers a limited enrichment capability for polar compounds because is only available with PDMS coating.

A study has been conducted of the separation of sugar acids (gluconic, galacturonic and glucuronic acids) by capillary electrophoresis using indirect UV detection. We have tested various background electrolytes: p-hydroxibenzoic acid, sorbic acid, potassium hydrogen phthalate, protocatechuic acid, α-resorcylic acid and β-resorcylic acid. The choice between these electrolytes was made on the basis of studies of electrophoretic mobility and absorbance values at the wavelengths of our CE system. Of all the electrolytes tested, it was found that β-resorcylic acid best met the required characteristics. The best separation of the three acid was achieved with a time of 8 min, for an electrolyte consisting of 5 mM β-resorcylic acid, 1 mM TTAOH (pH 3.0), indirect detection at 214 nm, -20 kV of run voltage and capillary of 60 cm length and 75 µm i.d. It was found that the proposed method is applicable to samples of both must and wine, and that the samples do not require any prior treatment apart from centrifugation (only in the case of must), filtration and dilution in suitable proportion.

Headspace solid-phase microextraction (HS-SPME) was evaluated for analysing aromatic compounds in vinegar. The fibre used (a Carboxen-polydimethylsiloxane fibre), and the analytical conditions had been optimised in a previous work. The HS-SPME procedure developed shows detection and quantitation limits, and linear ranges adequate for analysing this type of compounds. The recoveries obtained were close to 100%, with repeatability values lower than 20%. However, considerable differences have been detected between different fibres. The method was applied to a variety of Sherry wine vinegars.

Nineteen commercially available aromatised vinegars, which were representative of this type of product, were tested to ascertain their phenolic and volatile composition and antioxidant activity. The aromatised vinegars came from different raw materials such as fruits, spices, herbs and vegetables. The antioxidant activity was determined by means of photochemiluminescence, phenolic profile by using ultra performance liquid chromatography with ultraviolet detection, and the volatile composition was determined by using stir bar sorptive extraction-gas chromatography-mass spectrometry.Nine polyphenolic compounds and 141 volatile compounds were identified. Vinegar aromatised with black truffle and rosemary obtained the highest values of antioxidant activity, followed by those aromatised with lemon, tarragon, aromatic herbs and vegetables. Antioxidant activity was highly correlated with the presence of trans-p-coutaric acid, trans-caftaric acid, 5-hydroxy-methylfurfural and furfural. Moreover, (Z)-3-hexen-1-ol was exclusive to the vinegar aromatised with tarragon, while p-menth-1,8-ol, dimethyl styrene, 4-methyl acetophenone and nootkatone were only found in vinegar aromatised with lemon.On the basis of the results from the cluster analysis of cases, it can be concluded that the grouping responds more to the trademark of each vinegar than to the raw material.

Despite the long history of sherry wine vinegar, new alternatives of consumption are being developed, with the aim of diversifying its market. Several new acetic-based fruit juices have been developed by optimising the amount of sherry wine vinegar added to different fruit juices: apple, peach, orange and pineapple. Once the concentrations of wine vinegar were optimised by an expert panel, the aforementioned new acetic fruit juices were tasted by 86 consumers. Three different aspects were taken into account: habits of consumption of vinegar and fruit juices, gender and age.Based on the sensory analysis, 50 g kg(-1) of wine vinegar was the optimal and preferred amount of wine vinegar added to the apple, orange and peach juices, whereas 10 g kg(-1) was the favourite for the pineapple fruit. Based on the olfactory and gustatory impression, and 'purchase intent', the acetic beverages made from peach and pineapple juices were the most appreciated, followed by apple juice, while those obtained from orange juice were the least preferred by consumers.New opportunities for diversification of the oenological market could be possible as a result of the development of this type of new product which can be easily developed by any vinegar or fruit juice maker company.

A stir bar sorptive extraction gas chromatography–mass spectrometry (SBSE–GC–MS) method has been used for the characterization of the volatile composition of 26 high quality vinegars of three different protected geographical indications (traditional balsamic vinegar of Modena, balsamic vinegar of Modena, and Sherry vinegar). SBSE technique provided the identification of 113 volatile compounds, which belong to different chemical families (short-chain esters, acids, acetates and alcohols, phenols, lactones and benzenic and furanic compounds). 39 volatile compounds were never previously reported in wine vinegars. This characterization contributed to the differentiation of the 100% of the studied samples on the basis of raw material (two different types of wine, and cooked must), aging type (static and dynamic) and aging time (25 years). Furanes and terpenes together with acids and alkanes were the most discriminant variables for raw material and aging time, respectively, whereas for aging type, these ones were acetates and esters.

Due to the diversity of vinegars on the market and the increase in demand, it is considered necessary to investigate and establish criteria for classifying them in order to obtain more information concerning their real origin. New spectroscopic techniques such us mid-infrared spectroscopy with Fourier transform (FT-IR) are capable of providing information in relation to these aspects. FT-IR combined with multivariate analysis has been used to classify vinegars according to the raw materials and production processes (with or without ageing in wood). Principal component analysis (PCA), partial least-squares discriminant analysis regression (PLS-DA) and stepwise linear discriminant analysis (SLDA) were used.The results obtained have been compared to those achieved using different analytical parameters (polyphenolic content, organic acids and volatile compounds). SLDA and PLS-DA results show the ability of mid-FT-IR spectra to discriminate among vinegars from different raw materials and with or without ageing in wood, with correct classification percentages similar to those obtained using different analytical parameters.The discriminative ability combined with other advantages (e.g. rapid and non-destructive analysis, low cost) makes this new FT-IR method a promising tool for the classification and/or differentiation of vinegars.

The volatile composition of 26 premium quality vinegars belonging to three different protected geographical indications (traditional balsamic vinegar of Modena, balsamic vinegar of Modena, and sherry vinegar) has been characterized by means of a solid-phase extraction (SPE) gas chromatography-mass spectrometry GC-MS method. Among the about 90 quantified compounds, short-chain fatty acids, furanic compounds, enolic derivatives, and some esters were found to discriminate the samples as a consequence of differences in the extent of Maillard reactions, presence of alcoholic fermentation, or duration of wood aging.

A solid-phase extraction method for the determination of volatile compounds in traditional balsamic vinegar (TBV) has been developed. The optimisation has been carried out using a two-level factorial design expanded further to a central composite design. LiChrolut-EN SPE cartridges were used and the optimised analytical conditions were: 7 g of TBV diluted 1:4, 5 mL of washing water, and elution with 10 mL of dichloromethane. The linear ranges and detection and quantitation limits were adequate for the analysis of the studied compounds in TBV. The accuracy of the method was also studied: recoveries up to 80% and repeatability values lower than 15% were obtained for the majority of the studied compounds. Two TBVs of different age were analysed by the optimised method.

Stir bar sorptive extraction was evaluated for analysing volatiles in vinegar. The procedure developed shows detection and quantitation limits, and linear ranges adequate for analysing this type of compounds. The accuracy obtained was close to 100%, with repeatability values lower than 13%. The extraction efficiency is inversely affected by the acetic acid content. Although the absolute areas decrease, the compound area/internal standard area ratio remains constant, so for quantitative analysis, the acetic acid concentration does not affect the analytical data. The method was compared with a previous SPME method. Similar performance characteristics were obtained for both methodologies, with lower detection and quantitation limits and better repeatability reproducibility values for SBSE. Both analytical methods were used to analyse a variety of vinegars. The results obtained from both methods were in agreement.

Headspace solid-phase microextraction (HS-SPME) was evaluated for analysing aromatic compounds in vinegar. The fibre used (a Carboxen-polydimethylsiloxane fibre), and the analytical conditions had been optimised in a previous work. The HS-SPME procedure developed shows detection and quantitation limits, and linear ranges adequate for analysing this type of compounds. The recoveries obtained were close to 100%, with repeatability values lower than 20%. However, considerable differences have been detected between different fibres. The method was applied to a variety of Sherry wine vinegars.

Headspace solid-phase microextraction has been applied to the analysis of aroma compounds in vinegar. Silica fibre coated with Carboxen–polydimethylsiloxane was found to be more efficient at extracting these compounds than other fibres such as those coated with polydimethylsiloxane, Carbowax–divinylbenzene, and polydimethylsiloxane–divinylbenzene, but its repeatability was low. Different parameters such as extraction time, temperature of the sample during the extraction, ionic strength, and sample volume were optimised using a two-level factorial design expanded further to a central composite design. This chemometric tool is very appropriate in screening experiments where the aim is to investigate several possibly influential and/or interacting factors. The extraction efficiency is inversely affected by the acetic acid content—an increase in the acetic acid concentration decreases the extraction efficiency. No interference is observed with the increase in content of polyphenols.