Nuclear Magnetic Resonance and Headspace Solid-Phase Microextraction Gas Chromatography as Complementary Methods for the Analysis of Beer Samples

Production and characterization of anthocyanin-rich beer from black wheat by an efficient isolate Saccharomyces cerevisiae CMS12

Beer is the world's third most popular fermented beverage. It is typically made from malted barley. Tropical countries must import barley from temperate countries for brewing, which is an expensive process. Therefore, it is critical to investigate alternative possible substrates for beer production in order to meet the growing demand for high-nutritional-quality beer. The current study involves the creation of a fermented beverage from anthocyanin-rich black wheat with the help of yeast, Saccharomyces cerevisiae CMS12, isolated from fruit waste. Characterization (UV, HPLC, NMR, FTIR, and ICPMS) was then performed, as well as a comparative study with white (amber) wheat beer. Further, process parameters optimization included initial sugar concentration, inoculum size, and pH. Black wheat wort contained 568 mg GAE/L total phenolic content, 4.67 mg/L anthocyanin concentration, 6.8% (v/v) alcohol content, and a pH of 4.04. The sensory analysis revealed that black wheat beer was more acceptable than white wheat beer. The developed fermented beverage has enormous commercialization potential.

Investigation of Solid Phase Microextraction Gas Chromatography–Mass Spectrometry, Fourier Transform Infrared Spectroscopy and 1H qNMR Spectroscopy as Potential Methods for the Authentication of Baijiu Spirits

The baijiu spirit is often the focus of fraudulent activity due to the widely varying prices of the products. In this work, Solid Phase Microextraction Gas Chromatography (SPME GCMS), Fourier Transform Infrared (FTIR) Spectroscopy and 1H qNMR spectroscopy were evaluated as potential methods to authenticate baijiu samples. Data were collected for 30 baijiu samples produced by seven different distilleries. The data from the SPME GCMS and FTIR methods were treated by a Principal Component Analysis to identify clusters that would suggest chemical differences in the products from different distilleries. The results suggest that SPME GCMS has the potential to be a fully portable method for baijiu authentication. FTIR did not appear suitable for authentication but can be used to find the %ABV range of the sample. 1H quantitative NMR (1H qNMR) was utilized to quantify the ethanol concentrations and calculate the observable congener chemistry comprising ester, ethanol, methanol, fusel alcohol, and organic acids. Discrepancies in ethanol content were observed in three samples, and a lack of major congeners in two samples indicates the possible presence of a counterfeit product. Detailed and quantitative congener chemistry is obtainable by NMR and provides a possible fingerprint analysis for the authentication and quality control of baijiu style, producer, and the length of the ageing process.

Application of NMR and Chemometrics for the Profiling and Classification of Ale and Lager American Craft Beer

In this paper, Nuclear Magnetic Resonance spectroscopy (NMR)-based metabolomics were applied for the discrimination of ale and lager craft American beers. A modified pulse sequence that allows the efficient suppression of the water and ethanol peaks was used to achieve high-quality spectra with minimal sample preparation. The initial chemometrics analysis generated models of low predictive power, indicating the high variability in the groups. Due to this variability, we tested the effect of various data pretreatment and chemometrics approaches to improve the model’s performance. Spectral alignment was found to improve the classification significantly, while the type of normalization also played an important role. NMR combined with statistical and machine-learning techniques such as orthogonal projection to latent structures discriminant analysis (OPLS-DA) and random forest was able to discriminate between ale and lager beers, thus providing an important tool for the quality control and analysis of these products.

Investigating the Potential of an In-Situ Method for Monitoring the Malting of Barley Using Solid Phase Microextraction with a Portable Gas Chromatography Mass Spectrometry Instrument

An improved understanding of the malting process could have a significant impact on the efficient production of quality malt for the brewing industry. Analysis of volatile organic compounds produced during the malting process is one approach towards achieving this goal. In-situ methods avoid the possibility of contamination and chemical changes occurring during sample transport and storage. This paper describes the investigation of an in-situ sampling method for the detection of volatile organic compounds produced during the malting of barley. Solid Phase Microextraction Gas Chromatography Mass Spectrometry (SPME-GC/MS) was used to identify compounds. The investigated method involved the direct exposure of an SPME fiber in the kiln during barley malting. Using this method, compounds including aldehydes, ketones, and esters were detected. Some changes in volatile organic compound composition were observed during the production of pale malt at a commercial malting house.

Functionality of Special Beer Processes and Potential Health Benefits

Consumers’ demand for functional fermented food that can fulfill nutritional needs and help maintain a balanced diet while also having a positive impact on one’s health status is increasing all over the world. Thus, healthy choices could include beverages with nutrients and bioactive compounds which can be used as an effective disease-prevention strategy. Regular beer has certain health benefits which inspire further research with the prospect of obtaining special functional beers with little or no alcohol content. As observed, the special beer market remains highly dynamic and is predicted to expand even further. Therefore, brewers need to keep up with the consumers’ interests and needs while designing special beers, namely nonalcoholic beers (NABs), low-alcohol beers (LABs), and craft beers (CBs). Thus, understanding the potential uses of bioactive compounds in special beer, the wide range of therapeutic effects, and the possible mechanisms of action is essential for developing healthier beverages. This review aimed to evaluate the nutritional features of special beers, and their proven or potential beneficial actions on one’s health status and in preventing certain diseases.

Investigation of Antioxidant and Elastase Inhibitory Activities of Geum urbanum Aerial Parts, Chemical Characterization of Extracts Guided by Chemical and Biological Assays

This study presents the bioguided chemical investigation of the 80% aqueous methanol extract of Geum urbanum aerial parts. Liquid–liquid partitioning of this extract in solvents of increasing polarity combined with biological screening showed that the ethyl acetate (EtOAc) soluble fraction was the most active part of the extract. This fraction was chemically profiled by a 13C nuclear magnetic resonance (NMR)-based dereplication method, resulting in the identification of 14 compounds. The dereplication process was followed by the purification of unknown and minor compounds of the EtOAc fraction. A new glycosylated phenol, namely, 3-(3,4-dihydroxyphenyl)propyl-α-l-rhamnopyranoside, together with 6 known compounds were isolated. Their structures were elucidated by spectroscopic methods including NMR and high-resolution electrospray ionization mass spectrometry. The antioxidant activity of fractions and isolated compounds were evaluated by 2,2,1-diphenyl-1-picrylhydrazyl and hydroxyl radical scavenging, and by cupric ion reducing antioxidant capacity assays. In parallel, their enzyme inhibitory property against human neutrophil elastase was assessed. Four subfractions, essentially containing polyphenols and triterpenes, exhibited a significant elastase inhibitory activity and an ellagitannin showed a very high radical scavenging activity.

Characterization of the Key Aroma Compounds in Proso Millet Wine Using Headspace Solid-Phase Microextraction and Gas Chromatography-Mass Spectrometry

The volatile compounds in proso millet wine were extracted by headspace solid-phase microextraction (85 μm polyacrylate (PA), 100 μm polydimethylsiloxane (PDMS), 75 μm Carboxen (CAR)/PDMS, and 50/30 μm divinylbenzene (DVB)/CAR/PDMS fibers), and analyzed using gas chromatography-mass spectrometry; the odor characteristics and intensities were analyzed by the odor activity value (OAV). Different sample preparation factors were used to optimize this method: sample amount, extraction time, extraction temperature, and content of NaCl. A total of 64 volatile compounds were identified from the wine sample, including 14 esters, seven alcohols, five aldehydes, five ketones, 12 benzene derivatives, 12 hydrocarbons, two terpenes, three phenols, two acids, and two heterocycles. Ethyl benzeneacetate, phenylethyl alcohol, and benzaldehyde were the main volatile compounds found in the samples. According to their OAVs, 14 volatile compounds were determined to be odor-active compounds (OAV > 1), and benzaldehyde, benzeneacetaldehyde, 1-methyl-naphthalene, 2-methyl-naphthalene, and biphenyl were the prominent odor-active compounds (OAV > 50), having a high OAV. Principal component analysis (PCA) showed the difference of distribution of the 64 volatile compounds and 14 odor-active compounds with four solid-phase microextraction (SPME) fibers.