Comparative Investigation of Aroma-Active Volatiles in ("Ruixue", "Liangzhi", "Crystal Fuji," and "Guifei") Apples by Application of Gas Chromatography-Mass Spectrometry-Olfactometry (GC-MS-O) and Two-Dimensional Gas Chromatography-Quadrupole Mass Spectrometry (GC × GC-qMS) Coupled with Sensory Molecular Science.

Aroma dramatically impacts the overall flavor profiles and consumer acceptance; therefore, it is necessary to conduct a comprehensive analysis of the aroma characteristics of apples. In this study, the aroma differences among four popular apple varieties ("Ruixue", "Liangzhi", "Crystal Fuji," and "Guifei") were compared using two extraction methods (headspace-solid phase microextraction, and solvent-assisted flavor evaporation) coupled with gas chromatography-mass spectrometry-olfactometry (GC-MS-O) and two-dimensional gas chromatography-quadrupole mass spectrometry (GC × GC-qMS). A total of 82 odorants were identified via GC-MS-O, and 143 volatiles were identified by GC× GC-qMS.

Comparison of two data processing approaches for aroma marker identification in different distilled liquors using comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry dataset.

Whisky, brandy, rum, and Chinese baijiu are popular distilled spirits globally, and the volatile components play an essential role in the aroma of these distilled liquors. Volatile compounds in whisky, brandy, rum, and three main aroma types of Chinese baijiu (strong, light, and sauce) were investigated using comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry (GC×GC-TOFMS). Two significant variable detection approaches, the variable importance in the projection (VIP) and nonparametric test (Mann-Whitney U test), were compared to determine the volatile markers among these samples.

Can Electronic Nose Replace Human Nose?-An Investigation of E-Nose Sensor Responses to Volatile Compounds in Alcoholic Beverages.

Electronic nose (E-nose) technology is frequently attempted to simulate the human olfactory system to recognize complex odors. Metal oxide semiconductors (MOSs) are E-noses' most popular sensor materials. However, these sensor responses to different scents were poorly understood.

Multidisciplinary evaluation of plant growth promoting rhizobacteria on soil microbiome and strawberry quality.

The natural soil environment is considered one of the most diverse habitats containing numerous bacteria, fungi, and larger organisms such as nematodes, insects, or rodents. Rhizosphere bacteria play vital roles in plant nutrition and the growth promotion of their host plant. The aim of this study was to evaluate the effects of three plant growth-promoting rhizobacteria (PGPR), Bacillus subtilis, Bacillus amyloliquefaciens, and Pseudomonas monteilii for their potential role as a biofertilizer.

Isolation, Characterization, and Compositional Analysis of Polysaccharides from Pinot Noir Wines: An Exploratory Study.

It has been reported that polysaccharides in wine can interact with tannins and other wine components and modify the sensory properties of the wine. Unfortunately, the contribution of polysaccharides to wine quality is poorly understood, mainly due to their complicated structure and varied composition. In addition, the composition and molecular structure of polysaccharides in different wines can vary greatly.

Evaluation of Sulfur-Based Biostimulants for the Germination of Sclerotia and Their Interaction with Soil.

White rot is an economically significant disease of . The pathogen produces long-lived sclerotia that germinate in response to sulfur-containing compounds released from roots. Diallyl disulfide (DADS) was the primary organic sulfur compound detected in the rhizosphere soil of two garlic cultivars, "California Early and Late", growing in greenhouse conditions.

Lipid metabolic characteristics and marker compounds of ripened Pu-erh tea during pile fermentation revealed by LC-MS-based lipidomics.

Ripened Pu-erh tea (RPT) is a unique microbial fermented tea. Herein, we investigated the lipid composition of RPT and its metabolic changes during pile fermentation, by nontargeted lipidomics profiling and quantitative analysis using liquid chromatography-mass spectrometry (LC-MS). A total of 485 individual lipid species covering 26 subclasses were detected, and fatty acid ester of hydroxy fatty acid (FAHFA) was detected in tea for the first time.

Blue Light-Mediated, Photocatalyst-Free Decarboxylative Alkylation of Heteroaryl Sulfinimines.

We report a diastereoselective, photocatalyst-free decarboxylative alkylation of (hetero)aryl sulfinimines using redox-active esters under blue light. High yields and diastereoselectivities can be achieved under mild conditions, and we demonstrate its utility as a synthetic method, especially for medicinal chemists.

Composition of Pinot Noir Wine from Grapevine Red Blotch Disease-Infected Vines Managed with Exogenous Abscisic Acid Applications.

Grapevine red blotch disease (GRBD) has negative effects on grape development and impacts berry ripening. Abscisic acid (ABA) is a plant growth regulator involved in the initiation of berry ripening. Exogenous abscisic acid application was compared to an unsprayed control on GRBD-positive Pinot noir vines during two vintages, and the total monomeric anthocyanin, total phenolics, phenolic composition, and volatile profile were measured in wines.

Insight into aroma dynamic changes during the whole manufacturing process of chestnut-like aroma green tea by combining GC-E-Nose, GC-IMS, and GC × GC-TOFMS.

Processing is the crucial factor for green tea aroma quality. In this study, the aroma dynamic changes throughout the manufacturing process of chestnut-like aroma green tea were investigated with gas chromatography electronic nose (GC-E-Nose), gas chromatography-ion mobility spectrometry (GC-IMS), and comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC × GC-TOFMS). GC-IMS identified 33 volatile compounds while GC × GC-TOFMS identified 211 volatile components.

Volatile Analysis of Wuliangye Baijiu by LiChrolut EN SPE Fractionation Coupled with Comprehensive GC×GC-TOFMS.

Wuliangye baijiu is one of the most famous Chinese liquors with a protected geographical indication. This study used LiChrolut EN-based solid-phase extraction (SPE) and fractionation combined with comprehensive two-dimensional chromatography-time-of-flight mass spectrometry (GC×GC-TOFMS) to unveil its volatile composition. The volatiles were isolated with LiChrolut EN-based SPE and traditional liquid-liquid extraction (LLE).

Untargeted Headspace-Gas Chromatography-Ion Mobility Spectrometry in Combination with Chemometrics for Detecting the Age of Chinese Liquor (Baijiu).

This paper proposes the combination of headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS) and chemometrics as a method to detect the age of Chinese liquor (Baijiu). Headspace conditions were optimized through single-factor optimization experiments. The optimal sample preparation involved diluting Baijiu with saturated brine to 15% alcohol by volume.

Profiling polar lipids in whey protein phospholipid concentrate by LC-HRMS/MS.

Bioactive polar lipids in the milk fat globular membrane can be recovered and enriched during whey protein processing into a co-product called whey protein phospholipid concentrate (WPPC). A food-grade solvent successfully extracted polar lipids from powdered dairy products, and lipids can be fractionated under temperature-induced crystallization. This study investigates the specific lipid species present in ethanol extracted lipid residues from commercially available WPPC using a UPLC-Q-TOF-MS/MS lipidomics method.

In vivo and in vitro aroma release in surimi gel with different cross-linking degrees by proton transfer reaction-mass spectrometry.

Transglutaminase-induced cross-linking has been suggested as a strategy to govern surimi gels' texture. To achieve the aroma regulation of surimi gels by cross-links, surimi gels were treated with microbial transglutaminase to get different cross-linking degrees, and in vivo and in vitro aroma releases were investigated by a proton transfer reaction-mass spectrometry (PTR-MS). Seventeen compounds in surimi gels were detected by PTR-MS.

Tandem Solid-Phase Extraction Columns for Simultaneous Aroma Extraction and Fractionation of Wuliangye and Other Baijiu.

Wuliangye baijiu is one of the most famous baijiu in China, with a rich, harmonic aroma profile highly appreciated by consumers. Thousands of volatiles have been identified for the unique aroma profile. Among them, fatty acid esters have been identified as the main contributors to the aroma profile.

Smoked-Derived Volatile Phenol Analysis in Wine by Stir Bar Sorptive Extraction-Gas Chromatography-Mass Spectrometry.

Smoke-derived taint has become a significant concern for the U.S. wine industry, particularly on the west coast, and climate change is anticipated to aggravate it.

Sensory characterization of Baijiu pungency by combined time-intensity (TI) and temporal dominance of sensations (TDS).

Pungency is increasingly being recognized as an important factor of overall sensory quality, palatability, and consumer preference of distilled spirits. The characterization of pungency is necessary to evaluate the potential sensory quality of distilled spirits. In this study, the temporal profiles of pungency of Baijiu with different aging times were evaluated using time-intensity (TI) and temporal dominance of sensations (TDS) methods, considering both pungency intensity and pungency sub-qualities.

Sensory evaluation of fresh/frozen mackerel products: A review.

Mackerel has received considerable attention in the global food market as one of the most important pelagic commercial fish species. The quality of mackerel is influenced by species, season, fishing area, nutritional status, catching method, handling, and storage. Due to the mackerel's perishability, its quality is mainly measured by sensory procedures.

Characterization of Aroma-Active Compounds in Northern Highbush Blueberries "Bluecrop" ( "Bluecrop") and "Elliott" ( "Elliott") by Gas Chromatography-Olfactometry Dilution Analysis and Odor Activity Value.

Aroma-active compounds in northern highbush blueberries "Bluecrop" ( "Bluecrop") and "Elliott" ( "Elliott") were isolated using solvent extraction followed by solvent-assisted flavor evaporation. The aroma-active compounds were compared by aroma extract dilution analysis (AEDA) on a polar and a chiral column and odor activity values (OAVs). The results showed that both cultivars had similar aroma-active compounds, but the flavor dilution (FD) factors and OAV values varied, responsible for the subtle aroma differences.

Direct ethanolic extraction of polar lipids and fractional crystallization from whey protein phospholipid concentrate.

Polar lipids, including sphingomyelin (SM) and other sphingolipids, have nutritional implications in many important metabolic pathways. Milk and whey are valuable sources of these bioactive lipids, differing in SM content compared with other plant-based lecithins in the food industry. Dairy lipids were extracted from whey protein phospholipid concentrate powder by direct exposure to a food-grade solvent, ethanol.

Aroma dynamic characteristics during the process of variable-temperature final firing of Congou black tea by electronic nose and comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry.

The drying technology is crucial to the quality of Congou black tea. In this study, the aroma dynamic characteristics during the variable-temperature final firing of Congou black tea was investigated by electronic nose (e-nose) and comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC × GC-TOFMS). Varying drying temperatures and time obtained distinctly different types of aroma characteristics such as faint scent, floral aroma, and sweet fragrance.

Phospholipid analysis in whey protein products using hydrophilic interaction high-performance liquid chromatography-evaporative light-scattering detection in an industry setting.

The main objective of this work was to develop an analytical method that can be used in a dairy manufacturing facility for the quantitation of phospholipids in dairy products. Total lipids from a dairy matrix were obtained first by Folch extraction. The total lipid extract was then applied to a silica gel-based solid-phase extraction column, and triglycerides and other nonpolar lipids were separated from the phospholipids and sphingolipids.

Unraveling the chemosensory characteristics of strong-aroma type Baijiu from different regions using comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry and descriptive sensory analysis.

Comprehensive 2D gas chromatography-time-of-flight mass spectrometry was combined with descriptive sensory analysis to elucidate the specificity of strong-aroma type Baijiu (Chinese liquor) from different regions, based on regionally distinct flavor characterized by chemical and sensory profiles. Numerous potential aroma compounds (262) were identified, among which 58 aroma compounds were significantly different between the samples from Sichuan and Jianghuai regions. Relationships between these potential aroma compounds and sensory attributes were investigated by partial least squares regression and network analysis.

Comparative Characterization of Aroma Compounds in Silver Carp (), Pacific Whiting (), and Alaska Pollock () Surimi by Aroma Extract Dilution Analysis, Odor Activity Value, and Aroma Recombination Studies.

Aroma compounds in three surimi samples, made from freshwater silver carp () and saltwater Pacific whiting () and Alaska pollock (), were characterized by aroma extract dilution analysis, odor activity value, and odor recombination study. Results demonstrated that the most potent aroma-active compounds in the surimi were hexanal, ()-4-heptenal, ()-4-decenal, (,)-2,6-nonadienal, (,)-2,4-nonadienal, (,)-2,4-decadienal, (,)-2,4-decadienal, (,,)-2,4,6-nonatrienal, (,,)-2,4,7-tridecatrienal, and ()-4,5-epoxy-()-2-decenal, contributing fishy, green, oily, or metallic odors. The other aroma contributors in surimi were 1-octen-3-one, 1-octen-3-ol, dimethyl disulfide, dimethyl trisulfide, and methional.

Introduction to the Second International Flavor and Fragrance Conference.

The Second International Flavor and Fragrance Conference was successfully held on May 28-31, 2018, in Wuxi, China. The congress shared the progresses and discoveries in the research areas of flavor and fragrance perception, flavor analysis, thermal and biomediated generation of flavor, biological activities of aroma and flavor, and flavor and fragrance encapsulation and delivery technologies. This special issue collected some original research papers as well as reviews on basic taste, flavor analysis, aroma and taste characterization, essential oil bioactivity, and other related topics.