Comparing the deodorizing effects of different perilla leaf forms on steamed oysters by sensory and GC-MS analyses

The odor profiles of the hepatopancreas and gonad of Eriocheir sinensis were evaluated by sensory analysis, electronic nose, and gas chromatography-mass spectrometry (GC–MS) analysis. The results of sensory analysis and E-nose showed good correlation, which indicated that the hepatopancreas and gonad of female crabs both contributed to the overall aroma of “XieHuang”, while only the hepatopancreas of male crabs played an important part in the overall aroma of “XieGao”. For further GC–MS analysis, a total of 53 volatile compounds were identified and quantified. The quantity of volatile compounds in each category of hepatopancreas were similar to that of the mixture samples (XieHuang/XieGao). However, the differences between gonad and the mixture samples were mainly focused in aldehydes, ketones, furans, S-containing compounds, and N-containing compounds, which mainly include 2-methylbutanal, 2-methyl-2-butenal, acetone, 4-isopropylpyridine, and 2-isobutyl-4-methylpyridine in female crabs, and 2-methylpropanal, 2-methylbutanal, (E,E)-2,4-heptadienal, acetone, 1-octen-3-one, 2-butanone, dimethyl sulfide, and 4-isopropylpyridine in male crabs.

Konjac glucomannan (KGM) is one of the non-digestible dietary polysaccharides. Hydration of KGM at elevated temperature in the presence of calcium hydroxide affects the aggregation of KGM, making a konjac glucomannan gel formation that has a fish-like off odor. Trimethylamine (TMA) in konjac glucomannan gel has been investigated by solid-phase microextraction and analyzed by GC–MS. A fish-like off odor generated in the process of gelation has been remarkably reduced by treatment of the gel formation with fermented vinegar in which acetic acid concentration-treated group was over 1% (v/v), soaking time, for 10 min. Together with the instrumental analysis, a fish-like off odor generated from the same treatment was also analyzed by sensory evaluation. Acetic acid treatment at a concentration of over 1% (v/v) resulted in significant decrease in the fish-like off odor (p < 0.05) supporting the action mechanism of acetic acid as a proton donor for the reaction with TMA. Correlation between TMA content by GC–MS analysis and fish-like off odor by sensory evaluation was statistically significant by ANOVA, Duncan's multiple range test, operated by SPSS program (R 2 = 0.9848, p < 0.05).

‘Fetească regală’, the most cultivated white Romanian grape variety produces elegant wines with flowery notes and white fruits (especially apricot and citrus) hues, with a good acidity. Its volatile profile (esters, terpenes, higher alcohols) and phenolic compounds are of great interest to the wine industry, especially regarding the influence pre-fermentative stages have on their extraction, as most producers choose to follow this path. This study analyses how different pre-fermentative treatments (addition of bentonite, glutathione, tannins, clarifying enzymes) change the final profile of the product. The four variants are the most used prefermentative methods. A sensorial analysis of the obtained wines was performed and the obtained data was correlated with GC-MS and HPLC analysis. 25 volatile compounds were identified and quantified through headspace analysis, using different compound libraries, while through HPLC the presence and quantity of 14 major phenolic compounds was determined. Statistical analysis (One Way Anova) was applied to establish the influence of the pre-fermentative treatments on the quantitative presence of the analysed groups of compounds. The applied treatments bring changes to the final wines’ profile by increasing the quantity of some phenolic compounds (gallic, protocatechic, p-hydroxybenzoic, gentisic, vanillic and caffeic acid ). From a sensorial point of view, all prefermentative treatments bring a smoother feel of obtained wines, with lower acidities and less of a ‘green’ character. The final results can be used by industry by adding or removing from their technological process certain steps that have influence on aroma compounds of ‘Fetească regală’ wines.

Traditional analytical methods for assessing oil oxidation frequently depend on expensive and intricate equipment or elaborate procedures, thereby hindering their practical use in everyday situations. Sensory evaluation and GC-MS analysis indicated that during storage, the peroxide value (PV) and aldehyde content of pecan oil increased, consistent with progressive oxidation, while the acid value (AV) remained stable. The shelf-life prediction model further underscores its reliability as an oxidation marker. The coefficient of determination (R2) for the first-order kinetic model at temperatures of 20, 40, 50, and 60 °C ranged from 0.9183 to 0.9841. The correlation coefficients between the measured and predicted shelf-life values were 0.9993 for cold-pressed pecan oil (CPO) and 0.9866 for hot-pressed pecan oil (HPO). A filter-paper-based colorimetric aldehyde sensor was developed for the visual assessment of pecan oil shelf-life, which leverages the chemical reaction between hydroxylamine sulfate and aldehydes to generate a distinct naked-eye color shift from red to purple-blue-this enables the qualitative identification of whether cold-pressed (CPO) and hot-pressed (HPO) pecan oil complies with the national peroxide value (PV) limit of 0.25 g/100 g or exceeds it. Specifically, CPO is deemed to be expired when a* ≤ 11 and HPO when a* ≤ 15; consistent red-to-purple-blue color changes for the sensor yielded 100% sensitivity and 100% specificity for both oils at the national PV limit, thereby validating its application as a highly accurate qualitative (pass/fail) indicator for oil oxidation. By contrast, sensory evaluation can also reliably distinguish when pecan oil exceeds the national PV limit qualitatively, yet it lacks quantitative accuracy due to inherent subjective biases.

Roccaverano Protected Designation of Origin (PDO) is a fresh soft cheese produced in Roccaverano area (Italy). This study aimed to evaluate Roccaverano PDO microbiota, together with aromatic profile and sensory analysis to be compared with 15 non-PDO cheeses of the same type. Microbiota was evaluated through shotgun metagenomics sequencing, while GC-MS analysis was conducted to study volatile organic compounds (VOCs) presence and concentration. Sensory analyses were conducted through ONAF (Italian National Organization of Cheese Tasters) evaluation parameters followed by flash profile sensory analysis of selected cheeses. The results demonstrated Lactococcus lactis predominance in both non-PDO and PDO cheeses, while Streptococcus thermophilus was more abundant in non-PDO group. A higher abundance of Kluyveromyces lactis was observed in Roccaverano PDO, which exhibited greater fungal diversity compared to non-PDO cheeses. Metagenome-Assembled Genomes of 26 L. lactis and 19 Leuconostoc mesenteroides showed absence of significant differences in terms of average nucleotide identity and pangenomes partitions. The ONAF sensory evaluation demonstrated a higher average score of Roccaverano PDO group. Flash profile analysis demonstrated that lactic aroma/odour, acid, astringent, vegetal odour, exotic fruit and fermented aroma, hazelnut flavour and sweet were associated with high ONAF scores. The concentration of butanoic acid, 2-methyl-, ethyl ester and butanoic acid, 3-methyl- (sweat, acid, rancid related) were higher in PDO cheeses, while reads related to butanoate metabolism were less abundant compared to non-PDO samples. Several fungal species (included K. lactis) were associated with astringents, acid and chalky flavours. Roccaverano PDO demonstrates unique characteristics even maintaining a certain degree of variability between samples.

The aroma of cooked rice is a key factor in the evaluation of taste quality for rice grading, which greatly affects consumer acceptance. Combining the results of instrumental analysis and sensory evaluation to comprehensively analyse the aroma of cooked rice is a new strategy. The aroma characteristics of fifteen cooked rice varieties were analysed by gas chromatography–mass spectrometry (GC–MS) and descriptive sensory analysis. Based on the aroma descriptors obtained by gas chromatography‐olfactometry (GC‐O) analysis and the odour activity value (OAV) of aroma compounds, the aroma profiles of cooked rice were preliminarily explained by bipartite network and aroma fingerprint. The Pearson correlation coefficients between the OAV results of aroma compounds and sensory data were calculated to construct the aroma association network. The results showed that the aroma attributes of cooked rice were significantly correlated with certain aroma compounds identified by GC–MS, such as aldehydes and heterocycles. The aroma attributes of cooked grain, popcorn, grassy, nutty, and fruity could be well explained by the results of GC–MS analysis. The purpose of the study is to better understand the relationship between aroma characteristics and chemical composition, as well as to provide a theoretical basis for evaluating and predicting the aroma of cooked rice using GC–MS analysis.

The aroma fingerprints and discrimination analysis of shiitake mushrooms under different drying conditions were performed by GC-IMS, GC-MS, and descriptive sensory analysis (DSA) with advanced chemometric methods. Three samples (A, B, and C) were treated with varied drying degree and rate. The sample A and C were at the same drying degree and the sample B and C were at the same drying rate. The GC-IMS volatile fingerprints, including the three-dimensional topographic map, topographic map, and gallery plot, showed that 29 compounds showed higher signal intensities in sample B. Moreover, 28 volatile compounds were identified by HS-SPME-GC-MS and only 8 compounds were ever detected by GC-IMS. The sample B not only had more varieties of volatile compounds, but also showed significant higher contents than sample A and C, especially C8 compounds (p < 0.05). Additionally, sample B showed the highest intensity in mushroom-like, chocolate-like, caramel, sweat, seasoning-like, and cooked potato-like odors by DSA. PCA, fingerprint similarity analysis (FSA) and PLSR further demonstrated that the sample B was different from sample A and C. These results revealed that samples with different drying degree were different and drying degree exerted more influence on the volatile flavor quality than the drying rate. This study will provide a foundation and establish a set of comprehensive and objective methods for further flavor analysis.

Leaf tenderness influences green tea quality, yet its role in flavour formation remains unclear. This study analysed green teas from Camellia sinensis cv. ‘Chuancha No. 2’ with three tenderness levels—single bud (C1B), one-bud with one-leaf (C1B1L), and one-bud with two-leaves (C1B2L)—via sensory evaluation, chemical profiling, and GC–MS analysis. C1B showed the best appearance and a chestnut-like, refreshing aroma. C1B1L featured floral notes and a mellow, umami taste, while C1B2L was stronger and more full-bodied. C1B had higher free amino acids and lower polyphenols and caffeine; C1B1L had the highest polyphenol content. Among 97 volatiles, 11 had ROAV > 1. Five common aroma compounds, namely 1-octen-3-ol, geraniol, hexanal, benzeneacetaldehyde, and 2-pentylfuran, were identified as key contributors to the aroma profile. Geraniol, most abundant in C1B1L, shaped its floral aroma. These origins are supported by established pathways, including lipid-derived oxidation products, glycoside-released geraniol, and amino-acid-derived benzeneacetaldehyde. This study clarifies how tenderness drives flavour divergence and identifies compounds supporting sensory variation in green tea.

Determination of the effects of different washing processes on aroma characteristics in silver carp mince by MMSE–GC–MS, e-nose and sensory evaluation

Three Beninese food condiments (ABS1(24h), IBS2(48h) and SBS3(48h)) were produced by controlled fermentation of African locust beans using inocula of pure cultures of Bacillus subtilis, BS1, BS2 and BS3, respectively. Quantitative and qualitative assessments of the volatile compounds in the condiments produced have been performed using the Likens-Nickerson simultaneous distillation-extraction method and GC-MS analysis, followed by a sensory evaluation in comparison with the spontaneously fermented condiments. A total of 94 volatile compounds have been found including 53 compounds identified in relatively high concentrations and were subdivided into seven main groups with the predominance of four major groups: pyrazines, aldehydes, ketones and alcohols. Compared to the spontaneously fermented condiments, volatile compounds identified in controlled fermented condiments have been found in high number and in concentrations which varied according to the inoculum of B. subtilis used. The condiments produced with starter cultures scored significantly (P < 0.05) higher for odour than the spontaneously fermented condiments. But the overall acceptability (7/10) of the two types of condiments was similar. The investigated B. subtilis, BS1, BS2 and BS3 can be considered as potential starter cultures for the fermentation of African locust beans to produce good quality of Beninese food condiments.

Discrimination of fresh-cut broccoli freshness by volatiles using electronic nose and gas chromatography-mass spectrometry

Application of Kluyveromyces marxianus, Lactobacillus delbrueckii ssp. bulgaricus and L. helveticus for sourdough bread making

Characterization of key odor-active compounds in commercial high-salt liquid-state soy sauce by switchable GC/GC × GC–olfactometry–MS and sensory evaluation

Reaction between Cysteine, Glucose and Serine was carried out to study the volatiles formed via Maillard reaction and their antioxidant activity. The simultaneous distillation–extraction technique was used for trapping the volatile components followed by GC–MS analysis. Thirty Six compounds were identified with the predominance of carbonyls and sulfur–containing compounds in the volatiles of this model system. Sensory evaluation was performed for the model system product according to the International Standard Methods (ISO). The results showed a high increase in roasted and burnt meat attributes. The sensory results of the model system product were confirmed by the presence of high concentrations of some volatile compounds having meat–like aroma such as 2-methyl-3-furanthiol and 2-furylmethanethiol attributes and remarkable increase in the like– roasted meaty aroma. The radical scavenging activity of cysteine, glucose and serine model system was quantified spectrophotometrically, using DPPH radical. The activity of the model system product was found to be slightly lower than that of gallic acid and BHA, but it was much higher than that of cinnamic acid (200 ppm. for each). A highly antioxidative activity was recorded by the model system which may be due to the presence of some compoundssuch as 2-furylmethanethiol, 2-acetylthiazole, 4-hydroxy-5-methyl-3(2H)-furanone.

Two strains of Bacillus subtilis designated YY-10 and BY-2, were isolated from the surface of tobacco and found to be capable of significant lignin degradation. The predominant lignin-degrading enzymes produced by these strains were lignin peroxidase (LiP) and manganese peroxidase (MnP), respectively. A notable distinction was observed in the organoleptic evaluation and volatile flavor compounds, as determined by sensory evaluation and GC–MS analysis. The content of volatile flavor compounds, such as geranylacetone, meglumine trienone B, and meglumine trienone C, was found to be significantly increased in roasted tobacco treated with YY-10. This treatment has been shown to reduce the astringent flavor of the roasted tobacco and improve the aroma, which in turn could improve the quality of the roasted tobacco. Conversely, the quality and aroma levels of the roasted tobacco treated with the crude enzyme solution of the BY-2 strain were reduced. Transcriptome analysis revealed that the expression of genes related to amino acid metabolism, genetic material biosynthesis, and protein synthesis was up-regulated in the YY-10 strain compared with the BY-2 strain, which promoted the biosynthesis of LiP. This study provides a preliminary elucidation of the potential mechanism by which YY-10 enhances the quality of tobacco leaves through lignin-degrading enzyme production, thus establishing a research foundation for the subsequent treatment of waste tobacco raw materials and industrial applications.