An alcoholic beverage (35.4% v/v ethanol) was produced by distillation of the fermented broth obtained by continuous whey fermentation with a lactose-fermenting yeast Kluyveromyces marxianus. Forty volatile compounds were identified in this drink by gas chromatography. Higher alcohols were the most abundant group of volatile compounds present, with isoamyl, isobutyl, 1-propanol, and isopentyl alcohols being found in highest quantities (887, 542, 266, and 176 mg/l, respectively). Ethyl acetate had the highest concentration (138 mg/l) among the esters. Besides higher alcohols and esters, other components, including aldehydes, acids and terpenes were also identified in the whey spirit. Considering that the quality of an alcoholic beverage can be evaluated by the relation between isoamyl alcohol/ 2-methyl-1-propanol and 2-methyl-1-propanol/1-propanol, which have to be higher than unity, it was concluded that a novel spirit of acceptable organoleptic characteristics can be produced by cheese whey continuous fermentation with K. marxianus.

a b s t r a c tThe main aim of this work was to produce fruit wines from pulp of gabiroba, cacao, umbu, cupuassu and jaboticaba and characterize them using gas chromatographyemass spectrometry for determination of minor compounds and gas chromatography-flame ionization detection for major compounds. Ninetynine compounds (C 6 compounds, alcohols, monoterpenic alcohols, monoterpenic oxides, ethyl esters, acetates, volatile phenols, acids, carbonyl compounds, sulfur compounds and sugars) were identified in fruit wines. The typical composition for each fruit wine was evidenced by principal component analysis and Tukey test. The yeast UFLA CA 1162 was efficient in the fermentation of the fruit pulp used in this work. The identification and quantification of the compounds allowed a good characterization of the fruit wines. With our results, we conclude that the use of tropical fruits in the production of fruit wines is a viable alternative that allows the use of harvest surpluses and other underused fruits, resulting in the introduction of new products into the market.

A significant part of the compounds present in wines having six carbon atoms, the C 6 -compounds, derive from grape polyunsaturated fatty acids (primarily originated from membrane lipids), namely linoleic and ␣-linolenic acids, through a cascade of enzymatic reactions. This biochemical pathway yield C 6 -aldehydes, which are subsequently reduced to C 6 -alcohols, which can, in turn, be esterified to produce esters. As the C 6compounds derive from varietal precursors, they could hypothetically contribute to judge wine origin and affiliation. In this way, two C 6 -alcohols, (E)-3-hexenol and (Z)-3-hexenol, have been referred as the most important because its ratio can act as an indicator of the variety of origin.This study presents the results, concerning the concentration of the three main C 6 -alcohols, 1-hexanol, (E)-3-hexenol and (Z)-3-hexenol, as well as ratios between them, for 43 monovarietal wines from Vinhos Verdes demarcated region, belonging to six white -Alvarinho (8), Arinto (1), Avesso (9), Azal (1), Loureiro (17) and Trajadura (4) -and three red -Amaral (1), Borraçal (1) and Vinhão (1) -grape varieties. Wines were produced at experimental scale using slightly different winemaking practices and representing various terroirs and vintages, being analyzed after different conservation periods.The results showed that (E)-3-hexenol/(Z)-3-hexenol ratio clearly discriminates Loureiro wines from those of Alvarinho, Avesso and Trajadura. Moreover, 1-hexanol/(E)-3-hexenol and 1-hexanol/(Z)-3-hexenol ratios may also be able to discriminate Vinhos Verdes monovarietal wines, and can act on a second level differentiation. The remaining monovarietal wines produced results which may be observed as indicative, since only one sample of each was analysed.

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a b s t r a c tMead is a traditional drink that contains 8%e18% (v/v) of ethanol, resulting from the alcoholic fermentation of diluted honey by yeasts. Mead fermentation is a time-consuming process and the quality of the final product is highly variable. Therefore, the present investigation had two main objectives: first, to determine the adequate inoculum size of two commercial wine-making strains of Saccharomyces cerevisiae for the optimisation of mead fermentation; and second, to determine if an increase in yeast pitching rates in batch fermentations altered the resulting aroma profiles. Minor differences were detected in the growth kinetics between the two strains at the lowest pitching rate. With increasing pitching rates net growth of the strain ICV D47 progressively decreased, whereas for the QA23 the increasing inoculum size had no influence on its net growth. The time required to reach the same stage of fermentation ranged from 24 to 96 h depending on the inoculum size. The final aroma composition was dependent on the yeast strain and inoculum size. Fourteen of the twenty-seven volatile compounds quantified could contribute to mead aroma and flavour because their concentrations rose above their respective thresholds. The formation of these compounds was particularly pronounced at low pitching rates, except in mead fermented by strain ICV D47, at 10 6 CFUs/mL. The esters isoamyl acetate, ethyl octanoate and ethyl hexanoate were the major powerful odourants found in the meads. The results obtained in this study demonstrate that yeast strain and inoculum size can favourably impact mead's flavour and aroma profiles.

Cheese whey (CW) and deproteinised cheese whey (DCW) were investigated for their suitability as novel substrates for the production of kefir-like beverages. Lactose consumption, ethanol production, as well as organic acids and volatile compounds formation, were determined during CW and DCW fermentation by kefir grains and compared with values obtained during the production of traditional milk kefir. The results showed that kefir grains were able to utilise lactose from CW and DCW and produce similar amounts of ethanol (7.8-8.3 g/l), lactic acid (5.0 g/l) and acetic acid (0.7 g/l) to those obtained during milk fermentation. In addition, the concentration of higher alcohols (2-methyl-1-butanol, 3-methyl-1-butanol, 1-hexanol, 2-methyl-1-propanol, and 1-propanol), ester (ethyl acetate) and aldehyde (acetaldehyde) in cheese whey-based kefir and milk kefir beverages were also produced in similar amounts. Cheese whey and deproteinised cheese whey may therefore serve as substrates for the production of kefir-like beverages similar to milk kefir.

To evaluate the potential for fermentation of raspberry pulp, sixteen yeast strains (S. cerevisiae and S. bayanus) were studied. Volatile compounds were determined by GC-MS, GC-FID, and GC-PFPD. Ethanol, glycerol and organic acids were determined by HPLC. HPLC-DAD was used to analyse phenolic acids. Sensory analysis was performed by trained panellists. After a screening step, CAT-1, UFLA FW 15 and S. bayanus CBS 1505 were previously selected based on their fermentative characteristics and profile of the metabolites identified. The beverage produced with CAT-1 showed the highest volatile fatty acid concentration (1542.6 μg/L), whereas the beverage produced with UFLA FW 15 showed the highest concentration of acetates (2211.1 μg/L) and total volatile compounds (5835 μg/L). For volatile sulphur compounds, 566.5 μg/L were found in the beverage produced with S. bayanus CBS 1505. The lowest concentration of volatile sulphur compounds (151.9 μg/L) was found for the beverage produced with UFLA FW 15. In the sensory analysis, the beverage produced with UFLA FW 15 was characterised by the descriptors raspberry, cherry, sweet, strawberry, floral and violet. In conclusion, strain UFLA FW 15 was the yeast that produced a raspberry wine with a good chemical and sensory quality.

Three wine-making residues (grape seeds, skins and stems), and corn cobs were evaluated as support material for immobilization of Saccharomyces cerevisiae and the ethanol production by the immobilized cells was assessed. The main objective of this study was to find an abundant and low cost material suitable for the cells immobilization and able to be used in a next step of wine production by immobilized yeast cells. The four natural materials were used as support in two different forms: untreated, and treated by a sequence of acid and basic reactions. Untreated grape skin and corn cobs provided the highest cell immobilization results (25.1 and 22.2 mg cells/g support, respectively). The maximum ethanol production yield (about 0.50 g/g) was also obtained when the cells were immobilized in these untreated materials. It was also found that the support materials released nutrients to the medium, which favored the yeast development and the ethanol production. The use of immobilized cells systems under agitated conditions gave ethanol yields similar to those obtained by the static fermentations, but the immobilized cell concentration was significantly lower. In brief, static fermentation with cells immobilized on grape skins or corn cobs appear to be an interesting alternative for use on wine-making. The use of grape skins, particularly, which is a by-product of the wine elaboration, could be of larger interest to obtain an integrated wine production process with by-product reuse.