Pomace Brandy Quality of Cultivar Riesling White from Kutjevo Vinegrowing Region S

917 Bulgarian Journal of Agricultural Science, 21 (No 5) 2015, 917-925 Agricultural Academy POMACE BRANDY QUALITY OF CULTIVAR RIESLING WHITE FROM KUTJEVO VINEGROWING REGION S. JAKOBOVIĆ1 and M. JAKOBOVIĆ2 1 Croatian Academy of Sciences and Arts, Institute for Scientific and Artistic Work, Pozega, 34000 Požega, Croatia 2Polytechnic in Pozega, 34000 Pozega, Croatia Abstract JAKOBOVIĆ, S. and M. JAKOBOVIĆ, 2015. Pomace brandy quality of cultivar Riesling White from Kutjevo vinegrowing region. Bulg. J. Agric. Sci., 21: 917–925 The research on pomace brandy from grape pomace cultivar Riesling White from Kutjevo vinegrowing region was conducted in the year 2004. The experiment with pomace obtained after pressing mash (pomace K) was set in five variants with three repetitions (pomace fermentation with epiphyt microflora, fermentation of pomace supplemented with yeast, treatment of pomace before boiling with commercial preparation of pectolitic enzymes – three different enzymes). Two series of experi- ments were carried out in the year 2005: pomace obtained after pressing mash (series K) and pomace remaining after separation of the free-run juice (series J). In that year with two main variants (pomace fermentation with epiphyt microflora and fermentation of pomace supplemented with yeast), the experiment of pomace treatment with one of the applied preparations of pectolitic enzymes was repeated. The analysis of the chemical composition of pomace brandy comprised the determination of the alcohol, the total titratable acidity, the share of ester and the share of total aldehydes, the concentration of methanol, n-propanol, isobutanol, 2-butanol, isoamyl alcohol, n-hexanol, ethyl acetate and ethyl lactate. Based on the average values of basic chemical compounds, pomace brandies of all experimental variants obtained from Riesling White pomace in the year 2004 and 2005 satisfied the criteria of quality according to the Pravilnik o jakim alkoholnim i alkoholnim pićima and regula- tory rules, Definition, Description and Presentation of Spirit Drinks: Council Regulation No 1576/89, with the exception of pomace brandies produced in the year 2005 from pressed pomace fermented with epiphytic yeasts, as well as brandies of the same pomace treated with pectolitic enzyme before fermentation conducted with epiphyt yeasts. In these pomace brandies methanol concentration was above the allowed marginal values. The chemical composition of pomace brandies differed sig- nificantly in particular years as well as in relation to the experimental series. Key words: pomace brandy, pomace, pectolitic enzymes, distillation, methanol Introduction mash and wine. Pomace consists of solid parts of grapes in which the proportion of seeds is around 25%, skins 50% and Pomace brandy, brandy produced by the distillation of fer- stems around 25% (Silva et al., 2000).The factors important mented grape marc is of distinctive sensory properties and for the quality of pomace are health status and the degree chemical composition that distinguish it from the beverages of grape ripeness (Da Porto and Zironi, 1997; Silva et al., obtained by the distillation of wine, as well as those produced 2000), aromatic properties of cultivars (Versini, 1992a), as by the distillation of fermented crushed grapes. The compo- well as the technology of vinification (Radovanovic, 1986; sition and sensory properties of brandy result from the spe- Paunovic and Danicic, 1967; Paunovic and Djurisic, 1983; Da cific structure of pomace, its chemical and microbiological Porto and Zironi, 1997; Silva et al., 2000; Cortés et al., 2005; composition which is different from the composition of the Apostolopoulou et al., 2005). In accordance with the regu- E-mail: [email protected], [email protected] 918 S. Jakobović and M. Jakobović lations (Pravilnik o jakim alkoholnim i alkoholnim pićima; lou et al., 2005) the degree of grape ripeness (Apostolopoulou Definition, Description and Presentation of Spirit Drinks: et al., 2005), the strength of the pressing and prolonged storage Council Regulation No 1576/89), pomace brandy must con- of pomace (Cortés et al., 2005). Increased concentrations of tain at least 37.5% vol. of alcohol, volatile matter content of at amyl alcohols (described as “alcoholic,” “sweet” and “suffo- least 140 g/hl a.a. and methanol up to 1000 g/hl a.a. The share cating” aromas) could have negative influence on the distillate of ethanol is of the key importance for the flavor and body of aroma, as reported by Apostolopoulou et al. (2005). pomace brandy, however, it contributes a little to its aroma According to the same source, 1-hexanol is considered to (Silva et al., 2000). The share of alcohol in Italian grappa is at positively influence the aroma of distillate if its concentrations least 37.5% vol., but it usually reaches 50% vol. (Versini and are lower than 20 mg/l. High concentrations of 1-hexanol se- Odello, 1990). Methanol is the natural ingredient of brandies riously damage the sensory properties of distillates and are produced from grape. Because of its toxicity, concentration associated with “green” scents (Cantagrel et al., 1995). The of methanol in the spirit drinks is limited by regulations. Var- presence of 2-butanol is considered harmful to the quality of ious factors that affect the concentration of methanol in grape the pomace brandy due to the unpleasant smell which is asso- marc have been reported in professional literature. They are ciated with this alcohol (Silva et al., 1996). The total concen- associated with the cultivar (Versini, 1992a), the intensity of tration of higher alcohols in the pomace brandies studied by action of pectolitic enzymes (Silva et al., 2000), pH levels (Da Paunovic and Đurisic (1983) ranged from 2220 to 6930 mg/l Porto, 1997), the structure of mash and the share of the liquid a.a., depending on the composition of pomace and fermenta- phase (Paunovic and Djurisic, 1981), boundary of separating tion conditions. Portuguese brandies had an average concen- the first distillate flow (Silva and Malcata, 1999), as well as tration of total higher alcohols from 1876.4 mg/l, Spanish oru- the effective separation of the last distillate flow (Apostolo- jo 1939 mg/l and Italian grappa 1799 mg/l (Silva et al., 2000) poulou et al., 2005). using the same sequence for the displayed alcohol strength of The data on the concentration of methanol in pomace 45 ± 4. 5% vol., 58.1% vol., and 72.9 ± 7.7% volume. The con- brandy vary widely. The share of methanol in Greek pomace centration of 2-butanol in pomace brandy from Spain ranged brandy (tsipuro), produced by traditional methods in small from 0.00 to 16.9 mg/l for home-produced, while in industrial households, was from 86 to 143 mg% ml a.a. (Apostolopou- it was 0.00 to 44.9 mg/l (Cortés et al., 2005). In pomace bran- lou et al., 2005). Silva et al. (2000) provided a comparative dies produced in industrial conditions the concentration of overview of the chemical composition of Portuguese, Span- 2-butanol ranged from 80 to 946 mg/l (Paunovic and Đurisic, ish and Italian pomace brandies according to which the con- 1983).Concentrations of 1-hexanol in industrial pomace bran- centration of methanol in Portuguese pomace brandy was dies ranged from 0.00 to 133 mg/l (Cortés et al., 2005). 3389.2 ± 1279.9 mg/l; in Spanish orujo 5169 mg/l; in Ital- Among comparatively analyzed pomace brandies the ian grappa 8869.2 ± 4338.3 mg/l, with the alcohol content of highest 1-hexanol content of 162 mg/l was found in orujo 45 ± 4.5% vol. in Portuguese pomace brandy, 58.1% vol. in (Silva et al., 2000). Low concentrations of this alcohol (0.9 mg Spanish oruje and 72.9 ± 7.7% vol. in Italian grappa. The in- % ml a.a.) were reported for Greek brandies (Apostolopoulou creased methanol content (more than 2% vol.) can be found in et al., 2005).There is relatively little data on the movement of pomace brandies produced in industrial conditions, which is the total acidity of pomace brandy in contemporary profes- explained as a consequence of the strong pressing of pomace sional literature. The average concentration of organic acids using continuous presses or prolonged storage of fermented in the experimental pomace brandy produced in laboratory pomace during which a loss of alcohol occurred (Paunovic conditions was 0.17 g/l, and in pomace brandies produced in and Djurisic, 1983). industrial conditions 0.45 g/l (Paunovic and Djurisic, 1983). Cortés et al. (2005) reported that industrial pomace brandy Recognizable level of acetic acid was 200 mg/l (Diéguez et produced from pomace pressed in a pneumatic press, had sev- al., 2002).Ethyl acetate ester is the most important ester with en times higher concentration of methanol (an average of 5303 respect to its intense smell and has a significant impact on the mg/l with 63.8% vol. of alcohol) from the pomace brandy pro- sensory properties of distillate (Silva et al., 1996; Apostolo- duced in small households from pomace obtained by manual poulou, 2005).The increased concentration of this ester indi- pressing of mash which contained an average of 704 mg/l of cates prolonged storage of pomace and possible acetic acid methanol with an average 52.7% vol. of alcohol. Most of the bacteria contamination. The data on the proportion of ethyl higher alcohols are formed in alcohol fermentation by yeasts acetate in pomace brandy vary. The concentration of ethyl and they are formed parallel with the formation of ethanol acetate in Portuguese pomace brandies ranged from 50.4 to (Jackson, 1994). The share of hexanol in the distillate is con- 528 mg/l with an average concentration of 210 mg/l which, nected with the varietal origin, (Versini, 1992a; Apostolopou- according to Silva et al. (1996), can be considered relatively Pomace Brandy Quality of Cultivar Riesling White from Kutjevo Vinegrowing Region 919 low for brandies.

Load more