The application of headspace gas chromatographic method for the determination of ethyl alcohol in craft beers, wines and soft drinks

Optimization of a craft ale-type beer enriched with cañihua malt (Chenopodium pallidicaule) and banana passionfruit juice (Passiflora tripartita var. mollisima)

The global expansion of the craft beer market has driven the incorporation of native ingredients to enhance the sensory and nutritional profiles of beer. This study focused on optimizing a craft Ale-type beer enriched with Cañihua Malt (CM) and Banana Passionfruit Juice (BPJ) using a D-optimal experimental design. The aim was to evaluate how varying concentrations of these ingredients (CM: 15-25 %, BPJ: 5-15 %) influence the physicochemical, technological, and sensory attributes of beer. Results demonstrated that the malting process significantly improved the nutritional composition of cañihua, increasing fiber content (23.32 g/100 g), phenolic compounds (141.13 mg GAE/100 g), GABA (229.48 mg/100 g), and antioxidant capacity (1975.41 μmol TE/g dw). These enhancements positively affected the physicochemical properties of beer, especially foam stability and body. The addition of BPJ significantly modified the physicochemical characteristics of beer, particularly by reducing the pH and increasing the acidity. Sensory analysis showed high consumer acceptance, with positive evaluations for aroma, appearance, and body, particularly in samples containing moderate levels of CM (15-16 %) and BPJ (5-10 %). Optimization using the desirability function identified ideal concentrations of 24%-25 % CM and 5 % BPJ, achieving a balance in critical parameters such as foam stability, density, pH, and bitterness. These findings underscore the potential to combine CM and BPJ to develop a distinctive craft beer with enhanced sensory attributes and nutritional benefits.

From inspection to analysis: A combined approach to identifying counterfeit whiskeys using HS-GC-FID and bottle integrity

Counterfeiting of alcoholic beverages, particularly high-value spirits such as whiskey, presents significant challenges for regulators, manufacturers, and consumers. In this study, we introduce and validate a novel application of headspace extraction (HS) followed by gas chromatography with flame ionization detection (GC-FID) for the quantitative determination of ethanol content in 42 suspected counterfeit brazilian samples of whiskeys. This method, in conjunction with visual inspection of material inconsistencies, offers a combined approach to identify potential cases of fraud. The HS-GC-FID findings revealed that only 19% of the analyzed samples had ethanol content in the limits declared on the label, emphasizing the role of ethanol content as a chemical marker for suspected beverage fraud.

Candidatus Methanosphaera massiliense sp. nov., a methanogenic archaeal species found in a human fecal sample and prevalent in pigs and red kangaroos

Methanosphaera stadtmanae was the sole Methanosphaera representative to be cultured and detected by molecular methods in the human gut microbiota, further associated with digestive and respiratory diseases, leaving unknown the actual diversity of human-associated Methanosphaera species. Here, a novel Methanosphaera species, Candidatus Methanosphaera massiliense (Ca. M. massiliense) sp. nov. was isolated by culture using a hydrogen- and carbon dioxide-free medium from one human feces sample. Ca. M. massiliense is a non-motile, 850 nm Gram-positive coccus autofluorescent at 420 nm. Whole-genome sequencing yielded a 29.7% GC content, gapless 1,785,773 bp genome sequence with an 84.5% coding ratio, encoding for alcohol and aldehyde dehydrogenases promoting the growth of Ca. M. massiliense without hydrogen. Screening additional mammal and human feces using a specific genome sequence-derived DNA-polymerase RT-PCR system yielded a prevalence of 22% in pigs, 12% in red kangaroos, and no detection in 149 other human samples. This study, extending the diversity of Methanosphaera in human microbiota, questions the zoonotic sources of Ca. M. massiliense and possible transfer between hosts.IMPORTANCEMethanogens are constant inhabitants in the human gut microbiota in which Methanosphaera stadtmanae was the only cultivated Methanosphaera representative. We grew Candidatus Methanosphaera massiliense sp. nov. from one human feces sample in a novel culture medium under a nitrogen atmosphere. Systematic research for methanogens in human and animal fecal samples detected Ca. M. massiliense in pig and red kangaroo feces, raising the possibility of its zoonotic acquisition. Host specificity, source of acquisition, and adaptation of methanogens should be further investigated.

Determination of Methanol, Acetaldehyde, and Ethyl Acetate in Thousand Folds of Ethanol Sample by Headspace Gas Chromatography with Mass Spectrometry

Alcohol beverages have been widely consumed in several parts of the world. In this study, volatile organic compounds in alcoholic beverages including acetaldehyde, ethyl acetate, methanol, and higher ethanol were investigated and evaluated using a headspace gas chromatograph equipped with a mass spectrometer. This study evaluated the suitability of the chromatographic system, linearity, limit of detection, and limit of quantification, accuracy, and precision of the single and simultaneous determination of acetaldehyde, ethyl acetate, and methanol in thousand folds of ethanol. Results showed that the acetaldehyde concentration in local beer samples and local manual product liqueur samples ranged from 4.65 to 13.22 mg/L and from 5.55 to 75.96 mg/L, respectively, but in local industrial product liqueur samples, acetaldehyde was not detected. Methanol was only detected in a few local beer samples and locally manually produced liqueur samples within low concentrations. Ethyl acetate was only detected in all local beer samples, but it was not present in local industrial product liqueur samples.

Fatal Methanol Poisoning Caused by Drinking Industrial Alcohol: Silesia Region, Poland, April-June 2022

Methanol poisonings caused by drinking industrial alcohol remain a severe problem worldwide. Education on types of alcohol and their harmfulness and legal regulations limiting the industrial alcohol trade seem to be the keys to reducing the number of poisonings. Methanol distribution in different tissues after absorption is not well understood. This research aimed to quantify the methanol and formic acid distribution in body fluids and tissue material in post-mortem samples collected from 19 fatal victims of massive intoxication with industrial alcohol in the Silesia Region (Poland) who died between April and June 2022. The samples were analyzed using a gas chromatography-flame ionization detector (GC-FID), and correlation coefficients for methanol and formic acid were determined. The results show a wide distribution of methanol and formic acid in human post-mortem biological fluids (blood, urine, vitreous humor, bile, and cerebrospinal fluid) and tissues (muscle, kidney, liver, spleen, lung, and brain). The strongest correlation for methanol concentration in blood and body fluids/tissues was obtained in the cerebrospinal fluid (r = 0.997) and for formic acid in muscle tissue (r = 0.931). The obtained results may be a valuable tool in toxicological analysis and improve medical standards of early diagnosis and targeted treatment.