Aroma Intensity Research Articles

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

Aroma dramatically impacts the overall flavor profiles and consumer acceptance; therefore, it is necessary to conduct a comprehensive analysis of the aroma characteristics of apples. In this study, the aroma differences among four popular apple varieties ("Ruixue", "Liangzhi", "Crystal Fuji," and "Guifei") were compared using two extraction methods (headspace-solid phase microextraction, and solvent-assisted flavor evaporation) coupled with gas chromatography-mass spectrometry-olfactometry (GC-MS-O) and two-dimensional gas chromatography-quadrupole mass spectrometry (GC × GC-qMS). A total of 82 odorants were identified via GC-MS-O, and 143 volatiles were identified by GC× GC-qMS. Among them, 41 key aroma-active compounds (butanal, ethyl acetate, 3-methylbutanal, methyl butanoate, 2-methylpropyl acetate, ethyl 2-methylbutanoate, ethyl 3-methylbutanoate, butyl acetate, hexanal, 2-methylbutyl acetate, 1-butanol, 2-methylpropyl butanoate, 3-methylbutyl acetate, (E)-2-hexenal, butyl butanoate, butyl 2-methylbutanoate, hexyl acetate, hexyl butanoate, hexyl, 2-methylbutanoate, 1-octen-3-ol, 3-methylthiopropanol, 1,3-octanediol, linalyl acetate, and so on) with high odor activity values (OAVs) and AI value (odor activity values ≥1 or aroma intensity ≥3) were identified. Partial least-squares-discriminant analysis showed that Ruixue exhibited a high "fruity" note, Guifei and Crystal Fuji had the greatest "wood," "floral," and "sweet" notes, while Liangzhi presented a significant "green" note. This study provided flavor chemistry support for the apple quality control and production.

Sensory profile and color and oxidative stabilities of sliced restructured cooked hams with added S-nitroso-N-acetylcysteine as a nitrite replacement

The objective of this study was to evaluate the effects of replacing sodium nitrite by S-nitroso-N-acetylcysteine (NAC-SNO) at different addition levels (50, 150, and 300mg of equivalent nitrite–Neq/kg) on the sensory profile and on the quality characteristics of restructured cooked hams during sliced storage (up to 60 days at 4°C). The addition of NAC-SNO did not affect (P > 0.05) the pH of the products and resulted in lower (P < 0.05) residual nitrite content (1.79 ± 0.61mg/kg) and higher (P < 0.05) TBARS values (0.86 ± 0.44mg MAD/kg) than nitrite added samples (8.43 ± 2.37mg/kg and 0.66 ± 0.25mg MAD/kg, respectively). During storage, an increasing trend in lipid oxidation was observed regardless of the curing agent used. The addition of 50mg NEq/kg of NAC-SNO resulted in products with a more yellowish color tone (higher h values) and less intensity (lower C* values) than all the other products. The equimolar addition of 150mg NEq/kg of NAC-SNO resulted in a similar pink color acceptance to nitrite; however, they were characterized by a higher (P < 0.05) characteristic flavor and aroma intensity and obtained greater (P < 0.05) sensory acceptance than nitrite. The addition of 150mg NEq/kg of NAC-SNO was suggested as a substitute for nitrite to achieve the desired stability and sensory characteristics of cooked cured products.

HS–SPME combined with GC–MS and GC–O for characterization of key aroma-active compounds in fruity and grassy peppers (Capsicum chinense Jacq.)

Pepper (Capsicum spp.) is highly popular due to its unique flavor. However, there was limited research on the primary volatiles that influence the different flavors of fresh peppers. In this study, peppers with three aroma compound types denoted as “grassy,” “fruity,” and “no special aroma” (control) were analyzed using sensory evaluation combined with gas chromatography–mass spectrometry (GC–MS) and gas chromatography–olfactometry (GC–O). Altogether, 393 volatiles were identified by GC–MS, and the main volatiles in peppers (C. chinense Jacq.) were esters and terpenoids. GC–O and relative odor activity value analysis revealed that 2-isobutyl-3-methoxypyrazine had a highly bitter, spicy aroma intensity in all peppers. Hexanal and trans-2-hexenal were the main aroma-active compounds in grassy peppers. In addition, citronellal was determined to be a crucial aroma-active compound in fruity peppers. This study offers a theoretical foundation for guiding the growth of the pepper processing industry and breeding.

Volatile flavor characteristics of scallops (Chlamys farreri) with different drying methods were analyzed based on GC-IMS and GC-O-QTOF

To investigate the effects of different drying methods on the flavor of scallops, headspace gas chromatography-ion mobility spectrometry (HS-GC-IMS) combined with gas chromatography-olfactometry-quadrupole time-of-flight (GC-O-QTOF) was used to analyze the flavor of scallops processed by five drying methods. A total of 62 volatile organic compounds (VOCs) were identified by GC-IMS. 27 characteristic aroma compounds were identified by GC-O-QTOF, and the highest content was trimethylamine. 17 aroma compounds with GC-O ≥ 6 were screened by the time-intensity method, and the maximum aroma intensity value of 2-acetyl-1-pyrroline was 9.9 aroma compounds with relative odor activity value (ROAV) ≥ 1 were identified. Using GC-O ≥ 6 and ROAV ≥1 as the criteria, 6 differential aroma compounds were further screened, and the results proved that naturally dried scallops had a heavier fishy odor. These findings will provide deeper insights into the processing of scallops.

Quantifying the sweetness intensity and impact of aroma in honey from four floral sources.

Unlike many commercial sweeteners for which sweetness dose-response curves have been constructed, honey's sweetness has yet to be quantified. Honey differs from most commercial sweeteners in that it has a robust aroma; this aroma may impact its perceived sweetness. This study quantified the sweetness intensity and the impact of aroma on the perceived sweetness of four different honey varieties (clover, wildflower, alfalfa, and orange) compared to sucrose. Each sweetener evaluated was diluted to six concentrations in water ranging from 12.5g/L to 125g/L. Panelists (n=55) rated the sweetness intensities with and without aroma, in replicate, on the Global Sensory Intensity Scale. Additionally, the volatile organic compounds in the honey samples were profiled using gas chromatography-mass spectrometry (GC/MS) analysis. Honey and sugar were equivalently sweet at a given concentration (g/L), with aroma present (p=0.251). Additionally, honey and sugar were not equivalently sweet without aroma; aroma significantly increased sweetness intensities for all sweeteners (p=0.042) and especially honeys. In a 100g/L solution, the aromas in honey increased its sweetness by 23%-43%, depending on the floral source. Compounds with sweet aroma characteristics were identified at high concentrations in all honey samples using GC/MS analysis, including furfural, benzaldehyde, benzene acetaldehyde, and dimethyl sulfide. Additionally, (S)-limonene and toluene were present in high quantities in the orange and alfalfa samples. This study can inform appropriate honey usage levels and identify major volatiles that may enhance sweetness. PRACTICAL APPLICATION: Honey sweetness has not been determined quantitatively, despite the widespread use of honey among consumers and product formulators. Sweetness enhancement by honey aroma volatiles may support a reduction in added sugars while maintaining sweetness intensity.

The Comparison and Brewing Value of Saaz Hop Pedigree

The well-known hop variety, Saaz, which gives the Pilsner lager beer its characteristic hop aroma, may be threatened by climate change in the future. Therefore, new Saaz-related hop varieties, including Saaz Late, Saaz Brilliant, Saaz Comfort, and Saaz Shine, were recently bred. A comparison study was carried out to evaluate whether these varieties are acceptable for traditional lagers. For this purpose, sensorial and chemical analyses of hops and related beers, namely, an analysis of hop resins and oils, were performed. Sensory profiles of Saaz varieties are very similar (fine, hoppy aroma; floral; herbal), except for Saaz Comfort, which has a slightly higher aroma intensity, and Saaz Shine, which has the most noticeable fruity scent, with traces of citrus. The chemical profiles are also very similar, with α-humulene, β-pinene, (E)-β-farnesene, β-caryophyllene, and myrcene being the most abundant. Decoction mashing and kettle hopping technology with bottom fermentation show that the compared varieties result in very similar lager beers with hoppy, floral, herbal, fruity, and spicy aromas. Typical hop oils include farnesol, linalool, methyl geranate, β-pinene, and limonene. The high concentration of farnesol in beer correlates with the concentrations of (E)-β-farnesene and farnesol in hops. New Saaz varieties are widely used to produce Pilsner lager without affecting the traditional sensory aroma of this widespread style. Varieties have a higher yield of approximately 25% and bitter acid concentrations of approximately 15%, with Saaz Comfort comprising approximately 100%. Furthermore, the concentration of hop oils is approximately 40% higher in Saaz Shine than a traditional Saaz variety. Moreover, Saaz Shine and Saaz Comfort have very good resistance to drought, which is an important property from a climate change perspective.

Revealing the Potential of Star Anise Essential Oil: Comparative Analysis and Optimization of Innovative Extraction Methods for Enhanced Yield, Aroma Characteristics, Chemical Composition, and Biological Activities

ABSTRACTStar anise has been used for a long time in improving human health and curing diseases, owing to its unlimited components with complex chemical structures and a wide range of bioactivities. This study is aimed to investigate the influence of extraction methods (steam distillation, ethanol Soxhlet extraction, supercritical carbon dioxide extraction, subcritical n‐butane extraction) on the yield, aroma properties, chemical composition, and bioactivity of star anise essential oils. Electronic nose detection revealed the essential oils from subcritical extraction exhibited the most intense aroma, while the essential oils from ethanol Soxhlet extraction had a more complex aroma profile. Fourier‐transform infrared analysis showed the presence of benzene rings, carbonyl groups, C=C, and aromatic ether bonds in the essential oils extracted through different methods. The major components were heterocyclic olefins, heterocyclic oxygenates, and aromatic oxygenates, as well as certain amounts of flavonoids and polyphenols. Correlation analysis revealed the relative contents of volatile trans‐anethole, wormwood, d‐limonene, cineole, and trans‐α‐citronelene were strongly associated with the antibacterial activity of the essential oils. Similarly, the contents of volatile components (d‐limonene, cineole) and non‐volatile components (total flavonoids and total polyphenols) were strongly correlated with the DPPH scavenging activity of the essential oils. These results confirm the effectiveness of the ethanol Soxhlet extraction method in retaining the bioactivity of the essential oils. Finally, with a Box–Behnken central composite design of response surface and single‐factor experiments, the optimal extraction conditions for the ethanol Soxhlet method were determined: ultrasonic frequency of 80 kHz, crushing particle size of 60 meshes, liquid–material ratio of 8:1 (mL:g), and ultrasonic time of 35 min. Under these conditions, the essential oil yield was 25.51% ± 0.21%. Overall, these findings highlight the significance of extraction methods in obtaining high‐quality star anise essential oils with desirable aroma properties and potent bioactivities.

Characterization of Changes in Ripening Process of Volatile Apple Compounds Based on HS-SPME-GC-MS Analysis

The aim of this study was to identify the aromatic compounds present in different apple varieties and to gain insights into the changes in the aromatic compounds during ripening. Three apple varieties (“Red Astrachan”, “Ning Qiu”, and “Golden Delicious”) at different stages of ripening were selected for this study; their peel and pulp were analyzed via headspace solid-phase microextraction (HS-SPME)–gas chromatography–mass spectrometry (HS-SPME-GC-MS), and 30 volatile compounds were identified. The samples’ differences were analyzed using heat map cluster analysis, principal component analysis (PCA), and an independent samples t-test. The results showed that the content of aromatic compounds in the peel was higher than that in the pulp. The relative content of esters in the aromatic compounds of the three apple varieties followed the order of pulp &gt; peel and “Ning Qiu” &gt; “Golden Delicious” &gt; “Red Astrachan”. This suggests that “Ning Qiu” combines the advantages of its parents in terms of its aroma content. The highest concentrations of aroma compounds in “Red Astrachan” and “Ning Qiu” accumulate before the ripening stage, and care should be taken to choose an appropriate harvesting time according to the different needs during production. The main compounds of “Red Astrachan” are aldehydes and C8 esters, while those of “Ning Qiu” and “Golden Delicious” are alkenes and esters. After analyzing the relative odor activity values (rOAVs) of key volatile compounds and their aroma descriptors during the harvest period, acetic acid pentyl ester, butanoic acid hexyl ester, hexanoic acid hexyl ester, and 2-ethyl-1-Hexanol were found to contribute the most to the overall flavor of the peel and pulp. “Ning Qiu” combines the parental advantages of the concentrated peel of “Red Astrachan” and the astringent pulp of “Golden Delicious”, with compounds in its composition that give a pleasing aroma. Mature “Ning Qiu” fruits have a more intense aroma and fruity flavor. The development of flavor-specific varieties has provided the theoretical basis for future research in molecular hybridization, molecular-assisted breeding, and the molecular biology of apple flavor synthesis and metabolism.

Multimodal Hong Kong: Perceiving pedestrian footbridge spaces in a high-density area through soundscape and smellscape perspectives

In prior research on Hong Kong's acoustic environment, noise has been the primary focus, highlighting its diverse sources and its detrimental impact on physical and mental health. However, there is still limited exploration of multi-sensory perspectives in Hong Kong. Mong Kok is one of the world's most densely populated areas, with a density of 130,000 people per square kilometre. Amid the bustling urban life, interactions and activities of residents, tourists, and vendors contribute to the complex soundscape. The area offers a diverse array of markets, street food, and intense aromas, creating a dynamic smellscape. This study focuses on the Mong Kok East pedestrian footbridge (connecting Mong Kok East Station to Nathan Road, approximately 400 metres), selecting six locations on and beneath the footbridge. During the on-site sensory walk experiment (n=30), we recorded ambient sounds and reproduced the soundscape in the laboratory to compare experiences stemming from various sensory modes. The sensory walk includes evaluating soundscape, smellscape, and an overall assessment. Participant feedback helps highlight what they are most concerned about, and the usage patterns and preferences of the six locations reflect the desired soundscape and smellscape, guiding recommendations for sensory design in high-density spaces.

Physico-chemical and sensory characteristics of red oncom, a traditional fermented food from Indonesia, based on the variability of ingredients and processing steps

Red oncom, a traditional fermented food from Indonesia, was produced differently using various ingredients and unstandardized production processes. The study aimed to evaluate the influence of raw materials and production processes on the physicochemical and sensory characterization of red oncom collected from nine different producers in three different regions. The study showed that there are three different categories of red oncom varied depending on the ingredients such as peanut press cake, okara, and tapioca waste. In addition to processes, the variability in inoculum preparation, ingredient preparations, and incubation period were identified. Okara flour generated a higher moisture content, soft and compact texture. Sensory profiling revealed that oncom made of okara flour had a higher intensity of musty aroma, beany aroma, orange color, red color, and sour aftertaste attributes. The soft and compact texture and fully covered mycelium of Neurospora fungi that gave an even surface orange color in red oncom made from okara was preferred by the panelists. The use of peanut press cake resulted in red oncom with higher fat content, a hard texture, and a higher intensity of nutty aroma and bitter taste attributes. The hard texture and a higher intensity of bitter taste caused red oncom made from peanut cake to be less preferred by panelists. In conclusion, the characteristic and chemical composition of red oncom varied depending on the ingredients, processes, and region.

Recent advances in the preservation effects of spice essential oils on fruits and vegetables

Spice essential oils (SEOs) are currently a prominent area of investigation in food preservation due to their natural, effective, and environmentally friendly properties. This review discussed the latest research progress concerning the application of SEO in fruits and vegetables preservation. The article commenced with an overview of the sources of SEOs and their main components, explored their bioactivities, antimicrobial mechanisms, and the microencapsulation and nanotechnology utilizing spice essential oils. Further research explored the applications of SEOs in culinary, pharmaceuticals, cosmetics, agriculture, and food industries, with a focus on evaluating their effectiveness in extending the shelf-life of fruits and vegetables. Additionally, it discusses limitations such as intense aroma and toxicity concerns, while also outlining prospects for future research and applications in the food sector. Overall, SEOs offer promising avenues for effectively prolonging the storage period of post-harvested fruits and vegetables while maintaining their quality attributes.

Effect of different freezing temperatures on the physical, technological, and organoleptic properties of aged semimembranosus muscles from farmed fallow deer (Dama dama)

Although venison could play an important role in human nutrition, this meat remains undervalued and still contributes very little to the formal meat industry. Moreover, information on processing methods of fallow deer meat and overall quality is still very limited. The objective of this study was to determine how physical, technological, and organoleptic properties differ between 14-day-aged vacuum-packaged fallow deer meat stored either chilled or frozen at different temperatures (-10°C, -18°C, -40°C and -80°C) for six months. Physical, technological, and organoleptic analyses were conducted on semimembranosus muscles (SM) obtained from farmed fallow deer bucks (n = 10). Freezing significantly increased meat redness, yellowness, chroma values, cooking loss and tenderness compared to fresh meat but did not affect pH values, lightness, thawing, or grilling loss. Mean pH readings were 5.5–5.6, being highest in the samples measured one day after slaughter. Freezing at -80°C had the most pronounced effect on some sensory attributes, namely, the highest game meat aroma intensity, sour odour, sour flavour and the lowest chewiness. The findings indicate that a freezing temperature of -18°C and subsequent slow thawing might be preferential in terms of maintaining fallow deer meat quality.

Gamma Irradiation and Exogenous Proline Enhanced the Growth, 2AP Content, and Inhibitory Effects of Selected Bioactive Compounds against α-Glucosidase and α-Amylase in Thai Rice.

Exogenous proline can improve the growth, aroma intensities, and bioactive compounds of rice. This study evaluated the effects of gamma irradiation under proline conditions on the 2-acetyl-1-pyrroline (2AP), phenolic, and flavonoid contents of rice. Moreover, the bioactive compounds of gamma-irradiated rice under proline conditions that inhibited α-glucosidase and α-amylase were evaluated by in silico study. A low gamma dose (40 Gy) induced the highest rice growth under 5 mM proline concentration. The highest 2AP content was stimulated at a gamma dose of 5－100 Gy under 10 mM proline concentration. At 500 and 1,000 Gy gamma dose, the highest flavonoid and phenolic contents of rice were stimulated. 1-(2-Hydroxy-5-methylphenyl)-ethanone, which had the highest binding affinity (-7.9 kcal/mol) against α-glucosidase, was obtained at 500 and 1,000 Gy gamma dose under 5 and 10 mM proline concentrations. Meanwhile, 6-amino-1,3,5-triazine-2,4(1H,3H)-dione, which had the highest binding affinity (-6.3 kcal/mol) against α-amylase, was obtained under 10 mM proline concentration in non-gamma-irradiated rice. The results indicate that using a combination of gamma irradiation and exogenous proline is suitable for producing new rice varieties. Moreover, the bioactive compounds that were obtained in new rice varieties exhibited health benefits, especially for diabetes mellitus treatment (inhibition of α-glucosidase and α-amylase).

The interaction of Lactiplantibacillus plantarum and Latilatilactobacillus sakei regulated the formation of characteristic quality attributes of low-salt fermented tilapia

The regulation of quality characteristics of fermented aquatic food based on microbial metabolic interaction is a hot spot in the innovative processing of aquatic products around the world. In this study, electronic sensory system, gas phase method and liquid phase method based on mass spectrometry were used to study the effects of the interaction between Lactiplantibacillus plantarum and Latilactobacillus sakei on the quality and flavor of dry-cured tilapia. The targeted supplementation of Latilactobacillus sakei S199 can improve the texture and flavor characteristics of tilapia meat fermented by Lactiplantibacillus plantarum 550. Latilactobacillus sakei S199 can cross metabolize with Lactiplantibacillus plantarum 550 to produce more 1-Octen-3-ol, 3-methyl-1-Butanol, 1-Hexanol, 2-ethyl-1-Hexanol, (E)-2-Octen-1-ol, 2-Heptanone, 3-Octanone, 2-Pentyl-Furan, and 2,5-diethyltetrahydro-Furan, and reduce the content of Heptanal, Nonanal, and Benzaldehyde to enhance the aroma of fermented tilapia fish. The aroma intensity increased by three times, from 129.46 μg/kg to 373.02 μg/kg, white the bitterness of tilapia meat fermented by the two bacteria was reduced by half, from 231.26 μg/g to 153.65 μg/g. The interaction of Lactiplantibacillus plantarum 550 and Latilactobacillus sakei S199 promoted proteolysis and utilized the FAAs and other small molecular compounds to generate other flavor compounds. The results were helpful to understand the effect of the interaction between Lactiplantibacillus plantarum 550 and Latilactobacillus sakei S199 on the flavor formation of dry cured tilapia.

The shaping of milk-flavored white tea: More than a change in appearance

Tea's popularity and flavor are influenced by factors like cultivation and processing methods and shaping techniques also have an impact on tea flavor. This study employed targeted metabolomics and chemometrics to investigate how shaping techniques affect the flavor of milk-flavored white tea (MFWT). The results showed that the tea cake sample with the shortest pressing time (Y90) has the highest amino acid content and milky aroma intensity. There were variations in amino acids, catechins, and soluble sugars among MFWT samples with different shaping techniques. The total contents of amino acids and catechins in tea cake sample (Y90) were significantly lower than those in the loose tea sample (SC) and bundle-like tea sample (SG), while the total sugar content was significantly higher than that in SC (P<0.05). Additionally, the content of volatiles presenting milky aroma (VIP&OAV>1) in Y90 remained lower relative to SC and SG (P<0.05), but the proportion was not different from that in SC and SG, minimally affecting the overall flavor. The short-time pressing method might be suitable for mass production of MFWT. These findings provide insights into improving the tightness of the appearance of MFWT with minimal impact on tea flavor.

Pengaruh Proporsi Angkak (Red Mold Rice) Terhadap Karakteristik Fisikokimia dan Organoleptik Sosis Ikan Nila

The boiling process causes the color of the meat in the sausage to fade, so efforts are needed to improve the color of tilapia sausage using natural dyes that are safe for consumption. The addition of angkak was chosen for food coloring so that it can affect the level of consumer acceptance. The purpose of this study was to determine the effect of the addition of angkak proportion on the physicochemical characteristics and organoleptic score of tilapia sausage produced. The treatment added is the proportion of angkak which consists of 6 concentrations, namely 0%, 0.5%, 1%, 1.5%, 2% and 2.5% (% calculated from the total weight of tilapia and tapioca flour). The test parameters were water content, fat content, protein content, antioxidant activity, color intensity, hardness, and organoleptic test of taste, aroma, color, and texture. The best treatment was tilapia sausage with the addition of 1.5% angkak proportion (A3) with an average moisture content of 61.85%; protein 15.87%; fat 15.35%; antioxidant activity 40.49%; texture hardness 31.59 N; color intensity: brightness (L) 44.85; redness (a) 23.37; yellowness (b) 13.05; organoleptic: color 4.23 (red); taste 3.86 (moderately savory); aroma 2.63 (not fishy); texture 4.43 (chewy). Keywords: tilapia sausage, angkak

Volatile aroma compound-based decoding and prediction of sweet berry aromas in dry red wine

To explore the volatile markers of typical sweet berry flavors in dry red wine, Marselan, Cabernet Sauvignon, Merlot, and Cabernet Franc wines were pretreated using solid-phase microextraction (SPME) and liquid-liquid extraction-solvent-assisted flavor evaporation (LLE-SAFE), and key odorants were analyzed using sensomics approach. Results indicated that Marselan wines exhibited intense sweet berry aromas compared to other varieties wines. Omission tests on one- and four-year-aged wines identified β-damascenone, isoamyl acetate, 2,3-butanediol, phenylethanol as sweet aroma markers, while geranyl acetone, ethyl isobutyrate, ethyl 2-methylbutyrate as berry aroma markers, which were verified by partial least squares regression. Meanwhile, optimal flavor intensity prediction models between sweet/berry aroma and volatile markers natural logarithms concentration were created with all wines. Moreover, consistent with aroma intensity, most berry markers content increased during aging while sweet markers decreased. This study completes the analytical methodology for volatile markers of wine typical aroma and provides theoretical support for wine flavor prediction.

Sugar profile and sensory properties of honey from different geographical zones and botanical origins in Tanzania

Honey composition and sensory properties depend greatly on its botanical and geographical origins. In this study, the sugar profile and sensory properties of honey samples from different geographical zones and botanical origins in Tanzania were investigated. Thirty-two samples (3 zones x 2 origins x 4 samples) + (2 zones × 1 origin x 4 samples) were collected from the seven regions in five zones as follows; Simiyu (lake zone), Tabora and Dodoma (central zone), Manyara (northern zone), Morogoro (eastern zone), and Kigoma and Katavi (western zone) and evaluated for sugar profile and sensory properties using standards methods. Honey samples were primarily composed of fructose (39.5–47 g/100 g), glucose (32.0–35.0 g/100 g) and a small amount of sucrose (5.1 ± 0.50–7.3 ± 0.7 g/100 g). The total sugar ranged from 72.6 to 75.8 g/100 g/100g. The variations in sugar contents between zones and botanical origin were significant (p < 0.05) except for glucose. Sample from miombo origin in the lake and eastern zones had the highest fructose value (41.9 ± 0.8–42.04 ± 4.34 g/100 g) compared to lowest values (39.5 ± 2.17 g/100g) in a western zone while northern and lake zones had significantly (p < 0.05) highest and lowest sucrose values respectively. In all zones, acacia samples had higher fructose and sucrose contents than their miombo counterparts. As for the sensory profile, miombo samples in the western zone had significantly (p < 0.05) higher colour (8.0 ± 0.64) and aroma (7.5 ± 1.09) intensities while the lake zone samples had higher clarity (6.9 ± 1.76) than other zones’ samples. The findings have demonstrated that the geographical and botanical origins have a significant impact on the sugar profile and sensory profile of Tanzania honey. However, despite the variations, the consumption of honey from these zones and origins should be encouraged in light of their nutritional and related known health benefits.

Characterization of Key Aroma Compounds of Soy Sauce-like Aroma Produced in Ferment of Soybeans by Bacillus subtilis BJ3-2.

Fermented soybeans are popular among many for their rich soy sauce-like aroma. However, the precise composition of this aroma remains elusive, with key aroma compounds unidentified. In this study, we screened the candidate genes ilvA and serA in BJ3-2 based on previous multi-omics data, and we constructed three mutant strains, BJ3-2-ΔserA, BJ3-2-ΔilvA, and BJ3-2-ΔserAΔilvA, using homologous recombination to fermented soybeans with varying intensities of soy sauce-like aroma. Our objective was to analyze samples that exhibited different aroma intensities resulting from the fermented soybeans of BJ3-2 and its mutant strains, thereby exploring the key flavor compounds influencing soy sauce-like aroma as well analyzing the effects of ilvA and serA on soy sauce-like aroma. We employed quantitative descriptive sensory analysis (QDA), gas chromatography-olfactometry-mass spectrometry (GC-O-MS), relative odor activity value analysis (rOAV), principal component analysis (PCA), orthogonal partial least squares-discriminant analysis (OPLS-DA), and partial least squares regression analysis (PLSR). QDA revealed the predominant soy sauce-like aroma profile of roasted and smoky aromas. GC-MS detected 99 volatile components, predominantly pyrazines and ketones, across the four samples, each showing varying concentrations. Based on rOAV (>1) and GC-O, 12 compounds emerged as primary contributors to soy sauce-like aroma. PCA and OPLS-DA were instrumental in discerning aroma differences among the samples, identifying five compounds with VIP > 1 as key marker compounds influencing soy sauce-like aroma intensity levels. Differential analyses of key aroma compounds indicated that the mutant strains of ilvA and serA affected soy sauce-like aroma mainly by affecting pyrazines. PLSR analysis indicated that roasted and smoky aromas were the two most important sensory attributes of soy sauce-like aroma, with pyrazines associated with roasted aroma and guaiacol associated with smoky aroma. In addition, substances positively correlated with the intensity of soy sauce-like aroma were verified by additional experiments. This study enhances our understanding of the characteristic flavor compounds in soy sauce-like aroma ferments, provides new perspectives for analyzing the molecular mechanisms of soy sauce-like aroma formation, and provides a theoretical framework for the targeted enhancement of soy sauce-like aroma in various foods.

Interactions among key aroma compounds and the influence of taste substances on aroma perception in Gouda cheese

The compounds 2,3-diacetyl, acetoin, hexanoic acid, and isobutyric acid are key aroma contributors significantly affecting consumer preference for Gouda cheese. However, the interaction mechanisms among these aroma compounds and the influence of taste substances on their perception remain unclear. In this study, the olfactory thresholds of these aroma compounds were first determined using systematic analysis based on flavoromics. The interactions between these key aroma compounds and the effects of taste substances on their perception in Gouda cheese were then investigated using S-curve, σ-τ plot, and aroma intensity methods. The thresholds for 2,3-diacetyl, acetoin, hexanoic acid, and isobutyric acid were found to be 0.203 mg/kg, 1.046 mg/kg, 0.673 mg/kg, and 2.710 mg/kg, respectively, in a simulated Gouda cheese matrix. Interaction studies revealed synergistic effects between 2,3-diacetyl and acetoin, as well as between hexanoic acid and isobutyric acid. Additionally, the aroma-taste sensory interaction study indicated that the enhancement of 2,3-diacetyl and acetoin aromas was most pronounced at sodium chloride concentrations of 0.95 g/100 g or 1.50 g/100 g and sucrose concentrations of 10.00 g/100 g or 15.85 g/100 g in the Gouda cheese matrix. These findings provide theoretical support and practical references for improving the aroma quality of Gouda cheese.