Flavor Analysis Research Articles

Application of GC-IMS in Detection of Food Flavor Substances

Gas chromatography-ion migration spectroscopy (GC-IMS) is an effective method for the separation and sensitive detection of volatile organic compounds (Vocs). This technology combines the advantages of high separation ability of GC and rapid response of IMS, with fast response speed, high sensitivity, convenient operation and low cost. It has been widely used in the fields of drug detection, disease monitoring and environmental protection, especially in the field of food flavor analysis. This review first introduces the working principle of GC-IMS, and then summarizes the application of GC-IMS in the detection of flavor substances in food in recent years. Finally, the future paths in the research and development of GC-IMS are discussed.

The genetic and functional analysis of flavor in commercial tomato: the FLORAL4 gene underlies a QTL for floral aroma volatiles in tomato fruit.

SUMMARYTomato (Solanum lycopersicum L.) has become a popular model for genetic studies of fruit flavor in the last two decades. In this article we present a study of tomato fruit flavor, including an analysis of the genetic, metabolic and sensorial variation of a collection of contemporary commercial glasshouse tomato cultivars, followed by a validation of the associations found by quantitative trait locus (QTL) analysis of representative biparental segregating populations. This led to the identification of the major sensorial and chemical components determining fruit flavor variation and detection of the underlying QTLs. The high representation of QTL haplotypes in the breeders’ germplasm suggests that there is great potential for applying these QTLs in current breeding programs aimed at improving tomato flavor. A QTL on chromosome 4 was found to affect the levels of the phenylalanine‐derived volatiles (PHEVs) 2‐phenylethanol, phenylacetaldehyde and 1‐nitro‐2‐phenylethane. Fruits of near‐isogenic lines contrasting for this locus and in the composition of PHEVs significantly differed in the perception of fruity and rose‐hip‐like aroma. The PHEV locus was fine mapped, which allowed for the identification of FLORAL4 as a candidate gene for PHEV regulation. Using a gene‐editing‐based (CRISPR‐CAS9) reverse‐genetics approach, FLORAL4 was demonstrated to be the key factor in this QTL affecting PHEV accumulation in tomato fruit.

Analysis of flavor and other metabolites in lemon juice (Citrus limon) from Huanglongbing-affected trees grafted on different rootstocks.

Flavor perception integrates sensory input from chemical receptors triggered by taste- and aroma-active metabolites to contribute to food flavor quality. Many factors alter flavor quality. Disease affects aroma and flavonoid constituents, causing off-flavors in plants. Huanglongbing (HLB) disease negatively affects citrus, although lemons are more tolerant. Lemon juice quality of HLB-affected fruits is not well studied. Lemon juice aroma-active compounds were profiled in this study using gas chromatography/mass spectrometry-olfactometry, and other metabolites contributing to overall flavor quality were investigated. Lemon juice from different rootstocks was discriminated using the metabolic profile. Flavor and other lemon juice metabolites also distinguished symptomatic from asymptomatic trees. Pathway enrichment analysis demonstrated that biosynthesis pathways of the Phosphotransferase system (PTS), and Starch and sucrose metabolism involving fructose, glucose and sucrose, were highly influenced by HLB status. This study provides the first comprehensive view of lemon juice metabolites, including alterations resulting from rootstock differences or disease severity.

Analysis of flavor and taste attributes differences treated by chemical preservatives: a case study in strawberry fruits treated by 1-methylcyclopropene and chlorine dioxide.

Flavor and taste attributes of fruits varied by different preservatives treatments. Changes in sugars, organic acids, amino acids as well as volatiles of strawberries treated with 1-methylcyclopropene (1-MCP) and/or chlorine dioxide (ClO2) were evaluated during storage period in this study. Our results revealed that the decreases of tartaric acid, malic acid, citric acid, titratable acidity (TA), sucrose and soluble sugar contents were significantly inhibited by 1-MCP + ClO2. The fructose and glucose contents of all groups remained stable and slightly increased at the last period of 10days. However, different treatments had no influence on content of succinic acid. Moreover, the highest sweet taste (77.37mg 100g-1 fresh weight) and lowest bitter taste (3.44mg 100g-1 fresh weight) free amino acids (FAA) were observed in the strawberries treated by 1-MCP combined with ClO2 treatment as compared to other treatments and control. (E)-2-hexenal was the most abundant volatile and showed a significant increase trend during strawberry storage. More interestingly, ethyl butyrate, fruit-like aroma, could be recovered in content by 1-MCP, ClO2 alone and their combination treatment. Compared with other treatments, the significant different flavor in ClO2 treatment was identified by principle component analysis. In addition, methyl hexanoate and 4-methoxy-2,5-dimethylfuran-3(2H)-one (DMMF) were the major factors that affected the volatile organic compounds (VOCs) of strawberries through the whole storage. Taken together, 1-MCP coupled with ClO2 could be a complex preservative to maintain strawberries quality by regulating the flavor and taste attributes.

Development of a Gas Chromatography-Flame Ionization Method for the Detection and Quantification of 12 Flavoring Agents in Supplementary Feed.

A flavoring agent is a compound that serves to add flavor with a pleasant scent and is used as a feed additive. Current flavor analysis methods include reflux pretreatment, titration, neutralization titration, and inversion; these are all analytical methods in which deviations and errors between experiments are generated. Titration methods are characterized by difficult selectivity analysis both for mixtures containing two or more types of flavoring agents and also for very low content samples. Current analysis methods are therefore particularly unsuitable for these sample types. Thus, more precise and accurate analysis of flavor agents is needed. This study intends to develop and verify a multi-component simultaneous analysis method that can accurately confirm the guaranteed content of 12 flavor agents of supplementary feeds distributed in the market, the goal being to establish a universally trusted method. Method validation was performed according to the International Conference on Harmonization (ICH) and International Union of Pure and Applied Chemistry (IUPAC) guidelines. Method validation was performed in terms of linearity, sensitivity, selectivity, accuracy, and precision. The limits of detection (LOD) for the instrument employed in these experiments ranged from 0.44-4.77 mg/kg, and the limits of quantification (LOQ) ranged from 1.32-14.31 mg/kg. Average recoveries of the 12 flavoring agents ranged from 75.1-111.4%. Maximum %RSD values for intraday and interday peak area variation are 13.09% and 13.08%, respectively. A novel and simple method for detecting 12 flavoring agents in animal feed supplements using a gas chromatography-flame ionization detector (GC-FID) was developed.

Characterization of key aroma compounds in Huangjiu from northern China by sensory-directed flavor analysis

Huangjiu (yellow rice wine) from Shanxi province, with a dominant Zao-aroma (fermented grain aroma), is particularly popular in northern China. The key aroma compounds in Huangjiu from Shanxi province were characterized by sensory-directed flavor analysis. A total of 106 compounds separated with solvent-assisted flavor evaporation (SAFE) distillation were identified by gas chromatography-olfactometry (GC-O) coupled with aroma extract dilution analysis (AEDA) and odor specific magnitude estimation (Osme). Forty-seven of them were further quantitated and 21 odorants had odor activity values (OAVs) ≥ 1. The aroma profiles of three recombination models had >95.84% similarities to their corresponding samples. And then, the omission/addition tests further confirmed that β-phenylethanol, 3-methylbutanoic acid, ethyl lactate, sotolon, 2-acetyl-1-pyrroline, vanillin, ethyl cinnamate, ethyl 3-phenylpropionate, 3-methylbutanal, and methional were the key odorants for Huangjiu from Shanxi province. Meanwhile, it was firstly confirmed that ethyl cinnamate and ethyl 3-phenylpropionate played the key roles in the overall aroma of Huangjiu.

Improvement of Bread Quality by Adding Wheat Germ Fermented with Lactobacillus plantarum dy-1

Fermentation has been considered as an effective way to improve the nutritional and sensory quality of food materials. In this paper, fermented wheat germ (FWG) was prepared by fermentation with Lactobacillus plantarum dy-1 and added as an ingredient in bread making for nutrition and quality improvement. The amounts ranged from 1 % to 6 % of FWG were added into ingredients for bread making, the similar amounts of raw wheat germ (RWG) were used as control, and the wheat flour without germ addition was used as blank. Then, bread quality was evaluated through nutrition, texture, and flavor analyses. The results showed that 4% of FWG addition had the ability to increase the specific volume, slow down the aging process, and improve the color and luster of bread. A significant increase in free amino acid content was observed in the FWG bread, which could be helpful to enrich the flavor substances in bread. The flavor analysis of bread showed that more volatile compounds mainly alcohols and aldehydes were present in FWG bread compared with RWG bread. In the fermentation process, the pH value was decreased and the total titratable acidity (TTA) was enhanced to inhibit the growth of microorganisms. Therefore, the addition of FWG could not only enhance its nutritional properties, but also improve the flavor, quality, and structural features of bread. Moreover, it exhibited a good availability to extend the shelf life of bread.

Flavor Analysis and Strain Exploitation of Fermented Rice Noodles

<p align="justify">Fermented rice noodles is popular for its unique flavor, but the study on flavor is lacking, especially the screening of corresponding strains. For the first time, the relationship of microorganism and flavor was unveiled, based on the research of a typical fermented rice noodles from Guilin in China. Flavors were dissected by HPLC-MS, GC-MS, GC-MS-O (Gas chromatography-mass and spectrometry-olfactometry) analyses, while microbial community was investigated by amplicon sequencing and metagenomics, afterwards microorganisms and flavors were connected via correlation analysis and function annotation, hen strains could be explored based on the analyses. Ethanol, 1-butanol,3-methyl-, 2-butanone, 3-hydroxy-, acetic acid and phenylethanol were discovered to be key flavors, biogenic amines were not abundant enough to have bad effect on flavor, but putrescine, tyramine and histamine produced in fermentation needed supervision for safety. Analysis indicated that fermentation was dominated by lactic acid bacteria. Further analysis revealed that Lactobacillus, Acetobacter and Lactococcus were primary creators for these key flavors. In particular, Lactobacillus showed great potential in flavor forming. Additionally, later experiment suggested that samples fermented by L. fermentum and L. plantarum (both belong to Lactobacillus) possessed great flavors, when L. fermentum also showed the ability to inhibit mold and reduce biogenic amine content.</p>

Flavor Analysis of Mrps Made from Different Enzymolysis Products by Gas Chromatography-Mass Spectrometry

Beef-bone protein hydrolysates were obtained by Flavourzyme (F), Protamex (P), Flavourzyme followed by Protamex (Fp), Protamex followed by Flavourzyme (Pf), and combination of Flavourzyme and Protamex (DE). Samples without any enzymes served as the control (C). Subsequently, the six hydrolysates were subjected to Maillard reaction for further investigation of the contribution of enzymatic hydrolysis to flavor. SPME-GC-MS (gas chromatograph-mass spectrometer) was applied to analyze the volatile substances and taste components. The results showed that the content of volatile compounds detected by the 6 samples was significantly different, while there was little difference in the type of compounds.

Flavor Analysis of Mrps Made from Different Enzymolysis Products Based on Electronic Nose and Electronic Tongue

The effects of different enzymatic hydrolysis methods on the odor and taste of the Maillard reaction products of minced beef-bone protein were studied. Electronic nose and electronic tongue were applied to analyze the volatile substances and taste components. The results indicated that the Maillard reaction products (MRPs) had improved organoleptic and meaty characteristics, especially that of Pf and DE groups. Moreover, DE is the most potential treatment for producting meat flavor as it consume less energy source and improves production efficiency.

New grape varieties for production of high-quality wines, and assessment methodology for varietal characteristics of the product

In recent years, Russian and international breeders have produced a great many of new varieties of Vitis vinifera grapes as well as interspecies hybrids, distinguished by a high quality of fruit and other useful economic and biological features. Having a big reserve of technologically important substances and hygienic factors of grapevine, the resistant varieties may prove especially efficient for the production of premium-class wines. The appearance of high-end Russian wines with protected geographical indication (PGI) and protected appellation of origin (PAO), first of all, fits in with the requirements of international markets. It is a necessary criterion for product quality and safety assurance at the highly competitive global market, and development of universally recognized brands. It also helps resolve a number of socio-economic issues, such as formation of winemaking culture, and production of wines of guaranteed quality from own grapes. This study is devoted to substantiating the necessity for development of methods of formation of single information databases on characteristic features of PGI and PAO wines, including their distinctive organoleptic, physical and chemical properties (extract components – the cation-anion composition, organic acids, total phenolic and anthocyanin content; unique colour characteristics), as well as the application of the system of organoleptic assessment of wines with the use of descriptive analysis of wine colour, flavour and taste. It is well-timed and relevant to determine the regularities of realization of the varietal potential of a grapevine plant in terms of climatic conditions of growing and geographical origin based on the study of the endogenous and exogenous components of wines with the use of the methods of high-performance capillary electrophoresis, spectral photometry, organoleptic analysis, and statistical techniques. This research generalizes and puts forth a contemporary view of varietal and geographical identification of wines. It is shown that the proposed research guideline is highly sought-after, and it is of fundamental and practical importance for the development of regional and national selection, genetic, viticultural and winemaking industries.

Three flavor neutrino conversions in supernovae: slow & fast instabilities

Self induced neutrino flavor conversions in the dense regions of stellar core collapse are almost exclusively studied in the standard two flavor scenario. Linear stability analysis has been successfully used to understand these flavor conversions. This is the first linearized study of three flavor fast instabilities. The 'fast' conversions are fascinating distinctions of the dense neutrino systems. In the fast modes the collective oscillation dynamics are independent of the neutrino mass, growing at the scale of the large neutrino-neutrino interaction strength (105 km−1) of the dense core. This is extremely fast, in comparison to the usual 'slow' collective modes driven by much smaller vacuum oscillation frequencies (100 km−1). The three flavor analysis shows distinctive characteristics for both the slow and the fast conversions. The slow oscillation results are in qualitative agreement with the existing nonlinear three flavor studies. For the fast modes, addition of the third flavor opens up possibilities of influencing the growth rates of flavor instabilities when compared to a two flavor scenario.

Higgs bosons with large couplings to light quarks

A common lore has arisen that beyond the Standard Model (BSM) particles, which can be searched for at current and proposed experiments, should have flavorless or mostly third-generation interactions with Standard Model quarks. This theoretical bias severely limits the exploration of BSM phenomenology, and is especially constraining for extended Higgs sectors. Such limitations can be avoided in the context of Spontaneous Flavor Violation (SFV), a robust and UV complete framework that allows for significant couplings to any up or down-type quark, while suppressing flavor-changing neutral currents via flavor alignment. In this work we study the theory and phenomenology of extended SFV Higgs sectors with large couplings to any quark generation. We perform a comprehensive analysis of flavor and collider constraints of extended SFV Higgs sectors, and demonstrate that new Higgs bosons with large couplings to the light quarks may be found at the electroweak scale. In particular, we find that new Higgses as light as 100 GeV with order $\sim$ 0.1 couplings to first or second generation quarks, which are copiously produced at LHC via quark fusion, are allowed by current constraints. Furthermore, the additional SFV Higgses can mix with the SM Higgs, providing strong theory motivation for an experimental program looking for deviations in the light quark-Higgs couplings. Our work demonstrates the importance of exploring BSM physics coupled preferentially to light quarks, and the need to further develop dedicated experimental techniques for the LHC and future colliders.

Systematic evaluation of the physicochemical properties and the volatile flavors of yak meat during chilled and controlled freezing-point storage.

In this study, the physicochemical properties (total volatile basic nitrogen (TVB-N), pH, and peroxide value) and the volatile flavors of yak meat were systematically evaluated during chilled (0°C) and controlled freezing-point (- 2°C) storage. The TVB-N reached 15.21mg/100g after 18days of storage at 0°C, which exceeded the secondary freshness value according to the Chinese national standard. For storage at - 2°C, the TVB-N did not exceed 15mg/100g until 24days. Compared with storage at 0°C, the samples stored at - 2°C had a slower rate of increase in TVB-N, pH, and peroxide values. The changes in volatile compounds in yak meat during storage at - 2°C and 0°C for 24days were investigated using headspace solid-phase microextraction (HS-SPME) followed by gas chromatography-mass spectrometry (GC-MS). The correlations between the changes in the volatile compound contents and meat quality deterioration revealed significant negative correlations (r min = 0.902, p < 0.05) between some aldehyde flavor components (nonanal, heptanal, benzaldehyde, decanal, and myristal) and TVB-N in the samples stored at controlled freezing-point and chilled temperatures. The decreases in nonanal, benzaldehyde, and myristal contents in yak meat followed zero order reaction kinetics. This result indicated, because of the highly selective and sensitive colorimetric detection method, that volatile compounds can effectively predict the decay in quality of yak meat stored at low temperature in advance. Thus, based on physicochemical and volatile flavor analyses, a new method is proposed to investigate the storage and preservation of yak meat.

Effects of Extended Aging on the Flavor Characteristics of Grass and Grain Fed Australian Beef Longissimus Thoracis

ObjectivesThe objective of this study was to investigate the effects of extended wet ageing on the flavor characteristics, of grass and grain fed Australian beef lumborum thoracis.Materials and MethodsCube rolls (HAM #2244) were collected from grass and grain fed cattle (n = 30) at a commercial abattoir near Brisbane, Australia. Cube rolls were vacuum packaged and shipped under refrigeration (0–2°C) to Texas Tech University. Each cube roll was cut into 2.5-cm steaks and labeled according to position from posterior to anterior end. Steaks were vacuumed packaged, stored through the appropriate postmortem ageing period (35, 45, 55, or 65 d postmortem), and then frozen until further analysis. One steak from each cube roll was used for trained descriptive flavor analysis with 8 trained panelists comprised of mostly graduate students from Texas Tech University. Flavor attributes of cooked steaks were scored using 100-point anchored line scales (0 = none, 50 = moderate, and 100 = strong).Data were analyzed used PROC GLIMMIX of SAS with diet, postmortem ageing, and their interaction as fixed effects and panelist as a random effect. Final temperature was tested as a covariate for all the flavor attributes.ResultsAn interaction was detected only for the bitter flavor and overall juiciness (P ≤ 0.03). Beef flavor ID, fat-like, metallic, umami, and sweet were not influenced by diet or postmortem ageing (P &gt; 0.05). Ageing influenced bloody serumy flavor (P &gt; 0.05) with 45 d samples having greater flavor than 55 d samples, but not differing (P &gt; 0.05) from any other ageing period. Diet and ageing influenced rancid flavor (P &gt; 0.05), with grass fed samples having a stronger rancid flavor than grain fed samples. Samples aged 65 d had a stronger rancid flavor than 45 or 55-d samples, and 35-d samples had the lowest rancid flavor. Diet and ageing influenced grassy flavor (P &gt; 0.05), again being stronger in grass than grain fed samples. Samples aged 35 d had a weaker (P &gt; 0.05) grassy flavor than any other ageing period, which did not differ (P &gt; 0.05). Diet and ageing had an effect on liver-like flavor (P &lt; 0.05) with stronger flavors in grain than grass fed samples and liver-like flavor increasing with postmortem ageing time. Sour flavor was affected by diet only (P &lt; 0.05) with grass fed samples having stronger sour flavor than grain fed samples. Ageing had an effect on overall tenderness (P &lt; 0.05); samples aged 35 d were least tender, and samples aged 45 d were more tender than 55 d samples but did not differ from 65 d samples.ConclusionThe results suggest that beef flavor as measured by beef flavor ID and umami were not impacted by extended ageing; however, some off-flavors grew stronger as ageing time extended. Flavor attributes such as rancid, grassy, sour were stronger in grass than grain fed samples, but grain fed has a stronger liver-like flavor. Ageing influenced both overall tenderness and juiciness, but typically not in a linear fashion.

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.

Sensory-directed flavor analysis of off-flavor compounds in infant formula with deeply hydrolyzed milk protein and their possible sources

Off-flavor compounds in IF-DHMP were identified using sensory-directed analysis. In total, 56 types of aroma-active compounds were identified in the off-flavor (OF) samples, positive control (PC) samples, and accelerated oxidation (AO) samples. The Aroma Extraction Dilution Analysis (AEDA) results showed that methional, generated via Maillard reaction, was the most important component with the highest dilution factor in OF. The results of aroma recombination, omission and spiking experiment revealed that compounds such as pentanal, methional, (E)-2-nonenal, 3-methylbutanal, (E)-2-heptenal, nonanal, (E,E)-2,4-heptadienal, 1-penten-3-one, 1-octen-3-one, and (E,E)-2,4-nonadienal were the major sources of off-flavor in OF. We observed that the off-flavor in OF samples originated due to proteolysis, Maillard reaction, or lipid oxidation during processing rather than due to lipid oxidation during storage.

COMPARATIVE ANALYSIS OF AROMA PROPERTIES OF Pleurotus ostreatus INDUSTRIAL STRAINS

Flavor properties of mushrooms are an important criterion that determines the selection of strains for industrial cultivation. The purpose of the study was to determine growth parameters and aroma profile of six most common industrial Pleurotus ostreatus (Jacq.) P. Kumm. strains in the process of intensive cultivation on sunflower husk. To achieve this purpose, methods of sensory profile analysis and ultraviolet spectroscopy were used.Sensory profile analysis of flavor showed that fruit bodies of the IBK-1535 and IBK-1543 strains had the highest intensity of the mushroom note of aroma.Spectrophotometric analysis demonstrated that mushroom hexane extracts had light absorption maxima in the ranges of 207-210 nm and of 250-290 nm. Thus, the spectrum of the strain IBK-1535 had the highest intensity in the whole range of wavelengths.The screening of P. ostreatus strains allows us to recommend the IBK-1535 and IBK-1543 strains, which have a high growth rate and productivity, as well as the most pronounced characteristic mushroom aroma, for industrial cultivation.

Comparative flavor analysis of eight varieties of Xinjiang flatbreads from the Xinjiang Region of China

AbstractBackground and objectivesThe volatile and nonvolatile compounds of eight types of Xinjiang baked flatbreads were measured to identify their characteristic components, with key odorants determined using the relative odor activity values (ROAVs).FindingsElectronic nose results indicated that Walnut Nang aroma differed significantly from that of other Xinjiang flatbreads. GC‐MS results demonstrated that the principal volatile compounds in flatbreads were mostly aldehydes, alcohols, and ketones, with volatile profiles of flatbreads varying greatly. Among the flavor components tested, aldehydes with ROAVs higher than 1 contributed most significantly to overall aroma. In Rose Nang, aldehydes and alcohols were key odorants, with (E,E)‐2,4‐decadienal playing a major role in most flatbreads. All tested flatbreads were distinguishable using the electric tongue and discriminant factor analysis. Sugar analysis revealed lower maltose but higher glucose, sucrose, and fructose levels in Rose Nang compared to other samples. Finally, umami taste amino acids were dominant in all tested Xinjiang flatbreads.ConclusionsOur comparative analysis of the flavor substances of different kinds of Xinjiang baked flatbreads lays a foundation for research on flavor formation.Significance and noveltyThe analysis could provide a useful basis in the development of processing methods for Xinjiang flatbreads.

Ordering volatile openings: instrumentation and the rationalization of bodily odors

ABSTRACT Odors define many things: plants, foods, people. Although the rise of instrumental flavor and odor analysis techniques from the 1950s to 1980s, largely driven by the food and perfumery industries, allowed scientists unprecedented access to knowledge about the structures and origins of odorific molecules, these techniques and their influence on the social imagination remain relatively unexamined. Working at the intersection of Gender, Food, and Science and Technology Studies, this paper examines how the technique of gas chromatography-olfactometry (GC-O), key to how perfumers and flavorists managed sensory experience, was mobilized to scientifically categorize the bodily odors of immigrants and women as other. Through analysis of the instrumental and sensory techniques used to quantify as well as qualify bodily odor, I examine how researchers mimicked patterns for ordering the world of taste and smell in their efforts to characterize and master women’s bodily odors. The indexing of bodily odors through GC-O highlighted the porous nature of the body and its smells, even as researchers, physicians, and producers of feminine “hygiene” products promoted commercial anti-fungal medications, douches, and suppositories for their promise to reign in the excess smells of the body and its microbial and mycobial companions.