The Comparison and Brewing Value of Saaz Hop Pedigree
1
Research Institute of Brewing and Malting, Prague, Lípová 511/15, 120 00 Prague, Czech Republic
2
Department of Crop Science, Breeding and Plant Medicine, Faculty of AgriSciences, Mendel University in Brno, Zemědělská 1, 613 00 Brno, Czech Republic
3
Hop Research Institute Co., Ltd., Saaz, Kadaňská 2525, 438 01 Žatec, Czech Republic
*
Author to whom correspondence should be addressed.
Beverages 2024, 10(4), 101; https://doi.org/10.3390/beverages10040101
Submission received: 9 August 2024
/
Revised: 29 August 2024
/
Accepted: 2 September 2024
/
Published: 22 October 2024
Abstract
:The well-known hop variety, Saaz, which gives the Pilsner lager beer its characteristic hop aroma, may be threatened by climate change in the future. Therefore, new Saaz-related hop varieties, including Saaz Late, Saaz Brilliant, Saaz Comfort, and Saaz Shine, were recently bred. A comparison study was carried out to evaluate whether these varieties are acceptable for traditional lagers. For this purpose, sensorial and chemical analyses of hops and related beers, namely, an analysis of hop resins and oils, were performed. Sensory profiles of Saaz varieties are very similar (fine, hoppy aroma; floral; herbal), except for Saaz Comfort, which has a slightly higher aroma intensity, and Saaz Shine, which has the most noticeable fruity scent, with traces of citrus. The chemical profiles are also very similar, with α-humulene, β-pinene, (E)-β-farnesene, β-caryophyllene, and myrcene being the most abundant. Decoction mashing and kettle hopping technology with bottom fermentation show that the compared varieties result in very similar lager beers with hoppy, floral, herbal, fruity, and spicy aromas. Typical hop oils include farnesol, linalool, methyl geranate, β-pinene, and limonene. The high concentration of farnesol in beer correlates with the concentrations of (E)-β-farnesene and farnesol in hops. New Saaz varieties are widely used to produce Pilsner lager without affecting the traditional sensory aroma of this widespread style. Varieties have a higher yield of approximately 25% and bitter acid concentrations of approximately 15%, with Saaz Comfort comprising approximately 100%. Furthermore, the concentration of hop oils is approximately 40% higher in Saaz Shine than a traditional Saaz variety. Moreover, Saaz Shine and Saaz Comfort have very good resistance to drought, which is an important property from a climate change perspective.
1. Introduction
Hops (Humulus lupulis L.) are among the most important raw materials in beer production because of their bitter and aromatic properties. Hop breeding in the Czech Republic mostly focuses on fine-aroma hops. The Saaz fine aroma bred by Oswald is the most well-known variety in the world [1].
In 2011, the fine aroma Saaz Late variety, which is related to the original Saaz, was registered [2]. Subsequently, in 2019, three new varieties were registered, namely, Saaz Brilliant, Saaz Comfort, and Saaz Shine [3]. These varieties share several identical features with Saaz; therefore, a complex and long-term study describing their pedigree and breeding methods and comparing hop resin contents, hop oil profiles, and aroma yields was carried out [4].
Few articles have dealt with the Saaz variety to date. In the study of Eyers et al., four hop varieties were compared, namely, Target, Saaz, Hallertauer Hersbrucker, and Cascade. Odor-active compounds were identified using GC–MS (gas chromatography with mass spectrometry). The authors mainly focused on substances with a “noble” aroma, often described as herbal and spicy [5].
The terpenoid metabolomic pattern of hop essential oil derived from the Saaz variety was determined using headspace solid-phase microextraction combined with GC–MS. The authors identified 27 terpenoid metabolites with dominating monoterpenes and sesquiterpenes, followed by oxygenated monoterpenes and hemiterpenes. Myrcene, α-humulene, and β-caryophyllene were the main compounds, representing approximately 80% of the total volatile fraction in the hop essential oil. The hop aroma of the Saaz variety was described as “very mild with pleasant hoppy notes” [6].
Another study mentioning odor-active compounds in Saaz compared strongly hopped beers made with Saaz, Hersbrucker, and Cascade varieties with unhopped beer using GC–O (GC with Olfactometry) and sensory evaluation. According to this study, citrus and floral notes characterized the hop aroma of Saazer beer. Linalool, geraniol, and β-ionone were shown to contribute to the floral notes based on the Charm and aroma values [7].
Saaz and Challenger hop pellets were used for the analysis of beer aromas derived from hops using sensorial AEDA (Aroma Extract Dilution Analysis). Hop aromatic compound identification in beer was performed using GC–O. Beer brewed with a late kettle addition of Saaz hops was described as “fruity (citrus), flowery, spicy, fresh, beer-like” and more pleasant than Challenger. One spicy/hoppy compound that was unmodified from hop to beer proved responsible for the most intense odor in both hopped beer extracts. However, the chemical structure of this compound was not revealed [8].
The impact of seven Slovenian, one American, and four Czech hop varieties, including Saaz, in single-hopped beers (both kettle- and dry-hopped) was evaluated using GC–MS and sensorial analysis. Dominant compounds in Saaz hop were identified as myrcene, (E)-β-farnesene, and α-humulene, whereas limonene, linalool, farnesol, myrcene, (E)-β-farnesene, and α-terpinol were identified in the major hop oils in kettle-hopped beer [9].
A recent study focusing on pilot brewing tests of the three Saaz varieties (S. Brilliant, S. Shine, and S. Comfort) monitored the sensory profiles of kettle and kettle+dry single-hopped pale lager beers. While kettle+dry beers hopped with new Saaz varieties were distinguished from beer hopped with original Saaz in the triangle test, kettle-hopped beers were very similar, except for S. Comfort [10]. Similarly, in a previous study, S. Late did not differ from Saaz when kettle-hopped beer was prepared [2].
This study aimed to reveal and compare the impact of five Saaz-related varieties in kettle-hopped beer prepared via traditional Pilsner lager beer technology, double decoction mashing, kettle hopping, bottom fermentation, and cool and long lagering. Basic sensorial and chemical analyses of hops and beers were performed according to well-known methods. Changes in hop oil profiles during wort boiling and fermentation are discussed based on a previously described chemical transformation.
2. Materials and Methods
2.1. Chemicals
Standards of α-pinene (99.0%), β-pinene (99.0%), isobutyl isobutyrate (98.0%), isoamyl isobutyrate (98.0%), myrcene (75.0%), limonene (97.0%), ocimene (90.0%), linalool (97.0%), methyl hexanoate (98.0%), methyl heptanoate (99.8%), methyl octanoate (99.8%), methyl nonanoate (99.8%), methyl decanoate (99.0%), 2-nonanone (99.0%), 2-decanone (98.5%), 2-undecanone (99.0%), 2-dodecanone (98.5%), 2-tridecanone (97.0%), (E)-β-farnesene (90.0%), α-humulene (90.0%), β-caryophyllene (98.0%), methyl geranate (AldrichCPR), α-terpineol (97.0%), terpinen-4-ol (95.0%), geranyl acetate (99.0%), (Z)-geraniol (nerol) (90.0%), α-ionone (90.0%), β-ionone (95.0%), α-irone (90.0%), β-caryophyllene oxide (98.0%), farnesol (90.0%), and 1-hepten-3-ol were purchased from Sigma-Aldrich (Germany). Dichlormethane, n-hexane, and acetonitrile of reagent grade were obtained from Honeywell (USA). Deionized water was prepared using Milli-Q system (Millipore, Burlington, MA, USA).
2.2. Hop Sample Analysis
2.2.1. Hop Oils Analysis
Hops were homogenized during post-harvest processing, and six independent samples of each variety were sampled and finely grounded. Hop oils were extracted from hop samples via solid–liquid extraction. A 50 mg portion of a grounded sample with 5 µL of internal standard 1-hepten-3-ol (7.8 g/L) was mixed with 400 µL of the dichloromethane/acetonitrile (2:1, v/v) solution. The mixture was heated at 50 °C for 60 min, then cooled down and finally transferred into a vial containing 400 µL of water to wash the extract from highly polar interferents via liquid–liquid extraction for 1 min (three times). The phases of water and organic extracts were separated via centrifugation (3 min, 1200 rpm).
The organic extract was analyzed via the heart-cut GCxGC method using a gas chromatograph Agilent 7890 B equipped with LTM column modules, the Deans-switch system, FID, and QQQ MS 7000D (Agilent Technologies, Santa Clara, CA, USA). Separations were primarily carried out on DB-5MS UI (15 m × 0.25 mm × 0.25 µm, 5%-phenyl-dimethylpolysiloxane) connected to MS detection. Heart-cut aliquots analyzed using the dean-switch system were sent to the second-column HP-INNOWAX (30 m × 0.25 mm × 0.25 µm, polyethyleneglycol) connected to FID. The sample 1 µL injection was performed in a split mode (10:1) at 250 °C. Separation on the first column was performed with a ramped flow: 4 mL/min (1 min)–2 mL/min (0.6 min)–1 mL/min (14.5 min) of helium (Air Products, the Czech Republic), and gradient temperature program was 60 °C (1 min)–200 °C/min–80 °C (0.5 min)–50 °C/min–110 °C (1 min)–25 °C/min–140 °C (1 min)–25 °C/min–160 °C (3 min)–25 °C/min–180 °C (1 min)–25 °C/min–260 °C (0 min)–50 °C/min–300 °C (2 min). Separation on the second column was maintained at the constant pressure of 42 psi, and the temperature program was as follows: 50 °C (8 min), 20 °C/min–100 °C (1 min), and 30 °C/min–255 °C (1 min). MS detection was performed in the dMRM mode (see Appendix A Table A1) at standard ion source conditions (70 eV, 230 °C). The flame-ionization detection was maintained at 270 °C, with a flow rate of air, hydrogen, and nitrogen at 400, 30, and 25 mL/min, respectively.
Each sample was prepared three times and measured twice. Therefore, the resulting value is an average of 4 measurements. Individual hop oils in a real sample were quantified based on a calibration curve with the addition of an internal standard.
2.2.2. Hop Resin Analysis
The determination of hop resins was performed according to the EBC method [11]. Each sample was measured in triplicate.
2.3. The Brewing Test
A hop garden of tested varieties was located at 50°19′47.7″ N 13°37′05.4″ E (Stekník, Czech Republic). Hop cones were harvested in the state of technological ripeness and dried at a temperature of 55–60 °C. The material was packed in an inert atmosphere and stored at 0 °C. Just before the analysis and brewing, dry hop cones were ground.
The beer samples were prepared in 250 L at the research brewhouse of Kaspar-Schulz (Germany). The grist composition for each brew was 33 kg of Pilsner malt (Benešov, Czech Republic) with an extract-dry basis of 81.5% and color of 4.2 units EBC. The double decoction mashing regime was used with a mash-in and mash-out temperature of 46 and 75 °C, respectively. The maximum turbidity of sweet wort was set to 20 EBC, with the last set to 50 EBC. The sweet wort volume before boiling was 210 L. Single kettle hopping with 100% of the tested hop variety was carried out in three doses for 75 min: 30% at the be-ginning, 40% at the 20th minute 30% and at the 15th minute before the end of boiling.
Beer samples were fermented identically at 12 °C with yeast W34/70 from Fermentis in cylindroconical tanks for seven days. The maturation took place at 2 ± 0.5 °C for 21 days. Finally, the samples were filtered on a plate filter with S10N filter plates (Hobra Školník, Broumov, the Czech Republic) and bottled without access to oxygen.
The experiment was performed twice, and the results were processed together.
2.4. Beer Sample Analysis
Hop oils were extracted from beer via steam distillation (Büchi, Distillation Unit K-350, Flawil, Switzerland): 2 × 50 mL of beer samples containing 250 µL of internal standard cis-3-hepten-1-ol (100 mg/L) were distilled for 4 min. Subsequently, the obtained distillate was shaken with 10 mL of a mixture of dichloromethane/hexane (1:1, v/v) at 250 rpm for 1 h. The mixture was cooled to 4–6 °C to allow the water and organic extract to fully sepa-rate, the organic extract was analyzed (not water part) using the previously described GC–MS method [12].
2.5. Sensory Analysis of Beer
Sensory analyses were carried out by a professional 12-member sensory panel. The assessors were selected and trained according to ISO 8586:2023 and ISO 11132:2021 [17,18]. The sensory evaluations were conducted in a sensory laboratory equipped according to ISO 8589:2007 [19]. The assessors were familiar with and trained using certified beer flavor standards (FlavorActive™, Great Britain). The beer samples were served in glass cups in volumes of approximately 100 mL at 10 ± 2 °C.
The sensory profile of beer was evaluated using basic parameters of beer such as fullness, bitterness, astringency, sourness, sweetness, hoppy, estery, and yeasty on a six-point scale (intensity: 0—no; 1—very low; 5—very high). Assessors had to specify in detail the intensity of particular hop aromas such as hoppy, fruity, citrusy, floral, spicy, herbal, and woody.
Projective mapping was performed in two sessions (the brewing test repeated in each session). The assessors obtained six samples (five tested and one control, i.e., one randomly selected sample) with randomly assigned codes and were asked to arrange the samples on white paper based on their mutual sensory similarity/dissimilarity; similar samples were placed closer to each other than dissimilar samples. The assessors also characterized each sample in a short description. The final arrangement of samples in the plane was transformed to x and y coordinates (the lower left corner of the paper was set as the origin). The obtained data were processed using Generalized Procrustes Analysis (GPA) in XLSTAT software (version 2021.4.1. Addinsoft, Paris, France).
Hop oil concentrations in hop and beer samples were evaluated via principal component analysis (PCA) to visualize samples in multivariate space (Rstudio, version 1.1.456. with R v 4.0.1) using FactoMineR (version 2.3) and factoextra (version 1.0.7).
3. Results and Discussion
The basic parameters of the GC–MS method for analyzing hop oils in hops are given in Table 1.
The used heart-cut GCxGC enables a wider linear operating range (up to 107) [20]. The hop resin concentrations are given in Table 2.
S.Comfort has the highest concentration of α-acids (3.95 wt%,), however the lowest concentration of cohumulone (18.94%). These results are reflected in the lowest final bitterness of tested beer hopped using S. Comfort, as shown in Table 3.
This phenomenon, where the resulting bitterness is influenced by the cohumulone percentage in the total alpha acid content, was described in several previous studies. In 1972, Rigby studied the utilization of individual homologs of α-acids and identified that cohumulone is utilized more efficiently than humulone [21]. Furthermore, Ono et al. demonstrated that the relative amount of formed isocohumulone was significantly higher than isohumulone and isoadhumulone during wort boiling [22]. Moreover, the relative amount of isocohumulone lost during fermentation is lower than isohumulone and isoadhumulone. Irwin et al. and Jacobsen et al. concluded likewise [23,24]. Irwin et al. stated that cohumulone is better utilized than humulone and adhumulone, likely due to higher losses of humulone and adhumulone, and isohumulone and isoadhumulone in the kettle and fermenter, respectively [23]. More recently, Jaskula et al. and Protsenko et al. determined this phenomenon using a detailed kinetic study [25,26].
The other significant extreme among the studied Saaz varieties is a high β-acid concentration in S. Late (4.22 wt%), reflecting a very low α/β ratio (0.63). S. Brilliant has the highest α/β ratio (1.49), which is more than double that of S. Late. The main trends show good correlation with long-term data described previously [4].
Specific hop oil concentrations are given in Table 4.
Our methodology allowed us to compare the profiles of 31 hop oils forming basic groups as monoterpenes; sesquiterpenes; their oxidized forms or alcohols; esters; and aldehydes and ketones, referred to in the text as carbonyls, among Saaz varieties. According to the literature, monoterpenes and sesquiterpenes represent the main constituents of the studied hops [27,28]. Monoterpenes range from 1250 to 18,400 mg/kg, which represents 22.6 to 35.2% of quantified compounds. The monoterpene comparison is given in Table 4; the variety with highest and lowest concentration of monoterpenes is Saaz and S. Late, respectively. Moreover, the varieties showed the highest concentrations of β-pinene (780–1385 mg/kg) and myrcene (353–466 mg/kg). The (E)-β-ocimene concentration is approximately 40–60 mg/kg. Sesquiterpenes are the most abundant group, ranging from approximately 2050 to 4860 mg/kg in Saaz and S. Brilliant, which represents approximately 57.2 to 67.8%. α-Humulene is the most dominant concentration (approximately 900–2720 mg/kg), followed by β-farnesene (approximately 610–1650 mg/kg) and β-caryophyllene (approximately 390–950 mg/kg). The other compounds represent a significantly smaller portion, with alcohols ranging from 2.0 to 7.5% (especially demonstrated in farnesol, linalool, and β-caryophyllene oxide), esters from 1.2 to 2.7%, and carbonyls from 1.0 to 3.5%.
The samples in multivariate space are visualized in Figure 1. Every variety formed its well-separated cluster, closely correlating with the genetic origin of these varieties and the aroma of hops [4]. S. Late and S. Brilliant have the ancestor variety in their genotype, i.e., original Saaz; S. Comfort and S. Shine were bred using different varieties, such as Serebrianka and Sládek, respectively. The aroma of Saaz, S. Late, and S. Brilliant is similar (fine hoppy aroma with floral and herbal scent); however, S. Comfort and S. Shine have a sharper and more intense aroma with spicy and fruity notes in the background, respectively.
In general, the main hop oil profile in the Saaz variety correlates with a study from 2012, where the authors identified 27 terpenoid metabolites in the Saaz variety, including monoterpenes (56.1%), sesquiterpenes (34.9%), oxygenated monoterpenes (1.41%), and hemiterpenes (0.04%) [6]. Eyres compared tentatively odor-active compounds in the Saaz, Target, Hallertauer Hersbrucker, and Cascade varieties and identified 14-hydroxy-β-caryophyllene as a compound responsible for “woody and cedarwood” notes, along with geraniol, linalool, and α-ionone. The Charm values of geraniol and linalool were the highest among the four studied hop varieties [5].
The chemical profiles of hop oils correspond well with the sensory analysis discussed in a previous study [4]. In general, Saaz varieties have a traditional fine hoppy aroma pronounced by herbal and floral notes. Both S. Comfort and S. Shine have sharper aromas with pronounced spicy and fruity notes, respectively. They are more noticeable than the other Saaz varieties. S. Comfort and S. Shine also form close clusters in the PCA graph due to higher concentrations of geranyl acetate, myrcene, limonene, ocimene derivates, linalool, farnesol, β-farnesene, and β-caryophyllene.
The basic parameters of beers prove that the beers are very similar, as shown in Table 3. The values of the original extract, alcohol by weight, and volume are close to 12.5% (w/w), 4.0% (w/w), and 3.0% (v/v), respectively. This is reflected in very similar apparent and real extracts (approximately 3.0 and 5.0, respectively). Color and haze are also well-balanced among brews.
A slightly larger difference was noted in the final bitterness, ranging from 36 to 41 BU, caused by a different proportion of α-acid homologs (discussed above). In practice, fluctuation in beer bitterness between brews are well-known and unwanted fact [29].
Furthermore, beers were compared according to hop oil content via PCA (see Figure 2).
Compared to Figure 2, single-hopped beers no longer form autonomous clusters due to hop oil biotransformation during wort boiling and fermentation. The newly formed hop oil profile is shown in Table 5.
While the main group fractions in hops are monoterpenes and sesquiterpenes, their oxidized forms are dominant in beer as published previously [27]. Due to the absence of polar functional groups, myrcene, α-humulene, and β-caryophyllene have very low solubility causing evaporation during kettle hopping and fermentation, in which they are washed out by carbon dioxide. Thus, terpene hydrocarbons do not generally contribute to the hop aroma of beer except for dry-hopped beer [30,31]. However, their oxidized derivatives formed during wort boiling can impact the so-called “noble” or kettle hop aroma [32].
Oxidized forms of monoterpenes and sesquiterpenes represent 88.5–91.3%, which corresponds to a concentration of approximately 112–216 mg/L (see Table 5). The highest concentration of these alcohols was found in S. Shine. Farnesol contributes most to this concentration (86–180 mg/L), followed by linalool (17–32 mg/L), α-terpineol (3–5 mg/L), nerol (2–3 mg/L), and traces of terpin-4-ol (<1 mg/L).
The thermochemical conversion of β-farnesene to farnesol was described in a previous study. A boiling model was used to monitor the stereoisomeric changes in several terpene alcohols from boiling. Farnesol was not detected in the original hops but in two samples after thermochemical conversion [33]. Farnesol formation was also mentioned in a review [27] and a recent study comparing the sensory and chemical profiles of kettle and kettle+dry single-hopped beers using S. Brilliant, S. Comfort, and S. Shine. In this case, farnesol was a major sesquiterpene alcohol in kettle hop beer [10].
Hypothetically, some yeast strain could be a potential source of farnesol in beer, as described by Muramatsu et al. who used squalene synthetase-deficient mutant Saccharomyces cerevisiae ATCC 64,031 for farnesol production [34]. However, the optimal pH range for extracellular farnesol production was from 7.0 to 8.0; moreover, an acidic medium with a pH below 4.0 was optimal for intracellular farnesol and its isomer nerolidol [34]. Naturally, a significant proportion of farnesol in beer may come directly from the hops. However, significant concentrations of farnesol in hops were determined only in Saaz Brilliant, Saaz Comfort, and Saaz Shine, which was the largest (approximately 470 mg/kg). In Saaz and Saaz Late, its concentration was only approximately 25 mg/kg. Therefore, the possibility of farnesol formation from farnesene is quite probable.
Linalool, α-terpineol, nerol, and terpin-4-ol are the autoxidative products of myrcene during bowling and fermentation [27]. Moreover, monoterpene alcohols, namely, linalool, geraniol, and their isomers, nerol and a-terpineol, are produced in hops during hop cone ripening, hop processing, and aerobic storage [35]. These terpene alcohols occur in hops as free and esterified volatiles [36] and are bound to carbohydrates/glycosides [37]. During beer production, the thermal, enzymatic, and acid-catalyzed cleavage of these compounds triggers aglycone release, thus enhancing beer aroma [37].
The second hop oil group consists of esters that represent 5 to 9% or 10–14 mg/L with the highest S. Late concentration. The most abundant derivative among all varieties is Z-methyl geranate, followed by geranyl acetate. The group of aldehydes and ketones is minimally represented, at less than 0.5 mg/L.
The chemical results are in good agreement with sensorial analysis, as shown in Table 6.
Beers generally have a fine bitter taste and hoppy aroma with herbal and floral notes, presenting slight minute differences. A hop aroma is formed via the synergy of major and minor hop oils, such as farnesol (floral, lemongrass, and jasmine), linalool (floral), geraniol (floral and rose), α-terpineol (lilac, rose, and woody), nerol (floral, lime, and citrus), Z-methyl geranate (floral, herbal, and fruity), geranyl acetate (fruity and floral), and myrcene (herbal, resinous, green, and spicy) [38]. Only beers hopped with S. Brilliant and S. Comfort have a slightly stronger hop aroma. However, these detailed differences in sensory profiles were not distinguished with projective mapping.
These results also agree with the long-term results of hop evaluation where Saaz varieties are hardly recognizable to untrained assessors. Very similar aromas typically contain both Saaz and S. Brilliant, as S. Comfort has a slightly higher aroma intensity and S. Shine has the most noticeable fruity aroma with traces of citrus notes [4]. These fine differences are almost not apparent when traditional kettle-hopped technology is used. Nevertheless, more significant differences may be noted after dry hopping, as shown in a recently published study [10].
4. Conclusions
These findings show that “new” varieties of the Saaz pedigree are well used to produce Pilsner lager without affecting the traditional sensory aroma of this widespread style. This is a particularly important insight from the climate change perspective. Moreover, new varieties have a higher yield of approximately 25% and higher bitter acid concentrations, namely, Saaz Comfort at approximately 100% and others at approximately 15%. Saaz Shine has higher hop oil concentrations (approximately 40%) than a traditional Saaz variety [4]. Furthermore, the high concentration of farnesol and linalool in beer correlated with a high concentration of β-farnesene and myrcene in Saaz hops, respectively, significantly contributing to the typical fine hop aroma of Pilsner lager.
Author Contributions
Conceptualization, J.O. and V.N.; methodology, T.V.; validation, T.V.; formal analysis, L.S. and J.P.; investigation, L.S.; resources, J.O., V.N. and L.S.; data curation, J.P.; writing—original draft preparation, L.S. and J.O.; writing—review and editing J.O.; supervision, J.O.; project administration, J.O.; funding acquisition, J.O. All authors have read and agreed to the published version of the manuscript.
Funding
This research was funded by the Ministry of Agriculture of the Czech Republic under grant number QK21010136.
Data Availability Statement
Data are contained within the article and Appendix A.
Conflicts of Interest
All co-authors are grant investigators QK21010136. The authors declare no conflicts of interest.
Nomenclature
AEDA: Aroma Extract Dilution Analysis; BU, Bitterness Units; GC–O, Gass Chromatography with Olfactometry; GC–MS, Gass Chromatography with Mass Spectrometry; PCA, Principal Component Analysis.
Appendix A
Table A1.
Conditions of dynamic Multiple Reaction Monitoring and retention times of analytes at MS/MS or FID detectors.
Table A1.
Conditions of dynamic Multiple Reaction Monitoring and retention times of analytes at MS/MS or FID detectors.
| Compound Name | RT—MS | RT-FID | Precursor Ion | Product Ion | Dwell | CE |
|---|---|---|---|---|---|---|
| Isobutyl isobutyrate | 6.36 | - | 89 | 43 | 38.5 | 10 |
| Isobutyl isobutyrate | 6.36 | - | 88 | 73 | 38.5 | 10 |
| Isobutyl isobutyrate | 6.36 | - | 88 | 51 | 38.5 | 10 |
| Methyl hexanoate | 6.51 | - | 99 | 71 | 30.2 | 5 |
| Methyl hexanoate | 6.51 | - | 99 | 43 | 30.2 | 10 |
| Alpha-pinene | 6.77 | - | 93 | 77 | 28.8 | 10 |
| Alpha-pinene | 6.77 | - | 93 | 51 | 28.8 | 30 |
| 3-hepten-1-ol (ISTD) | 6.93 | - | 96 | 81 | 26.0 | 10 |
| 3-hepten-1-ol (ISTD) | 6.93 | - | 96 | 41 | 26.0 | 20 |
| Beta-pinene | 7.33 | 7.96 | - | - | - | - |
| Myrcene | 7.33 | 8.23 | - | - | - | - |
| Isoamyl isobutyrate | 7.53 | - | 89 | 43 | 15.6 | 10 |
| Isoamyl isobutyrate | 7.53 | - | 71 | 43 | 15.6 | 10 |
| Isoamyl isobutyrate | 7.53 | - | 71 | 41 | 15.6 | 20 |
| Isobutyl isobutyrate | 6.36 | - | 89 | 43 | 38.5 | 10 |
| Isobutyl isobutyrate | 6.36 | - | 88 | 73 | 38.5 | 10 |
| Isoamyl isobutyrate | 7.53 | - | 71 | 41 | 15.6 | 20 |
| Methyl heptanoate | 7.60 | - | 113 | 43 | 14.7 | 5 |
| Methyl heptanoate | 7.60 | - | 97 | 55 | 14.7 | 10 |
| Methyl heptanoate | 7.60 | - | 74 | 73 | 14.7 | 5 |
| Limonene | 7.85 | 8.74 | - | - | - | - |
| Ocimene (izomer 1) | 7.85 | 8.89 | - | - | - | - |
| Ocimene (izomer 2) | 8.00 | 9.03 | - | - | - | - |
| 2-nonanone | 8.55 | - | 71 | 43 | 29.1 | 5 |
| 2-nonanone | 8.55 | - | 71 | 41 | 29.1 | 20 |
| Linalool | 8.68 | - | 121 | 93 | 26.7 | 10 |
| Linalool | 8.68 | - | 121 | 77 | 26.7 | 20 |
| Linalool | 8.68 | - | 93 | 77 | 26.7 | 10 |
| Linalool | 8.68 | - | 93 | 51 | 26.7 | 30 |
| Methyl octanoate | 8.94 | - | 87 | 55 | 35.7 | 10 |
| 2-decanone | 9.85 | 10.86 | - | - | - | - |
| Terpinen-4-ol | 9.85 | 11.46 | - | - | - | - |
| Alpha-terpineol | 9.99 | 12.15 | - | - | - | - |
| Methyl nonanoate | 10.16 | - | 87 | 55 | 40.4 | 10 |
| Cis-geraniol (Nerol) | 10.34 | - | 93 | 77 | 52.2 | 10 |
| Cis-geraniol (Nerol) | 10.34 | - | 93 | 51 | 52.2 | 30 |
| Z-methyl geranate | 11.04 | - | 123 | 81 | 32.2 | 10 |
| Z-methyl geranate | 11.04 | - | 123 | 43 | 32.2 | 20 |
| Z-methyl geranate | 11.04 | - | 114 | 83 | 32.2 | 10 |
| Z-methyl geranate | 11.04 | - | 114 | 55 | 32.2 | 20 |
| 2-undecanone | 11.17 | - | 71 | 43 | 25.8 | 10 |
| Methyl decanoate | 11.53 | 12.41 | - | - | - | - |
| E-methyl geranate | 11.58 | 12.68 | - | - | - | - |
| Geranyl acetate | 12.27 | - | 121 | 93 | 48.1 | 10 |
| Geranyl acetate | 12.27 | - | 121 | 77 | 48.1 | 20 |
| 2-dodecanone | 12.43 | - | 71 | 43 | 29.1 | 10 |
| Alpha-ionone | 13.01 | - | 193 | 172 | 16.1 | 10 |
| Alpha-ionone | 13.01 | - | 193 | 121 | 16.1 | 20 |
| Alpha-ionone | 13.01 | - | 159 | 129 | 16.1 | 20 |
| Alpha-ionone | 13.01 | - | 159 | 105 | 16.1 | 20 |
| Alpha-ionone | 13.01 | - | 136 | 121 | 16.1 | 5 |
| Alpha-ionone | 13.01 | - | 136 | 93 | 16.1 | 10 |
| Beta-caryophyllene | 13.09 | - | 161 | 105 | 14.1 | 20 |
| Beta-caryophyllene | 13.09 | - | 161 | 91 | 14.1 | 20 |
| Beta-caryophyllene | 13.09 | - | 133 | 105 | 14.1 | 10 |
| Beta-caryophyllene | 13.09 | - | 133 | 91 | 14.1 | 10 |
| Beta-farnesene | 13.18 | - | 161 | 105 | 13.1 | 20 |
| Beta-farnesene | 13.18 | - | 161 | 91 | 13.1 | 20 |
| Beta-farnesene | 13.18 | - | 133 | 105 | 13.1 | 10 |
| Alpha-humulene | 13.47 | 13.86 | - | - | - | - |
| 2-tridecanone | 13.59 | 14.05 | - | - | - | - |
| Beta-ionone | 13.62 | 14.24 | - | - | - | - |
| Alpha-irone (izomer 1) | 13.96 | - | 136 | 121 | 26.2 | 10 |
| Alpha-irone (izomer 1) | 13.96 | - | 136 | 93 | 26.2 | 10 |
| Alpha-irone (izomer 2) | 14.23 | - | 136 | 121 | 30.0 | 10 |
| Alpha-irone (izomer 2) | 14.23 | - | 136 | 93 | 30.0 | 10 |
| Beta-caryophyllene oxide | 14.74 | - | 149 | 121 | 27.4 | 10 |
| Beta-caryophyllene oxide | 14.74 | - | 149 | 65 | 27.4 | 20 |
| Beta-caryophyllene oxide | 14.74 | - | 121 | 93 | 27.4 | 10 |
| Beta-caryophyllene oxide | 14.74 | - | 121 | 77 | 27.4 | 20 |
| Beta-caryophyllene oxide | 14.74 | - | 109 | 67 | 27.4 | 10 |
| Farnesole | 15.48 | - | 107 | 91 | 31.6 | 20 |
| Farnesole | 15.48 | - | 107 | 65 | 31.6 | 30 |
| Farnesole | 15.48 | - | 69 | 41 | 31.6 | 5 |
| Farnesole | 15.48 | - | 69 | 39 | 31.6 | 20 |
References
- Vent, L. Osvaldův odkaz. Chmelařství 1999, 72, 13–15. [Google Scholar]
- Mikyška, A.; Slabý, M.; Jurková, M.; Krofta, K.; Patzak, J.; Nesvadba, V. Saaz Late—The Czech Hop Variety Recommended for Czech Beer. Kvasny Prum. 2013, 59, 296–305. [Google Scholar] [CrossRef]
- Nesvadba, V.; Charvátová, J. New fine aroma varieties of hops (Humulus lupulus L.) Saaz Brilliant, Saaz Comfort, Saaz Shine and Mimosa. Kvasny Prum 2020, 66, 320–330. [Google Scholar] [CrossRef]
- Olšovská, J.; Straková, L.; Nesvadba, V.; Vrzal, T.; Malečková, M.; Patzak, J.; Donner, P. Saaz—Fine aroma hop pedigree. A review of current knowledge. Beverages 2024, 10, 90. [Google Scholar] [CrossRef]
- Eyres, G.T.; Marriott, P.J.; Dufour, J.P. Comparison of odor-active compounds in the spicy fraction of hop (Humulus lupulus L.) essential oil from four different varieties. J. Agric. Food Chem. 2007, 55, 6252–6261. [Google Scholar] [CrossRef]
- Goncalves, J.; Figueira, J.; Rodrigues, F.; Camara, J.S. Headspace solid-phase microextraction combined with mass spectrometry as a powerful analytical tool for profiling the terpenoid metabolomic pattern of hop-essential oil derived from Saaz variety. J. Sep. Sci. 2012, 35, 2282–2296. [Google Scholar] [CrossRef]
- Kishimoto, T.; Wanikawa, A.; Kono, K.; Shibata, K. Comparison of the odor-active compounds in unhopped beer and beers hopped with different hop varieties. J. Agric. Food Chem. 2006, 54, 8855–8861. [Google Scholar] [CrossRef]
- Lermusieau, G.; Bulens, M.; Collin, S. Use of GC-olfactometry to identify the hop aromatic compounds in beer. J. Agric. Food Chem. 2001, 49, 3867–3874. [Google Scholar] [CrossRef]
- Mikyška, A.; Olšovská, J.; Slabý, M.; Štěrba, K.; Čerenak, A.; Košir, I.J.; Pavlovič, M.; Kolenc, Z.; Krofta, K. Analytical and sensory profiles of Slovenian and Czech hop genotypes in single hopped beers. J. Inst. Brew. 2018, 124, 209–221. [Google Scholar] [CrossRef]
- Mikyška, A.; Štěrba, K.; Slabý, M.; Nesvadba, V.; Charvátová, J. Brewing tests of new fine aroma hop varieties (Humulus lupulus L.) Saaz Brilliant, Saaz Comfort and Saaz Shine. Kvasny Prum. 2021, 67, 464–473. [Google Scholar] [CrossRef]
- Analytica EBC. 7.7—α- and β-Acids in Hops and Hop Products by HPLC. Available online: https://brewup.eu/ebc-analytica/hops-and-hop-products/and-acids-in-hops-and-hop-products-by-hplc7/7.7 (accessed on 12 July 2024).
- Štěrba, K.; Čejka, P.; Čulík, J.; Jurková, M.; Krofta, K.; Pavlovič, M.; Mikyška, A.; Olšovská, J. Determination of Linalool in Different Hop Varieties Using a New Method Based on Fluidized-Bed Extraction with Gas Chromatographic-Mass Spectrometric Detection. J. Am. Soc. Brew. Chem. 2015, 73, 151–158. [Google Scholar] [CrossRef]
- Analytica EBC. 9.2.6—Alcohol in Beer by Near Infrared Spectroscopy. Available online: https://brewup.eu/ebc-analytica/beer/alcohol-in-beer-by-near-infrared-spectroscopy/9.2.6 (accessed on 12 July 2024).
- Analytica EBC. 9.4—Original, Real and Apparent Extract and Original Gravity of Beer. Available online: https://brewup.eu/ebc-analytica/beer/original-real-and-apparent-extract-and-original-gravity-of-beer/9.4 (accessed on 12 July 2024).
- Analytica EBC. 9.6—Colour of Beer: Spectrophotometric Method. Available online: https://brewup.eu/ebc-analytica/beer/colour-of-beer-spectrophotometric-method-im/9.6 (accessed on 12 July 2024).
- Analytica EBC. 9.8—Bitterness of Beer. Available online: https://brewup.eu/ebc-analytica/beer/bitterness-of-beer-im/9.8 (accessed on 12 July 2024).
- ISO 8586:2023, Sensory Analysis—Selection and Training of Sensory Assessors. Available online: https://www.iso.org/standard/76667.html (accessed on 17 October 2024).
- ISO 11132:2021 Sensory Analysis—Methodology—Guidelines for the Measurement of the Performance of a Quantitative Descriptive Sensory Panel. Available online: https://www.iso.org/standard/76669.html (accessed on 17 October 2024).
- ISO 8589:2007 Sensory Analysis—General Guidance for the Design of Test Rooms. Available online: https://www.iso.org/standard/36385.html (accessed on 17 October 2024).
- Sparkman, O.D.; Penton, Z.; Kitson, F.G. Gas Chromatography and Mass Spectrometry: A Practical Guide, 2nd ed.; Academic Press: Cambridge, MA, USA, 2011. [Google Scholar]
- Rigby, F.L.A. Theory on the Hop Flavor of Beer. Proc. Am. Soc. Brew. Chem. 1972, 30, 46–50. [Google Scholar] [CrossRef]
- Ono, M.; Kakudo, Y.; Yamamoto, Y.; Nagami, K.; Kumada, J. Quantitative Analysis of Hop Bittering Components and its Application to Hop Evaluation. J. Am. Soc. Brew. Chem. 1984, 42, 167–172. [Google Scholar] [CrossRef]
- Irwin, A.J.; Murray, C.R.; Thompson, D.J. An Investigation of the Relationships between Hopping Rate, Time of Boil, and Individual Alpha-Acid Utilization. J. Am. Soc. Brew. Chem. 1985, 43, 145–152. [Google Scholar] [CrossRef]
- Jacobsen, T.; Hage, T.; Kristensen, R.; Malterud, K.E. Hop Utilization in the Brewery—An Interbrewery Comparison. J. Am. Soc. Brew. Chem. 1989, 47, 62–67. [Google Scholar] [CrossRef]
- Jaskula, B.; Kafarski, P.; Aerts, G.; De Cooman, L. A kinetic study on the isomerization of hop alpha-acids. J. Agric. Food Chem. 2008, 56, 6408–6415. [Google Scholar] [CrossRef]
- Protsenko, L.; Ryzhuk, S.; Liashenko, M.; Shevchenko, O.; Litvynchuk, S.; Yanse, L.; Milosta, H. Influence of alpha acids hop homologues of bitter and aromatic varieties on beer quality. Ukr. Food J. 2020, 9, 425–436. [Google Scholar] [CrossRef]
- Rettberg, N.; Biendl, M.; Garbe, L.A. Hop Aroma and Hoppy Beer Flavor: Chemical Backgrounds and Analytical Tools-A Review. J. Am. Soc. Brew. Chem. 2018, 76, 1–20. [Google Scholar] [CrossRef]
- Lermusieau, G.; Collin, S. Varietal discrimination of hop pellets. II. Comparison between fresh and aged samples. J. Am. Soc. Brew. Chem. 2001, 59, 39–43. [Google Scholar] [CrossRef]
- Jaskula-Goiris, B.; Aerts, G.; De Cooman, L. Hop α-acids isomerisation and utilisation: An experimental review. Cerevisia 2010, 35, 57–70. [Google Scholar] [CrossRef]
- Haley, J.; Peppard, T.L. Differences in Utilization of the Essential Oil of Hops during the Production of Dry-Hopped and Late-Hopped Beers. J. Inst. Brew. 1983, 89, 87–91. [Google Scholar] [CrossRef]
- Fritsch, H.T.; Schieberle, P. Identification based on quantitative measurements and aroma recombination of the character impact odorants in a Bavarian Pilsner-type beer. J. Agric. Food Chem. 2005, 53, 7544–7551. [Google Scholar] [CrossRef] [PubMed]
- Peppard, T.L.; Ramus, S.A.; Witt, C.A.; Siebert, K.J. Correlation of Sensory and Instrumental Data in Elucidating the Effect of Varietal Differences on Hop Flavor in Beer. J. Am. Soc. Brew. Chem. 1989, 47, 18–26. [Google Scholar] [CrossRef]
- Liu, Z.C.; Liu, Y.M.; Wang, L.P. Investigation of Stereoisomer Distribution and Thermochemical Conversion of Eight Terpene Alcohols Derived from Different Varieties of Chinese Hops (Humulus lupulus L.). J. Am. Soc. Brew. Chem. 2020, 78, 185–194. [Google Scholar] [CrossRef]
- Muramatsu, M.; Ohto, C.; Obata, S.; Sakuradani, E.; Shimizu, S. Alkaline pH enhances farnesol production by Saccharomyces cerevisiae. J. Biosci. Bioeng. 2009, 108, 52–55. [Google Scholar] [CrossRef]
- Foster, R.T.; Nickerson, G.B. Changes in Hop Oil Content and Hoppiness Potential (Sigma) during Hop Aging. J. Am. Soc. Brew. Chem. 1985, 43, 127–135. [Google Scholar] [CrossRef]
- Forster, A.; Gahr, A.; Van Opstaele, F. On the Transfer Rate of Geraniol with Dry Hopping. Brew. Sci. 2014, 67, 60–62. [Google Scholar]
- Kollmannsberger, H.; Biendl, M.; Nitz, S. Occurrence of glycosidically bound flavour compounds in hops, hop products and beer. Monatsschr. Brauwiss 2006, 59, 83–89. [Google Scholar]
- Biendl, M.; Engelhard, B.; Forster, A.; Gahr, A.; Lutz, A.; Mitter, W.; Sch, R. Hops—Their Cultivation, Composition and Usage, 1st ed.; Fachverlag Hans Carl: Nürnberg, Germany, 2015; pp. 215–216. [Google Scholar]
Figure 1.
Principal component analysis of Saaz varieties and their hop oil content.
Figure 2.
Principal component analysis of single-hopped beers by relative Saaz varieties and their hop oil content.
Figure 2.
Principal component analysis of single-hopped beers by relative Saaz varieties and their hop oil content.
Table 1.
Validation parameters of heart-cut GC method to determine hop oil concentrations in hop and beer.
Table 1.
Validation parameters of heart-cut GC method to determine hop oil concentrations in hop and beer.
| Essential Oil | Absolute Recovery | Correction Factor | LOD | LOQ | Relative Uncertainty |
|---|---|---|---|---|---|
| (%) | (mg/kg) | (mg/kg) | (%) | ||
| Isobutyl isobutyrate | 87.3 | - | 0.98 | 3.25 | 20.0 |
| Methyl hexanoate | 87.7 | - | 0.16 | 0.54 | 25.0 |
| α-Pinene | 78.9 | - | 1.42 | 4.75 | 25.0 |
| Isoamyl isobutyrate | 98.6 | - | 0.30 | 1.01 | 25.0 |
| Methyl heptanoate | 96.0 | - | 0.60 | 2.00 | 25.0 |
| 2-Nonanone | 157.3 | 0.64 | 0.70 | 2.34 | 25.0 |
| Linalool | 166.8 | 0.60 | 0.94 | 3.13 | 15.0 |
| Methyl octanoate | 93.9 | - | 0.79 | 2.64 | 25.0 |
| Methyl nonanoate | 88.9 | - | 1.02 | 3.41 | 25.0 |
| (Z)-Geraniol (Nerol) | 101.7 | - | 1.48 | 4.92 | 25.0 |
| (Z)-Methyl geranate | 96.5 | - | 0.88 | 2.94 | 10.0 |
| 2-Undecanone | 94.0 | - | 2.29 | 7.64 | 10.0 |
| Geranyl acetate | 96.7 | - | 1.92 | 6.39 | 25.0 |
| 2-Dodecanone | 105.8 | - | 0.96 | 3.20 | 15.0 |
| α-Ionone | 107.7 | - | 2.23 | 7.42 | 25.0 |
| β-Caryophyllene | 70.0 | 1.43 | 1.73 | 5.76 | 10.0 |
| (E)-β-Farnesene | 82.0 | - | 1.76 | 5.86 | 10.0 |
| α-Irone | 116.0 | - | 0.53 | 1.77 | 25.0 |
| β-Caryophyllene oxide | 96.8 | - | 1.78 | 5.92 | 25.0 |
| Farnesole | 91.4 | - | 0.55 | 1.83 | 15.0 |
| β-Pinene | 51.4 | 1.94 | 1.38 | 4.59 | 20.0 |
| Myrcene | 73.7 | 1.36 | 0.71 | 2.38 | 25.0 |
| Limonene | 80.5 | - | 0.52 | 1.74 | 25.0 |
| (E)-β-Ocimene | 81.1 | - | 0.30 | 1.00 | 25.0 |
| 2-Decanone | 119.5 | - | 2.53 | 8.45 | 10.0 |
| Terpinen-4-ol | 100.4 | - | 1.29 | 4.30 | 25.0 |
| α-Terpineol | 96.1 | - | 1.61 | 5.35 | 25.0 |
| Methyl decanoate | 98.4 | - | 0.62 | 2.07 | 10.0 |
| (E)-Methyl geranate | 98.6 | - | 0.67 | 2.22 | 15.0 |
| α-Humulene | 86.5 | - | 0.52 | 1.74 | 20.0 |
| 2-Tridecanone | 101.6 | - | 1.51 | 5.03 | 25.0 |
| β-Ionone | 102.3 | - | 0.85 | 2.85 | 25.0 |
Table 2.
Hop resin content in studied hop samples.
| Variety | Cohumulone (% rel.) | Colupulone (% rel.) | α-Acids (wt%) | β-Acids (wt%) | α/β | X (wt%) | DMX (wt%) |
|---|---|---|---|---|---|---|---|
| Saaz | 20.59 | 40.66 | 3.84 | 3.94 | 0.97 | 0.34 | 0.06 |
| S. Late | 22.93 | 40.18 | 2.64 | 4.22 | 0.63 | 0.30 | 0.03 |
| S. Brilliant | 21.01 | 42.62 | 3.42 | 2.30 | 1.49 | 0.09 | 0.02 |
| S. Comfort | 18.94 | 42.91 | 3.95 | 3.49 | 1.13 | 0.35 | 0.08 |
| S. Shine | 20.92 | 46.79 | 3.42 | 2.73 | 1.26 | 0.33 | 0.02 |
Mean value of three measurements. X—xanthohumol; DMX—desmethylxanthohumol.
Table 3.
Basic chemical parameters of single-hopped beers.
| Saaz | S. Late | S. Brilliant | S. Comfort | S. Shine | |
|---|---|---|---|---|---|
| Original extract (% w/w) | 12.6 ± 0.2 | 12.4 ± 0.1 | 12.5 ± 0.0 | 12.3 ± 0.1 | 12.6 ± 0.1 |
| Alcohol (% v/w) | 5.0 ± 0.2 | 5.0 ± 0.2 | 5.1 ± 0.0 | 5.0 ± 0.1 | 5.1 ± 0.2 |
| Alcohol (% w/w) | 3.9 ± 0.2 | 3.9 ± 0.1 | 4.0 ± 0.0 | 3.9 ± 0.1 | 3.9 ± 0.2 |
| Apparent Extract (% w/w) | 3.2 ± 0.2 | 3.0 ± 0.2 | 2.9 ± 0.0 | 3.0 ± 0.1 | 3.2 ± 0.4 |
| Real Extract (% w/w) | 5.0 ± 0.1 | 4.8 ± 0.1 | 4.8 ± 0.0 | 4.8 ± 0.1 | 5.0 ± 0.3 |
| Apparent Attenuation (%) | 74.4 ± 2.0 | 75.5 ± 1.7 | 76.6 ± 0.1 | 75.8 ± 0.1 | 74.7 ± 3.1 |
| Real Attenuation (%) | 60.1 ± 1.6 | 61.0 ± 1.4 | 62.0 ± 0.0 | 61.0 ± 0.5 | 60.0 ± 2.5 |
| Bitterness (BU) | 39 ± 1 | 41 ± 1 | 37 ± 1 | 36 ± 1 | 37 ± 2 |
| Color (u. EBC) | 8.9 ± 0.4 | 9.5 ± 0.1 | 9.2 ± 0.0 | 8.5 ± 0.1 | 9.4 ± 0.3 |
Mean value of six measurements ± standard deviation.
Table 4.
Hop oil profile in studied samples of Saaz varieties.
| Saaz | S. Late | S. Brilliant | S. Comfort | S. Shine | |
|---|---|---|---|---|---|
| mg/kg | mg/kg | mg/kg | mg/kg | mg/kg | |
| Isobutyl isobutyrate | 2.04 ± 0.18 | 3.26 ± 0.11 | 3.27 ± 0.15 | 3.16 ± 0.27 | 3.13 ± 0.15 |
| Methyl hexanoate | <0.5 | <0.5 | <0.5 | <0.5 | <0.5 |
| (Z)-Methyl geranate | 3.31 ± 0.08 | 4.93 ± 0.06 | 3.63 ± 0.03 | 3.61 ± 0.11 | 2.65 ± 0.05 |
| Isoamyl isobutyrate | <1.0 | <1.0 | <1.0 | <1.0 | 1.38 ± 0.25 |
| Methyl heptanoate | <2.0 | <2.0 | <2.0 | <2.0 | <2.0 |
| Methyl decanoate | 6.80 ± 0.52 | 3.48 ± 0.35 | 3.25 ± 0.26 | 4.42 ± 0.19 | 3.07 ± 0.24 |
| (E)-Methyl geranate | 65.64 ± 5.16 | 79.71 ± 1.37 | 57.21 ± 1.35 | 87.73 ± 4.54 | 67.50 ± 1.62 |
| Methyl octanoate | <2.0 | <2.0 | <2.0 | <2.0 | <2.0 |
| Methyl nonanoate | <3.0 | <3.0 | <3.0 | <3.0 | <3.0 |
| Geranyl acetate | <3.0 | <3.0 | <3.0 | <3.0 | <3.0 |
| Sum of esters | 75.75 | 91.38 | 67.36 | 98.92 | 77.73 |
| % of esters | 1.3 | 2.6 | 1.4 | 1.5 | 1.1 |
| β-Pinene | 1384.54 ± 170.13 | 778.83 ± 46.80 | 904.48 ± 34.42 | 1138.58 ± 78.01 | 1101.61 ± 83.69 |
| Myrcene | 353.21 ± 32.95 | 398.93 ± 16.31 | 363.21 ± 18.07 | 466.83 ± 33.00 | 418.31 ± 20.25 |
| Limonene | 5.76 ± 0.5 | 6.35 ± 0.54 | 6.03 ± 0.29 | 8.40 ± 1.06 | 8.28 ± 0.53 |
| (E)-β-Ocimene | 61.53 ± 5.73 | 39.26 ± 1.13 | 38.10 ± 2.69 | 55.02 ± 4.50 | 50.44 ± 1.36 |
| 3-Carene | 34.89 ± 2.23 | 27.44 ± 1.83 | 32.37 ± 2.03 | 40.64 ± 2.91 | 41.24 ± 1.01 |
| α-Pinene | <1.0 | <1.0 | <1.0 | <1.0 | <1.0 |
| Sum of monoterpens | 1839.93 | 1250.81 | 1344.19 | 1709.47 | 1619.88 |
| % of monoterpens | 32.1 | 35.2 | 27.7 | 25.8 | 22.6 |
| Terpinen-4-ol | <1.0 | <1.0 | <1.0 | <1.0 | <1.0 |
| α-Terpineol | 5.23 ± 0.63 | 4.00 ± 0.14 | 2.43 ± 0.47 | 3.34 ± 0.48 | 4.74 ± 0.43 |
| (Z)-Geraniol (Nerol) | <2.0 | <2.0 | <2.0 | <2.0 | <2.0 |
| Linalool | 25.33 ± 1.05 | 33.98 ± 0.74 | 22.24 ± 0.71 | 46.35 ± 1.21 | 42.94 ± 0.46 |
| Farnesol | 25.94 ± 8.97 | 23.73 ± 1.38 | 75.97 ± 2.57 | 249.63 ± 6.10 | 472.46 ±12.96 |
| β-Caryophyllene oxide | 55.40 ± 9.57 | 37.89 ± 2.29 | 12.65 ± 0.48 | 26.98 ± 1.44 | 19.28 ± 1.39 |
| Sum of alcohols | 111.90 | 99.60 | 113.29 | 326.30 | 539.42 |
| % of alcohols | 2.0 | 2.8 | 2.3 | 4.9 | 7.5 |
| (E)-β-Farnesene | 611.99 ± 71.65 | 743.19 ± 10.85 | 1174.97 ± 21.24 | 1645.14 ± 62.96 | 1196.47 ± 32.28 |
| β-Caryophyllene | 771.26 ± 101.62 | 394.79 ± 7.34 | 598.57 ± 12.58 | 887.71 ± 27.36 | 941.03 ± 28.82 |
| α-Humulene | 2112.50 ± 249.88 | 897.23 ± 30.83 | 1448.47 ± 49.22 | 1833.86 ± 115.25 | 2722.25 ± 81.06 |
| Sum of sesquiterpens | 3495.75 | 2035.21 | 3222.01 | 4366.71 | 4859.75 |
| % of sesquiterpens | 61.1 | 57.2 | 66.5 | 65.9 | 67.8 |
| 2-Decanone | 14.59 ± 0.42 | 3.86 ± 0.63 | 8.13 ± 0.25 | 8.69 ± 0.58 | 3.44 ± 0.63 |
| 2-Undecanone | 101.46 ± 4.97 | 41.36 ± 0.59 | 49.30 ± 0.47 | 59.11 ± 1.27 | 32.59 ± 1.25 |
| 2-Dodecanone | 11.64 ± 0.2 | 4.38 ± 0.06 | 7.34 ± 0.11 | 8.94 ± 0.35 | 4.35 ± 0.09 |
| 2-Tridecanone | 67.72 ± 7.36 | 29.39 ± 1.18 | 34.56 ± 1.19 | 45.03 ± 4.73 | 26.95 ± 2.52 |
| β-Ionone | <2.0 | <2.0 | <2.0 | <2.0 | <2.0 |
| α-Ionone | <2.0 | <2.0 | <2.0 | <2.0 | <2.0 |
| 2-Nonanone | 6.37 ± 0.56 | <2.0 | 2.27 ± 0.35 | 3.12 ± 0.22 | 1.72 ± 0.19 |
| α-Irone | <2.0 | <2.0 | <2.0 | <2.0 | <2.0 |
| Sum of carbonyls | 201.78 | 78.99 | 101.60 | 124.89 | 69.05 |
| % of carbonyls | 3.5 | 2.2 | 2.1 | 1.9 | 1.0 |
Mean value of six measurements ± standard deviation.
Table 5.
Hop oil profiles in single-hopped beers by relative Saaz varieties.
| Saaz | S. Late | S. Brilliant | S. Comfort | S. Shine | |
|---|---|---|---|---|---|
| mg/L | mg/L | mg/L | mg/L | mg/L | |
| Isobutyl isobutyrate | <1.00 | 1.34 ± 0.61 | 1.67 ± 0.61 | 1.06 ± 0.44 | 1.46 ± 0.52 |
| Methyl hexanoate | <0.50 | <0.50 | <0.50 | <0.50 | <0.50 |
| (Z)-Methyl geranate | 8.48 ± 0.67 | 14.42 ± 2.32 | 8.49 ± 1.72 | 10.92 ± 1.07 | 10.48 ± 1.72 |
| Isoamyl isobutyrate | <1.00 | <1.00 | <1.00 | <1.00 | <1.00 |
| Methyl heptanoate | <0.50 | <0.50 | <0.50 | <0.50 | <0.50 |
| Methyl decanoate | <0.50 | <0.50 | <0.50 | <0.50 | <0.50 |
| (E)-Methyl geranate | <1.00 | <1.00 | <1.00 | <1.00 | <1.00 |
| Methyl octanoate | <0.50 | <0.50 | <0.50 | <0.50 | <0.50 |
| Methyl nonanoate | <0.50 | <0.50 | <0.50 | <0.50 | <0.50 |
| Geranyl acetate | 1.30 ± 0.38 | 1.71 ± 0.63 | 2.71 ± 1.46 | 2.01 ± 0.63 | 2.46 ± 1.98 |
| Sum of esters | 9.78 | 17.47 | 12.87 | 13.99 | 14.54 |
| % of esters | 7.7 | 8.0 | 9.8 | 7.8 | 6.2 |
| β-Pinene | <0.5 | <0.5 | <0.5 | <0.5 | <0.5 |
| Myrcene | 2.71 ± 0.51 | 3.22 ± 0.85 | 3.37 ± 0.59 | 4.71 ± 1.17 | 5.05 ± 1.99 |
| Limonene | <0.5 | <0.5 | <0.5 | <0.5 | <0.5 |
| (E)-β-Ocimene | <1.00 | <1.00 | <1.00 | <1.00 | <1.00 |
| 3-Carene | 1.59 ± 1.79 | 1.05 ± 1.61 | 1.98 ± 2.81 | 1.18 ± 1.38 | 1.05 ± 1.93 |
| α-Pinene | <1.00 | <1.00 | <1.00 | <1.00 | <1.00 |
| Sum of monoterpens | 4.30 | 4.27 | 5.35 | 5.89 | 6.10 |
| % of monoterpens | 3.4 | 1.9 | 4.1 | 3.3 | 2.6 |
| Terpinen-4-ol | 0.46 ± 0.26 | 0.78 ± 0.35 | 0.61 ± 0.27 | 0.64 ± 0.23 | 0.55 ± 0.32 |
| α-Terpineol | 3.24 ± 0.25 | 5.12 ± 0.36 | 4.01 ± 0.78 | 4.41 ± 0.15 | 4.74 ± 0.84 |
| (Z)-Geraniol (Nerol) | 3.14 ± 0.38 | 2.04 ± 0.53 | 2.72 ± 0.16 | 1.90 ± 0.12 | 2.09 ± 0.25 |
| Linalool | 17.25 ± 1.46 | 32.11 ± 2.60 | 19.31 ± 3.43 | 28.82 ± 2.51 | 27.76 ± 7.50 |
| Farnesol | 86.98 ± 30.04 | 155.34 ± 6.80 | 85.54 ± 31.24 | 122.00 ± 21.82 | 179.58 ± 10.00 |
| β-Caryophyllene oxide | 1.49 ± 0.29 | 2.53 ± 0.22 | 0.64 ± 0.16 | 1.10 ± 0.13 | 0.80 ± 0.14 |
| Sum of alcohol | 112.57 | 197.92 | 112.83 | 158.87 | 215.52 |
| % of alcohol | 88.5 | 90.1 | 86.1 | 88.6 | 91.3 |
| (E)-β-Farnesene | <2.00 | <2.00 | <2.00 | <2.00 | <2.00 |
| β-Caryophyllene | <0.50 | <0.50 | <0.50 | <0.50 | <0.50 |
| α-Humulene | 0.50 ± 0.23 | <0.50 | <0.50 | 0.55 ± 0.30 | <0.50 |
| Sum of sesquiterpens | 0.50 | 0.00 | 0.00 | 0.55 | 0.00 |
| % of sesquiterpens | 0.4 | 0.0 | 0.0 | 0.3 | 0.0 |
| 2-Decanone | <1.00 | <1.00 | <1.00 | <1.00 | <1.00 |
| 2-Undecanone | <1.00 | <1.00 | <1.00 | <1.00 | <1.00 |
| 2-Dodecanone | <1.00 | <1.00 | <1.00 | <1.00 | <1.00 |
| 2-Tridecanone | <1.00 | <1.00 | <1.00 | <1.00 | <1.00 |
| β-Ionone | <0.50 | <0.50 | <0.50 | <0.50 | <0.50 |
| α-Ionone | <0.50 | <0.50 | <0.50 | <0.50 | <0.50 |
| 2-Nonanone | <1.00 | <1.00 | <1.00 | <1.00 | <1.00 |
| α-Irone | <0.50 | <0.50 | <0.50 | <0.50 | <0.50 |
| Sum of carbonyls | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 |
| % of carbonyls | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
Mean value of six measurements ± standard deviation.
Table 6.
Bacis sensory parameters of single-hopped beers.
| Saaz | S. Late | S. Brilliant | S. Comfort | S. Shine | Saaz | |
|---|---|---|---|---|---|---|
| Fullness | 3.0 | 2.7 | 2.9 | 3.0 | 3.0 | 3.0 |
| Bitterness | 2.1 | 2.2 | 1.8 | 1.9 | 1.9 | 2.1 |
| Astringency | 1.2 | 1.2 | 1.2 | 1.1 | 1.2 | 1.2 |
| Sourness | 1.4 | 1.5 | 1.3 | 1.5 | 1.6 | 1.4 |
| Sweetness | 1.5 | 1.5 | 1.5 | 1.6 | 1.6 | 1.5 |
| Hoppy (overall) | 2.0 | 2.1 | 2.3 | 2.3 | 2.1 | 2.0 |
| Estery | 1.3 | 1.2 | 1.2 | 1.2 | 1.4 | 1.3 |
| Yeasty | 1.0 | 1.3 | 1.2 | 1.0 | 1.0 | 1.0 |
| Hop aroma (in detail) | hoppy, herbal, floral, spicy | hoppy, floral, fruity, woody, spicy | hoppy, fruity, herbal, floral, woody | hoppy, fruity, herbal, spicy | hoppy, fruity, floral, herbal, spicy | hoppy, herbal, floral, spicy |
Mean value of 12 evaluations with six-point scale (0—none; 1—very low intensity; 5—very high intensity). Data processing: trimmed mean value of relative uncertainty from 24 individual evaluations was 0.5.
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content. |
© 2024 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
Share and Cite
MDPI and ACS Style
Olšovská, J.; Straková, L.; Nesvadba, V.; Vrzal, T.; Přikryl, J. The Comparison and Brewing Value of Saaz Hop Pedigree. Beverages 2024, 10, 101. https://doi.org/10.3390/beverages10040101
AMA Style
Olšovská J, Straková L, Nesvadba V, Vrzal T, Přikryl J. The Comparison and Brewing Value of Saaz Hop Pedigree. Beverages. 2024; 10(4):101. https://doi.org/10.3390/beverages10040101
Chicago/Turabian StyleOlšovská, Jana, Lenka Straková, Vladimír Nesvadba, Tomáš Vrzal, and Jaroslav Přikryl. 2024. "The Comparison and Brewing Value of Saaz Hop Pedigree" Beverages 10, no. 4: 101. https://doi.org/10.3390/beverages10040101
APA StyleOlšovská, J., Straková, L., Nesvadba, V., Vrzal, T., & Přikryl, J. (2024). The Comparison and Brewing Value of Saaz Hop Pedigree. Beverages, 10(4), 101. https://doi.org/10.3390/beverages10040101
Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.
