Changes in the Chemical Composition of Plum Distillate During Maturation with Oak Chips under Different Conditions

U radu je ispitan utjecaj dozrijevanja u kontaktu s hrastovim trijeskama na sastav i koncentraciju destilata šljive. Destilatu šljive su tijekom starenja dodane lagano pržene trijeske francuskog hrasta (Quercus sessiflora i Quercus robur) ili trijeske dobivene od starih bačava u kojima je odležao konjak. Ispitan je utjecaj količine dodanih trijeski, temperature, načina dozrijevanja (statičnog ili uz cirkulaciju) te primjene ultrazvuka. Dozrijevanjem destilata šljive u prisutnosti hrastovih trijeski povećala se količina ekstraktibilnih organskih spojeva (uključujući tanine) i promijenila boja destilata, u ovisnosti o vrsti i količini dodanih trijeski te uvjetima dozrijevanja. Koncentracija se šećera, kao što su glukoza, ksiloza i arabinoza, povećala ovisno o uvjetima dozrijevanja i vrsti trijeski. Razgradnjom lignina oslobođene su određene količine sinapaldehida, siringaldehida, coniferaldehida i vanilina, u ovisnosti o uvjetima pokusa. Od hlapljivih spojeva, koncentracija se viših alkohola i alifatskih (acikiličkih) aldehida u većem broju varijanti pokusa smanjila, dok se koncentracija furanskih aldehida, ovisno o vrsti i količini trijeski te uvjetima dozrijevanja, povećala. Koncentracija se estera, poput etilacetata u većem broju varijanti pokusa smanjila, a etil-kaproata, etil-kaprilata i etil- -kaprata postupno povećala. Neki su fenoli i laktoni pronađeni u uzorcima destilata nakon dozrijevanja, a najmanje su koncentracije tih spojeva pronađene u uzorcima destilata dozrelog u kontaktu s hrastovim trijeskama dobivenim od bačava u kojima je odležao konjak.This study investigates the effect of ageing on the qualitative and quantitative composition of plum distillate in contact with oak wood chips. Maturation was performed with lightly toasted French oak (Quercus sessiflora and Quercus robur) chips or oak chips made from fragments of empty barrels that had been used for ageing cognac. The effects of oak chip dose, process temperature, ageing system (static or circulatory) and ultrasound treatment were assessed. Maturation of plum distillate samples with oak chips resulted in higher levels of extractable organics (including tannins) and colour changes, which were correlated with the type and dose of oak chips, and the conditions of maturation. The content of sugars such as glucose, xylose and arabinose also increased, depending on the conditions and type of oak chips. Degradation of lignin resulted in liberation of sinapaldehyde, syringaldehyde, coniferaldehyde and vanillin, with intensities depending on the applied parameters. In terms of volatiles, decreases in the concentration of higher alcohols and aliphatic aldehydes were observed in the majority of maturation experiments, while concentrations of furanic aldehydes increased depending on the type and dose of oak chips, as well as on the conditions of maturation. The quantities of esters such as ethyl acetate decreased in the majority of experimental variants, whereas concentrations of ethyl caproate, ethyl caprylate and ethyl caprate increased gradually. Some phenols and lactones were detected in all matured samples, with the lowest levels found in the samples aged with oak chips made from cognac barrels

Buckwheat as an Interesting Raw Material for Agricultural Distillate Production

The objective of this study was to assess the suitability of buckwheat grain for agricultural distillate production. The effects of the method of starch liberation on the physicochemical composition of the prepared mashes, fermentation results, the concentration of volatile compounds in the obtained distillates, and their organoleptic features, were investigated. The raw materials used were two cultivars of buckwheat grains, Panda and Kora. Both cultivars were characterized by similar starch content, however Panda cultivar had a significantly higher content of reducing sugars. Fermentation of the Kora cultivar-based mashes resulted in a higher fermentation efficiency (up to approximately 85% of the theoretical yield) compared to the Panda cultivar-based mashes (up to approx. 75%). Of the tested methods of starch liberation, the pressure-thermal treatment was revealed as superior, especially in the case of the Panda cultivar. In the case of the Kora cultivar, both the pressure-thermal method and the pressureless method of starch liberation resulted in a high process efficiency (up to 85% of the theoretical). Supplementation of the buckwheat mashes with (NH4)2HPO4 improved fermentation results. The highest scores in sensory assessment were given to distillates from mashes prepared with the pressure-thermal treatment, which contained relatively low concentrations of undesirable compounds, such as acetaldehyde and methanol, and revealed pleasant organoleptic features

Characterization of chemical contamination existing in raw spirits

Na podstawie przeglądu dostępnych publikacji opisano mechanizmy oraz przyczyny powstawania produktów ubocznych fermentacji alkoholowej, obniżających jakość spirytusów surowych. Produkty te należą do następujących grup substancji chemicznych: związki karbonylowe, kwasy karboksylowe, estry, metanol oraz alkohole wyższe. Wskazano również na czynniki, które w istotny sposób mogą wpływać na ich nadmierną koncentrację.The mechanism and reasons of the by-products formation during the alcohol fermentation, making worse the quality of raw spirits, are discussed basing on the review of available publications. There are presented the factors having the influences as: carbonyl compounds, carboxylic acids, esters, methanol and higher alcohols. Factors, which can cause an exceeding concentration of this groups of compounds in raw spirits are denoted

Synteza wyższych alkoholi w zacierach żytnich

Formation of by-products during alcoholic fermentation is a complex process. Particular attention should be paid to generation of higher alcohols because of its complex mechanism and dynamics. In XIX century the higher alcohols were thought about as "bacterial metabolites of spoilage" that contaminate alcoholic beverages. At the beginning of XX century Ehrlich proved that these compounds were produced by yeast from amino acids and they naturally occurred in all alcoholic beverages derived from spirits of agricultural origin. The quantity and profile of fusel alcohols in the wash depend on many factors such as raw materials used to prepare the sweet mash, yeast strain and the inoculum dose, supplements added to the mash. Investigations of many researchers prove that higher alcohols are formed through catabolic and anabolic pathways. They are either products of amino acid catabolism -as was found by Ehrlich or by-products of amino acid synthesis from pyruvate through the anabolic pathway. The occurrence of fusel alcohols in raw spirits from agricultural distilleries is a result of the presence of amino acids, sugars and products of their metabolism mainly aldehydes, in fermented mashes.Powstawanie poszczególnych produktów ubocznych podczas fermentacji alkoholowej, to proces bardzo złożony. Na szczególną uwagę, ze względu na mechanizm i dynamikę powstawania, zasługują wyższe alkohole. W XIX wieku, dominująca była opinia, że alkohole wyższe to "bakteryjne metabolity zepsucia", którymi skażone były napoje alkoholowe. Na początku XX wieku znane już były prace Ehrlicha, który wykazał, że wyższe alkohole są syntetyzowane przez drożdże z aminokwasów, a zatem są składnikami występującymi naturalnie we wszystkich napojach alkoholowych wyprodukowanych z alkoholu etylowego pochodzenia rolniczego. Na ilość fuzli w zacierze odfermentowanym, jak również na ich skład jakościowy, ma wpływ wiele czynników m.in.: rodzaj surowca użytego do przygotowania zacieru, rodzaj i wielkość inokulum drożdży oraz rodzaj pożywek, a także sposób prowadzenia fermentacji. Prace analityczne różnych autorów dowiodły, że wyższe alkohole mogą powstawać na drodze szlaku katabolicznego i anabolicznego. Szlak kataboliczny dotyczy przemian aminokwasów- w/w teoria Ehrlicha. Prekursorem w szlaku anabolicznym jest pirogronian, a fuzle są produktami pobocznymi, powstającymi podczas syntezy aminokwasów. Można jednoznacznie wnioskować, że występowanie fuzli w destylatach rolniczych jest efektem obecności w środowisku fermentacyjnym aminokwasów, cukrów oraz produktów ich przemiany, głównie aldehydów

Impact of Cationic and Neutral Gemini Surfactants on Conidia and Hyphal Forms of Aspergillus brasiliensis

This study investigates the biological activity of two cationic gemini surfactants, hexamethylene-1,6-bis-(N,N-dimethyl-N-dodecylammonium bromide) C6 and pentamethylene-1,5-bis-(N,N-dimethyl-N-dodecyla,.mmonium bromide) C5, and their two neutral analogs, hexamethylene-1,6-bis-(N-methyl-N-dodecylamine) (A6) and pentamethylene-1,5-bis-(N-methyl-N-dodecylamine) (A5). Experiments were performed with Aspergillus brasiliensis, which is used in the standard tests for biocides. The minimal inhibitory concentration (MIC) values for conidia and mycelium were determined using the dilution method. The viability of the conidia was evaluated using the plate count method. The dry mass of the mycelium was determined using the thermogravimetric method. Ergosterol was extracted from the mycelium and evaluated by gas chromatography. The effect of gemini surfactants on fungal morphology was observed using scanning electron microscopy. Cationic gemini surfactants were found to be active at lower concentrations compared to their non-ionic analogues, rapidly reducing the total number of conidia that were able to grow. They also decreased both the ergosterol content in the mycelium and its dry weight. These results suggest that cationic gemini surfactants C6 and C5 could have a wide range of practical applications as active compounds. However, it should be remembered that usage at too low concentrations, below the MIC, will only lead to short-term disturbances in the development of conidia and mycelium

Development of the Method for Determination of Volatile Sulfur Compounds (VSCs) in Fruit Brandy with the Use of HS–SPME/GC–MS

Volatile sulfur compounds (VSCs) play an important role in the aroma profile of fermented beverages. However, because of their low concentration in samples, their analysis is difficult. The headspace solid-phase microextraction (HS–SPME) technique coupled with gas chromatography and mass spectrometry (GC–MS) is one of the methods successfully used to identify VSCs in wine and beer samples. However, this method encounters more obstacles when spirit beverages are analyzed, as the ethanol content of the matrix decreases the method sensitivity. In this work, different conditions applied during HS–SPME/GC–MS analysis, namely: ethanol concentration, salt addition, time and temperature of extraction, as well as fiber coating, were evaluated in regard to 19 sulfur compounds. The best results were obtained when 50/30 μm Divinylbenzene/Carboxen/Polydimethylsiloxane (DVB/CAR/PDMS) was used to preconcentrate the analytes from the sample at 35 °C for 30 min. The dilution of samples to 2.5% v/v ethanol and the addition of 20% w/v NaCl along with 1% EDTA significantly improves the sensitivity of extraction. The optimized method was applied to three fruit brandy samples (plum, pear, and apple) and quantification of VSCs was performed. A total of 10 compounds were identified in brandy samples and their concentration varied greatly depending on the raw material used from production. The highest concentration of identified VSCs was found in apple brandy (82 µg/L)

Markers of Chemical and Microbiological Contamination of the Air in the Sport Centers

This study aimed to assess the markers of chemical and microbiological contamination of the air at sport centers (e.g., the fitness center in Poland) including the determination of particulate matter, CO2, formaldehyde (DustTrak™ DRX Aerosol Monitor; Multi-functional Air Quality Detector), volatile organic compound (VOC) concentration (headspace solid-phase microextraction coupled with gas chromatography–mass spectrometry), the number of microorganisms in the air (culture methods), and microbial biodiversity (high-throughput sequencing on the Illumina platform). Additionally the number of microorganisms and the presence of SARS-CoV-2 (PCR) on the surfaces was determined. Total particle concentration varied between 0.0445 mg m−3 and 0.0841 mg m−3 with the dominance (99.65–99.99%) of the PM2.5 fraction. The CO2 concentration ranged from 800 ppm to 2198 ppm, while the formaldehyde concentration was from 0.005 mg/m3 to 0.049 mg m−3. A total of 84 VOCs were identified in the air collected from the gym. Phenol, D-limonene, toluene, and 2-ethyl-1-hexanol dominated in the air at the tested facilities. The average daily number of bacteria was 7.17 × 102 CFU m−3–1.68 × 103 CFU m−3, while the number of fungi was 3.03 × 103 CFU m−3–7.34 × 103 CFU m−3. In total, 422 genera of bacteria and 408 genera of fungi representing 21 and 11 phyla, respectively, were detected in the gym. The most abundant bacteria and fungi (>1%) that belonged to the second and third groups of health hazards were: Escherichia-Shigella, Corynebacterium, Bacillus, Staphylococcus, Cladosporium, Aspergillus, and Penicillium. In addition, other species that may be allergenic (Epicoccum) or infectious (Acinetobacter, Sphingomonas, Sporobolomyces) were present in the air. Moreover, the SARS-CoV-2 virus was detected on surfaces in the gym. The monitoring proposal for the assessment of the air quality at a sport center includes the following markers: total particle concentration with the PM2.5 fraction, CO2 concentration, VOCs (phenol, toluene, and 2-ethyl-1-hexanol), and the number of bacteria and fungi

The evaluation of microbial contamination in the working environment of tanneries

Background: Due to their animal material processing, tannery workers may be exposed to biological agents. The aim of the study was the microbial contamination assessment of tanneries with different production specifications. Health risk was estimated based on particle size distribution. Moreover, indicators of microbial contamination of tanneries were selected. Materials and Methods: The studies were conducted in 2 types of tanneries - processing raw hides and producing chrome-tanned leather. Air was sampled with MAS-100 Eco Air Sampler, leathers using RODAC Envirocheck® contact plates and swab method, microbial numbers were determined by a culture method. For the bioaerosols size distribution analysis, a six-stage Andersen sampler was used; identification was performed using microscopy and biochemical methods. Microbial contamination was identified by 16S RNA and ITS1/2 rDNA analysis for bacteria and fungi respectively. Results: The microbial number in the air ranged between 1.2×103 and 3.7×103 CFU/m3. While on the leather, it ranged between 7.6×101 and 5.5×105 CFU/100 cm2. Bacteria dominated in the tanneries (air: 51-92%, leathers: 60-100%). Results indicate that potential health risks arise from the fungal small bioaerosol particles presence (0.65-2.1 μm). Eleven indicator microorganisms were determined: B. pumilus, B. subtilis, B. cereus, C. lubricantis, C. cladosporioides, P. commune, P. echinulatum, P. chrysogenum, P. crustosum, C. parapsilosis and C. albidus. Conclusions: Microbial contamination evaluation in the tanneries showed the increased bacteria and fungi number in the air in relation to the outdoor air, which indicates an occupational inhalation risk to workers. The designated indicators of microbial contamination in the tanneries are associated with their specific and potentially pathogenic working environment. Med Pr 2014;65(1):15–3

Ethanolic Fermentation of Rye Mashes: Factors Influencing the Formation of Aldehydes and Process Efficiency

High concentrations of aldehydes may result in poor-quality agricultural distillate. We investigate the influence of the method of mash preparation, the initial pH of the mashes, and different yeast strains on the fermentation efficiency and concentration of aldehydes from C2 (acetaldehyde) to C7 (enanthaldehyde) in rye mashes. The tested factors were revealed to have a differentiated influence on both the process efficiency and the concentrations of aldehydes, especially in the case of the dominant acetaldehyde. Mashes obtained from steamed rye grain showed significantly higher fermentation efficiencies than those prepared by the pressureless method. Increasing the pH of the sweet mashes from 4.5 to 6.0 resulted in significantly higher concentrations of acetaldehyde, especially in the case of steamed rye grain. Moreover, an increase in the concentrations of other aldehydes, i.e., from C3 (propionaldehyde) to C5 (valer- and isovaleraldehyde) was observed. A high fermentation efficiency and the lowest acetaldehyde concentrations were obtained from steamed rye mashes with an initial pH of 4.5, fermented using the yeast strains DistilaMax GW and DistilaMax HT. DistilaMax HT yeast also provided a relatively low concentration of acetaldehyde in mashes with an initial pH in the range of 4.5–5.5 prepared by the energy-saving pressureless method