Odor-active Compounds Research Articles

Unveiling the aromatic intricacies of Wuyi Rock Tea: A comparative study on sensory attributes and odor-active compounds of Rougui and Shuixian varieties

The distinctive fragrance of Wuyi Rock Tea (WRT) has garnered high attention in recent years. Herein, we conducted a comprehensive comparison of the sensory attributes and odor-active compounds (OACs) between two quintessential WRTs, namely Rougui (RGT) and Shuixian (SXT). Sensory analysis revealed that RGT exhibited a more pronounced fruity aroma, while SXT had a more complex and intricate sensory profile. By using gas chromatography-olfactory mass spectrometry (GC-O-MS) and two-dimensional gas chromatography time-of-flight mass spectrometry (GC × GC-TOF-MS) analyses, 26 OACs were identified. Among them, 12 compounds with odor activity values > 1 were recognized as key OACs. Noteworthily, eight compounds, including 6-methyl-5-hepten-2-one, 2-ethyl-3,5-dimethylpyrazine, 2,3-diethyl-5-methylpyrazine, linalool, methyl salicylate, geraniol, (E)-β-ionone, and (E)-nerolidol, were shared by both teas. The unique compounds for RGT were (E)-linalool oxide and (Z)-jasmone, while those for SXT were β-cyclocitral and α-ionone. These findings offer valuable insights for better understanding the flavor differences between the two most important types of WRT.

Chemical, microbiological, textural, and sensory characteristics of pilot-scale Caciofiore cheese curdled with commercial Cynara cardunculus rennet and crude extracts from spontaneous and cultivated Onopordum tauricum

The aim of this study was the chemical, microbiological, textural, and sensory characterization of pilot-scale prototypes of an Italian ewe’s raw milk cheese (Caciofiore) curdled with commercial Cynara cardunculus rennet, used as a control, and crude extracts obtained from flowers of either spontaneous or cultivated Onopordum tauricum. Hence, the control and experimental cheese prototypes produced in two rounds of cheesemaking trials were assayed, at the end of their 60-day maturation, for the following features: pH, titratable acidity, dry matter, fat, total and soluble nitrogen (TN and SN, respectively), ash, salt, protein, lactose, viable plate counts and composition of the bacterial and fungal populations, color, texture, volatile organic compounds (VOCs), and olfactory attributes by sensory analysis (the latter for the sole prototypes curdled with the commercial rennet and the extract obtained from cultivated O. tauricum). The data overall collected showed a very low impact of the type of thistle rennet on the analyzed cheese traits, with significant differences being exclusively found for SN/TN%, titratable acidity, color, and adhesiveness. By contrast, a higher impact of the cheesemaking round was seen, with significant differences being observed for salt content, load of presumptive lactobacilli, thermophilic cocci, and Escherichia coli, and levels of the following VOCs: 2,3-butanedione, 2-pentanone, 1-butanol, 2-heptanone, 3-methyl-1-butanol, 2-heptanol, 2-nonanone, dimethyl trisulfide, 2-methyl propanoic acid, butanoic acid, and 3-methyl butanoic acid. Sensory analysis revealed a strong ewe’s cheese odor, accompanied by other olfactory notes, such as pungent, sour curd, sweet, and Parmesan cheese-like notes, in all the analysed cheese prototypes. Moreover, key odor active compounds, including butanoic acid, ethyl butanoate, 2,3-butanedione, 1-octen-3-one, and dimethyl trisulfide, were identified by GC-olfactometry analysis. Regarding the odor attributes as determined by sensory analysis, again the type of rennet had an almost negligible impact, with significant differences being only perceived for 1 or 2 out of 20 odor attributes, depending on the analytical conditions applied. Although some aspects deserve further investigation, the results herein collected confirm that O. tauricum can be regarded as an alternative source of thistle rennet for the manufacture of Caciofiore cheese, and more in general, Mediterranean ewe’s milk cheeses.

Enhancing the aroma of white whole sorghum flour using supercritical carbon dioxide

Removal of undesired odor-active compounds from sorghum flour is vital for the widespread production of sorghum-based foods. This study investigated the use of supercritical carbon dioxide (SCCO2) for the extraction of volatile compounds (VCs) from white sorghum flour. The extraction temperature (33.18–66.81 °C), pressure (8.18–41.82 MPa), and time (1.32–4.68 h) were optimized for the removal of 11 VCs (decane, undecane, tetradecane, dodecane, hexanal, nonanal, hexanol, dodecanol, limonene, styrene, and butylated hydroxytoluene) from whole white sorghum flour using a central composite response surface design. The maximum VC removal (∼89%) was obtained at 60 °C and 15 MPa with 2 h extraction time. SCCO2 extraction at higher pressures (> 15 MPa) or lower temperatures (<60 °C) did not improve the VC removal. After SCCO2 treatment, water absorption index, oil absorption capacity, and swelling power increased, whereas moisture/lipid contents, water solubility index, and particle size reduced significantly (p<0.05). The lightness of the sorghum flour treated with SCCO2 increased significantly compared to untreated sorghum flour, while the yellowness decreased after SCCO2 extraction (p<0.05). Overall, this study developed a novel green approach to enhancing the aroma of sorghum flour, which has a high potential for scale-up, and generating sorghum flours with more neutral flavors for numerous food applications.

Influence of peeling on volatile and non-volatile compounds responsible for aroma, sensory, and nutrition in ginger (Zingiber officinale).

Industrial use of ginger after peeling results in large amounts of agro-waste. To provide a basic reference for the sustainable processing of ginger products as a spice, we investigated the differences between unpeeled ginger, peeled ginger, and corresponding ginger peel, in terms of aroma, sensory profiles, and nutrition relevant physicochemical properties. The results showed that the total concentrations of identified odor-active compounds in unpeeled ginger, peeled ginger, and ginger peel were 876.56, 672.73, and 105.39mg/kg, respectively. Unpeeled ginger exhibited more intense citrus-like and fresh impressions compared to peeled ginger, revealed by descriptive sensory analyses. This is relevant to the high odor activity values of odorants such as β-myrcene (pungent, citrus-like), geranial (citrus-like), citronellal (citrus-like, sourish), and linalool (floral, fresh). In parallel, unpeeled ginger contained higher total polyphenol (84.49mg/100g) and total sugar content (33.4g/kg) in comparison with peeled ginger (76.53mg/100g and 28.6g/kg).

Investigation on the changes of odor-active compounds of Amomum tsao-ko during natural drying

To characterize the key odorants in Amomum tsao-ko (AT) and to investigate their changes during natural drying, volatile compounds of AT were extracted and analyzed by solvent extraction combined with solvent-assisted flavor evaporation and gas chromatographymass spectrometry–olfactometry. A total of 41 aroma-active compounds with flavor dilution factors ranging from 3 to 6561 were identified in AT. Fourteen odorants were determined to be the key odorants by quantitation analyses, odor activity value (OAV) calculations, recombination and omission experiments. To further investigate the changes in aroma components in AT during natural drying, the concentrations and OAVs of odor-active compounds were measured at 0, 2, 4, 6, 8, 12, 16, and 20 days. The results showed that the number of aroma-active components did not change during natural drying, but their content changed with different trends. The concentration of geraniol showed a continuous upward trend; those of hexanal, octanal, nonanal and pinocarvone decreased first and then increased; those of α-pinene, sabinene, 2-nonanone, (E)-2-octenal, 2-nonanol, 4-terpineol, epidolichodial and (E,E)-2,4-dodecadienal changed on a fluctuating trend, while those of the other 28 compounds showed a trend of first increasing and then decreasing. These results provide a theoretical basis for further utilization of AT.

Characterization of Volatile Flavor Compounds in Dry-Rendered Beef Fat by Different Solvent-Assisted Flavor Evaporation (SAFE) Combined with GC-MS, GC-O, and OAV.

To comprehensively understand the volatile flavor composition of dry-rendered beef fat, solvent-assisted flavor evaporation (SAFE) with four extraction solvents (dichloromethane, pentane, ethyl ether, and methanol) combined with gas chromatography-mass spectrometry (GC-MS) and gas chromatography-olfactormetry (GC-O) were performed. GC-MS analysis found 96 different volatile compounds in total using the four extraction solvents. According to the GC-MS results and the heat map and principal component analysis (PCA), most of the volatile compounds resulted from dichloromethane and pentane extraction, followed by ethyl ether. Methanol extraction found a few volatile compounds of higher polarity, which was supplementary to the analysis results. Moreover, GC-O analysis found 73 odor-active compounds in total using the four extraction solvents. The GC-O results found that pentane and dichloromethane extraction had a significantly larger number of odor-active compounds than ethyl ether and methanol extraction. This indicated that pentane and dichloromethane were more effective solvents for the extraction of odor-active compounds than the other two solvents. Finally, a total of 15 compounds of odor-active values (OAVs) ≥ 1 were determined to be the key aroma compounds in the dry-rendered beef fat, including 2-methyl-3-furanthiol, 3-methylthiopropanal, (E,E)-2,4-nonadienal, 12-methyltridecanal, and 1-octen-3-one.

Unveiling the Aromas and Sensory Evaluation of Hakko Sobacha: A New Functional Non-Dairy Probiotic Fermented Drink.

At the dawn of a food transition encouraging the consumption of healthy and sustainable non-dairy probiotic products, the development of a fermented functional drink based on Sobacha is considered. Sobacha is an infusion of roasted buckwheat seeds widely consumed in Asian countries for its health benefits. As fermentation improves the nutritional and organoleptic status of grains, the mixed fermentation process involved in the development of kombucha beverages (fermented sweet tea) is conducted by inoculating a symbiotic culture of bacteria and yeasts into the transposable matrix (Sobacha instead of tea). Sobacha, a healthy pseudo-cereal matrix with promising aromas, could be fermented to potentially develop an innovative drink, named "Hakko Sobacha". This neologism would reveal the fermented character of the infusion, Hakko meaning fermented in Japanese. Considering the beverage characterization, the kinetics of the volatile organic compound syntheses were determined using stir-bar sorptive extraction followed by gas chromatography coupled to mass spectrometry analysis. Odor-active compounds were theoretically calculated to estimate the flavor composition. Finally, sensory analyses highlighted the appreciation and preferences of the consumer towards the beverages. The fermentative yield differences observed between the two buckwheat concentration modalities tested seemed to be correlated with the sugar and nutrient levels available from the starch (buckwheat) matrix. Having characterized Hakko Sobacha, this study proposed the possibility of developing new beverages by monitoring the fermentative process. This should enable improved control and enhancement of their sensorial properties, which could in turn lead to greater customer acceptability.

Characterization of odor-active compounds in Dahongpao Wuyi Rock Tea (Camellia sinensis) by sensory-directed flavor analysis

Different methods for extraction and analysis of odor-active compounds in Dahongpao (DHP) Wuyi Rock Tea (WRT) were compared. The results showed that two-dimensional gas chromatography–olfactometry–mass spectrometry (GC×GC–O–MS) is a better method than GC–O–MS, stir bar sorptive extraction (SBSE) can extract more odor-active compounds. Aroma extraction dilution analysis (AEDA) and odor activity value (OAV) further indicated that 15 compounds were the most important odor-active compounds in DHP: phenethyl alcohol, (E)-β-ionone, nonanal, linalool, hexanal, geraniol, benzaldehyde, α-ionone, methyl salicylate, 6-methyl-5-hepten-2-one, geranylacetone, benzyl alcohol, tea pyrrole and hexyl hexanoate. The roasting process affected the overall odor characteristics of DHP, and appropriate roasting would enhance the sensory quality of DHP. As the roasting temperature increases, the contribution of compounds such as tea pyrrole, 2-ethyl-6-methylpyrazine, and 2,6-dimethylpyrazine to the roasted and burnt odor of the samples gradually increase, and the concentration of typical floral compounds such as phenethyl alcohol, (E)-β-ionone, α-ionone and linalool increase decidedly under light fire roasting, which was consistent with the sensory evaluation results. This study is helpful to further guide the production process of DHP.

Profiling the Major Aroma-Active Compounds of Microwave-Dried Jujube Slices through Molecular Sensory Science Approaches.

To discriminate the aroma-active compounds in dried jujube slices through microwave-dried treatments and understand their sensory attributes, odor activity value (OAV) and detection frequency analysis (DFA) combined with sensory analysis and analyzed through partial least squares regression analysis (PLSR) were used collaboratively. A total of 21 major aromatic active compounds were identified, among which 4-hexanolide, 4-cyclopentene-1,3-dione, 5-methyl-2(5H)-furanone, 4-hydroxy-2,5-dimethyl-3(2H)furanone, 3,5-dihydroxy-2-methyl-4-pyrone were first confirmed as aromatic compounds of jujube. Sensory evaluation revealed that the major characteristic aromas of dried jujube slices were caramel flavor, roasted sweet flavor, and bitter and burnt flavors. The PLSR results showed that certain compounds were related to specific taste attributes. 2,3-butanedione and acetoin had a significant positive correlation with the roasted sweet attribute. On the other hand, γ-butyrolactone, 4-cyclopentene-1,3-dione, and 4-hydroxy-2,5-dimethyl-3(2H)furanone had a significant positive impact on the caramel attributes. For the bitter attribute, 2-acetylfuran and 5-methyl-2(5H)-furanone were positively correlated. Regarding the burnt flavor, 5-methyl-2-furancarboxaldehyde and 3,5-dihydroxy-2-methyl-4-pyrone were the most influential odor-active compounds. Finally, 2-furanmethanol and 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one were identified as the primary sources of the burnt and bitter flavors. Importantly, this work could provide a theoretical basis for aroma control during dried jujube slices processing.

Identification of key volatile and odor-active compounds in 10 main fragrance types of Fenghuang Dancong tea using HS-SPME/GC-MS combined with multivariate analysis

Fenghuang Dancong tea (FHDC), a famous oolong tea originating from Guangdong Province in China, is known for its rich and unique fragrance. Nevertheless, the identification of the key aroma compounds with the difference fragrance types of FHDC remains uncertain. In order to characteristic the volatile components in different fragrance types of FHDC, 10 well-known fragrance types of FHDC and Tieguanyin (TGY) as a control were analyzed by headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography mass spectrometry (GC–MS). Results indicated that 172 volatile compounds were identified as common volatile compounds among all the tea samples. A total of 16 compounds were identified as key compounds that could be used to distinguish between FHDC and TGY. Among the 10 FHDC fragrance types, indole, hotrienol, benzyl nitrile, and jasmine lactone were found to be the most abundant compounds. Despite the presence of certain similarities in aroma components, each type exhibits unique fragrance characteristics as a result of variation in compound composition content and proportion. Furthermore, using statistical and odor activity value analysis, 20 aroma-active compounds were recognized as potential characteristic markers accountable for the diverse fragrance types of FHDC. This research enhances our comprehension of the various fragrance types of FHDC and provides reference values for their rapid identification in the market.

Characterization of odor properties of human milk: Effect of inter-individual nutrient differences on key odor-active compounds and odor attributes

Odor is an important indicator of human milk (HM) quality, with a proven function. Here, the effect of inter-individual nutrient differences on key odor-active compounds (OACs) and odor attributes of HM samples was investigated using flavor analysis techniques and correlation network analysis. A total of ninety-four OACs were identified from 30 HMs, of which 24 key OACs could represent the basic odor characteristics of HMs. Fat content was closely related to the amounts of OACs, with aldehydes being the most abundant species and having the highest correlation with fat content. Of them, nonanal and octanal were the most important OACs in HM, having both high flavor dilution factor (2 ∼ 64, 4 ∼ 128) and odor activity values (<1 ∼ 37, 2 ∼ 36) in most samples. Additionally, different pattern of synergism between key OACs contribute to each odor attribute of HM. These findings will provide insights for subsequent in-depth studies of HM flavor.

Aroma generation in sponge cakes: The influence of sucrose particle size and sucrose source.

The influence of sucrose source and particle size was investigated in relation to the volatile and aromatic properties of sponge cakes. Six sponge cake formulations were studied using two sucrose sources (sugarbeet and sugarcane), at two particle sizes (large and small) with controls. Volatiles profiles and odour active compounds were identified by gas chromatography mass spectrometry and olfactometry. Sixty two volatile compounds were identified, incorporating twenty five odour active compounds/co-eluting compounds, with 5 odours perceived without any corresponding volatile. Particle size had the greatest impact on volatile abundance, with particle size especially influencing pyrazine abundance. Five odour active volatiles (methional, furfural, 2,3-dimethylpyrazine, heptanal and (E)-2-octenal) contributed most to the aroma of these sponge cakes. Small particle size particularly from sugarbeet yielded higher levels of some Maillard and caramelisation reaction compounds, such as furfural (spicy/ bready), where larger particle size supressed volatile abundance in comparison to the control.

Characterization of the key odorants in fresh Amomum tsao-ko Crevost et Lemaire fruit by gas chromatography-olfactometry, quantitative analysis and aroma reconstitution

To decode key odorants (KOs) in fresh Amomum tsao-ko Crevost et Lemaire fruit (FAF) and investigate the effect of isolation methods on KOs and enantiomer ratios, volatiles were isolated using both direct solvent extraction combined with solvent-assisted flavor evaporation (DSE-SAFE) and hydrodistillation (HD) and analyzed by gas chromatography‒mass spectrometry/olfactometry. In total, 55 odor-active compounds with flavor dilution factors between 1 and 8192 were identified, of which 36 and 39 odorants were detected in the SAFE and HD isolates, respectively. By quantitative analysis and odor activity value calculation, 22 odorants in the SAFE isolate and 25 odorants in the HD isolate were determined to be FAF KOs. The differences in the concentrations and the number of KOs caused the two isolates to have different odor characteristics. The recombination experiment further confirmed the results. Among the three studied chiral odorants, including linalool, 4-terpenol, and α-terpineol, the (S)-(−)-enantiomer was dominant, and the (S)-(−)-enantiomer inverted into the (R)-(−)-enantiomer during HD.

Comparison of aroma properties of infant formulas: Differences in key aroma compounds and their possible origins in processing

Aroma is an important attribute of infant formula (IF). In this study, 218 volatiles and 62 odor-active compounds were detected from IF by dynamic headspace sampling combined with comprehensive 2-dimensional gas chromatography-olfactometry-mass spectrometry. Aldehydes and ketones were determined as the most abundant odor-active compounds. Among them, the contents of pentanal and hexanal were the most abundant, while 1-octen-3-one had the highest flavor dilution factor and odor activity value in most of the IF. Sensory evaluation and electronic nose analysis showed that the skimming process, the fatty acid composition, and powdered or liquid milk base used for the production of IF may be important factors resulting in their differences in aroma profiles and compounds. These differences were assumed to be mainly ascribed to the Maillard reaction and lipid oxidation, which were largely influenced by the temperature and water activity.

Evaluation of the Chemosensoric Properties of Commercially Available Dog Foods Using Electronic Sensors and GC-MS/O Analysis.

Pet owners think of their animals as part of their family, which further promotes the growth of the pet food market, encouraging pet owners to select nutritious, palatable, and high-quality foods for pets. Therefore, the evaluation of taste and volatile compounds in pet foods is essential to improve palatability. In this study, the sensory characteristics of taste and odor compounds in 10 commercially available dry dog foods were investigated using electronic tongue (E-tongue), electronic nose (E-nose), gas chromatography-mass spectrometry (GC-MS), and gas chromatography-olfactometry (GC-O). Dry dog foods were separated based on the sensory properties of taste and volatile compounds through the multivariate analysis of integrated results of the E-tongue and E-nose. A total of 67 odor active compounds were detected through GC-MS and GC-O, and octanal, nonanal, 2-pentyl furan, heptanal, and benzaldehyde were identified as key odor compounds which may have positive effects on food intake. The multivariate analysis was used to classify samples based on key odor compounds. Volatile compounds responsible for aroma properties of samples were evaluated using GC-O and multivariate analysis in this present study for the first time. These results are expected to provide fundamental data for sensory evaluation in producing new dog foods with improved palatability.

Comparison of Flavor Profile Relationship of Soy Sauce under Different Storage Conditions.

To elucidate the relation of flavor in soy sauce (SS) kept at room temperature (SSAT) and SS kept under accelerated aging condition (SSAA), four analytical instruments, including electronic nose (E-nose), electronic tongue (E-tongue), gas chromatography-mass spectrometry-olfactory combined with solvent assisted flavor evaporation, and amino acid analyzer, were applied for analyzing the overall flavor profiles and flavor constituents in SSAT and SSAA. The results of E-nose and E-tongue showed overall flavor profile in SSAT for 3 weeks was similar to that of SSAA for 1 week, and 6 weeks (SSAT) was similar to 2 weeks (SSAA). In SS, a total of 35 odor-active compounds were identified and quantitated, and 22 compounds with odor activity value ≥1 were determined as key odorants. The compounds with the highest concentration were 4-hydroxy-2,5-dimethyl-3(2H)-furanone (28,756 μg/mL), followed by acetic acid (8838 μg/mL) and maltol (7984 μg/mL). The heatmap and hierarchical cluster analysis indicated that the concentrations of key odorants and amino acids in SSAT for 3 weeks was close to those of SSAA for 1 week, and 6 weeks (SSAT) was similar to 2 weeks (SSAA). Based on the results obtained above, it was concluded that the flavor changes in SSAA for 1 week were equivalent to those in SSAT for 3 weeks.

Identification of key odor-active compounds and development of odor wheels in rubber product industries using TD/GC-O-MS, OAV, and statistical analysis

Accurate identification of key odorants has become a challenging and urgent task due to the increasing severity of odor nuisance. This study aims to rapidly and accurately identify 20 key odorants in different rubber product industries and treatment procedures using a combination of sensory evaluation, gas chromatography–olfactory–mass spectrometry (GC-O-MS), statistical analysis, and odor activity value (OAV) analysis. The identified odorants include alcohols, acids, aldehydes, ketones, sulfides, aromatic compounds, alkanes, alkenes, and other compounds. These compounds are categorized as sour, odorous, bitter, rubbery, and foul rubber-like, which are commonly associated with odor pollution in the rubber product industry. An odor wheel specific to rubber product enterprises is developed by combining chemical analysis with sensory evaluation of odorants. This odor wheel can be used for rapid traceability and identification of odor pollution at industrial sites. Results present a novel approach and theoretical framework for the traceability and control of odor pollution in the rubber industry.

Characterization of the key odorant compounds in ‘Qinguan’ apples (Malus × domestica)

‘Qinguan’ apple is native to China with the outstanding qualities of disease resistance and long storage time. In this study, gas chromatography-mass spectrometry (GC-MS) was used to identify the volatile compounds in peel and flesh of post-harvest ‘Qinguan’ apples. Ninety-four and seventy volatile compounds were identified in ‘Qinguan’ peel and flesh, respectively. Esters and alcohols were predominant in ‘Qinguan’ peel, while alcohols were identified as the main volatiles in ‘Qinguan’ flesh. Odor-active compounds and the sensory profile of ‘Qinguan’ apples were investigated by aroma extract dilution analysis-gas chromatography-olfactometry (AEDA-GC-O) and sensory description analyses. The sensory profile of ‘Qinguan’ apples was mainly characterized by aroma descriptors of fruity and green categories. Among the 15 odor-active compounds with flavor dilution factor (FD) ranging from 3 to 81, hexyl acetate, α-farnesene, hexanol, and hexanal (with FD = 81) were shown to be the most potent odor-active compounds in ‘Qinguan’ apples. Based on the results obtained from GC-MS, AEDA-GC-O, and omission tests, hexyl acetate as the most abundant ester in peel was suggested to be one of the characteristic aroma compounds of ‘Qinguan’ apple, contributing to its strong fruity aroma note, while the other characteristic aroma compound, α-farnesene, was responsible for the green note.

Reutilization of berry press residues in minced Baltic herring (Clupea harengus membras) – Effect on lipid oxidation and sensory characteristics during cold storage

Lipid oxidation is one of the main causes of quality deterioration in dark-muscled fish. This study investigated the effect of berry side streams of juice pressing or oil extraction at different concentrations on lipid oxidation and sensory quality of minced Baltic herring (Clupea harengus membras) stored at 1 °C. Lipid oxidation was assessed by determining the peroxide value and volatile secondary oxidation products. Generic descriptive analysis and gas chromatography-olfactometry were used to investigate the odor, flavor, and odor-active compounds of minces. Based on the peroxide value and formation of hexanal, 1-penten-3-ol, and 3,5-octadien-2-one, a concentration of 1.5 g/100 g of lingonberry-bilberry juice press residue and sea buckthorn juice press and oil extraction residue was sufficient to retard and reduce the extent of oxidation. Furthermore, the addition of these residues inhibited the formation of fishy odors during 3 days of storage. The control mince stored for 3 days showed the highest number and intensities of oxidation products such as (Z)-4-heptenal, 2,3-pentanedione, and (E,Z)-2,6-nonadienal, while their formation was retarded in the mince containing press residue from sea buckthorn. Berry press residues were efficient in controlling lipid oxidation of minced Baltic herring during storage and have the potential to mask potentially unpleasant fishy odor and flavor.

Pulsed electric field processing of green tea-infused chardonnay wine: Effects on physicochemical properties, antioxidant activities, phenolic and volatile compounds

Pulsed electric field (PEF) was used to develop a novel Chardonnay wine infused with green tea, where the physicochemical characteristics (pH, titratable acidity, color) were modulated. The PEF processing conditions were optimized via response surface methodology by evaluating antioxidant activity (assessed by DPPH, FRAP and ABTS assays), total free phenolic content (TPC), total free flavonoid content (TFC), and volatile content. The optimum conditions were determined as electric field strength 1.3 kV/cm and pulse number 10. The PEF-processed green tea-infused wines were also analyzed for the phenolic and volatile profiles. A total of 178 phenolics and non-phenolics were identified by HPLC-DAD-ESI-QTOF-MS/MS in the PEF-treated wines. The application of PEF resulted in additional 20 phenolic compounds and 14 non-phenolic compounds absent in either Chardonnay or green tea. Catechin was the most abundant phenolic compound, while the enhanced antioxidant power was mainly driven by epigallocatechin. There were 49 volatiles detected by HS-SPME-GC-MS in the PEF-treated wines, with 15 volatiles as odor-active compounds. Under both artificial saliva spiked and non-spiked conditions, green tea infusion diminished fruity, floral and spicy odors, and intensified citrus and green odors. The PEF treatment (0.1 and 0.5 kV/cm) could impart more intense citrus and green aromas from tea to wine. Saliva addition decreased the release of volatile acids, alcohols, esters and aldehydes, and increased the release of benzenoids and terpenes. This study forecasted a promising future of PEF as a time and energy efficient technique in the production of flavored wine with enhanced functionalities and desired aromas.