Effects of storage time on flavor characteristics of bran-free fermented Baijiu by using electronic sensory, descriptive sensory analysis, GC × GC-MS, and ICP-MS.

By examining and analyzing bran-free fermented Baijiu (BFB) with varying storage periods (0-20 years), it was observed that the overall concentration of volatile compounds initially increases and subsequently decreases over time. Furthermore, BFB exhibited more kinds of long chain esters, higher concentration of acetals, and reduced furfural content. The process of cellaring can enhance the aged, sweet, and fruity aroma of BFB. 16 flavor compounds, including 1,1-diethoxyethane, ethyl dodecanoate, and ethyl hexadecanoate, can be used as markers for vintage BFB, and electronic sensory technology was capable of discerning BFB in different years. The results of redundancy analysis (RDA) showed a positive correlation between metals and aldehydes, esters, and ketones, while indicating a negative correlation with acids and alcohols. Al, Fe, and Ca underwent the most significant changes during storage period, and they were positively correlated with differential substances, such as benzaldehyde, vanillin, ethyl isovalerate, and ethyl palmitate (P < 0.01).

Fast and non-invasive identification of Baijiu based on Tyndall effect and chemometrics.

The value of Baijiu is affected by its flavor, age, and adulteration. Therefore, a simple and rapid identification method is crucial for the market. In this study, we present a rapid, non-intrusive identification technique for Baijiu utilizing the Tyndall effect combined with chemometrics analysis. Our experiment begins illuminating Baijiu with a 405 nm wavelength laser and recording the resulting bright light path due to the Tyndall effect. To further analyze the color and brightness information, Principal Component Analysis (PCA), Linear Discriminant Analysis (LDA), Hierarchical Cluster Analysis (HCA), and Multilayer Perceptron (MLP) were employed. This study establishes correlations between the brightness of the Tyndall light path and seven trace flavor compounds in Baijiu. The findings demonstrate that this method effectively identifies the flavor, age cellar, and adulteration of Baijiu and also quantitatively detects the concentrations of flavor compounds. Additionally, an analysis platform was developed to enable the rapid identification of Baijiu.

Unravelling caramelization and Maillard reactions in glucose and glucose + leucine model cakes: Formation and degradation kinetics of volatile markers extracted during baking.

A large number of volatile compounds are formed during the baking of foods by reactions such as caramelization and Maillard reactions. Elucidating the reaction mechanisms may be useful to predict and control food quality. Ten reaction volatile markers were extracted during baking of solid model cakes implemented with known amounts of precursors (glucose with or without leucine) and then quantified by Thermal desorption-Gas chromatography-Mass spectrometry. The kinetic data showed that the level of air convection in the oven had no significant influence on the reaction rates. In contrast, increasing baking temperatures had a nonlinear accelerating impact on the generation of newly formed volatile compounds with a bell-shaped kinetic curve found for most of the markers at 200 °C. The presence of leucine triggered the activation of the Maillard and Strecker routes with a specific and very rapid formation of 3-Methylbutanal and pyrazines. A dynamic model was developed, combining evaporation flow rate and kinetic formation and consumption of reaction markers. It can be used to describe, for two furanic compounds of different volatilities, the vapor concentrations in the oven from the concentrations measured in the model cakes.

Relationship between microstructure formation and in vitro starch digestibility in baked gluten-starch matrices.

Increased prevalence of diabetes prompts the development of foods with reduced starch digestibility. This study analyzed the impact of adding soluble dietary fiber (inulin-IN; polydextrose-PD) to baked gluten-starch matrices (7.5-13%) on microstructure formation and in vitro starch digestibility. IN and PD enhanced water-holding capacity, the hardness of baked matrices, and lowered water activity in the formulated matrices, potentially explaining the reduced starch gelatinization degree as IN or PD concentration increased. A maximum gelatinization decrease (26%) occurred in formulations with 13% IN. Micro-CT analysis showed a reduction in total and open porosity, which, along with the lower gelatinization degree, may account for the reduced in vitro starch digestibility. Samples with 13% IN exhibited a significantly lower rapidly available glucose fraction (8.56 g/100 g) and higher unavailable glucose fraction (87.76 g/100 g) compared to the control (34.85 g/100 g and 47.59 g/100 g, respectively). These findings suggest the potential for developing healthier, starch-rich baked foods with a reduced glycemic impact.

Effect of different isolation sources of Lactococcus lactis subsp. lactis on volatile metabolites in fermented milk.

Lactococcus lactis subsp. lactis (L. lactis subsp. lactis) is a commonly used starter cultures in fermented dairy products, contributing distinct flavor and texture characteristics with high application value. However, the strains from different isolates have different contributions to milk fermentation. Therefore, this study aimed to investigate the influence of L. lactis subsp. lactis isolated from various sources on the volatile metabolites present in fermented milk. In this study, L. lactis subsp. lactis from different isolation sources (yogurt, koumiss and goat yogurt) was utilized as a starter culture for fermentation. The volatile metabolites of fermented milk were subsequently analyzed by headspace solid phase microextraction gas chromatography-mass spectrography (HS-SPME-GC-MS). The results indicated significant differences in the structure and abundance of volatile metabolites in fermented milk produced with different isolates (R2Y = 0.96, Q2 = 0.88). Notably, the strains isolated from goat yogurt appeared to enhance the accumulation of ketones (goat yogurt vs yogurt milk: 50 %; goat yogur vs koumiss: 27.3 %)and aldehydes (goat yogurt vs yogurt milk: 21.4 %; goat yogurt vs koumiss: 54.5 %) in fermented milk than strains isolated from koumiss and yogurt milk. It significantly promoted the production of 8 flavor substances (1 substance with OAV ≥ 1 and 6 substances with OAV > 0.1) and enhanced the biosynthesis of valine, leucine, and isoleucine. This study provides valuable insights for the application of Lactococcus lactis subsp. lactis isolated from different sources in fermented dairy production and screening of potential starter cultures.

A comparative study of Lachancea thermotolerans fermentative performance under standardized wine production conditions.

The study explores diverse strains of Lachancea thermotolerans in single-inoculum wine fermentation conditions using synthetic grape must. It aims to analyze the role of the species without external influences like other microorganisms or natural grape must variability. Commercial strains and selected vineyard isolates, untested together previously, are assessed. The research evaluates volatile and non-volatile chemical compounds in final wine, revealing significant strain-based variations. L. thermotolerans notably produces lactic acid and consumes malic acid, exhibiting moderate ethanol levels. The volatile profile displays strain-specific impacts, affecting higher alcohol and ester concentrations compared to S. cerevisiae. These effects vary based on the specific compounds. Using a uniform synthetic must enables direct strain comparisons, eliminating grape-related, environmental, or timing variables in the experiment, facilitating clearer insights into the behavior of L. thermotolerans in wine fermentation. The study compares for the first time all available commercial strains of L. thermotolerans.

The effective of bacterial community dynamics driven by different starter cultures on the flavor development of Chinese fermented sausages.

This study aimed to understand the community successions driven by different starters and their effects on the flavor development of Chinese fermented sausages. The results showed that the bacterial genus (67.6%) and pH (32.4%) were the key factors influencing the volatile profile. Inoculated the starters composed of Pediococcus and staphylococci maintained the stable community succession patterns dominated by staphylococci (samples T and S). Although the highly acidic environment (pH < 5.2) caused the community to exhibit a fluctuation in succession pattern, the inoculation of Latilactobacillus paracasei (sample Y) maintained microbial diversity and was conducive to the accumulation of aldehydes and esters. In sample P, inoculated the starter with Latilactobacillus and Staphylococcus also maintained microbial diversity, the moderately acidic environment (pH > 5.4) resulted in a stable succession pattern of the microbial community, and it was not conducive to the accumulation of aldehydes, alcohols and esters.

Comprehensive evaluation of aroma and taste properties of different parts from the wampee fruit.

Wampee is a tropical fruit having high medicinal value. To fully realize the fruit's potential, it is essential to reveal the flavor characteristics. In this study, a comprehensive analysis of the aroma and taste profiles of different parts from the wampee fruit was conducted. The aroma profile was analyzed by E-nose, and 67 volatile components were identified through HS-SPME-GC-MS. Among them, 11 were considered as crucial compounds. Additionally, 42 volatile components were identified by HS-GC-IMS, with 22 compounds showing a variable importance in projection scores greater than 1.0. Moreover, the taste profile and representative compounds were analyzed by E-tongue and HPLC, and 12 compounds were considered as important taste contributors based on taste activity value. These findings shed light on the various compounds responsible for the unique aroma and taste of the wampee fruit, providing theoretical foundation for exploring ways for its comprehensive utilization and development.

A comparative study on flavor trapping techniques from the viewpoint of odorants of hot-pressed rapeseed oil.

Rapeseed oil, as one of the three major vegetable oils in the world, its matrix effect makes the decoding flavor a challenge. Solid-phase microextraction (SPME), SPME-Arrow, headspace stir bar sorptive extraction (HSSE), direct thermal desorption (DTD), and solvent-assisted flavor evaporation (SAFE) were compared based on the odorants in hot-pressed rapeseed oil. Besides, methodological validation for 31 aroma standards was conducted to compare reliability and robustness of these approaches. DTD showed the largest proportion of acids, while the other techniques extracted a majority of nitriles. The highest number of odorants was detected by SAFE (31), followed by HSSE (30), SPME-Arrow (30), SPME (24), and DTD (14). SPME-Arrow showed the best performance in linearity, recovery, and reproducibility followed by SPME, HSSE, DTD, and SAFE. Results reveal the advantages and limitations of diverse methodologies and provide valuable insights for the selection of extraction methods in an oil matrix and flavor decoding.

Determination of mycotoxins by HPLC, LC-MS/MS and health risk assessment of the mycotoxins in bee products of Turkey.

The aim of this study is to determine the levels of deoxynivalenol (DON), HT-2 toxin (HT2), T-2 toxin (T2), and ochratoxin A (OTA) in bee products (bee pollen, propolis, honey and royal jelly) available in Turkey. In addition, exposure and health risk assessments were performed to identify the potential health risk of these mycotoxins. The mycotoxins were analyzed by high-performance liquid chromatography (HPLC) with a UV detector and positive samples were confirmed with liquid chromatography-tandem mass spectrometry (LC-MS/MS). The most common mycotoxins in all bee products were DON and T-2 toxin, with mean concentrations of 1.601 and 0.704 µg/per kg dry sample, respectively, followed by OTA and HT-2 toxin. It was determined that the mycotoxins taken as a result of consuming bee products in specified amounts do not pose a risk to health.

Comparison of potent odorants in raw and cooked mildly salted large yellow croaker using odor-active value calculation and omission test: Understanding the role of cooking method.

Cooking improves food aroma, but few studies have explored how cooking affects food aromas. Here, aroma changes in mildly salted large yellow croaker (Larimichthys crocea, MSLYC) after steaming, baking, frying, and deep frying was investigated. The raw fish was dominated by fishy notes but after cooking, the aroma became dominated by fatty notes. Nine volatiles, including hexanal, nonanal, (E, Z)-2, 6-nonadienal, (E, E)-2, 4-decadienal, 1-octen-3-ol, linalool, ethyl hexanoate, acetic acid and anethole, were identified as key odor-active compounds using GC-MS, OAV, and omission tests analyses. Changes in the concentrations of key odor-active compounds were mainly due to evaporation, oxidation of linolenic acids, and thermal catalyzed reactions. Interestingly, anethole was the key odor-active compound, providing new insight into the underlying reactions of cooked fish aroma.

Flavones interact with fiber to affect fecal bacterial communities in vitro.

This study investigated the effects of the sugarcane flavones diosmin, diosmetin, luteolin, and tricin, and their interactions with sugarcane fiber on the modulation of gut microbiota using in vitro batch fermentation. The alteration of fecal fermentation bacterial profile was analyzed using 16S rRNA sequencing data, while the bioavailability of fiber was indicated by short-chain fatty acid (SCFA) production and metabolism of polyphenols was measured directly by phenolic metabolites. Application of diosmin, diosmetin, luteolin, and tricin without fiber had no significant effect on the overall microbiota profile after 24 h of fermentation. When fiber alone was added, total SCFA production increased, specifically that of propionic and valeric acids. However, when flavones were combined with fiber, synergistic effects on the modulation of relative abundances of different bacterial taxa was noted. In particular, the proportion of Prevotella spp. was significantly increased by the combinations of diosmin, luteolin, and tricin with fiber.

Combined use of vacuum impregnation and encapsulation technologies for phenolic enrichment of strawberries.

Plant-based phenolic extracts have gained significant attention in the food industry due to their antimicrobial and health-promoting effects. However, their usage is limited because of poor water solubility and instability during processing. Therefore, encapsulation of phenolics with a suitable carrier system is essential for overcoming these problems and increasing their application in food products. In this study, encapsulated phenolic extracts were used for the first time in vacuum impregnation (VI). For this purpose, different phenolic extracts (cinnamon, turmeric, pomegranate peel) were obtained from the plant source. PPE was selected because it has the highest total phenolic content, antioxidant capacity, and antimicrobial activity against Botrytis cinerea. Then, PPE was encapsulated with different emulsifiers (T80, GMO, IN, WPI, and LEC). After the characterization and stability studies were performed, PPE encapsulated with T80 was used to produce a functional strawberry snack by VI technology. The results showed that the diffusion rate of EPPE was significantly increased compared to the control and PPE-VI group. EPPE-enriched strawberries were the preferred snack with high-quality characteristics.

Gut metabolites produced during in vitro colonic fermentation of the indigestible fraction of a maize-based traditional Mexican fermented beverage, Tejuino.

Tejuino, is a Mexican fermented beverage prepared by germination-fermentation or nixtamalization-fermentation (artisanal and commercial mode respectively) of maize. The aim of this study was to evaluate the gut metabolites, volatile, and phenolic compounds (PC) produced by the indigestible fraction (IF) of Tejuino during an in vitro colonic fermentation. Twenty-six PC in the IF were identified; the hydroxycinnamic acids (30-40 %) were the most abundant. In the IF of Tejuino pyrogallol, and urolithins were identified. Some of the representative PC of maize as maysin derivatives (apimaysin and 3-methoxymaysin) (flavonoids). The quantification of acetic and butyric acid become notable after 6 h of the colonic fermentation of IF of Tejuino. Ninety-seven volatile compounds were found, and the PCA shows the predominant compounds as short chain fatty acids, esters of organic acids and indole derivatives. These results suggest that Tejuino could be an important source of metabolites with high biological value.

Simulated digestion, dynamic changes during fecal fermentation and effects on gut microbiota of Avicennia marina (Forssk.) Vierh. fruit non-starch polysaccharides.

Grey mangrove (Avicennia marina (Forssk.) Vierh.) fruit is a traditional folk medicine and health food consumed in many countries. In this study, its polysaccharides (AMFPs) were obtained and analyzed by chemical and instrumental methods, with the results indicating that AMFPs consisted of galactose, galacturonic acid, arabinose, and rhamnose in a molar ratio of 4.99:3.15:5.38:1.15. The dynamic changes in AMFPs during the digestion and fecal fermentation processes were then investigated. The results confirmed that AMFPs were not depolymerized by gastric acid and various digestive enzymes. During fermentation, 56.05 % of the AMFPs were utilized by gut microbiota. Galacturonic acid, galactose, and arabinose from AMFPs, were mostly consumed by gut microbiota. AMFPs obviously decreased harmful bacteria and increased some beneficial microbiota, including Megasphaera, Mistuokella, Prevotella, and Megamonas. Furthermore, AMFPs obviously increased the levels of various short-chain fatty acids. These findings suggest that AMFPs have potential prebiotic applications for improving gut health.

Chitosan/bacterial cellulose films incorporated with tea polyphenol nanoliposomes for silver carp preservation.

This study aimed to develop chitosan/bacterial cellulose-based films loaded with tea polyphenol-loaded chitosan coated nanoliposomes (CS-TP-lip) as an active agent for food preservation. The effects of the CS-TP-lip on the physicochemical properties of composite films were systematically evaluated. The CS-TP-lip exhibited spherical shapes with an average particle size of about 300 nm. Scanning electron microscopy and Fourier transform infrared spectroscopy analyses suggested high compatibility between the CS-TP-lip and film matrix through intermolecular interactions. Furthermore, due to the CS-TP-lip's presence, the elongation at break and thermal stability of the films could be enhanced to reach 75.14 ± 1.2 % and 395.33 °C, respectively, and the stability of tea polyphenol could be increased to prolong its functioning time. The films were successfully used as packaging materials for fish fillet preservation. Therefore, the developed nanocomposite films exhibit great promise as a new generation of biodegradable, sustainable, and bioactive film for food preservation.

High-pressure homogenization: A potential technique for transforming insoluble pea protein isolates into soluble aggregates.

High-pressure homogenization (HPH) is a technique that impacts the aggregation of globular proteins. In this study, the effect of HPH (at a pressure of 30/50 MPa for three cycles) was investigated on the aggregation states and functional properties of insoluble commercial pea protein isolates (CPPI). Results showed that HPH significantly improved the solubility, foaming and emulsifying capacity of CPPI. Samples treated at 50 MPa demonstrated better foaming and emulsifying capacity than that at 30 MPa. Surface hydrophobicity, intrinsic fluorescence, SDS-PAGE and FTIR analysis revealed that insoluble precipitates/aggregates (most legumins included) of CPPI were broken down and converted into soluble aggregates. Low-pressure HPH (30 MPa) can break non-covalent bonds (hydrophobic interactions), whereas higher pressure (50 MPa) can further break covalent bonds (SS). The study sheds light on the mechanism of disruption of insoluble CPPI under HPH and proposes a method to enhance their techno-functional properties for application in food formulations.

Molecular interactions involved in the complexation process between buffalo whey proteins concentrate and folic acid.

Using buffalo whey proteins as carrier agents of sensitive molecules raises an interesting approach allowing adding value and minimizing the pollution impact of this by-product. In this context, this work aims to explore the molecular interactions between buffalo whey proteins concentrate (BWPC) and folic acid (FA). For this purpose, fluorescence, UV and FTIR analysis were performed on aqueous or solid dispersions of a buffalo whey protein concentrate (5 µM) (BWPC), with variable concentrations (0-20 µM) of FA. Fluorescence and absorption data were fitted by Stern-Volmer, Beckett, Förster resonance energy transfer, and sphere-of-action models (R2 > 0.9). Derived results suggest that BWPC strongly bind to FA through non-covalent interactions and form ground-state complexes. Additionally, BWPC improves the photostability of FA against UV radiation, and chemical denaturation negatively affects the binding properties. Obtained results encourage further studies of BWPC as carrier agents, which could promote innovative applications for this under-utilized proteins source.

Molecular simulations of the effects of substitutions on the dissolution properties of amorphous cellulose acetate.

The dissolution behavior of cellulose acetate (CA) is an extremely important property in its extensive applications and preparation of derivatives. In this paper, we proposed a molecular model building strategy to construct amorphous CA with various substituent distributions (different degrees of substitution and substitution positions). A protocol combing molecular dynamics simulation and density functional theory (DFT) was applied to systematically investigate the dissolution behavior of CAs, and the structural properties of CAs. The reduced cohesive energy and polarity of CAs caused by the increase in substituents would enhance its solubility. The interaction of solvent molecules and CAs and the diffusion of solvent molecules in CAs have a synergistic effect on the dissolution of CAs. The diffusion coefficient is the primary factor affecting the solubility. Moreover, substituents at different positions of the anhydroglucose units along the CAs chains would produce different steric hindrance effects, which in turn affect the dissolution behavior.

The polysaccharides from the fruits of Lycium barbarum L. confer anti-diabetic effect by regulating gut microbiota and intestinal barrier.

The antidiabetic effect and potential mechanisms of the polysaccharides from the fruits of Lycium barbarum L. (LBPs) by the mouse model of high-fat diet/streptozotocin-induced diabetes were investigated. Six-week oral administration of LBPs (200 mg/kg/day) resulted in improvement in the levels of fasting blood glucose (13.51% decrease) and glycated hemoglobin and ß-cell function in diabetic mice, and simultaneously induced a 3.3-fold increment in one taxon belonging to genus Allobaculum in gut bacterial community. The experiments of fecal microbiota transplantation and antibiotics treatment confirmed that the LBPs-mediated gut microbiota participated in the glycemic control of the diabetes management. Moreover, LBPs intervention guarded the intestinal barrier function via upregulating the expression of zonula occludens 1 both in vivo (analyzing the gut permeability in diabetic mice) and in vitro (using intestinal-like Caco-2/RAW264.7 cells co-culture inflammation model). Collectively, our study showed that LBPs could confer anti-diabetic effect through modifying gut microbiota and intestinal barrier.