Mushroom alcohol(1-octen-3-ol)and other 7 aroma compounds selected from Chinese dry-cured hams can enhance saltiness perception

Odor-induced saltiness enhancement of volatile compounds screened from duck stewed with chili pepper

Odor-induced saltiness enhancement (OISE) is thought to be a unique salt reduction technique which capitalizes on olfactory-gustatory interaction. Volatile compounds of stewed duck obtained from orthonasal (no-treatment) and retronasal (saliva-treatment) pathways and their capacity on OISE were analyzed by GC-O-MS and molecular simulation in order to ascertain the role of odors in duck stewed with chili pepper on saltiness enhancement. Totally 17 unique volatile compounds were identified in retronasal pathways. Eight salty-congruent volatile compounds were screened from the stewed duck, one of which being E-2-decenal, specific to retronasal volatile compounds following oral enzymatic digestion. These volatile compounds' OISE in NaCl solution was confirmed, and the retronasal pathway effect outweighed the orthonasal one. Molecular docking revealed that volatile compounds interacted with saltiness receptors through hydrogen bonding and hydrophobic force, which may be responsible for its enhanced saltiness. These findings suggest that olfactory pathways and specific odors might simultaneously mediate OISE.

Drying methods affected the fatty acids oxidation and bacterial community of traditional dry-cured ducks during processing and its relation with the aroma formation

The formation of volatile compounds in dry-cured ducks produced by hot and cold air circular drying (HCAD), hot air drying (HAD), and traditional sun drying (TSD) were analyzed by E-nose and GC-MS. The HCAD exhibited higher alcohols, aldehydes, esters, and furans than that of the other two. Six, five, and three key compounds were identified by OAV in HCAD, HAD, and TSD, respectively. Nonanal was the highest relative content of aldehydes in all groups. (E)-2-octenal was detected only in HCAD. HAD accelerated the oxidation of fatty acids. The POV and AV of HAD were 0.24 g/100 g and 2.02 mg/g when stored for 15 days, which were higher than that of HCAD and TSD. Proteobacteria, Actinobacteriota and Firmicutes were the most abundant phylum, Psychrobacter, Kocuria, and Macrococcus were the primary dominant genus. The hightest abundance of Firmicutes and Macrococcus in the HCAD-15d might contribute to the aroma formation. HCAD showed a better quality and flavor than TSD and HAD, indicating it is an innovative method for producing dry-cured duck.

Near-Infrared Spectroscopy Detection of Off-Flavor Compounds in Tench (Tinca tinca) After Depuration in Clean Water

Tench (Tinca tinca) is a warm-temperate, freshwater benthic fish with often unpleasant odors and flavors which result from its natural habitat. These characteristics may deter consumers; therefore, their removal would enhance the fish's palatability and market appeal. Thus, tench were grown in an aquaculture center and subjected to a clean water depuration system in which six sampling points were carried out at 0 h, 12 h, 24 h, 48 h, 72 h, and 96 h. An analysis was conducted using gas chromatography-mass spectrometry and near-infrared spectroscopy (NIRS), revealing acid derivatives as the predominant families of volatile organic compounds (VOCs). The main off-flavor VOCs were 3,5,5-trimethyl-1-hexene, dimethyl-8-hydronaphtalen, 1-octen-3-ol, diethyl phthalate, 2-methylisoborneol, and a-isomethylionone. Maximum concentrations were observed at 0 h, exceeding 300 μg/g for diethyl phthalate and being less than 55 μg/g for the remaining VOCs. The content progressively decreased from that point on. The spectra obtained by NIRS highlighted differences between the cleaning depuration treatments, exhibiting discrimination among the samples studied (PC1 = 77.8%; PC2 = 11.3%). Finally, dimethyl-8-hydronaphtalen and 2-methylisoborneol were linearly correlated with NIRS data, with RCV2 values of 0.94 and 0.96, respectively, and RMSECV values of 1.00 and 3.62 μg/g, respectively. Therefore, a clean water depuration system is appropriate to obtain fish with fewer off-flavor characteristics. Moreover, NIRS represents an accurate, inexpensive, and non-destructive technique to determine the optimal time for the water depuration of fish.

Optimization of the Meat Flavoring Production Process for Plant-Based Products Using the Taguchi Method

The development of plant-based meat substitutes is imperative for reducing animal fat intake and promoting dietary diversification. However, the flavor profiles of these products frequently fall short of consumer expectations. This study sought to optimize the production process of meat flavorings for plant-based products using the Taguchi method. The study investigated the effects of sugar type, concentration, and reaction temperature on the Maillard reaction products, sensory characteristics, and volatile organic compounds. The thermal process flavors were obtained from the flavor precursor by heating in a laboratory microwave station at 30 bar for 15 min. The variable factors were the type of sugar (fructose, glucose, xylose), its concentration (25, 50, and 100 mM), and the temperature of the reaction (140, 150, and 160 °C). The study's findings indicated that temperature emerged as the predominant factor influencing the formation of Maillard reaction products and the sensory characteristics of the flavorings. Specifically, 25 mM xylose-based flavorings prepared at 140 °C demonstrated the most notable meat flavor and the highest level of acceptability. Moreover, the analysis of volatile organic compounds revealed the presence of a diverse array of substances, including aldehydes, ketones, and alcohols, that are characteristic of meat flavor. A heat map of the volatile content was constructed to facilitate a comparison of the samples. The study demonstrates the effectiveness of the Taguchi method in optimizing the production process of meat flavorings for plant-based products and provides valuable insights for the development of more balanced odor profiles.

Changes of shrimp myofibrillar proteins hydrolyzed by Virgibacillus proteases: Structural characterization, mechanism visualization, and flavor compound formation

To explore the mechanism of Virgibacillus proteases on hydrolysis of shrimp myofibrillar protein (SMP) and formation of volatile compounds, the fermented broth of Virgibacillus halodenitrificans was purified and the protease was identified as peptidase S8. The enzyme had optimum activity at pH 7.0-8.5 and 40-50 °C, and showed good stability at pH 6.5-8.5 and 20-50 °C. The enzyme showed certain salt and metal ion tolerance. Inhibitor results indicated that the enzyme might belong to the serine protease family. V. halodenitrificans proteases (BP) had a stronger ability to degrade SMP compared to Bacillus subtilis proteases (BS). After 60 min of hydrolysis, the hydrolysis index and surface hydrophobicity value of the BP sample were 36.7 % and 177.5 higher than those of the BS sample, respectively. Various spectral measurement results showed that the structural conformation of the BP-treated SMP was significantly changed, with a smaller particle size (510.4 nm) and a lower zeta potential (-27.7 mV). Molecular docking results showed that the enzyme had the highest degradation capacity for myofibrillar heavy chains, followed by actin, and the lowest for myofibrillar light chains, with the interaction forces being hydrogen bonding and hydrophobic interactions. In addition, BP-treated SMP had higher levels of peptides, small molecular weight peptides (<1 kDa), and umami amino acids compared to the BS sample. Solid-phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS) results showed that BP hydrolysates contained more volatile compounds and key volatile compounds than BS hydrolysates. Pyrazines and alcohols were the main volatile flavor compounds in BS and BP hydrolysates, respectively.

Modulating the aroma and taste profile of soybean using novel strains for fermentation

A key factor influencing consumer acceptance of soybean products is the aroma and taste profile, which can be modulated through fermentation using unique microbial strains. This study aimed to identify and characterize novel microbial strains with the potential to enhance flavour profiles including umami, while reducing undesirable flavour notes such as beany aromas. The results showed an 800% (8-fold) increase in free amino acids in samples fermented with Rhizopus oryzae, which correlated with an increase in umami intensity as measured using an E-tongue. Samples fermented with Neurospora crassa also demonstrated an increase in methionine and cysteine, sulfur-containing amino acids that are deficient in raw soybean. Fermentation additionally resulted in a significant increase in fatty acids and alterations to the fatty acid profile. Notably, samples fermented with Penicillium camemberti, Penicillium nalgiovense, Penicillium chrysogenum, and Leuconostoc mesenteroides containing omega-3 fatty acids. Lastly, fermentation introduced desirable aroma compounds, including 'smoky', 'cheesy' and 'floral' notes, enhancing the sensory appeal of certain samples. This study demonstrates the innovative use of novel microbial strains in soybean fermentation as a promising strategy to modulate the aroma and taste profile of soybean products.

Changes of physicochemical and volatile flavor compounds of dry-cured Diqing Tibetan pig hams during fermentation

This study aimed to explore the flavor formation mechanism of Diqing Tibetan pig hams by investigating changes of their physicochemical and volatile flavor compounds during fermentation (0, 30, 90, 180, 360, and 540d) using amino acid analyzer , texture profile analysis, and gas chromatography-ion mobility spectroscopy (GC-IMS). During fermentation, the hams significantly decreased in moisture and centrifugal loss, while increased in chewiness, hardness, and proteolysis index, with their free amino acids content reaching the maximum at 360d and significantly decreasing at 540d. GC-IMS identified 78 volatile organic compounds, with the highest total content of alcohols and aldehydes at 180d, ketones and heterocycles at 360d, and esters at 540d. PLS-DA screened 24 volatile flavor markers, with aldehyde (2-methyl-2-propenal), ketone (2-heptanone-D), alcohol (3-methylbutanol-D), ester (ethyl3-methylbutanoate-M), and heterocyclic substances (2,3-dimethylpyrazine-M) as the main VFMs at 360d. The unique flavor of 540d Diqing Tibetan pig hams was attributed to their higher content of 3-methyl-2-butenal, 3-(methylthio) propanal, ethyl caproate and 2-butanone. These findings provide a scientific basis for the flavor formation mechanism of hams which favoring the further development processing strategies for Diqing Tibetan pig.

SAFE-GC-O-MS and descriptive sensory analysis were used to reveal the chemical sensory characteristics of sesame paste (tahini) at different storage stages

Understanding the evolution of aroma profiles in stored sesame paste (SP) is essential for maintaining its quality. This study investigated the storage quality of SP and potential aroma markers indicative of sensory degradation. The descriptive sensory analysis demonstrated changes in aroma attributes during storage, transitioning from roasted sesame and nutty aromas to fermented and green aromas. Physicochemical analysis showed deepening color, intensified lipid oxidation, decreased levels of bioactive components, increased particle aggregation, and deteriorated flowability over 63 days at 40 °C. Gas chromatography-olfactometry-mass spectrometry identified 37 aroma-active compounds, with pyrazines, aldehydes, and phenols identified as the major constituents. Partial least squares regression analysis revealed 2-ethyl-3-methyl-pyrazine, 2-methoxy-4-vinylphenol, and benzaldehyde as key aroma-active compounds contributing significantly to the distinctive aromas "roasted nut and roasted sesame" found in SP. Conversely, hexanal and dimethyl disulfide emerged as potential markers of undesirable aromas in SP, including "rancid, green, and fermented". These findings provide insights into SP changes during storage, which is vital for preservation and quality enhancement strategies.

Odor and taste characteristics, transduction mechanism, and perceptual interaction in fermented foods: a review

Fermentation is a critical technological process for flavor development in fermented foods. The combination of odor and taste, known as flavor, is crucial in enhancing people's perception and psychology toward fermented foods, thereby increasing their acceptance among consumers. This review summarized the determination and key flavor compound screening methods in fermented foods and analyzed the flavor perception, perceptual interactions, and evaluation methods. The flavor compounds in fermented foods could be separated, purified, and identified by instrument techniques, and a molecular sensory science approach could identify the key flavor compounds. How flavor compounds bind to their respective receptors determines flavor perception, which is influenced by their perceptual interactions, including odor-odor, taste-taste, and odor-taste. Evaluation methods of flavor perception mainly include human sensory evaluation, electronic sensors and biosensors, and neuroimaging techniques. Among them, the biosensor-based evaluation methods could facilitate the investigation of the flavor transduction mechanism and the neuroimaging technique could explain the brain's signals that relate to the perception of flavor and how they compare to signals from other senses. This review aims to elucidate the flavor profile of fermented foods and highlight the significance of comprehending the interactions between various flavor compounds, thus improving the healthiness and sensory attributes.

Disentangling the Tissue-Specific Variations of Volatile Flavor Profiles of the Lentinula edodes Fruiting Body

For Lentinula edodes, its characteristic flavor is the key determinant for consumer preferences. However, the tissue-specific volatile flavor variations of the fruiting body have been overlooked. Here, we comprehensively investigated the volatile flavor profiles of different tissues, including the pileus skin, context, gill, and stipe of the fruiting body, of two widely cultivated L. edodes strains (T2 and 0912) using the gas chromatography-mass spectrometry (GC-MS) technique combined with a multivariate analysis. We show that the eight-carbon and sulfur compounds, which represented 43.2-78.0% and 1.4-42.9% of the total volatile emissions for strains 0912 and T2, respectively, dominated their volatile profiles. Compared with strain T2, strain 0912 had a higher total content of eight-carbon compounds but a lower total content of sulfur compounds in the fruiting body. The sulfur compounds represented 32.2% and 42.9% of the total volatile emissions for strains 0912 and T2, respectively. In contrast, they constituted only 1.4% in the stipes of strain 0912 and 9.0% in the skin of strain T2. The proportions of the predominant C8 compounds (1-octen-3-one, 1-octen-3-ol, and 3-octanone) and sulfur compounds (lenthionine, 1,2,4-trithiolane, dimethyl disulfide, and dimethyl trisulfide) changed depending on the tissues and strains. Using machine learning, we show that the prediction accuracy for different strains and tissues using their volatile profiles could reach 100% based on the highly diverse strain- and tissue-derived volatile variations. Our results reveal and highlight for the first time the comprehensive tissue-specific volatile flavor variations of the L. edodes fruiting body. These findings underscore the significance of considering strain and tissue differences as pivotal variables when aiming to develop products with volatile flavor characteristics.