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1.
Food Chem ; 458: 140204, 2024 Jun 28.
Article in English | MEDLINE | ID: mdl-38964092

ABSTRACT

The bacterial derived osmolyte ectoine has been shown to stabilize cell structure and function, a property that may help to extend the shelf life of broccoli. The impact of ectoine on broccoli stored for 4 d at 20 °C and 90% relative humidity was investigated. Results indicated that 0.20% ectoine treatment maintained the quality of broccoli, by reducing rate of respiration and ethylene generation, while increasing the levels of total phenolics, flavonoids, TSS, soluble protein, and vitamin C, relative to control. Headspace-gas chromatography-mass spectrometry, transcriptomic and metabolomic analyses revealed that ectoine stabilized aroma components in broccoli by maintaining level of volatile compounds and altered the expression of genes and metabolites associated with sulfur metabolism, as well as fatty acid and amino acid biosynthesis pathways. These findings provide a greater insight into how ectoine preserves the flavor and nutritional quality of broccoli, thus, extending its shelf life.

2.
Meat Sci ; 216: 109588, 2024 Jul 01.
Article in English | MEDLINE | ID: mdl-38964226

ABSTRACT

This study examined the effects of replacing alkaline phosphate (AP) with bamboo fiber (BF), isolated pea protein (PP), and mushroom powder (MP) on the nutritional, technological, oxidative, and sensory characteristics of low-sodium mortadellas. Results indicated that this reformulation maintained the nutritional quality of the products. Natural substitutes were more effective than AP in reducing water and fat exudation. This led to decreased texture profile analysis (TPA) values such as hardness, cohesiveness, gumminess, and chewiness. The reformulation reduced the L* values and increased the b* values, leading to color modifications rated from noticeable to appreciable according to the National Bureau of Standards (NBS) index. Despite minor changes in oxidative stability indicated by increased values in TBARS (from 0.19 to 0.33 mg MDA/kg), carbonyls (from 2.1 to 4.4 nmol carbonyl/mg protein), and the volatile compound profile, the sensory profile revealed a beneficial increase in salty taste, especially due to the inclusion of MP, which was enhanced by the synergy with BF and PP. In summary, the results confirmed the potential of natural alternatives to replace chemical additives in meat products. Incorporating natural antioxidants into future formulations could address the minor oxidation issues observed and enhance the applicability of this reformulation strategy.

3.
J Chromatogr A ; 1730: 465125, 2024 Jun 29.
Article in English | MEDLINE | ID: mdl-38970877

ABSTRACT

In this study, we aimed to assess the feasibility of re-collecting breath samples using the Centri® (Markes International, Bridgend, UK) followed by two-dimensional gas chromatography coupled with time-of-flight mass spectrometry (GC×GC-TOFMS) analysis. The work was conducted in two main phases. In the first phase, we evaluated the re-collection performance by analyzing two sets of standards, including a Grob mix primary solution and a standard mixture of 20 selected volatile compounds (VCs) covering different classes of organic species commonly found in breath samples. The intra-day and inter-day precision (reported as relative standard deviation (RSD),%) for the re-collection of the Grob mix primary solution were in the range of 1 % to14 % and 3 % to12 %, respectively. The re-collection accuracy ranged from 78 % to 97 %. The intra-day RSD for the re-collection of the standard mixture of selected VCs was within 20 % for all compounds, except for acetone and nonane. The precision was within 25 % for all compounds, except for nonane, n-hexane, 1,4-dichlorobenzene, and decane, which exhibited less than 36 % RSD. The re-collection accuracy was in the range of 67 % to 129 %. In the second phase of the study, the re-collection performance in breath analysis was evaluated via five repetitive splitting and re-collection of six breath samples obtained from healthy adults, realizing a total of 30 breath analyses. Initially, we evaluated the re-collection performance by considering all features obtained from breath analysis and then focused on the 20 VCs commonly found in breath samples. The re-collection accuracy for total breath features ranged from 86 to 103 %, and the RSDs were in the range of 1.0 % to 10.4 %. For the selected VCs, the re-collection accuracy of all compounds, except for undecane and benzene, was in the range of 71 % to 132 %.

4.
Food Chem X ; 23: 101536, 2024 Oct 30.
Article in English | MEDLINE | ID: mdl-38974202

ABSTRACT

This study aimed to investigate the potential use of Aloe vera (AV) as a food additive given its critical importance in food safety and health. Specifically, the natural antimicrobial and antioxidant properties of AV were examined to prevent food spoilage and extend its shelf life. This study was conducted using commercially available aloe vera gel (AVG) and aloe vera extract (AVE). These samples were tested using gas chromatography-mass spectrometry (GC-MS). The analysis involves identifying and quantifying the components using natural helium gas. The antimicrobial and antifungal effects of these components were evaluated and compared with those reported in the literature. GC-MS analysis revealed that the Aloe vera gel and extract contained various volatile components, including phenolic compounds, anthraquinone glycosides, and different esters. According to GC-MS results of the two different forms of AV, the main volatile compounds of the gel form were levoglucosan, tridecanoic acid, decanoic acid methyl ester, octadecanoic acid methyl ester, octadecanoic acid, nonadeca-1.18-diyn-4.16-diol and squalene, whereas the extract form contained volatile compounds with antifungal activity such as tridecanoic acid, octadecanoic acid methyl ester, octadecanoic acid, nonanoic acid and eicosyl acetate. Both samples exhibited antimicrobial and antifungal activities, especially against pathogens such as Staphylococcus aureus, Candida albicans, Aspergillus niger, and Escherichia coli. This study demonstrated the potential of Aloe vera gel and extract as a natural preservative for use in food because of its constituent components. This study highlights the potential use of Aloe vera as a natural additive in the food industry. Due to its antimicrobial and antifungal properties, Aloe vera offers an organic alternative to chemical additives. Aloe vera is effective at preventing food spoilage and extending shelf life, making it a suitable option for meeting consumer demand for organic and natural products.

5.
Front Plant Sci ; 15: 1430204, 2024.
Article in English | MEDLINE | ID: mdl-38984161

ABSTRACT

Volatile compounds are important determinants affecting fruit flavor. Previous study has identified a bud mutant of 'Ehime 38' (Citrus reticulata) with different volatile profile. However, the volatile changes between WT and MT during fruit development and underlying mechanism remain elusive. In this study, a total of 35 volatile compounds were identified in the pulps of WT and MT at five developmental stages. Both varieties accumulated similar and the highest levels of volatiles at stage S1, and showed a downward trend as the fruit develops. However, the total volatile contents in the pulps of MT were 1.4-2.5 folds higher than those in WT at stages S2-S5, which was mainly due to the increase in the content of d-limonene. Transcriptomic and RT-qPCR analysis revealed that most genes in MEP pathway were positively correlated with the volatile contents, of which DXS1 might mainly contribute to the elevated volatiles accumulation in MT by increasing the flux into the MEP pathway. Moreover, temporal expression analysis indicated that these MEP pathway genes functioned at different developmental stages. This study provided comprehensive volatile metabolomics and transcriptomics characterizations of a citrus mutant during fruit development, which is valuable for fruit flavor improvement in citrus.

6.
Food Chem ; 457: 140128, 2024 Jul 02.
Article in English | MEDLINE | ID: mdl-38959682

ABSTRACT

Headspace-solid phase microextraction/gas chromatography-mass spectrometry (HS-SPME/GC-MS) and electronic nose (E-nose) technologies were implemented to characterize the volatile profile of aerial part from 40 coriander varieties. A total of 207 volatile compounds were identified and quantified, including aldehydes, alcohols, terpenes, hydrocarbons, esters, ketones, acids, furans, phenols and others. E-nose results showed that W5S and W2W were representative sensors responding to coriander odor. Among all varieties, the number (21-30 species) and content (449.94-1050.55 µg/g) of aldehydes were the highest, and the most abundant analytes were (Z)-9-hexadecenal or (E)-2-tetratecenal, which accounted for approximately one-third of the total content. In addition, 37 components were determined the characteristic constituents with odor activity values (OAVs) ≥ 1, mainly presenting citrusy, fatty, soapy and floral smells. Hierarchical cluster analysis (HCA) and principal component analysis (PCA) could effectively distinguish different varieties. This study provided a crucial theoretical basis for flavor evaluation and quality improvement of coriander germplasm resources.

7.
Free Radic Biol Med ; 222: 467-477, 2024 Jul 03.
Article in English | MEDLINE | ID: mdl-38969272

ABSTRACT

To investigate the effects of discharge plasma on Agropyron mongolicum seeds, various treatments including direct exposure to discharge plasma, combined treatment with discharge plasma and plasma-activated water (PAW) were applied to the seeds. The changes in germination rate, MDA content, and volatile compound levels of Agropyron mongolicum seeds after different treatments were examined. The results showed that the direct effect of plasma had no significant effect on the MDA content or germination rate of Agropyron mongolicum seeds due to the limited penetration depth. However, the combined effect of plasma and activated water could cause active nitrogen and oxygen particles to enter the seeds and cause oxidative stress damage. After 18 h of combined treatment, the MDA content increased significantly, and the germination rate decreased to below the semilethal dose, which was 33.44 %. After plasma treatment, 55 volatile compounds, mainly alcohols, aldehydes and ketones, were identified from the seeds of Agropyron mongolicum. Due to the oxidation and modification of the plasma, the content of most aldehydes increased with increasing reaction time. After screening, 13 volatile organic compounds could be used as potential markers to distinguish between different treatment methods. These results reveal the mechanism underlying the biological effects of plasma treatment on Agropyron mongolicum seeds.

8.
Article in English | MEDLINE | ID: mdl-38869184

ABSTRACT

Anaxagorea luzonensis A. Gray, a member of the Annonaceae family, has been used to treat a variety of illnesses for a long time. For the first time, A. luzonensis volatile compounds (ALVCs) were extracted from the leaves, and the components were identified using gas chromatography-mass spectrometry (GC-MS). Further, the main compositions of ALVCs were also assessed for their ability to bind with anti-inflammatory proteins using a docking model. In addition, in vitro tests e.g. inhibition of protein degradation and the inhibition of nitric oxide release using RAW264.7 macrophage cells were utilized for evaluating the anti-inflammatory activity. The results showed that the principal compounds of ALVCs were bulnesol (34.1 %), cubitene (17.8 %), ß-eudesmol (10.4 %), epi-longipinanol (5.9 %), and (Z)-nerolidyl acetate (5.5 %). Three compounds viz. bulnesol, cubitene, and ß-eudesmol bound firmly to cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX-2) and 5-lipoxygenase (5-LOX), as shown by the in silico analysis, similar to the positive control diclofenac. ALVCs effectively inhibited protein degradation with the IC50 of 31 ± 2.3 µg/mL and inhibited nitric oxide production with the IC50 of 43.30 ± 3.37 µg/mL. These findings showed that ALVCs might have a promising anti-inflammatory effect by blocking several inflammatory proteins.

9.
J Food Sci ; 2024 Jun 26.
Article in English | MEDLINE | ID: mdl-38922885

ABSTRACT

The deterioration of the quality of raw liquor caused by the low content of ethyl hexanoate in Nongxiangxing baijiu has become a pervasive problem in the baijiu industry. Therefore, this study attempted to increase the synthesis of ethyl hexanoate by microorganisms with high esterase activity to increase Zaopei fermentation. The results showed that biofortification was a feasible and important way to improve the quality of the raw liquor and increase the ethyl hexanoate content. Adding Bacillus subtilis, Staphylococcus epidermidis, and Millerozyma farinosa for biofortified fermentation disturbed the microbial community structure of Zaopei and increased the abundance of Wickerhamomyces, Saccharomyces, and Thermoascus. The contents of ethyl hexanoate, ethyl valerate, ethyl caprylate, and ethyl heptanoate also increased noticeably in baijiu. The results of E-nose and sensory analysis tested and verified that the baijiu in the fortified group had better flavor characteristics.

10.
J Sci Food Agric ; 2024 Jun 24.
Article in English | MEDLINE | ID: mdl-38924084

ABSTRACT

BACKGROUND: The main edible part of the Lou onion is the pseudostem, which is highly valued for its distinctive flavour. However, harvesting decisions for the pseudostem are often based on size and market price, with little consideration given to flavour. By clarifying the growth of flavour in pseudostems, farmers and consumers may benefit from evidence-based insights that help optimize harvesting time and maximize flavour quality. RESULTS: This study employed amino acid analysis and gas chromatography-ion migration spectroscopy (GC-IMS) to elucidate the compounds of the pseudostem across different growth phases, and 17 amino acids and 61 volatile substances. Subsequently, analysis revealed that 18 compounds, including arginine (Arg), aspartic acid (Asp), glutamic acid (Glu), valine (Val), (E)-2-nonenal, decanal, 2,4-nonadienal, 2-octenal, (Z)-4-decenal, 2,4-decadienal benzeneacetaldehyde, linalool, eugenol, (Z)-6-nonen-1-ol, methyl anthranilate, 2-acetylpyridine, 3-sec-butyl-2-methoxypyrazine, and 2,6-dichlorophenol, were the key compounds in determining the flavour characteristics of the pseudostems, as assessed by taste activity value and relative odour activity value calculations. In addition, correlation analysis, focusing on five amino acids and 38 volatile compounds with variable importance for predictive components scores of >1, identified anisaldehyde, eugenol, (Z)-6-nonen-1-ol, 2,4-decadienal, 3-sec-butyl-2-methoxypyrazine, Arg, Asp, and Val as the key differentiators and contributors to the pseudostems flavour profile. CONCLUSION: During the rapid growth of Lou onions just before the emergence of flower stems, the pseudostem exhibited the most prominent flavour, making this stage most suitable for harvesting compared to the regreening growth stage and the rapid growth period of the aerial bulbs. © 2024 Society of Chemical Industry.

11.
Microorganisms ; 12(6)2024 Jun 10.
Article in English | MEDLINE | ID: mdl-38930557

ABSTRACT

Cooked sausages packaged in a modified atmosphere (MAP: 20% CO2, 70% N2, <0.2% O2) with evident yellow stains were analyzed. The aims of this work were to study the microbial cause of the spoilage and to evaluate different antimicrobial compounds to prevent it. Leuconostoc gelidum was identified as the primary cause of the yellow coating in spoiled cooked sausage, as confirmed by its intentional inoculation on slices of unspoiled sausage. Leuconostoc gelidum was the main bacteria responsible for the yellow coating in spoiled cooked sausage, as confirmed by its intentional inoculation on slices of unspoiled sausage. The yellow color was also evident during growth in the model system containing cooked sausage extract, but the colonies on MRS agar appeared white, demonstrating that the food substrate stimulated the production of the yellow pigment. The spoilage was also characterized by different volatile compounds, including ketones, ethanol, acetic acid, and ethyl acetate, found in the spoiled cooked sausage packages. These compounds explained the activity of Leuc. gelidum because they are typical of heterofermentative LAB, cultivated either on food substrates or in artificial broths. Leuc. gelidum also produced slight swelling in the spoiled packages. The efficacy of different antimicrobials was assessed in model systems composed of cooked sausage extract with the antimicrobials added at food product concentrations. The data showed that sodium lactate, sodium acetate, and a combination of sodium lactate and sodium diacetate could only slow the growth of the spoiler-they could not stop it from occurring. Conversely, hop extract inhibited Leuc. gelidum, showing a minimal inhibitory concentration (MIC) of approximately 0.008 mg CAE/mL in synthetic broth and 4 mg CAE/kg in cooked sausage slices. Adding hop extract at the MIC did not allow Leuc. gelidum growth and did not change the sensorial characteristics of the cooked sausages. To our knowledge, this is the first report of the antimicrobial activities of hop extracts against Leuc. gelidum either in vitro or in vivo.

12.
Molecules ; 29(12)2024 Jun 07.
Article in English | MEDLINE | ID: mdl-38930786

ABSTRACT

The present study provides a comprehensive analysis of the chemical composition of essential oils from species of the Myrcia genus and their applications. The compiled results highlight the chemical diversity and biological activities of these oils, emphasizing their potential importance for various therapeutic and industrial applications. The findings reveal that Myrcia essential oils present a variety of bioactive compounds, such as monoterpenes and sesquiterpenes, which demonstrate antimicrobial activities against a range of microorganisms, including Gram-positive and Gram-negative bacteria, as well as yeasts. Furthermore, this study highlights the phytotoxic activity of these oils, indicating their potential for weed control. The results also point to the insecticidal potential of Myrcia essential oils against a range of pests, showing their viability as an alternative to synthetic pesticides. Additionally, species of the genus Myrcia have demonstrated promising hypoglycemic effects, suggesting their potential in diabetes treatment. This comprehensive synthesis represents a significant advancement in understanding Myrcia essential oils, highlighting their chemical diversity and wide range of biological activities. However, the need for further research is emphasized to fully explore the therapeutic and industrial potential of these oils, including the identification of new compounds, understanding of their mechanisms of action, and evaluation of safety and efficacy in different contexts.


Subject(s)
Oils, Volatile , Oils, Volatile/pharmacology , Oils, Volatile/chemistry , Anti-Infective Agents/pharmacology , Anti-Infective Agents/chemistry , Insecticides/chemistry , Insecticides/pharmacology , Myrtaceae/chemistry , Humans , Hypoglycemic Agents/pharmacology , Hypoglycemic Agents/chemistry , Animals , Plant Oils/pharmacology , Plant Oils/chemistry
13.
Molecules ; 29(12)2024 Jun 13.
Article in English | MEDLINE | ID: mdl-38930892

ABSTRACT

The Lamiaceae family, which includes several well-known aromatic plants, is scientifically relevant due to its essential oils (EOs). In this work, four EOs from Mediterranean species, namely Origanum vulgare L., Rosmarinus officinalis L., Salvia officinalis L., and Thymus vulgaris L., were evaluated for their volatile profiles and the biological activity in vitro to assess their potential use in the food and cosmetic sector. GC/MS analysis revealed dominant compounds, such as carvacrol, thymol, and eucalyptol. Regarding biological action, the samples exhibited antioxidant, cytotoxic, anti-inflammatory, antimicrobial, and antifungal activities, with O. vulgare and T. officinalis standing out. T. vulgaris showed the lowest EC50 in the reducing power assay, and O. vulgare had the lowest EC50 in the DPPH assay. Most EOs also displayed excellent anti-inflammatory responses and antifungal properties, with O. vulgare and T. vulgaris also demonstrating antibacterial activity. All EOs from Mediterranean species showed cytotoxicity against tumoral cell lines. Overall, the selected EOs stood out for their interesting bioactivities, with the obtained results underscoring their potential as natural preservatives and bioactive agents in various industrial applications, including food, pharmaceuticals, and cosmetics.


Subject(s)
Antioxidants , Lamiaceae , Oils, Volatile , Oils, Volatile/pharmacology , Oils, Volatile/chemistry , Lamiaceae/chemistry , Antioxidants/pharmacology , Antioxidants/chemistry , Humans , Anti-Inflammatory Agents/pharmacology , Anti-Inflammatory Agents/chemistry , Gas Chromatography-Mass Spectrometry , Origanum/chemistry , Salvia officinalis/chemistry , Cell Line, Tumor , Thymus Plant/chemistry , Anti-Infective Agents/pharmacology , Anti-Infective Agents/chemistry , Plants, Edible/chemistry , Plant Oils/chemistry , Plant Oils/pharmacology , Thymol/pharmacology , Thymol/chemistry , Microbial Sensitivity Tests , Cymenes
14.
J Fungi (Basel) ; 10(6)2024 Jun 14.
Article in English | MEDLINE | ID: mdl-38921407

ABSTRACT

Although only a few species of Tuber account for the major truffle sales volume, many species that are not considered delicacies are finding their way to the market, especially in regions where the traditionally appreciated ones do not occur. This is the case for whitish truffles. Specimens of whitish truffles were collected in pecan (Carya illinoinensis) orchards in Uruguay in October 2021. Morphological and molecular methods were used to characterize and assess their identity as Tuber maculatum Vittad. An SPME extraction of volatile compounds and GC-MS analyses were performed to characterize the aromatic profile of these specimens and evaluate their potential applications. Among the 60 VOCs detected, 3-octenone (mushroom odor), 3-octanol (moss, nut, mushroom odor), and 2H-pyran-2-one (no odor), followed by octen-1-ol-acetate (no odor) and 2-undecanone (orange, fresh, green odor) were the major compounds in T. maculatum fruiting bodies. The attributes of exotic edible mushrooms of commercial value in the region are highlighted. In particular, this work emphasizes the characteristics of truffles as a byproduct of pecan cultivation.

15.
Foods ; 13(12)2024 Jun 08.
Article in English | MEDLINE | ID: mdl-38928750

ABSTRACT

This study aimed to investigate the aroma effects of key volatile compounds in a new type of mulberry leaf Fu brick teas (MTs) and traditional Fu brick teas (FTs). Headspace solid-phase microextraction (HS-SPME), gas chromatography-mass spectrometry (GC-MS), sensory evaluation, and chemometrics were used to determine the differences in key flavour qualities between the two. The results showed that a total of 139 volatile components were identified, with aldehydes, ketones, and alcohols dominating. Orthogonal Partial Least Squares Discriminant Analysis (OPLS-DA) combined with the odour activity value (OAV) showed that seven aroma compounds had an OAV > 10, including 2-(4-methylcyclohex-3-en-1-yl) propan-2-ol with floral and fruity aroma and green attributes, 6-methylhept-5-en-2-one, (E)-6,10-dimethyl-5,9-Undecadien-2-one, (3E,5E)-octa-3,5-dien-2-one, Benzaldehyde, and (E)-3,7,11,15-tetramethylhexadec-2-en-1-ol, which were more abundant in MTs than FTs; Cedrol with sweet aroma attributes was more consistent in MTs than FTs, and we suggest that these odour compounds are important aroma contributors to MTs. Taken together, these findings will provide new insights into the mechanism of formation of the characteristic attributes of aroma in MTs.

16.
Foods ; 13(12)2024 Jun 18.
Article in English | MEDLINE | ID: mdl-38928865

ABSTRACT

The study used headspace solid-phase microextraction coupled with gas chromatography-time-of-flight mass spectrometry (HS-SPME-GC-TOF-MS) to analyze volatile compounds in leaves and fruits of Amomum tsaoko, Amomum paratsaoko, and Amomum koenigii. The composition and aroma of distinct metabolites were analyzed using multivariate statistical methods. A total of 564 volatile compounds were identified from three species of the genus Amomum, which were further divided into nine categories: terpenoids, carboxylic acids, alcohols, hydrocarbons, aldehydes, ketones, phenols, ethers, and other compounds. Terpenoids and alcohols were the most abundant. The content and types of compounds vary in A. tsaoko, A. paratsaoko, and A. koenigii, so mixing or substituting them is not advisable. We selected 45 metabolites based on the criteria of the variable importance in projection values (VIP > 1.5) and one-way ANOVA (p < 0.05). The top 19 metabolites with the most significant VIP values were chosen. Interestingly, (Z)-2-decenal was only found in Amomum koenigii, while nitroethane and nonanal were only present in cultivated A. tsaoko. Additionally, linalool, cineole, and (D)-limonene were the main components affecting the aroma of three species of the genus Amomum. The volatile components identified in this study provide a theoretical basis for analyzing the unique flavor of A. tsaoko, A. paratsaoko, and A. koenigii.

17.
Foods ; 13(12)2024 Jun 20.
Article in English | MEDLINE | ID: mdl-38928895

ABSTRACT

This study investigates the effect of pure yeast culture fermentation versus spontaneous fermentation on the volatile compound profile of industrially produced plum brandy. Using traditional distillation methods, the evolution of key volatile compounds is monitored at seven different moments during the distillation process. By integrating advanced analytical techniques such as GC-MS and sensory evaluation, significant differences in the composition of the distillates are highlighted, particularly in terms of ethyl esters and higher alcohols which are key to the sensory properties of the final product. Distillates produced with the addition of pure cultures gave higher concentrations of esters than those obtained by wild fermentation. The results of our industrial research show that the most critical step is to limit the storage of the input raw material, thereby reducing the subsequent risk of producing higher concentrations of 1-propanol. Furthermore, our results indicate that the heart of the distillate can only be removed up to an ethanol content of approximately 450 g/L and that the removal of additional ethanol results in only a 10% increase in the total volume of the distillate, which in turn results in an increase in boiler heating costs of approximately 30%.

18.
Food Chem X ; 22: 101508, 2024 Jun 30.
Article in English | MEDLINE | ID: mdl-38883913

ABSTRACT

Different spatial positions lead to inconsistent fermentation effects and flavors, however, the spatial heterogeneity of Qingxiangxing (QXX) Baijiu remains unknown. We investigated the microbes, flavors, and physicochemical properties of different layers in fermented grains of QXX Baijiu using Illumina HiSeq sequencing, two-dimensional gas chromatography-mass spectrometry (GC × GC-MS) and ultra-high performance liquid chromatography-mass (UHPLC-MS). A total of 79 volatiles, 1596 metabolites, 50 bacterial genera, and 52 fungal genera were identified. The contents distribution followed the order: upper layer > bottom layer > middle layer. Organic acids and derivatives were the main differential metabolites across the three layers. Starch, pH, and reducing sugar levels increased from the upper to bottom layer. Saccharomyces and Lactobacillus were dominant microbes. Pediococcus, the biomarker of upper layer, showed positive correlations with formic acid, ethyl lactate, acetic acid, ethyl linoleate, and ethyl oleate. These findings deepen our understanding of the fermentation and flavor formation mechanisms of QXX Baijiu.

19.
Food Chem X ; 22: 101514, 2024 Jun 30.
Article in English | MEDLINE | ID: mdl-38883919

ABSTRACT

The aim of this study was to explore the formation of volatile lipid oxidation products by the lipoxygenase (LOX)-hydroperoxide lyase (HPL)-mediated pathway in oat, barley and soy bean. LOX activity was found only in barley and soy bean samples, but the lipase and HPL activity was detected in all samples. HPL showed particularly high activity with 13-hydroperoxides, while the activity was quite low when using 9-hydroperoxides, especially in the oat and barley. The optimum pH for HPL in different samples was similar, i.e., pH 6-7. In this condition, the volatile compounds formed dramatically with aldehydes and furans as the dominant products. Furthermore, a remarkable enzymatic degradation of lipids occurred during the preparation of food models with highly refined rapeseed oil (RO) and rapeseed oil fatty acid (ROFA) emulsions, where the ROFAs were more prone to oxidation than RO. This study shows the significance of lipid-degrading enzymes in plant-food flavour formation.

20.
Foods ; 13(11)2024 May 25.
Article in English | MEDLINE | ID: mdl-38890880

ABSTRACT

The application of organic fertilizers is one of the most important agricultural measures aimed at improving the flavor and productivity of Lycopersicon esculentum, with the granulation and coating of organic fertilizers, which can reduce seepage losses of great significance to the ecosystem. In this study, Jingcai 8 tomato was selected as the test material. Headspace solid-phase microextraction and gas chromatography-mass spectrometry (HS-SPME-GC-MS) methods were used to investigate the effects of different pelletized organic fertilizers and various coating materials on the flavor profile of the tomatoes. The results indicated that 67 volatile organic compounds (VOCs) were identified in the tomato fruits and 62 volatile compounds were identified in the leaves under different fertilizer treatments. The volatile compound content of the fruits in the BP treatment group was 35.38 µg/g, which was higher than that in other treatment groups, and the volatile compound content of the leaves was lower. A differential compound analysis with log2|fold change| ≥ 1 and variable important in projection (VIP) > 1 highlighted styrene, 3-methyl-1-butanol, and (E, E)-2,4-hexadienal as the major up-regulated compounds and methyl salicylate as the major down-regulated compound in the tomato fruit BCK (control) vs. BP. Moreover, the α-phellandrene content decreased in the tomato leaves. In addition, an analysis of the tomato fruit differential compounds and compounds with odor activity values (OAV) of ≥ 1, considering the OAV values of characteristic aroma compounds, identified key compounds affecting the flavor of the tomato fruits under the BP treatment. These included 2-nonenal, (E)-2-pentylfuran, trans-ß-ionone, 1-penten-3-one, (E, E)-2,4-hexadienal, and 3-hexenol (fruity, floral, and herbaceous odors), (E, E)-2,4-heptadienal (fatty odor), and hexanal (green odor). The combined results analysis of the volatile compound content, differential compounds, and OAV values of characteristic aroma compounds aimed to clarify that the BP treatment group, which applied pelletized, large-grain organic fertilizer with polyurethane (pozzolanic + small-grain oil-coated + 2% paraffinic + 4% polyurethane) as a coating material, proved to be most effective in influencing the flavor of the tomato fruits. This finding lays the foundation for its potential commercial application in artificial orchards.

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