Exploring the composition and potential uses of four hops varieties through different extraction techniques.

Hydrophilic, lipophilic extracts and essential oil of four hops varieties from Slovenia were examined in this study. Lipophilic extracts were obtained by supercritical extraction (SFE), while for hydrophilic extracts ultrasound and microwave extraction were employed. Essential oils were isolated by the hydrodistillation process.

The Impact of Hop Freshness on Kettle-Hopped Beers.

Hops are an indispensable ingredient in beer, and the differences in their chemical composition impart the various tastes and aromas associated with different beers. However, during storage, hops undergo changes in their chemical composition. Here, the changes in aroma and bitterness of kettle-hopped beers were evaluated in an experiment conducted on three different hop varieties (Aurora, Celeia and Styrian Wolf) with five different hop storage index (HSI) values (0.

Corrigendum to: Impact of Successive Exploitation of a Starter Culture on Saccharide Uptake Dynamics from Wort (Published: Food Technol. Biotechnol. 59 (1) 16-23 (2021) https://doi.org/10.17113/ftb.59.01.21.6899).

[This corrects the article DOI: 10.17113/ftb.59.

Extraction of Polyphenols from Slovenian Hop ( L.) Aurora Variety Using Deep Eutectic Solvents: Choice of the Extraction Method vs. Structure of the Solvent.

Polyphenols from Slovenian hops ( L.) of the Aurora variety were extracted by different methods and using classical solvents and several deep eutectic solvents (DES) based on choline chloride as the hydrogen bond acceptor component. The obtained extract solutions were analyzed by HPLC for the content of extracted α- and β-acids and extracted xanthohumol.

The Stability of Hop ( L.) Resins during Long-Period Storage.

The stability of alpha-acids, beta-acids and hop storage index (HSI) values under different conditions (aerobic/anaerobic, 4 °C/room temperature) was studied in a two-year trial. Six different varieties (Celeia, Aurora, Bobek, Styrian Gold, Savinjski Golding and Styrian Wolf) were used in the form of cones and pellets. Alpha- and beta-acids were determined by HPLC and HSI by spectrophotometry.

Antimicrobial Properties of Different Hop () Genotypes.

The antimicrobial activity of hop extracts obtained from different hop genotypes were investigated against and . In this study the pure xanthohumol, purified β-acids rich fraction, as well as α-acids with β-acids rich fraction were used to test antimicrobial activity against and ; whereby, the antimicrobial activity of different hop extracts against was studied for the first time. Microbial susceptibility to purified hydroacetonic extracts from different hop varieties was investigated by the broth microdilution assay to determine the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC).

Changes in Hop ( L.) Oil Content and Composition during Long-Term Storage under Different Conditions.

Hop essential oil, in addition to alpha-acids, is one of the most valuable parameters for brewers, since it is responsible for beer aroma. The hop oil content and hop oil chemical composition deliver various aromas to beer. During storage, the hop chemical composition undergoes many physical and chemical changes that impact its quality.

Impact of Hop Freshness on Dry Hopped Beer Quality.

The hop plant is seasonal, but beer production continues throughout the whole year. The quality of hops begins to decrease immediately after harvesting; therefore, maintaining the highest possible quality is important. A good indicator of hop freshness is the hop storage index (HSI).

Differences in the Levels of the Selected Phytoestrogens and Stable Isotopes in Organic vs. Conventional Hops and Beer.

Xanthohumol (XN), isoxanthohumol (IX) and 8-prenylnaringenin (8-PN) are important prenylflavonoids present in hops with potential beneficial properties. In this study, we examined differences in the content of XN, IX and 8-PN in hops and beer produced under organic and conventional production regimes. A An ultra-high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS) method for analysing XN, IX and 8-PN in hops and beer was developed and validated, with LOQ ranging from 0.

Sub- and Supercritical Extraction of Slovenian Hops ( L.) Aurora Variety Using Different Solvents.

This work investigates the efficiency of supercritical fluid extraction of hops with a variety of solvents including carbon dioxide (CO), propane, sulfur hexafluoride (SF), and dimethyl ether (DME) at various densities (low-density and high-density). Operating parameters were 50 bar, 100 bar and 150 bar and 20 °C, 40 °C, 60 °C and 80 °C for all solvents, respectively. The influence of process parameters on the total yield of extraction and content of bitter acids in the extracts has been investigated.

Impact of Successive Exploitation of a Starter Culture on Saccharide Uptake Dynamics from Wort.

Research Background: The production of lager beer includes successive repitchings of a single starter culture. During the beer production process, the yeast is exposed to several stress factors which could affect the fermentation performance. An incomplete fermentation represents a waste of fermentable extract and leads to a beer with higher carbohydrate levels, which could result in a beer with an atypical flavour profile.

Metabolomic Analysis of Cannabinoid and Essential Oil Profiles in Different Hemp ( L.) Phenotypes.

Hemp ( L.) cannabinoids and terpenoids have therapeutic effects on human and animal health. Cannabis plants can often have a relatively high heterogeneity, which leads to different phenotypes that have different chemical profiles despite being from the same variety.

Hop Compounds: Extraction Techniques, Chemical Analyses, Antioxidative, Antimicrobial, and Anticarcinogenic Effects.

Hop plants comprise a variety of natural compounds greatly differing in their structure and properties. A wide range of methods have been developed for their isolation and chemical analysis, as well as for determining their antioxidative, antimicrobial, and antigenotoxic potentials. This contribution provides an overview of extraction and fractionation techniques of the most important hop compounds known for their health-promoting features.

The determination of the geographic origins of hops (Humulus lupulus L.) by multi-elemental fingerprinting.

For brewers, it is important to know the geographic origins of the hop plants (Humulus lupulus L.) used in their brewing processes since the contents and compositions of the bitter resins and essential oils in them depend on the environmental conditions during their growth. In this study, the multi-elemental profiles of hop plants from each of the world's main growing regions were determined by non-destructive energy dispersive X-ray fluorescence spectrometry (EDXRF).

Determination of the Geographical and Botanical Origin of Hops (Humulus lupulus L.) Using Stable Isotopes of C, N, and S.

A need exists for a reliable method to determine the geographical and botanical origin of hops. For this study, three sets of samples were collected: the first set comprised 5 German samples; the second set comprised samples of hops from 10 of the world's major hop-growing regions; and the third comprised the 4 main Slovenian regions. The samples were analyzed using isotope ratio mass spectrometry (IRMS) to obtain δC, δN, and δS values.

Comparison of sensory and chemical evaluation of lager beer aroma by gas chromatography and gas chromatography/mass spectrometry.

Background: Although the evaluation of beer is conducted by sensory experts, we cannot neglect the influence of human factors and subjectivity. This problem could be solved by the chemical analysis of the volatile part of beer aroma and, from this, we can build a database for the construction of a model that classifies samples in a comparable manner to sensory assessment.

Results: Twenty-two batches of the same beer brand were assessed by sensory evaluation and described chemically in terms of the contents of alcohols and esters (n = 9), hop essential oil compounds (n = 15) using gas chromatography (GC) and other aroma volatiles (n = 33) as analysed by head space solid-phase microextraction (SPME)-GC/mass spectrometry.

Antioxidant and Antimicrobial Properties of Veronica spicata L. (Plantaginaceae).

Tea made from Veronica spicata L. (syn. Pseudolysimachion spicatum (L.

Antimicrobial and Antioxidant Properties of Satureja Montana L. and S. Subspicata Vis. (Lamiaceae).

Satureja montanaL. and S. subspicata Vis.

The influence of serial repitching of Saccharomyces pastorianus on its karyotype and protein profile during the fermentation of gluten-free buckwheat and quinoa wort.

Gluten-free beer-like beverages from malted buckwheat and quinoa are somehow close to their commercial production, but rather high expenses are expected due to the relatively high price of grain, some technological adaptations of process and the need for external enzyme supplementation during mashing. One of the common and efficient cost reduction measures in the industrial scale is serial repitching of the yeast biomass, which has not been studied for the buckwheat and quinoa wort fermentation before. In that manner we have monitored possible changes in yeast's proteins and chromosomal DNA during eleven serial repitchings of the yeast Saccharomyces pastorianus strain TUM 34/70 for fermentation of the barley, buckwheat and quinoa wort.

Influence of two hop (Humulus lupulus L.) varieties on in vitro dry matter and crude protein degradability and digestibility in ruminants.

Background: Hop cones contain several antimicrobial substances. The aim of the study was to determine the effects of two hop varieties, Aurora and Dana, on substrate (diet for a dairy cow, producing 30 kg milk daily) in vitro dry matter (DM) and crude protein (CP) degradability and digestibility.

Results: In the in vitro trial freshly ground hops were added to the buffered rumen fluid in concentrations simulating the cow's daily intake of 50, 100 and 200 g of hops.

Effect of deodorization of camelina (Camelina sativa) oil on its phenolic content and the radical scavenging effectiveness of its extracts.

The influence of deodorization parameters (temperature (T), steam flow (S), time (t)) on the phenolic content and radical scavenging effectiveness (RSE) of methanolic extracts of camelina oil was investigated and analyzed by response-surface methodology (RSM). The phenolic content can be considered to be a linear function of all three parameters. A positive linear relationship between the content of phenolic compounds in deodorized oils and RSE was observed.

Investigation of chemical compounds, antioxidant and antimicrobial properties of teucrium arduini L. (lamiaceae).

In this paper chemical composition of the essential oil (analysed by GC and GC-MS), the content of phenolic compounds (analysed by HPLC), quantity of total phenols and total flavonoids (analysed by UV/Vis spectrophotometer), antioxidant and antimicrobial activities of ethanolic extracts were investigated in endemic Teucrium arduini L. in population of Mt Biokovo (Croatia). The oil was characterized by a high concentration of sesquiterpene hydrocarbons (70.

Characterization of commercial slovenian and cypriot fruit juices using stable isotopes.

The compositions of commercially available fruit juices on the Slovenian and Cypriot markets have been compared and checked against the corresponding declarations on the packaging. Values of delta(13)C in the pulp, sugars, and ethanol (produced by fermentation and distillation) have been obtained by isotope ratio mass spectrometry and (D/H)(I) and (D/H)(II) ratios determined by Site-specific Natural Isotope Fractionation NMR and compared with literature data. These data show that some juices on the Slovenian and Cypriot markets were adulterated.

Application of total reflection X-ray spectrometry in combination with chemometric methods for determination of the botanical origin of Slovenian honey.

This work on the botanical origin of various types of honey produced in Slovenia and based on the mineral content analyses by the total reflection X-ray spectrometry (TXRF) is a continuation of this group's preliminary work (Golob, T.; Doberšek, U.; Kump, P.

Fatty acid and stable carbon isotope characterization of Camelina sativa oil: implications for authentication.

The importance of authenticity characterization is an increasing and pressing requirement for all foods. Vegetable oil is one of the most studied foods because of its nutritional and medicinal properties in a correct diet. In this study, a total of 53 Camelina sativa samples, from all known growing areas, were chemically and isotopically characterized.