Optimization of fermentation conditions and quality evaluation of Chaenomeles sinensis glutinous rice wine.

The present study was conducted to optimize fermentation conditions for preparation of Chaenomeles sinensis Glutinous Rice Wine (CRW). The dynamic changes of main substances in the liquor during fermentation process, aroma components, biologically active substances and antioxidant capacity in the CRW after 6 months of aging were tested. The results showed that under optimized conditions, the yield and alcohol content of wine was 44.97 and 20.00%, respectively. After aging, 64 aroma components were detected in the wine, mainly alcohols and esters. The alcohol content of the CRW was 14.8%. Polyphenols and flavonoids reached 0.23 g/L and 0.037 g/L respectively. Furthermore, the CRW had an excellent free radical scavenging ability. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-024-05934-0.

Aroma Characterization of Roasted Meat and Meat Substitutes Using Gas Chromatography-Mass Spectrometry with Simultaneous Selective Detection and a Dedicated Software Tool, AromaMS.

The development of healthier and more sustainable food products, such as plant-based meat substitutes (PBMSs), have received significant interest in recent years. A thorough understanding of the aroma composition can support efforts to improve the sensory properties of PBMS products and promote their consumer acceptability. Here, we developed an integrated hardware and software approach for aroma analysis of roasted food based on simultaneous analysis with three complementary detectors. Following the standard procedure of aroma headspace sampling and separation using solid-phase microextraction-gas chromatography, the column flow was split into three channels for the following detectors for the selective detection of nitrogen and sulfur (N/S)-containing compounds: an electron ionization-mass spectrometry for identification through a library search, a nitrogen-phosphorous detector, and a flame-photometric detector (FPD)/pulsed-FPD. Integration of results from the different types of detectors was achieved using a software tool, called AromaMS, developed in-house for data processing. As stipulated by the user, AromaMS performed either non-targeted screening for all volatile organic compounds (VOCs) or selective screening for N/S-containing VOCs that play a major role in the aroma experience. User-defined parameters for library matching and the retention index were applied to further eliminate false identifications. This new approach was successfully applied for comparative analysis of roasted meat and PBMS samples.

The flavors of edible mushrooms: A comprehensive review of volatile organic compounds and their analytical methods.

Due to their distinctive flavors, edible mushrooms have gained attention in flavor-related research, and the quality of their flavors determines their consumption. The odor is a vital element of food flavor that significantly impacts consumers' perceptions and purchase decisions. The volatile organic compounds (VOCs) of the odorant ingredient is the primary factors affecting scent characteristics. VOCs analysis and identification require technical assistance. The production and use of edible mushrooms can be aided by a broader examination of their volatile constituents. This review discusses the composition of VOCs in edible mushrooms and how they affect flavors. The principles, advantages, and disadvantages of various methods for extraction, isolation, and characterization of the VOCs of edible mushrooms are also highlighted. The numerous VOCs found in edible mushrooms such as primarily C-8 compounds, organic sulfur compounds, aldehydes, ketones, alcohols, and esters are summarized along with their effects on the various characteristics of scent. Combining multiple extraction, isolation, identification, and quantification technologies will facilitate rapid and accurate analysis of VOCs in edible mushrooms as proof of sensory attributes and quality.

Screening of Yeast in Various Vineyard Soil and Study on Its Flavor Compounds from Brewing Grape Wine.

In order to screen out Saccharomyces cerevisiae suitable for table grape fermentation, and compare it with commercial Saccharomyces cerevisiae in terms of fermentation performance and aroma producing substances, differences of fermentation flavor caused by different strains were discussed. In this experiment, yeast was isolated and purified from vineyard soil, 26s rDNA identification and fermentation substrate tolerance analysis were carried out, and the causes of flavor differences of wine were analyzed from three aspects: GC-MS, PCA and sensory evaluation. The results showed that strain S1 had the highest floral aroma fraction, corresponding to its high production of ethyl octanoate and other substances, and it had the characteristics of high sugar tolerance. The fruit sensory score of S3 wine was the highest among the six wines. Through exploration and analysis, it was found that compared with commercial Saccharomyces cerevisiae, the screened strains had more advantages in fermenting table grapes. The flavor of each wine was directly related to the growth characteristics and tolerance of its strains.

Preparation of ß-Cyclodextrin(CD)/Flavour CD Powder and Its Application on Flavour Improvement of Regular Coffee.

To improve the overall sensory evaluation of regular coffee, a mixture of ß-CD/flavour CD powder was prepared by a freeze-drying method. Cyclodextrin inclusion complexes consist of eight compounds that are naturally present in coffee, specifically: 2,5-dimethylpyrazine, benzaldehyde, citral, linalool, limonene, phenethyl acetate, furfural, and ethyl acetate. These eight compounds naturally occur in coffee, making them safer than using other compounds. Moreover, these eight compounds are the primary active ingredients in coffee, significantly influencing its flavour profile. Therefore, choosing to complex these eight compounds with cyclodextrins can effectively enhance the taste of the coffee. XRD, FT-IR, and SDE-GC-FID were presented to study the formation of inclusion CD powder, the storage stability, chemical composition changes, and safety. Results show that by the cyclodextrin method of freeze-drying, the CD powder showed a stable encapsulated structure and increased stability of flavour compounds. Based on the coffee aroma analysis results, prepared CD powder can enhance the coffee's aroma score by 3.0-4.0 points and increase the flavour score by 2.1-3.5 points, and it can achieve preservation for a minimum of 181 days at 25 °C. Furthermore, under the requirements of the China national standard for additives, the mixture of ß-CD/flavour CD powder was used for the cup testing with four regular coffees to obtain improved coffees. With the full score is 10, improved coffees could score extra 3.0-4.0 points on aroma and 2.1-3.5 on flavour compared to regular coffee. In addition, the CD powder also improves the quality of the coffee in terms of aftertaste, body, and sweetness. Overall, ß-CD/flavour CD powders provide several advantages over the currently popular coffee bean processing methods, including improved reproducibility, enhanced controllability, and increased flexibility, while prioritizing safety. And it should be explored further with appropriate compounds given its potential for coffee aroma modulation.

Characterization of the Aroma Profile of Ginger Powder Produced by a Split-Stream Spray-Drying Process.

Freeze-dried ginger (Zingiber officinale) is renowned for its high quality, but it is expensive. As an alternative, spray drying can be explored for producing ginger powder. However, sugar rich feed solutions can lead to stickiness development during the process. Adding carrier materials increases costs and labeling. Accordingly, a split-stream spray-drying process was developed, where ginger fibers in their natural composition were reintroduced as a carrier material into the spray-drying process. The inlet and outlet temperatures were set at 220 and 80 °C, respectively, for optimal aroma retention. Using a stir bar sorptive extraction-gas chromatography-mass spectrometry-olfactometry, the results revealed that reintegrating ginger fibers significantly increased the concentration of eight key odorants. Although freeze-dried ginger retains more aroma, the total concentration of twenty-seven odorants in the developed spray-dried ginger was 1.9 times higher compared to frozen ginger.

Application of non-Saccharomyces yeasts with high ß-glucosidase activity to enhance terpene-related floral flavor in craft beer.

The rising interest in craft beer urging for novel yeasts that provide diverse attributes. This research aimed to explore the potential of four non-Saccharomyces yeasts with high ß-glucosidase activity in beer fermentation. Fermentation ability, adverse environment resistance and carbohydrate affinity were measured via growth and physiochemical parameters and, based on these results, a Candida glabrata (D18) yeast was selected for subsequent sequential fermentations. Aroma analysis of the fermented beer was then performed using gas chromatography-mass spectrometry, demonstrated that some glucoside-binding terpenes had been significantly increased. In two D18 involved groups, geraniol content increased 51.5/11-fold in the single and mixed fermentations, respectively, while linalool increased 1.36-fold in the mixed fermentation, providing the final beer product with unique floral and fruity characteristics. Principal component analysis and sensory evaluation were also applied to further demonstrate these distinctions. Overall, D18 was found to be a potential yeast for beer fermentation with unique properties.

Toward High-Throughput Analysis of Aroma Compounds Using Ultrahigh-Performance Liquid Chromatography-Tandem Mass Spectrometry: Screening of Key Food Odorants in Various Foods.

Recent studies show the immense capacities of the unified quantitation of aroma and taste compounds using liquid chromatography-mass spectrometry (LC-MS). The goal of this study was to highlight the broad application of this unified method. Thus, a stable isotope dilution analysis quantification method of the most important key food odorants in various food categories by LC-MS was developed. Using the well-known derivatization agent 3-nitrophenylhydrazine for carbonyl derivatization and a newly developed approach for alcohol and thiol derivatization, a method for the quantitation of 20 key food odorants was established. Intraday precision was determined to be ≤26%, and interday precision was between 24 and 31%. Limits of quantitation were determined between 0.014 and 283 µg/kg. The work shows that a wide array of aroma compounds can be analyzed accurately by LC-MS.

Reducing the background interference of liquid-liquid extraction method during Baijiu aroma analysis.

Liquid-liquid extraction coupled with gas chromatography-mass spectrometry (LLE-GC/MS) is a useful methodology for Baijiu aroma analysis. However, the background problems caused by LLE have rarely been investigated. In the present study, synthetic Baijiu was analyzed by traditional LLE-GC/MS to assess background problems, and a series of ghost peaks of some compounds were detected within the retention time of 47.0-60.0 min, including 2,4-di-tert-butylphenol (2,4-DTBP), palmitic acid and oleanitrile. 2,4-DTBP, which has a phenolic odor, is an important component in both strong and light-flavor Baijiu. Single-factor experiments confirmed that 2,4-DTBP is not a constituent of Baijiu but migrates from sodium sulphate and sodium chloride, and, high-temperature baking was an effective approach to eliminate these compounds. A combined strategy using standard cleaning coupled with high-temperature baking was proposed to reduce the background problems during LLE. Furthermore, more trace compounds could be identified through this process in the future.

30th Anniversary of comprehensive two-dimensional gas chromatography: Latest advances.

In this review, we report on the latest (2020-Early 2021) instrumental advances and applications of comprehensive two-dimensional gas chromatography (GC×GC), including its hyphenation with novel upstream or downstream processes (sample preparation approaches or detection technologies). We also discuss software and analysis workflow developments necessary to elaborate the dense chemical information obtained. Thirty years after its inception, the use of GC×GC, as the main analytical tool or as a complementary platform, is undoubtedly shifting toward more applied challenges in a vast breadth of applications. Therefore, we consider the major fields (energy, fuel, foodstuff, plant, biological, and environmental) in which GC×GC has been successfully used, discussing some of the recent innovative research works.

Fatty Acid Composition, Tocopherols, Volatile Compounds, and Sensory Evaluation of Low Morphine Yielding Varieties of Poppy (Papaver somniferum L.) Seeds and Oils.

Low morphine yielding winter ('Zeno Morphex') and summer ('Viola', 'Mieszko', 'Borowski') poppy varieties were investigated for their chemical composition and sensory properties. The oil content of the 13 seed samples as well as that of fatty acids, tocopherols, and volatile compounds in the respective oils were determined, and the sensory profiles of the seeds and oils were established. Linoleic acid made up 70.7-75.2% of the fatty acids. High amounts of γ-tocopherol were detected, especially in variety 'Viola' (287 ± 34 mg kg-1), while δ-tocopherol was only present in 'Zeno Morphex' (3.9 ± 0.6 mg kg-1). The most abundant volatiles were caproic acid (1.4-148 µg g-1), hexanal (0.9-15.2 µg g-1), 1-hexanol (0.3-20.1 µg g-1), limonene (1.3-9.4 µg g-1), and 2-pentylfuran (1.0-7.8 µg g-1). The sensory panel distinguished samples in particular by fatty/oily, rancid, sweet, and green attributes, the green aroma being correlated to three methoxypyrazines only present in summer poppies.

Effect of ageing on lees and distillation process on fermented sugarcane molasses for the production of rum.

The study aimed at evaluating the influence of fermented sugarcane molasses ageing on lees and the distillation process used for the production of rums. Molasses were freshly fermented or 3-months lees aged. Batch (PS: Pot Still) or continuous (CS: Coffey Still) distillation was carried out resulting in four different rum distillates. Gas chromatography and 3D-fluorescence enabled to differentiate rum distillates chemical composition according to the distillation process, regardless of the ageing on lees of fermented molasses. Differences in fluorescent PARAFAC components and volatile acids, acetals and carbonyls contents revealed the predominance of the physicochemical processes driven at the liquid-vapor interface of fermented molasses, generated by the distillation systems. Notwithstanding the distilling conditions, the long chain fatty ester content was significantly higher in the 3-months lees aged condition. Multivariate analysis highlighted that CS rum distillates were chemically more homogeneous than those obtained by PS that preserved the lees effect.

Rapid discrimination of Citrus reticulata 'Chachi' by headspace-gas chromatography-ion mobility spectrometry fingerprints combined with principal component analysis.

Dried pericarps of Citrus reticulata 'Chachi', named Guangchenpi (GCP), have been used as both food and medicine in China for centuries. Due to its special flavour and taste, the price of GCP is much higher than those of dried pericarps from other Citrus reticulata Blanco varieties (collectively called "Chenpi", CP). Therefore, some CP have been disguised has GCP by dishonest businessmen to obtain a higher profit. In this study, a simple, rapid, effective and economic analytical method based on headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS) was established to discriminate GCP and CP by their volatile organic compounds (VOCs). Principal component analysis (PCA) was performed to extract meaningful attributes from VOCs based on the GC-IMS chromatograms and to give the analysis results. Twelve, 12 and 14 markers were identified and established as the characteristic fingerprints of GCP analysis of 45 batches of samples via SE-54, OV-1701 and Inter Cap WAX gas chromatographic columns, respectively. The PCA results indicated that GCP and CP could be effectively discriminated. This study confirmed the potential of HS-GC-IMS combined with PCA as a reliable analytical screening technique to discriminate between GCP and CP.

Development of an in-mouth headspace sorptive extraction method (HSSE) for oral aroma monitoring and application to wines of different chemical composition.

An in-mouth headspace sorptive extraction (HSSE) procedure for the in-mouth volatile sampling of wine aroma compounds during wine tasting has been developed. The procedure is based on the application of a PDMS (polydimethylsiloxane) twister contained inside a tailored made glass tube placed into the headspace of the mouth after rinsing and spitting-off the wine, which is then followed by gas chromatography mass spectrometry analysis (GCMS). Various parameters that might affect the performance of the method (extraction time, aroma concentration) were firstly investigated. Despite the short selected in-mouth extraction time (30 s); the application of the in-mouth HSSE procedure using real wines allowed the detection of >30 volatile compounds from different chemical families in the oral cavity in a single run, and which are also present in the wine at very low concentrations. Additionally, the in-mouth HSSE profile allowed us to distinguish between wines types (with different non-volatile and volatile composition) in a similar way to that when using data from the headspace of the wine (wine-HSSE-GCMS). The simplicity, sensitivity, good repeatability and the easy automatization of this procedure, makes this technique a reliable and feasible tool to determine the chemical and biochemical changes of these compounds in the mouth in real physiological conditions providing useful -in vivo analytical data to better correlate with sensory studies.

Salicylaldehyde is a characteristic aroma component of buckwheat groats.

Salicylaldehyde (2-hydroxybenzaldehyde) was identified as a characteristic component of buckwheat groats aroma by a sensory analysis guided fractionation of the extract. The extract with the strongest odour was prepared by petroleum ether extraction of water soaked groats. This extract was further extracted with sodium hydrogen carbonate solution and purified by a preparative layer chromatography and identified by NMR, MS and IR spectroscopy. A capillary electrophoresis method was developed and used to determine salicylaldehyde content in buckwheat groats and flour samples. Traditionally dehulled buckwheat grain, which had the strongest odour, contained the highest concentration (1.6ppm) of salicylaldehyde with an odour activity value (OAV) of 216.

InnOscent system: Advancing flavor analysis using an original gas chromatographic analytical device.

Despite continuous advances in analytical and physiological knowledge, the comprehension of an aroma is still a challenge. Gas chromatography coupled to olfactometry (GC-O) is an efficient method to identify and estimate individual potential of odorants, but there is a gap between this individual characterization and the effective contribution of compounds in the mixture, which is due to complex chemical and perceptual interactions. Therefore, recombination and omission experiments are often performed to achieve an understanding of food aromas. In this study, a chromatographic device, developed to facilitate aroma analysis, is presented. It was configured to perform both (1) conventional analyses by GC coupled with a mass spectrometer, olfactometric port(s), and a flame ionization detector (FID), and (2) omission or recombination experiments. This dual capability is due to the singular configuration of the system using an ingenious combination of splitter and Deans switch microfluidics transfer modules, and the existence of multiple outlets. The operational status of the system was tested using a purposely simple mixture of compounds. The similarity of retention times (RT) and FID peak areas obtained for each outlet demonstrates that the multiple outlets of the system are equivalent. The reproducibility of retention times (RT) and FID peak areas obtained in switching and non-switching conditions, also demonstrates the efficiency of switching operations. The validation of the system enables multiple detectors to be connected to the outlets and complementary information can be obtained from the eluate. The connection of recovery disposals to the outlets provides fraction collection and recombination possibilities, which contribute much to the understanding of aroma-aroma interactions. As an illustration of the InnOscent system relevance for the comprehension of more complex aromas, the device was used to study the aroma of a wine made from Cabernet Franc grape variety. An olfactometric profile was efficiently produced with the device configured as a GC-MS coupled to a dual olfactometric port. The main odorant active compounds were identified. The omission approach, carried out with the system on isopropyl- and isobutyl-methoxypyrazines, demonstrates the significant contribution of these compounds to the aroma of the wine studied, despite an individual perception among the weakest of the aromagram. A similar approach can be used to evaluate the contribution of any compound to any aroma. This approach overcomes constraints of current methodologies associated to reconstituted model solutions and paves the way for a better understanding of aroma construction.

The analysis of aroma/flavor compounds in green tea using ice concentration linked with extractive stirrer.

Worldwide, green tea is one of the most popular beverages. It promotes blood circulation, liver function, and lowers the risk of cancer and cardiovascular diseases. This drink is characterized by the distinctive odors and flavors produced by its constituent compounds, with its value predicated on the amount and type of constituents extracted from the tea leaves during brewing. Ice concentration linked with extractive stirrer (ICECLES) is a novel sample preparation technique, especially applicable for the extraction of relatively polar compounds while retaining excellent extraction efficiencies for non-polar compounds. In this study, ICECLES was used to prepare green tea for analysis of aroma/flavor compounds by gas chromatography-mass spectrometry (GC-MS). ICECLES performed very well, revealing 301 constituents as compared to 245 for SBSE (i.e., 56 more constituents were detected via ICECLES). Moreover, ICECLES produced stronger signal to noise ratios for all except 4 of 301 constituents, with a maximum signal enhancement of 19. Of the constituents which were only detectable using ICECLES, some very important aroma/flavor and/or medicinal compounds were easily identified, including furfural, furfural alcohol, maltol, eugenol, 2-methylpyrazine, phenethyl alcohol, 2,6-dimethoxyphenol, and α-terpineol. Overall, we confirmed that ICECLES sample preparation followed by GC-MS consistently allowed more complete green tea aroma/flavor analysis, especially for relatively polar compounds, some of which are critical for flavor quality.

Review of the role and methodology of high resolution approaches in aroma analysis.

Analysis of the odour complexity in food and beverage products demands high resolution approaches for distinguishing individual aroma-impact compound(s), and for assessing their contribution to the global aroma of a sample. This paper aims to review current applications incorporating different advanced separation methodologies, and their roles in achieving high resolution aroma analysis. This includes prior low resolution gas chromatography-olfactometry (GC-O) with fractionation procedures using chemical manipulation, adsorption chromatography and ion exchange separation. Innovative multidimensional gas chromatography (MDGC) arrangements that are appropriately designed with olfactometry are of specific focus here. The revelation of resolved components using these integrated approaches provides significantly improved knowledge of aroma composition in samples.

Extension of a dynamic headspace multi-volatile method to milliliter injection volumes with full sample evaporation: Application to green tea.

An extension of multi-volatile method (MVM) technology using the combination of a standard dynamic headspace (DHS) configuration, and a modified DHS configuration incorporating an additional vacuum module, was developed for milliliter injection volume of aqueous sample with full sample evaporation. A prior step involved investigation of water management by weighing of the water residue in the adsorbent trap. The extended MVM for 1 mL aqueous sample consists of five different DHS method parameter sets including choice of the replaceable adsorbent trap. An initial two DHS sampling sets at 25°C with the standard DHS configuration using a carbon-based adsorbent trap target very volatile solutes with high vapor pressure (>10 kPa) and volatile solutes with moderate vapor pressure (1-10 kPa). Subsequent three DHS sampling sets at 80°C with the modified DHS configuration using a Tenax TA trap target solutes with low vapor pressure (<1 kPa) and/or hydrophilic characteristics. After the five sequential DHS samplings using the same HS vial, the five traps are sequentially desorbed with thermal desorption in reverse order of the DHS sampling and the desorbed compounds are trapped and concentrated in a programmed temperature vaporizing (PTV) inlet and subsequently analyzed in a single GC-MS run. Recoveries of 21 test aroma compounds in 1 mL water for each separate DHS sampling and the combined MVM procedure were evaluated as a function of vapor pressure in the range of 0.000088-120 kPa. The MVM procedure provided high recoveries (>88%) for 17 test aroma compounds and moderate recoveries (44-71%) for 4 test compounds. The method showed good linearity (r(2)>0.9913) and high sensitivity (limit of detection: 0.1-0.5 ng mL(-1)) even with MS scan mode. The improved sensitivity of the method was demonstrated with analysis of a wide variety of aroma compounds in brewed green tea. Compared to the original 100 µL MVM procedure, this extension to 1 mL MVM allowed detection of nearly twice the number of aroma compounds, including 18 potent aroma compounds from top-note to base-note (e.g. 2,3-butanedione, coumarin, furaneol, guaiacol, cis-3-hexenol, linalool, maltol, methional, 3-methyl butanal, 2,3,5-trimethyl pyrazine, and vanillin). Sensitivity for 23 compounds improved by a factor of 3.4-15 under 1 mL MVM conditions.

Sensor responses to fat food aroma: a comprehensive study of dry-cured ham typicality.

The physicochemical phenomena that explain the sensing mechanisms of gas sensors have been extensively investigated. Nevertheless, it is arduous to interpret the sensor signals in a practical approach when they response to complex mixtures of compounds responsible for food aroma. Thus, the concomitant interactions between the volatiles and the sensor give up a single response affected by synergic and masking effects between compounds. An experimental procedure is proposed to determine the individual contribution of volatile compounds in the sensor response, illustrated with the examples of aroma of dry-cured hams and metal oxide sensors. The results from mathematical correlations and the analyses of pure standards are previously analyzed to describe the behavior of sensors when interacting with individual compounds. A sensor based olfactory detector (SBOD) entailing the use of a capillary column connected to a sensor array as non-destructive detector in parallel with the flame detector served to provide definitive information about the individual contribution of volatile compounds to sensor responses. The sensor responses in this system, which is referred to as sensorgram, were interpreted by taking into account the volatile composition of the samples determined by GC.