Effects of Plant-Derived Polyphenols on the Antioxidant Activity and Aroma of Sulfur-Dioxide-Free Red Wine.

Significant efforts have been made in recent years to produce healthier wines, with the primary goal of reducing the use of sulfur dioxide (SO2), which poses health risks. This study aimed to assess the effectiveness of three plant-derived polyphenols (dihydromyricetin, resveratrol, and catechins) as alternatives to SO2 in wine. After a three-month aging process, the wines were evaluated using analytical techniques such as high-performance liquid chromatography, colorimetry, gas chromatography-olfactometry-mass spectrometry, as well as electronic nose and electronic tongue analyses, with the purpose to assess parameters including antioxidant activity, color, contents of volatile aroma compounds, and sensory characteristics. The results demonstrated various degrees of improvement in the antioxidant activity, aromatic intensity, and sensory characteristics of wines using polyphenols. Notably, dihydromyricetin (200 mg/L) exhibited the strongest antioxidant activity, with increases of 18.84%, 23.28%, and 20.87% in 2,2-diphenyl-1-picrylhydrazyl, 2,2'azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), and ferric-ion-reducing antioxidant power assays, respectively. Resveratrol (200 mg/L) made the most significant contribution to volatile aroma compounds, with an 8.89% increase in the total content of alcohol esters. In E-nose analysis, catechins (200 mg/L) showed the highest response to aromatic compounds and the lowest response to volatile sulfur compounds, while also exhibiting the best sensory characteristics. Therefore, the three plant-derived polyphenols investigated here exhibited the potential to enhance wine quality as alternatives to SO2. However, it is important to consider the specific impact of different polyphenols on wine; hence, suitable antioxidants should be selected in wine production according to specific requirements.

Sulfur dioxide-free wine with polyphenols promotes lipid metabolism via the Nrf2 pathway and gut microbiota modulation.

Moderate wine consumption is often associated with preventing obesity, yet concerns arise due to the health risks linked to its constituent antioxidant, SO2. Recent focus has turned to polyphenols as a potential substitute for SO2. This investigation explores the impact and mechanisms of sulfur dioxide-free wine enriched with polyphenols on lipid regulation. Through a comprehensive analysis involving oxidative stress, lipid metabolism, and gut microorganisms in high-fat-diet mouse models, this study reveals that sulfur dioxide-free wine containing the polyphenol resveratrol exhibits a heightened ability to regulate lipids. It modulates oxidative stress by influencing NF-E2-related factor 2, a crucial factor, while enhancing lipid metabolism and fatty acid ß-oxidation through key genes such as carnitine palmitoyltransferase I and peroxisome proliferator-activated receptor alpha. Furthermore, oral administration of sulfur dioxide-free wine supplemented with resveratrol demonstrates an increase in the relative abundance of beneficial intestinal microflora, such as Turicibacter, Allobaculum, Bacteroides, and Macellibacteroides, while decreasing the Firmicutes/Bacteroidetes ratio.

Investigating the impact of various sorghum types on the key aroma compounds of Sichuan Xiaoqu Baijiu through application of the sensomics approach.

The aroma of Sichuan Xiaoqu Baijiu (SXB) greatly benefits from the use of sorghum as its primary brewing ingredient. Nevertheless, the impact of different sorghum variety on the primary aroma compounds of SXB has not been thoroughly investigated. Gas chromatography-mass spectrometry (GC-MS) in conjunction with headspace solid phase microextraction (HS-SPME) and liquid-liquid extraction (LLE) were employed in this investigation. Using 5 sorghum varieties as raw materials, five different types of SXB were analysed for their aroma compounds using GC-MS, GC-O, AEDA, aroma recombination, and aroma omission. Key aroma compounds of SXB were successfully identified as ethyl acetate, ethyl 2-methylbutyrate, isoamyl acetate, ethyl hexanoate, ethyl heptanoate, ethyl lactate, ethyl octanoate, ethyl decanoate, phenylethyl acetate, ethyl laurate, ethyl palmitate, isoamyl alcohol, phenylethanol, 1,1-diethoxyethane, 3-hydroxy-2- butanone, furfural, and glacial acetic acid. Glacial acetic acid, ethyl acetate, ethyl lactate, phenylethyl acetate, acetoin, phenylethanol, and ethyl caproate were found to be the seven major aroma compounds that had the biggest impact on the variations of the five SXB aroma properties, according to partial least squares regression (PLS-R) analysis. The collinear network analysis also revealed that the largest positive correlation weight was discovered between the protein and furfural content, tannin content and cereal-like aroma profile while the highest negative correlation weight was found between the moisture and acetoin content. This study is a valuable resource for understanding how raw materials control the directional regulation of the sensory quality of the SXB liquor body.

Metabolomic Analysis of Fermented Tibetan Tea Using Bacillus circulans and Their Biological Activity on Mice via the Intestine-Hepatic Axis.

The use of Bacillus circulans as the sole starter provides better process control compared to natural fermentation. However, the chemical composition of fermented Tibetan tea by B. circulans and its regulatory effects on the intestine-liver axis has not been reported. For this purpose, a high-resolution liquid chromatography tandem mass spectrometry metabolomics approach was performed. The effects of fermented Tibetan tea on the intestine-liver axis of mice were also evaluated. Untargeted metabolomics analysis showed that the contents of catechin derivatives, flavonoids, phenolic acids, and terpenoids increased by 0.3, 2.38, 2.65, and 3.36%, respectively, compared with those before fermentation. Furthermore, 16S ribosomal RNA sequence analysis revealed that the relative abundance of Lactobacillus spp. in the intestine increased after consumption of fermented tea. Additionally, based on histological and quantitative PCR analyses, fermented Tibetan tea also improved intestinal development and intestinal barrier function in mouse, while increasing the antioxidant capacity of mouse liver. Thus, fermented Tibetan tea could provide beneficial health effects through the intestine-liver axis. These findings have facilitated the study of the chemical composition of Tibetan tea and provided theoretical support for its use as a natural beverage with intestinal probiotic functions.

Effects of Pu-erh and Dian Hong tea polyphenols on the gut-liver axis in mice.

Tea polyphenols (TP) are the most biologically active components in tea, with antioxidant, antiobesity, and antitumor properties, as well as the ability to modulate the composition and function of intestinal microbiota. This experimental study evaluated the chemical constituents of polyphenols in Pu-erh (PTP) and Dian Hong tea (DHTP). It also investigated the co-regulatory effects of PTP and DHTP on intestinal flora and liver tissues in mice using 16 S rRNA gene and transcriptome sequencing. The results revealed that DHT had higher concentrations of EGC (epigallocatechin), C (catechin), EC (epicatechin), and EGCG (epigallocatechin gallate). In contrast, PT had higher concentrations of GA (gallic acid), ECG (epicatechin-3-gallate), TF (theaflavin), and TB (theabrownin). PTP and DHTP consumption significantly reduced the rates of weight gain in mice. Microbial community diversity was significantly higher in PTP and DHTP-treated mice than in the control group. Notably, beneficial microbes such as Lactobacillus increased significantly in PTP-treated mice, whereas Lachnospiraceae increased significantly in DHTP-treated mice. Both PTP and DHTP improved the activity of the antioxidant enzymes (SOD) and total antioxidant capacity (T-AOC) in the liver. The transcriptome analysis revealed that the beneficial effects of PTP and DHTP were due to changes in various metabolic pathways, the majority of which were related to antioxidant and lipid metabolism. This study discovered that PTP and DHTP had beneficial effects in mice via the gut-liver axis.

Two-step biological approach for treatment of rapeseed meal.

Rapeseed meal (RSM) is an important source of protein, but its value is limited due to the poor digestibility and the presence of many antinutritional factors. In this study, a two-step biological method was developed for detoxifying RSM and increasing its protein value. In the first stage, various detoxifying enzymes and proteases were produced by Aspergillus niger during solid-state fermentation (SSF). In the second stage, coordinated enzymatic hydrolysis was employed to further degrade the antinutritional factors and macromolecular proteins in the fermented RSM. Following fermentation at 30 °C for 48 hr and enzymatic hydrolysis at 45 °C for 24 hr, the content of trichloroacetic acid soluble protein (TCA-SP) and glucosinolates (GLS) in RSM was increased by 81.70% and reduced by 30.06%, respectively, compared with that obtained using the SSF process alone. Moreover, to improve the efficiency of enzymatic hydrolysis, the yield of acid protease was increased by optimizing the composition of the medium so that the TCA-SP content was increased to 208.39 mg/g and accounted for 51.62% of the total RSM protein, which was 99.36% and 629.66% higher than that in the fermented RSM and control, respectively. Overall, these results demonstrate that the two-step process could be more effective for the degradation of the antinutritional factors and improvement of the protein quality of RSM compared to use of the SSF method alone, which may improve the utilization of RSM in food and animal feed. PRACTICAL APPLICATION: Rapeseed meal (RSM) is a protein source that provides high-quality nutrition and can be applied to the development of value-added products for humans and animal feed. To improve the utilization of RSM, a combined method of solid-state fermentation and enzymatic digestion was developed. Compared with the traditional solid-state fermentation method, the present method further improves the quality of RSM and demonstrates improved efficacy in increasing the small peptide content while reducing the levels of antinutritional factors.