Open AccessReview
Saccharomyces species in the Production of Beer
Beverages 2016, 2(4), 34; doi:10.3390/beverages2040034 -
Abstract
The characteristic flavour and aroma of any beer is, in large part, determined by the yeast strain employed and the wort composition. In addition, properties such as flocculation, wort fermentation ability (including the uptake of wort sugars, amino acids, and peptides), ethanol and
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The characteristic flavour and aroma of any beer is, in large part, determined by the yeast strain employed and the wort composition. In addition, properties such as flocculation, wort fermentation ability (including the uptake of wort sugars, amino acids, and peptides), ethanol and osmotic pressure tolerance together with oxygen requirements have a critical impact on fermentation performance. Yeast management between fermentations is also a critical brewing parameter. Brewer’s yeasts are mostly part of the genus Saccharomyces. Ale yeasts belong to the species Saccharomyces cerevisiae and lager yeasts to the species Saccharomyces pastorianus. The latter is an interspecies hybrid between S. cerevisiae and Saccharomyces eubayanus. Brewer’s yeast strains are facultative anaerobes—they are able to grow in the presence or absence of oxygen and this ability supports their property as an important industrial microorganism. This article covers important aspects of Saccharomyces molecular biology, physiology, and metabolism that is involved in wort fermentation and beer production. Full article
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Open AccessArticle
Extraction of Mangiferin and Chemical Characterization and Sensorial Analysis of Teas from Mangifera indica L. Leaves of the Ubá Variety
Beverages 2016, 2(4), 33; doi:10.3390/beverages2040033 -
Abstract
Mangiferin is present in various parts of Mangifera indica L. and has proven biological activities, such as antioxidant capabilities. The aim of this work was to evaluate the chemical composition of teas prepared from M. indica leaves, their potential use as a source
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Mangiferin is present in various parts of Mangifera indica L. and has proven biological activities, such as antioxidant capabilities. The aim of this work was to evaluate the chemical composition of teas prepared from M. indica leaves, their potential use as a source of mangiferin and their total phenolic compounds. Teas were prepared with young and mature leaves of M. indica at three (medicinal plant: solvent) ratios utilizing three different preparation techniques. The mangiferin content was analyzed via high-performance liquid chromatography (HPLC). The tea with the highest mangiferin content was characterized for its total phenolic content and antioxidant activity. The oxidative stability was also evaluated by quantifying mangiferin, total phenolics and antioxidant activity using two preservation treatments for 0, 24 and 48 h. Sensory analysis was performed to measure the acceptance of the tea. The type of leaf, preparation technique and concentration influenced the mangiferin content in the teas. The highest concentration of mangiferin was obtained through decoction at a 5% (w/v) medicinal plant concentration. This tea exhibited stability up to 48 h after preparation under both preservation treatments and provided a positive sensory acceptance for consumers with flavors added. In conclusion, teas made from M. indica leaves have great potential as sources of mangiferin and phenolic compounds. Full article
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Open AccessFeature PaperArticle
Influence of Wine Education on Wine Hedonic and Confidence Ratings by Millennial Wine Consumers of Different Ethnicities
Beverages 2016, 2(4), 32; doi:10.3390/beverages2040032 -
Abstract
Consumer wine preferences are not well understood. Anecdotally it is believed that preferences evolve over time, from sweet whites to full-bodied reds, as consumers become more experienced and familiar with wine. However, little is known about the change in wine preference or confidence
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Consumer wine preferences are not well understood. Anecdotally it is believed that preferences evolve over time, from sweet whites to full-bodied reds, as consumers become more experienced and familiar with wine. However, little is known about the change in wine preference or confidence with education and training. This research explored changes in consumers’ hedonic and confidence ratings for five commercial British Columbian (BC) wines (Ehrenfelser, Chardonnay, rosé, Pinot noir, Cabernet-Merlot) over a 12-week education/training period. Consumers (n = 133) completed a wine survey and evaluated the wines during the first and twelfth week of a university wine course, consisting of wine education and sensory training. Consumers provided hedonic (degree-of-liking) and confidence (degree-of-sureness) ratings for the visual, aroma and flavor characteristics of the wines, on 9-point and 5-point scales, respectively, before and after the 12-week wine course. Consumers were classified by gender (female, male), age and ethnicity. Kruskal Wallis, Mann-Whitney, Friedman, Wilcoxon Signed Rank and Chi-square tests and Spearman correlation coefficients were used to explore the effects of education/training on hedonic and confidence ratings. In general, consumers’ hedonic (visual, aroma, flavor) ratings increased significantly with education/training for the white and rosé wines (Ehrenfelser, Chardonnay, rosé) over the 12-week period. In contrast, consumer confidence increased substantially for all wine types. Surveys revealed, for the three largest subgroups of consumers (North American (NA), n = 38; European (EU), n = 31; Asian, n = 54), that NA and EU consumers had significantly higher frequency-of-purchase, frequency-of-purchase of Canadian wine, frequency-of-consumption and self-rated wine knowledge than Asian consumers. However, Asian consumers were willing to pay more for a bottle of wine compared to NA and EU consumers. This research provided insight into the millennial consumers and explored the nature and magnitude of changes in hedonic and confidence ratings with wine education/training. Full article
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Open AccessArticle
Tune That Beer! Listening for the Pitch of Beer
Beverages 2016, 2(4), 31; doi:10.3390/beverages2040031 -
Abstract
We report two experiments designed to assess the key sensory drivers underlying people’s association of a specific auditory pitch with Belgian beer. In particular, we assessed if people would rely mostly on the differences between beers in terms of their relative alcohol strength,
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We report two experiments designed to assess the key sensory drivers underlying people’s association of a specific auditory pitch with Belgian beer. In particular, we assessed if people would rely mostly on the differences between beers in terms of their relative alcohol strength, or on the contrast between the most salient taste attributes of the different beers. In Experiment 1, the participants rated three bitter beers (differing in alcohol content), using a narrow range of pitch choices (50–500 Hz). The results revealed that the beers were all rated around the same pitch (Mean = 232 Hz, SD = 136 Hz). In Experiment 2, a wider range of pitch choices (50–1500 Hz), along with the addition of a much sweeter beer, revealed that people mostly tend to match beers with bitter-range profiles at significantly lower pitch ranges when compared to the average pitch of a much sweeter beer. These results therefore demonstrate that clear differences in taste attributes lead to distinctly different matches in terms of pitch. Having demonstrated the robustness of the basic crossmodal matching, future research should aim to uncover the basis for such matches and better understand the perceptual effects of matching/non-matching tones on the multisensory drinking experience. Full article
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Open AccessFeature PaperReview
Saccharomyces cerevisiae in the Production of Fermented Beverages
Beverages 2016, 2(4), 30; doi:10.3390/beverages2040030 -
Abstract
Alcoholic beverages are produced following the fermentation of sugars by yeasts, mainly (but not exclusively) strains of the species, Saccharomyces cerevisiae. The sugary starting materials may emanate from cereal starches (which require enzymatic pre-hydrolysis) in the case of beers and whiskies, sucrose-rich
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Alcoholic beverages are produced following the fermentation of sugars by yeasts, mainly (but not exclusively) strains of the species, Saccharomyces cerevisiae. The sugary starting materials may emanate from cereal starches (which require enzymatic pre-hydrolysis) in the case of beers and whiskies, sucrose-rich plants (molasses or sugar juice from sugarcane) in the case of rums, or from fruits (which do not require pre-hydrolysis) in the case of wines and brandies. In the presence of sugars, together with other essential nutrients such as amino acids, minerals and vitamins, S. cerevisiae will conduct fermentative metabolism to ethanol and carbon dioxide (as the primary fermentation metabolites) as the cells strive to make energy and regenerate the coenzyme NAD+ under anaerobic conditions. Yeasts will also produce numerous secondary metabolites which act as important beverage flavour congeners, including higher alcohols, esters, carbonyls and sulphur compounds. These are very important in dictating the final flavour and aroma characteristics of beverages such as beer and wine, but also in distilled beverages such as whisky, rum and brandy. Therefore, yeasts are of vital importance in providing the alcohol content and the sensory profiles of such beverages. This Introductory Chapter reviews, in general, the growth, physiology and metabolism of S. cerevisiae in alcoholic beverage fermentations. Full article
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Open AccessReview
Drink Red: Phenolic Composition of Red Fruit Juices and Their Sensorial Acceptance
Beverages 2016, 2(4), 29; doi:10.3390/beverages2040029 -
Abstract
Consumers’ food quality perception and sensorial experience are important in food consumption behavior and food choice. Red fruit juices are appreciated fruit juices for almost all consumers, due to their flavor and intense red color. Studies have also shown that their phytochemical composition,
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Consumers’ food quality perception and sensorial experience are important in food consumption behavior and food choice. Red fruit juices are appreciated fruit juices for almost all consumers, due to their flavor and intense red color. Studies have also shown that their phytochemical composition, which is associated with their antioxidant activity, shows a protective effect against many chronic diseases. Nevertheless, the profile and concentration of anthocyanins are different in function of the fruit used; therefore, the color and health benefits of the juices also show differences. Some red fruit juices have lower concentrations of anthocyanins, for example strawberry, and others have higher concentrations, such as elderberry and black currant juices. High correlation was observed between antioxidant activity and red fruit juices’ total anthocyanins concentration. Therefore, this review will addresses red fruit juices phenolic composition, with a special focus on the challenges for future, and some ideas on the sensory impact. Full article
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Open AccessArticle
Assessment of Ethyl Carbamate Contamination in Cachaça (Brazilian Sugar Cane Spirit)
Beverages 2016, 2(4), 28; doi:10.3390/beverages2040028 -
Abstract
Cachaça is a sugar cane spirit produced in Brazil. Ethyl carbamate (EC), a potential carcinogenic compound, may be present in cachaça above the limit established by law. The purpose of this study was to determine the concentration of ethyl carbamate in cachaças recently
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Cachaça is a sugar cane spirit produced in Brazil. Ethyl carbamate (EC), a potential carcinogenic compound, may be present in cachaça above the limit established by law. The purpose of this study was to determine the concentration of ethyl carbamate in cachaças recently produced in Brazil in order to verify their compliance with the law. The concentration of ethyl carbamate was determined in 376 samples of cachaça through gas chromatography coupled to a mass spectrometer (GC-MS). The mean value of ethyl carbamate in the cachaças analyzed was 145 µg/L, and 24% of them were not in compliancy with the law (EC < 210 µg/L). However, compared to previous studies, advances have been observed regarding the adjustment of cachaças to the legal limit. Cachaças produced in large distilleries through continuous column distillation presented a mean value of 200 µg/L of ethyl carbamate. Cachaças produced in small distilleries using pot still distillation presented a mean content of 74 µg/L. Small producers have been more engaged in using good manufacturing practices to guarantee the quality of cachaças. Full article
Open AccessArticle
Influence of Sample Storage on the Composition of  Carbonated Beverages by MIR Spectroscopy
Beverages 2016, 2(4), 26; doi:10.3390/beverages2040026 -
Abstract
It is not uncommon for research and quality control samples, including carbonated beverage samples, to be refrigerated or frozen during peak periods of production and/or sampling, when analytical demand exceeds instrumental capacity. However, the effect of sub‐ambient temperatures on carbonated beverage composition during
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It is not uncommon for research and quality control samples, including carbonated beverage samples, to be refrigerated or frozen during peak periods of production and/or sampling, when analytical demand exceeds instrumental capacity. However, the effect of sub‐ambient temperatures on carbonated beverage composition during storage has not been well characterized. Mid‐infrared (MIR) spectroscopy combined with principal component analysis (PCA) and traditional chemical analyses were used to evaluate the effects of refrigeration (for 1 week) and freezing (for 1 or 6 weeks) on the composition of carbonated beverages, including sparkling water, sparkling wine, beer, and cider. Carbonated beverages were generally resistant to changes in pH, titratable acidity, alcohol, total phenolics, sugar, and color, during short‐term (1 week) storage. However, long‐term (6 week) freezing resulted in decreased total phenolics, with acidity also affected, albeit to a lesser extent. MIR spectroscopy combined with PCA enabled discrimination of carbonated beverages based on composition, with alcohol content having a significant influence. Examination of the MIR ‘fingerprint’ region indicated subtle compositional changes occurred in carbonated beverages following prolonged freezing. Full article
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Open AccessArticle
Some Contributions to the Study of Oenological Lactic Acid Bacteria through Their Interaction with Polyphenols
Beverages 2016, 2(4), 27; doi:10.3390/beverages2040027 -
Abstract
Probiotic features and the ability of two oenological lactic acid bacteria strains (Pediococcus pentosaceus CIAL‐86 and Lactobacillus plantarum CIAL‐121) and a reference probiotic strain (Lactobacillus plantarum CLC 17) to metabolize wine polyphenols are examined. After summarizing previous results regarding their resistance to lysozyme,
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Probiotic features and the ability of two oenological lactic acid bacteria strains (Pediococcus pentosaceus CIAL‐86 and Lactobacillus plantarum CIAL‐121) and a reference probiotic strain (Lactobacillus plantarum CLC 17) to metabolize wine polyphenols are examined. After summarizing previous results regarding their resistance to lysozyme, gastric juice and bile salts, the three strains were assessed for their ability to release phenolic metabolites after their incubation with a wine phenolic extract. Neither of the two bacteria were able to metabolize wine polyphenols, at least in the conditions used in this study, although a certain stimulatory effect on bacterial growth was observed in the presence of a wine‐derived phenolic metabolite (i.e., 3,4‐dihydroxyphenylacetic acid) and a wine phenolic compound (i.e., (+) ‐catechin). Bacteria cell‐free supernatants from the three strains delayed and inhibited almost completely the growth of the pathogen E. coli CIAL‐153, probably due to the presence of organic acids derived from the bacterial metabolism of carbohydrates. Lastly, the three strains showed a high percentage of adhesion to intestinal cells, and pre‐incubation of Caco‐2 cells with bacteria strains prior to the addition of E. coli CIAL‐153 produced a notable inhibition of the adhesion of E. coli to the intestinal cells. Full article
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Open AccessArticle
Bottled vs. Canned Beer: Do They Really Taste Different?
Beverages 2016, 2(4), 25; doi:10.3390/beverages2040025 -
Abstract
People often say that beer tastes better from a bottle than from a can. However, one can ask how reliable this perceived difference is across consumers. And, if reliable, one can further ask whether it is a purely psychological phenomenon (associated with the
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People often say that beer tastes better from a bottle than from a can. However, one can ask how reliable this perceived difference is across consumers. And, if reliable, one can further ask whether it is a purely psychological phenomenon (associated with the influence of packaging on taste perception), or whether instead it reflects some more mundane physico-chemical interaction between the packaging material (or packing procedure/process) and the contents. Two experiments were conducted in order to address these questions. In the main experiment, 151 participants at the 2016 Edinburgh Science Festival were served a special ‘craft beer’ in a plastic cup. The beer was either poured from a bottle or can (a between-participants experimental design was used). The participants were encouraged to pick up the packaging in order to inspect the label before tasting the beer. The participants rated the perceived taste, quality, and freshness of the beer, as well as their likelihood of purchase, and estimated the price. All of the beer came from the same batch (specifically a Session IPA from Barney’s Brewery in Edinburgh). None of the participants were familiar with this particular craft brew. Nevertheless, those who evaluated the beer from the bottle rated it as tasting better than those who rated the beer served from the can. Having demonstrated such a perceptual difference (in terms of taste), we then went on to investigate whether people would prefer one packaging format over the other when the beer from bottle and can was served blind to a new group of participants (i.e., when the participants did not know the packaging material). The participants in this control study (n = 29) were asked which beer they preferred. Alternatively, they could state that the two samples tasted the same. No sign of a consistent preference was obtained under such blind tasting conditions. Explanations for the psychological impact of the packaging format, in terms of differences in packaging weight (between tin and glass), and/or prior associations of quality with specific packaging materials/formats (what some have chosen to call ‘image molds’), are discussed. Full article
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Open AccessArticle
The Physicochemical Optimization and Acceptability of a Cashew Nut-Based Beverage Varying in Mango Juice and Sugar: A Pilot Study
Beverages 2016, 2(3), 23; doi:10.3390/beverages2030023 -
Abstract
The development of a lactose-free beverage comes as a new feeding alternative to a product with excellent nutritional and functional characteristics to individuals with food restrictions related to milk. Thus, this study aimed to develop a cashew nut beverage with added mango juice
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The development of a lactose-free beverage comes as a new feeding alternative to a product with excellent nutritional and functional characteristics to individuals with food restrictions related to milk. Thus, this study aimed to develop a cashew nut beverage with added mango juice and prebiotic substances by means of evaluating its sensory characteristics and physicochemical optimization. A 22 central composite rotatable design with five repetitions at the central point was applied to evaluate the effect of sugar and juice contents on the analyzed parameters. Data were evaluated by means of the response surface methodology, analysis of variance, and the means comparison test. Formulations with greater combined concentrations of juice and sugar obtained satisfactory acceptance. The means comparison test showed that the formulation that allows for the beverage’s greatest acceptance must contain 40% mango juice and 8% sugar. Soluble solids content was influenced only by the addition of sugar, where the formulations that presented greater solids concentration were the ones which obtained greater sensory acceptance. The beverage’s acidity was influenced only by the juice content, which, besides making formulations significantly more acid, did not affect their acceptance. Full article
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Open AccessArticle
A Colorimetric Method for the Determination of the Exhaustion Level of Granular Activated Carbons Used in Rum Production
Beverages 2016, 2(3), 24; doi:10.3390/beverages2030024 -
Abstract
Spectrophotometric measurement applied on saturated granular activated carbon (GAC) is not yet explored. A colorimetric method in the visible range has been developed in order to determine the exhaustion level of GAC used in rum production. Aqueous ammonia solution has been used as
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Spectrophotometric measurement applied on saturated granular activated carbon (GAC) is not yet explored. A colorimetric method in the visible range has been developed in order to determine the exhaustion level of GAC used in rum production. Aqueous ammonia solution has been used as an indicative agent to determine the extraction rate of taste compounds within the rum production process and the exhaustion degree of the GAC. The colorimetric results showed excellent correlation with the iodine number and the contact pH. The proposed colorimetric method opens possibilities for rum producers to improve the management and economical use of the activated carbon at the industrial scale. Full article
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Open AccessReview
Fruit Juice Production Using Ultraviolet Pasteurization: A Review
Beverages 2016, 2(3), 22; doi:10.3390/beverages2030022 -
Abstract
Ultraviolet (UV-C at 253.7 nm) technology has been the go-to alternative pasteurization and shelf-life extension treatment for beverages for the last two decades. It has been the focal point of non-thermal methods for fruit juice processing and has been studied extensively. UV-C technology
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Ultraviolet (UV-C at 253.7 nm) technology has been the go-to alternative pasteurization and shelf-life extension treatment for beverages for the last two decades. It has been the focal point of non-thermal methods for fruit juice processing and has been studied extensively. UV-C technology has been proven to produce microbiologically safe products with minimal negative impact towards quality of the products. However, due to the physicochemical characteristics of fruit juice, application of UV-C does have certain limitations and thus, there is a need to further study the effects of UV-C-treatment and equipment design. Critical decisions on the type of fruit product, juice color, juice composition, and juice physical characteristics, among other variables, are imperative to produce a safe and wholesome juice. Therefore, this paper serves as a source for development of UV-C technology for pasteurization and shelf-life extension of fruit juice to successfully obtain a final product with minimal changes of its nutritional component without neglecting the microbial safety. It reviews previous literatures involving ultraviolet-treated fruit juices, ranging from popular apple and orange juice to lesser-known pummelo and pitaya juice. The review also covers the aspect of microbiological and chemical safety, quality, and sensory characteristics as well as hurdle technology involving UV-C as the main method and the market potential with its cost implication of UV-C technology. Full article
Open AccessArticle
Brewing Technique of Mbege, a Banana Beer Produced in Northeastern Tanzania
Beverages 2016, 2(3), 21; doi:10.3390/beverages2030021 -
Abstract
Mbege is a beer made of banana (Musa spp.) and finger millet (Eleusine coracana). It is the most popular indigenous alcoholic beverage in northeastern Tanzania, and plays an important role in the economy of the region. In this study, we
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Mbege is a beer made of banana (Musa spp.) and finger millet (Eleusine coracana). It is the most popular indigenous alcoholic beverage in northeastern Tanzania, and plays an important role in the economy of the region. In this study, we observed and recorded a detailed traditional technique for brewing mbege. We observed that mbege production was divided into three major steps: nyalu preparation, mso preparation, and mixing. Fermented porridge made of ripened banana, called nyalu, was used as a source of yeasts. As a source of fermentable sugars, a sweet porridge made of germinated finger millet called mso was used. In mso preparation, a brewing technique to enhance the effectiveness of saccharification was used. After the preparation, these two types of porridge were mixed. The ethanol concentration of the mixture increased when it was fermented for 6 h, and it then became mbege. It was supposed that yeasts in the nyalu converted fermentable sugars in the mso into ethanol. We found that the brewing technique used in the production of mbege in northeast Tanzania was similar to that used in southern Tanzania. We also demonstrated that the stem bark of Rauvolfia caffra, which was called msesewe and used as an additive in mbege production, accelerated the fermentation of nyalu and therefore increased the rate of ethanol production in the brewing of mbege. This result was consistent with the traditional knowledge in the field about the effect of msesewe on mbege production. Full article
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Open AccessReview
Microbial Glycosidases for Wine Production
Beverages 2016, 2(3), 20; doi:10.3390/beverages2030020 -
Abstract
Winemaking is a complex process involving the interaction of different microbes. The two main groups of microorganisms involved are yeasts and bacteria. The yeasts present in spontaneous fermentation may be divided into two groups: the Saccharomyces yeasts, particularly S. cerevisiae; and the
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Winemaking is a complex process involving the interaction of different microbes. The two main groups of microorganisms involved are yeasts and bacteria. The yeasts present in spontaneous fermentation may be divided into two groups: the Saccharomyces yeasts, particularly S. cerevisiae; and the non-Saccharomyces yeasts, which include members of the genera Rhodotorula, Pichia, Candida, Debaryomyces, Metschtnikowia, Hansenula, and Hanseniaspora. S. cerevisiae yeasts are able to convert sugar into ethanol and CO2 via fermentation. They have been used by humans for thousands of years for the production of fermented beverages and foods, including wine. Their enzymes provide interesting organoleptic characteristics in wine. Glycosidases with oenological implications have been widely reported in yeasts, bacteria, and fungi. β-Glucosidase activity is involved in the release of terpenes to wine, thus contributing to varietal aroma. α-Rhamnosidase, α-arabinosidase, or β-apiosidase activities have also been reported to contribute to the wine production process. Oenococcus oeni (a lactic acid bacteria present in wine) also has numerous glycosidases, and their activities contribute to the liberation of several aromatic compounds which contribute to floral and fruity wine characteristics. Full article
Open AccessArticle
Understanding Consumer Preferences for Australian Sparkling Wine vs. French Champagne
Beverages 2016, 2(3), 19; doi:10.3390/beverages2030019 -
Abstract
Sparkling wine represents a small but significant proportion of the Australian wine industry’s total production. Yet, Australia remains a significant importer of French Champagne. This study investigated consumer preferences for Australian sparkling wine vs. French Champagne and any compositional and/or sensorial bases for
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Sparkling wine represents a small but significant proportion of the Australian wine industry’s total production. Yet, Australia remains a significant importer of French Champagne. This study investigated consumer preferences for Australian sparkling wine vs. French Champagne and any compositional and/or sensorial bases for these preferences. A range of French and Australian sparkling wines were analyzed by MIR spectroscopy to determine if sparkling wines could be differentiated according to country of origin. A subset of wines, comprising two French Champagnes, a French sparkling wine and three Australian sparkling wines, were selected for (i) descriptive analysis to characterize their sensory profiles and (ii) acceptance tests to determine consumer liking (n = 95 Australian wine consumers). Significant differences were observed between liking scores; on average, the $70 French Champagne was liked least and the $12 Australian sparkling wine liked most, but segmentation (based on individual liking scores) identified clusters comprising consumers with distinct wine preferences. Interestingly, when consumers were shown wine bottle labels, they considered French wines to be more expensive than Australian wines, demonstrating a clear country of origin influence. Full article
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Open AccessArticle
Phenolic Composition and Color of Single Cultivar Young Red Wines Made with Mencia and Alicante-Bouschet Grapes in AOC Valdeorras (Galicia, NW Spain)
Beverages 2016, 2(3), 18; doi:10.3390/beverages2030018 -
Abstract
Single cultivar wines made with two different red grape cultivars from AOC Valdeorras (Galicia, NW Spain), Mencia and Alicante Bouschet, were studied with the aim of determining their color and phenolic composition. Two sets of analyses were made on 30 wine samples of
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Single cultivar wines made with two different red grape cultivars from AOC Valdeorras (Galicia, NW Spain), Mencia and Alicante Bouschet, were studied with the aim of determining their color and phenolic composition. Two sets of analyses were made on 30 wine samples of 2014 vintage, after malolactic fermentation took place, to evaluate several physicochemical characteristics from these wines related to color and polyphenols. Several parameters related with color and the general phenolic composition of wines (total phenols index, color intensity, hue, total anthocyans, total anthocyanins, colored anthocyanins, chemical age index, and total tannins) were determined by UV-VIS spectrophotometry. Those analyses revealed that Alicante Bouschet wines presented, in general, a higher content of polyphenols and a more intense color than Mencia wines. Using HPLC-DAD, five anthocyanin monoglucosides and nine acylated anthocyanins were identified in both types of wine; each type of wine showed a distinctive anthocyanin fingerprint, as Alicante Bouschet wines contained a higher proportion of cyanidin-derived anthocyanins. Multivariate statistic studies were performed to both datasets to explore relationships among variables and among samples. These studies revealed relationships among several variables considered, and were capable to group the samples in two different classes using principal component analysis (PCA). Full article
Open AccessArticle
Influence of Steep Time on Polyphenol Content and Antioxidant Capacity of Black, Green, Rooibos, and Herbal Teas
Beverages 2016, 2(3), 17; doi:10.3390/beverages2030017 -
Abstract
Potential health benefits of tea consumption are often attributed to the antioxidant activity of polyphenols. Whether steep time, often variable in a real-life situation, makes a biological difference in terms of polyphenol content and antioxidant activity is uncertain. The study objective was to
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Potential health benefits of tea consumption are often attributed to the antioxidant activity of polyphenols. Whether steep time, often variable in a real-life situation, makes a biological difference in terms of polyphenol content and antioxidant activity is uncertain. The study objective was to characterize eight popular and commercially available teas for total polyphenol content (TPC) and antioxidant capacity in relation to steep time. Dragonwell (DW), Sencha (S), English Breakfast (EB), Golden Monkey (GM), Green Rooibos (GR), Red Rooibos (RR), Chamomile (C), and Peppermint (P) loose leaf teas were individually steeped in water for 1–10 min at 1 min intervals. TPC increased with longer durations of steep time; however, the majority of polyphenols observed after 10 minutes were extracted in the first 5 min regardless of tea type. After 5 min of steeping, differences (p < 0.05) in TPC were observed across teas (JS~EB~P > DW > GM~GR~RR > C). Different teas also varied in their ability to inhibit the free radical 2, 2-diphenyl-1-picrylhydrazyl (DPPH) when normalized for polyphenol concentration (1 µg/mL) and there was no effect due to steep time. Predicted antioxidant capacity of teas also demonstrated significant differences among teas after 5 and 10 min. In conclusion, steep time modulates TPC but not the antioxidative capacity of tea polyphenols. Full article
Open AccessReview
The Effect of Dietary Supplementation of Green Tea Catechins on Cardiovascular Disease Risk Markers in Humans: A Systematic Review of Clinical Trials
Beverages 2016, 2(2), 16; doi:10.3390/beverages2020016 -
Abstract
Green tea catechins (GTCs) are secondary plant metabolites that have been associated with health benefits in human trials. As such, they have the potential to reduce cardiovascular disease (CVD) risk; however, results are not consistent. This systematic review of the published data assessed
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Green tea catechins (GTCs) are secondary plant metabolites that have been associated with health benefits in human trials. As such, they have the potential to reduce cardiovascular disease (CVD) risk; however, results are not consistent. This systematic review of the published data assessed the putative effect of GTCs supplementation on anthropometric, blood pressure, and biochemical measures associated with CVD risk. It was conducted in accordance with the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines exploring four major electronic databases (MEDLINE, Cochrane Library, Web of Science, and Scopus). Studies were included if they were published in peer-reviewed journals in English from 1990 until October 2015, and were human double-blind randomized and placebo-controlled trials (RCTs). From 122,428 articles initially identified, after two levels of screening, seven studies met the inclusion criteria. The review revealed consistent and significant (p ≤ 0.05) reductions in body mass index (BMI), blood pressure and plasma lipids; however, this effect would have been less if between-group effects had been considered. The current evidence base also has considerable methodological limitations due to suboptimal statistical methods used in data analyses. Future research efforts must aim to rectify this paucity of evidence with well-designed and well-reported prospective studies. Full article
Open AccessArticle
Ultra High Pressure Homogenization of Soy Milk: Effect on Quality Attributes during Storage
Beverages 2016, 2(2), 15; doi:10.3390/beverages2020015 -
Abstract
The present work analyzed soy milk prepared from whole dehulled soybeans. The traditional method of soy milk preparation leads to wastage of about 35% of soybean solids in the form of okara, which gets filtered out. In the current study, soy milk was
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The present work analyzed soy milk prepared from whole dehulled soybeans. The traditional method of soy milk preparation leads to wastage of about 35% of soybean solids in the form of okara, which gets filtered out. In the current study, soy milk was prepared with practically 100% recovery of soybean solids and treated with continuous flow high pressure processing (207 and 276 MPa pressure, 121 and 145 °C exit temperatures, and 0.75 and 1.25 L/min flow rates), and the changes in the physical, chemical, microbial, and sensory properties during 28 days of storage at 4 °C were analyzed. The treated soy milk remained stable for 28 days. There was a significant reduction in the particle size of soybean solids which did not change during storage. The pH of the treated soy milk was significantly lower than the untreated soy milk and it reduced further upon storage. The soy milk was pasteurized with high pressure processing coupled with preheating. No lipoxygenase activity was detected. Compared to commercial samples, there was no significant difference in the astringency, bitterness, or chalkiness of soy milk prepared in the study. Full article