Aromatic Characteristics of Passion Fruit Wines Measured by E-Nose, GC-Quadrupole MS, GC-Orbitrap-MS and Sensory Evaluation

Effect of fermentation alcohol termination by ceramic membrane filtration on the aroma of sugarcane fruit wine

The study aimed to explore the impact of ceramic membrane filtration used to terminate the fermentation process on the aroma of low-alcohol sugarcane fruit wines as compared to traditional methods. The sugarcane fruit wine of termination fermentation by ceramic membrane filtration results in a more fruity character due to the higher content of some volatile compounds (hexanal, hexyl butanoate, butanoic acid butyl ester, hexanoic acid ethyl ester, and β-Damascenone). In comparison to traditional method (pasteurization), sugarcane fruit wine of termination fermentation by ceramic membrane filtration exhibits a greater abundance of the characteristic aroma compounds (hexanal, isobutyl isobutyrate, pentanal, and butanal) of sugarcane juice, resulting in a more pronounced sugarcane aroma. In addition, results showed that a total of 73 volatile compounds were identified in sugarcane wine, with 17 being identified as key differential compounds and 20 as key aroma-active compounds.

[Determination of four classes of 34 chlorinated persistent organic pollutants in seawater by solid-phase extraction and gas chromatography-electrostatic field orbitrap high resolution mass spectrometry]

Ocean acts as a "sink" for pollutants in the natural environment. Consequently, issues focused on marine pollution from terrestrial origin is attracting increasing attention. Persistent organic pollutants (POPs), including organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), short-chain chlorinated paraffins (SCCPs), and dechlorane plus isomers (DPs), are serious hazards for both the environment and humans. These POPs have been widely detected in the marine environment and are typically present at trace levels; however, separating and determining individual contaminants require large amounts of sampling and time. Establishing an accurate analytical method for determining typical POPs is critical for studying their environmental behavior and associated ecological risks to the marine environment. In this study, we developed a method based on solid-phase extraction (SPE) combined with gas chromatography-electrostatic field orbitrap high resolution mass spectrometry (GC-Orbitrap-HRMS) for determining 34 chlorinated POPs in seawater, including 25 OCPs, six PCB congeners, SCCPs and two DPs. The chromatographic conditions and MS parameters were optimized, and the effects of the extraction solvent and purification method were systematically studied. Dichloromethane exhibited satisfactory extraction efficiencies during the liquid-liquid extraction (LLE) of seawater samples, with recoveries of 73.1%-120.5% for OCPs, 87.2%-101.7% for PCBs, 105.5% for SCCPs, and 74.9%-78.6% for DPs, respectively. Purification using a SPE column with 500 mg of Florisil was adopted, and 9∶1 (v/v) n-hexane/acetone was confirmed as the eluent with recoveries between 68.2% and 122.8% for all the 34 chlorinated POPs. A DB-5MS (15 m×0.25 mm×0.10 μm) capillary chromatographic column was used to separate the target compounds, with an electron ionization (EI) source used to detect OCPs and PCBs, whereas SCCPs and DPs were determined in negative chemical ionization (NCI) source. All target compounds were analyzed in full-scan mode. An internal standard quantification method was used for OCPs and SCCPs while isotope dilution quantification was used for PCBs and DPs. The severe interference observed during the detection of chlorinated POPs in the mixture of co-extracted substances was completely eliminated following the purification. The 34 target chlorinated POPs exhibited good linearities in their corresponding ranges, with correlation coefficients (R2) exceeding 0.9. The method demonstrated low detection limits under the optimized conditions, with values of 0.009-0.061 ng/L for the 25 OCPs, 0.006-0.016 ng/L for the six PCBs, 2.78 ng/L for the SCCPs, and 0.021-0.023 ng/L for the two DPs, with lower limits of determination of 0.06-0.24, 0.02-0.06, 11.12, and 0.08-0.09 ng/L, respectively. Accuracy and precision were validated by the recoveries of samples spiked at low, medium, and high levels, which ranged between 70.6% and 128.9%. Relative standard deviations (n=6) were determined to be 0.2%-19.2%. These results highlight the suitability of the developed method for analyzing trace amounts of chlorinated POPs in seawater. The method is characterized by simple sample pretreatment, high sensitivity, fast analytical throughput, cost-effectiveness, and good stability for trace-level detection; hence, it is suitable for the rapid and accurate analysis of typical chlorinated POPs in seawater. This method is expected to play a significant role in marine environmental monitoring and the emergency surveillance of seawater pollution. The developed method was applied to seawater samples collected from Bohai, which revealed that the highest detection frequency (90%) was recorded for the SCCPs, while α-hexachlorocyclohexane (α-HCH) was only detected in 30% of the samples. All other OCPs were below the detection limit. PCB-52 was the only PCB congener detected in the seawater samples. The SCCPs were detected in much higher concentrations than the other POPs, with the highest value of 130.6 ng/L recorded. Consequently, particular attention must be paid to SCCPs.

The Antioxidant Capacity and Flavor Diversity of Strawberry Wine Are Improved Through Fermentation with the Indigenous Non-Saccharomyces Yeasts Hanseniaspora uvarum and Kurtzmaniella quercitrusa

The production of strawberry wine is an effective strategy for addressing the significant economic losses caused by strawberry spoilage. In recent years, there has been an increase in consumer demand for quality and flavor diversity in fruit wines. Therefore, it is necessary to develop novel strawberry wine products. In this research, we assessed and analyzed the influences of fermentation with Hanseniaspora uvarum, Kurtzmaniella quercitrusa, and Saccharomyces cerevisiae under four fermentation conditions on the fermentation kinetics, organoleptic characteristics, chemical compositions, antioxidant capacities, and flavor profiles of strawberry wines. Strawberry wines fermented with the indigenous non-Saccharomyces yeasts H. uvarum and K. quercitrusa showed higher 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-Azinobis-(3-ethylbenzothiazoline-6-sulfonate) (ABTS) free-radical-scavenging capacities and significantly different flavor profiles compared to strawberry wines fermented with S. cerevisiae. In addition, adjusting the initial soluble solids contents of strawberry juices and fermentation temperatures positively affected the quality and flavor profiles of strawberry wines fermented with the H. uvarum and K. quercitrusa strains. Under the condition of 18 °C-20 °Brix, strawberry wine fermented with K. quercitrusa presented the highest antioxidant capacity, with enhanced flavor diversity and color intensity. It is worth noting that K. quercitrusa can be an alternative yeast for producing high-quality strawberry wine with a distinct floral aroma.

The formation of volatiles in fruit wine process and its impact on wine quality

Fruit wine is one of the oldest fermented beverages made from non-grape fruits. Owing to the differences in fruit varieties, growing regions, climates, and harvesting seasons, the nutritional compositions of fruits (sugars, organic acids, etc.) are different. Therefore, the fermentation process and microorganisms involved are varied for a particular fruit selected for wine production, resulting in differences in volatile compound formation, which ultimately determine the quality of fruit wine. This article reviews the effects of various factors involved in fruit wine making, especially the particular modifications differing from the grape winemaking process and the selected strains suitable for the specific fruit wine fermentation, on the formation of volatile compounds, flavor and aroma profiles, and quality characteristics of the wine thus produced. KEY POINTS: • The volatile profile and fruit wine quality are affected by enological parameters. • The composition and content of nutrients in fruit must impact volatile profiles. • Yeast and LAB are the key determining factors of the volatile profiles of fruit wines.

Volatile Profile Characterization of Jujube Fruit via HS-SPME-GC/MS and Sensory Evaluation

Current research does not fully elucidate the key compounds and their mechanisms that define the aroma profile of fresh jujube fruits. Therefore, this study conducted a comprehensive analysis of both free and glycosidically bound aroma compounds in fresh jujube fruits of ten cultivars. Utilizing gas chromatography-mass spectrometry (GC-MS), we identified 76 volatile free aroma compounds and 19 glycosidically bound volatile compounds, with esters, aldehydes, and ketones emerging as the predominant volatile compounds in the jujube fruits. Odor activity value (OAV) analysis revealed that the primary aroma profile of the jujubes is characterized by fruity and fatty odors, with β-damascenone being a key contributor to the fruity aroma, and (E)-2-oct-en-1-al and nonanal significantly influencing the fatty aroma. Moreover, the integration of sensory evaluation and partial least squares regression (PLSR) analysis pinpointed octanal, (E)-2-oct-en-1-al, nonanal, β-damascenone, and pentanal as significant contributors to the jujube's characteristic aroma, while isoamyl acetate was identified as significantly influencing the fatty acid taste. This study not only underscores the complexity of the jujube aroma composition but also highlights the impact of environmental factors on aroma profiles, offering valuable insights into the sensory characteristics of jujube fruits.

Volatilomics of Fruit Wines

Volatilomics is a scientific field concerned with the evaluation of volatile compounds in the food matrix and methods for their identification. This review discusses the main groups of compounds that shape the aroma of wines, their origin, precursors, and selected metabolic pathways. The paper classifies fruit wines into several categories, including ciders and apple wines, cherry wines, plum wines, berry wines, citrus wines, and exotic wines. The following article discusses the characteristics of volatiles that shape the aroma of each group of wine and the concentrations at which they occur. It also discusses how the strain and species of yeast and lactic acid bacteria can influence the aroma of fruit wines. The article also covers techniques for evaluating the volatile compound profile of fruit wines, including modern analytical techniques.

Z, Cai X, Zhao X, Jiang Y, Miao B. Quality Assessment of Loquat under Different Preservation Methods Based on Physicochemical Indicators, GC–MS and Intelligent Senses

To explore the effects of different preservation methods on the quality of loquat after fresh-keeping treatment, various preservation techniques were employed. These included natural preservation (NP), vacuum freezing preservation (VFP), vacuum at room temperature preservation (VP) and freezing preservation (FP). The quality assessment involved analyzing the effects of these preservation methods using physicochemical indexes, a colorimeter, an electronic nose (E-nose), an electronic tongue (E-tongue) and gas chromatography–mass spectrometry (GC–MS). The results showed minor differences in loquat quality under different preservation methods, with sensory scores ranging from 55 to 78 and ΔE values ranging from 11.92 to 18.59. Significant variations were observed in moisture content (ranging from 53.20 g/100 g to 87.20 g/100 g), calorie content (ranging from 42.55 Kcal/100 g to 87.30 Kcal/100 g), adhesion (ranging from 0.92 to 1.84 mJ) and hardness (ranging from 2.97 to 4.19 N) (p < 0.05). Additionally, the free amino acid content varied from 22.47 mg/g to 65.42 mg/g. GC–MS analysis identified a total of 47 volatile flavor substances in varieties of loquats, including 13 aldehydes, 9 esters, 6 ketones, 2 acids, 3 alcohols, 2 phenols, 3 pyrazines, 1 furan and 8 other substances. The relative content of aldehydes was significantly higher than that of other chemicals. The VFP and FP samples exhibited higher aldehyde content compared to the NP and VP samples. Moreover, Orthogonal Partial Least Squares-Discriminant Analysis (OPLS-DA) revealed 18 marked compounds that could differentiate between 5 loquat species. Analysis using E-nose and E-tongue indicated significant changes in the olfactory and gustatory senses of loquats following preservation. The VFP samples demonstrated the most effective preservation of loquat quality with minimal impact. This study provides some theoretical guidance for the home preservation of loquats.

Sensory Determination of Peach and Nectarine Germplasms with Instrumental Analysis

The flavour and mouthfeel of peaches are crucial qualities of peach germplasm resources that significantly influence consumer preferences. In this study, we utilized 212 peach germplasm resources from the Nanjing Peach Resource Repository, National Fruit Germplasm facility, Jiangsu Academy of Agricultural Sciences as materials for sensory analysis, electronic nose analysis, and composition analysis via high-performance liquid chromatography (HPLC). In the sensory analysis, we divided 212 peach germplasms into three clusters based on hierarchical cluster analysis (d = 5). No.27, No.151, and No.46 emerged as the most representative of these clusters. The electronic nose was used to conduct an evaluation of the aroma profiles of the 212 peach germplasms, revealing that the primary distinguishing factors of peach aroma can be attributed to three sensors: W1S (methane), W1W (terpenes and organosulfur compounds), and W5S (hydrocarbons and aromatic compounds). The primary differences in the aromatic substances were characterized by sensors W2W (aromatic compounds, sulphur, and chlorine compounds) and W1C (aromatic benzene). The HPLC analysis indicated that the persistence of peach sensory characteristics was positively correlated with acids and sourness and negatively correlated with sweetness and the ratio of sugar to acids. The overall impression of the 212 peach germplasms revealed a negative correlation with acids, while a positive correlation was observed between the overall impression and the ratio of sugar to acids. Therefore, this study substantially contributes to the preliminary screening of the analysed specific characteristics of peach germplasms such as No.27, No.46, No.151, and No.211. These selections may provide valuable information for the potential creation of superior germplasm resources.

Investigation of aroma characteristics of seven Chinese commercial sunflower seed oils using a combination of descriptive Analysis, GC-quadrupole-MS, and GC-Orbitrap-MS

The aroma characteristics of seven commercial Chinese sunflower seed oils were investigated in this study using descriptive analysis, headspace solid-phase microextraction coupled with GC-quadrupole-MS (LRMS, low-resolution mass spectrometry), and GC-Orbitrap-MS (HRMS, high-resolution mass spectrometry). GC-Orbitrap-MS quantified 96 compounds, including 18 alcohols, 12 esters, 7 ketones, 20 terpenoids, 11 pyrazines, 6 aldehydes, 6 furans, 6 benzene ring-containing compounds, 3 sulfides, 2 alkanes, and 5 nitrogen-containing compounds. Moreover, 22 compounds including 5 acids, 1 amide, and 16 aldehydes were quantified using GC-Quadrupole-MS. To our knowledge, 23 volatile compounds were reported for the first time in sunflower seed oil. All the seven samples were found to have a 'roasted sunflower seeds' note, 'sunflower seeds aroma' note and 'burnt aroma' note and only five of them had 'fried instant noodles' note, three had 'sweet' note and two had 'puffed food' note. Partial least squares regression was used to screen the candidate key volatiles that caused the aroma differences among these seven samples. It was observed that 'roasted sunflower seeds' note was positively correlated with 1-octen-3-ol, n-heptadehyde and dimethyl sulfone, whereas the 'fried instant noodles' and 'puffed food' demonstrated a positive correlation with pentanal, 3-methylbutanal, hexanal, (E)-2-hexenal and 2-pentylfuran. Our findings provide information to the producers and developers for quality control and improvement of sunflower seed oil.