Metabolomics and HS-SPME-GC-MS-based analysis of quality succession patterns and flavor characteristics changes during the fermentation of Lycium barbarum and Polygonatum cyrtonema compound wine.

This work set out to investigate how the physicochemical markers, volatiles, and metabolomic characteristics of mixed fermented the fermentation of Lycium barbarum and Polygonatum cyrtonema compound wine (LPCW) from S. cerevisine RW and D. hansenii AS2.45 changed over the course of fermentation. HS-SPME-GC-MS combined with non-targeted metabolomics was used to follow up and monitor the fermentation process of LPCW. In total, 43 volatile chemical substances, mostly alcohols, esters, acids, carbonyl compounds, etc., were discovered in LPCW. After 30 days of fermentation, phenylethyl alcohol had increased to 3045.83 g/mL, giving off a rose-like fresh scent. The biosynthesis of valine, leucine, and isoleucine as well as the metabolism of alanine, aspartic acid, and glutamic acid were the major routes that led to the identification of 1385 non-volatile components in total. This study offers a theoretical foundation for industrial development and advances our knowledge of the fundamental mechanism underlying flavor generation during LPCW fermentation.

Exploring the effects of the fermentation method on the quality of Lycium barbarum and Polygonatum cyrtonema compound wine based on LC-MS metabolomics.

This study aimed to examine the effect of fermentation methods on the quality of Lycium barbarum and Polygonatum cyrtonema compound wine (LPW) by combining non-targeted metabolomic approaches with chemometrics and path profiling to determine the chemical and metabolic properties of LPW. The results demonstrated that SRA had higher leaching rates of total phenols and flavonoids, reaching 4.20 ± 0.10 v/v ethanol concentration. According to LC-MS non-targeting genomics, the metabolic profiles of LPW prepared by different mixtures of fermentation methods (Saccharomyces cerevisiae RW; Debaryomyces hansenii AS2.45) of yeast differed significantly. Amino acids, phenylpropanoids, flavonols, etc., were identified as the differential metabolites between different comparison groups. The pathways of tyrosine metabolism, biosynthesis of phenylpropanoids, and metabolism of 2-oxocarboxylic acids enriched 17 distinct metabolites. SRA stimulated the production of tyrosine and imparted a distinctive saucy aroma to the wine samples, providing a novel research concept for the microbial fermentation-based production of tyrosine.

Dynamic analysis of microbial communities and flavor properties in Merlot wines produced from inoculation and spontaneous fermentation.

The microbiota is of great importance in forming flavor compounds and improving sensory characteristics during wine fermentation. Understanding microbial succession is critical for controlling its contribution to wine flavor with predictable sensory quality. In this study, microbial community composition and characteristic flavor compounds were identified during the inoculation fermentation (IF) and spontaneous fermentation (SF) to provide a basis for exploring the relationship between these microorganisms and volatile components. The results demonstrated that SF had higher fungal community diversity and lower bacterial community diversity than IF. Eleven (11) fungal and 10 bacterial genera (relative abundance > 0.1 %) were considered beneficial microbiota. Saccharomyces, Hanseniaspora, and Alternaria were the leading fungal genera in SF. Massilia, Nesterenkonia, and Halomonas were the predominant bacteria in IF, while Tatumella and Ochrobactrum were mainly from SF. In addition, the microbial community composition was reshaped via correlational analysis between microbiota succession and physicochemical properties, mainly attributed to the changes in environmental factors during fermentation. The SF wines had more aromatic higher alcohols, acetate esters, and terpenes. Also, the sensory evaluation showed that the SF wines were characterized by more fruity, floral, intense, and typical aromas. The associations between the microbial community and the volatile components indicated that the dominant species largely determined the characteristic flavor compounds during fermentation.

Effect of fermentation methods on the quality and in vitro antioxidant properties of Lycium barbarum and Polygonatum cyrtonema compound wine.

Lycium barbarum and Polygonatum cyrtonema are known for their medicinal, edible, and ornamental properties. The sensory indices of the novel high-quality L. barbarum and P. cyrtonema compound wine (LPCW) fermented by Saccharomyces cerevisiae RW and Debaryomyces hansenii AS2.45 under different inoculation methods were analyzed. The alcohol content of the LPCW ranged from 3.88 to 4.75 % under three mixed inoculations. The total saponin and total polysaccharide contents in LPCW inoculated with D. hansenii first and S. cerevisiae after 24 h were 4.39 mg/mL and 0.21 mg/mL, respectively. Ethyl butyrate, citronellol, and 3-(methylthio) propanol were unique metabolites of D. hansenii. 4-Methoxybenzoic acid was the core product of brewing of by S. cerevisiae. Except for wine inoculated with S. cerevisiae only, the acceptability scores of all the LPCW samples were higher than 7.3. Our data provided the foundation for the development and application of medicinal and food homologous substances in food fermentation.

Indigenous Non-Saccharomyces Yeasts With ß-Glucosidase Activity in Sequential Fermentation With Saccharomyces cerevisiae: A Strategy to Improve the Volatile Composition and Sensory Characteristics of Wines.

Non-Saccharomyces (NS) yeasts with high ß-glucosidase activity play a vital role in improving the aroma complexity of wines by releasing aroma compounds from glycosidic precursors during fermentation. In this study, the effect of sequential inoculation fermentation of Meyerozyma guilliermondii NM218 and Hanseniaspora uvarum BF345 with two Saccharomyces cerevisiae strains [Vintage Red™ (VR) and Aroma White™ (AW)] on volatile compounds and sensory characteristics of wines was investigated. Prior to winemaking trials, the sequential inoculation times of the two NS yeasts were evaluated in synthetic must, based on changes in strain population and enzyme activity. The intervals for inoculation of NM218 and BF345 with the S. cerevisiae strains were 48 and 24 h, respectively. In the main experiment, sequential inoculation fermentations of the two strains with S. cerevisiae were carried out in Cabernet Sauvignon (CS) and Chardonnay (CH) grape must. The oenological parameters, volatile composition, and sensory characteristics of the final wines were assessed. No clear differences were observed in the oenological parameters of the sequentially fermented CH wines compared with the control, except for residual sugar and alcohol. However, in CS wines, the total acid contents were significantly lower in the wines fermented by sequential inoculation compared to the control. Both NM218 and BF345 improved the aroma complexity of wines by increasing esters and terpenes when inoculated with S. cerevisiae strains compared to inoculation with S. cerevisiae strains alone. NM218 resulted in a more positive effect on CS wine aroma, with higher levels of citronellol and trans-nerolidol. BF345 significantly enhanced the floral and fruity aromas of CH wine by producing higher concentrations of geranyl acetone, ß-damascenone, trans-nerolidol, and nerol. Both NM218 and BF345 yeasts could potentially be used to improve wine aroma and overall quality, especially wine floral and fruity aromas, when used in sequential inoculation with S. cerevisiae.

Enzymatic Characterization of Purified ß-Glucosidase from Non-Saccharomyces Yeasts and Application on Chardonnay Aging.

The application of ß-glucosidase from non-Saccharomyces yeasts to improve wine aroma has been widely explored. However, few enzymes are active under the severe conditions of wine aging (high ethanol concentration, low temperature, and low pH). Therefore, the application of ß-glucosidase in wine aging needs further research. In this study, the ß-glucosidases Mg-ßgl and Hu-ßgl extracted from Meyerozyma guilliermondii NM218 and Hanseniaspora uvarum BF345 were purified and used in young Chardonnay wines aged for 50 days. The enzyme activity of the two enzymes was measured. The effects of the two enzymes and a commercial ß-glucosidase (An-ßgl) on the volatile composition and sensory quality of the wine were also determined. The results showed that Mg-ßgl and Hu-ßgl had high specific activity of 1.95 U/mg and 2.11 U/mg, respectively, maintaining the activity of 70-80% at 20 °C, pH of 3.0-4.0, and 15% ethanol, corresponding to wine aging conditions. Analysis of volatiles with GC-MS showed a 65-70% increase in total terpenoids and new detection of C13-norisoprenoids when the wines were treated with the three ß-glucosidases. In addition, wines treated with Mg-ßgl and Hu-ßgl had more hexanol, phenylethanol, ethyl octanoate, ethyl heptanoate, and ethyl caprate than wines treated without and with An-ßgl. In sensory analysis, the judges showed a greater preference for Hu-ßgl-treated wines, to which they attributed pleasant sweet, floral, honey, pomelo, and banana aromas. The results of this study not only offer a way to improve flavor complexity in wine but also provide a reference for the use of other edible sources of ß-glucosidase in wine aging.

Antioxidant effect of yeast on lipid oxidation in salami sausage.

Salami is a kind of fermented meat product with rich nutrition and unique flavor. Because it is rich in fat, it is easy to oxidize to produce bad flavor. Compared with the way of adding artificial or natural antioxidants to reduce the degree of sausage oxidation, the antioxidant characteristics of developing the starter itself deserve more attention. In this study, firstly the antioxidant activities of 5 strains of yeast were measured in vitro, and then the mixture of yeast and Lactobacillus rhamnosus YL-1 was applied to fermented sausage model. The effect of the starter in the sausage model was investigated through physicochemical parameters, degree of fat oxidation, free fatty acid content, and though volatile flavor compound analysis, sensory evaluation and various indexes after storage were observed. Metagenomics was used to explore metabolic pathways, functional genes and key enzymes related to lipid oxidizing substances in sausage in yeast. The results showed that Wickerhamomyces anomalus Y12-3 and Y12-4 had strong tolerance to H2O2, and had higher SOD and CAT enzyme activities. The addition of yeast effectively reduced the material value of peroxidation value and active thiobarbiturate in salami. In flavor analysis, the content of flavor compounds associated with lipid oxidation, such as hexanal, heptanal, nonanal and (E)-2-decenal were significantly lower with the use of Debaryomyces hansenii Y4-1 and Y12-3. Meanwhile, the possible pathways of yeast metabolism of flavor substances related to lipid oxidation (mainly aldehydes) were discussed with the help of metagenomic techniques. According to the results of metagenomics, fatty acid degradation (ko00071) metabolic pathway was related to the degradation of aldehydes through aldehyde dehydrogenase, which was the potential key enzyme.

Effect of XlogP and hansen solubility parameters on the prediction of small molecule modified docetaxel, doxorubicin and irinotecan conjugates forming stable nanoparticles.

Small molecule-chemotherapeutic drug conjugate nanoparticles (SMCDC NPs) has a great advantage in improving drug loading. However, the factors which influence these conjugates forming stable nanoparticles (NPs) are currently unclear. In our previous studies, we synthesized a series of fatty acid-paclitaxel conjugates and suggested that the changes in the hydrophobic parameters (XlogP), solubility parameters and crystallinity of these fatty acid-paclitaxel conjugates were the key factors for affecting these small molecule-chemotherapeutic drug conjugates (SMCDCs) forming stable NPs in water. Here, we selected clinically widely used chemotherapeutic drug (docetaxel (DTX), doxorubicin (DOX) and irinotecan (Ir)) as model drug, and chose three straight-chain fatty acids (acetic acid (Ac), hexanoic acid (HA) and stearic acid (SA)) and one branched small molecule (N-(tert-butoxycarbonyl) glycine (B-G)) to synthesize 12 SMCDCs. Our results indicated that our prediction criterions obtained from paclitaxel conjugates were also appropriated for these synthesized SMCDCs. We suggested that the present studies expanded the scope of application of the above-mentioned influencing factors, provided research ideas for the rational design of SMCDC forming NPs and a basis for screening NPs with good anticancer activity.

Functional Characteristics of Lactobacillus and Yeast Single Starter Cultures in the Ripening Process of Dry Fermented Sausage.

Dry fermented sausage is popular among the world because of its rich nutrition and unique flavor. Starter cultures play an important role in the quality of dry fermented sausage. In this study, probiotics lactic acid bacteria Lactobacillus delbrueckii N102, Latilactobacillus sakei H1-5, Debaryomyces hansenii Y4-1, and Wickerhamomyces anomalus Y12-3 were isolated from food-borne materials. The physicochemical properties, microbial populations, TBARS, lipolysis, proteolysis, and volatile flavor compounds of dry fermented sausages with different starter cultures were evaluated comparatively during the ripening process. The results showed that both L. delbrueckii N102 and L. sakei H1-5 grow well and could rapidly reduce the pH value of the products. At the same time, they could significantly reduce the number of Enterobacter putrefaciens, so as to ensure the safety of the products. In addition, the strains N102 promoted the formation of flavor compounds 2,3-butanedione, 3-hydroxy-2-butanone, and carnosine, whereas taurine content of batch H1-5 was significantly increased, while yeast y4-1 and y12-3 could also grow faster in sausage and promoted the esters and alcohols formation such as ethyl acetate and linalool, with the formation of γ-aminobutyric acid by y4-1. Compared with lactic acid bacteria, yeasts showed to contribute more in flavor formation and effective inhibition of lipid oxidation. The starter cultures played different roles in flavor contribution and had obvious differentiation in the ripening process of dry fermented sausage.

Antitumor activity of the bioreductive prodrug 3-(2-nitrophenyl) propionic acid-paclitaxel nanoparticles (NPPA-PTX NPs) on MDA-MB-231 cells: in vitro and in vivo.

BACKGROUND: 3-(2-Nitrophenyl) propionic acid-paclitaxel (NPPA-PTX) is a paclitaxel (PTX) bioreductive prodrug synthesized by our lab. We hypothesize that NPPA-PTX can self-assemble to form nanoparticles (NPs). MATERIALS AND METHODS: In the present research, the theoretical partition coefficient (XlogP) and Hansen solubility parameters of NPPA-PTX were calculated. NPPA-PTX nanoparticles prepared by NPPA-PTX and DSPE-PEG (NPPA-PTX:DSPE-PEG =1:0.1, w/w) (NPPA-PTX@PEG NPs) were prepared and characterized. The cellular uptake, in vitro antitumor activity, in vivo targeting effect, tumor distribution, in vivo antitumor activity, and safety of NPPA-PTX@PEG NPs were investigated. RESULTS: Our results indicate that NPPA-PTX can self-assemble to form NPPA-PTX@PEG NPs. Both the cellular uptake and safety of NPPA-PTX@PEG NPs were higher than those of Taxol. NPPA-PTX@PEG NPs could target tumor tissues by a passive targeting effect. In tumor tissues, NPPA-PTX@PEG NPs could completely transform into active PTX. The in vivo antitumor activity of NPPA-PTX@PEG NPs was confirmed in MDA-MB-231 tumor-bearing nude mice. CONCLUSION: The bioreductive prodrug NPPA-PTX could self-assemble to form NPs. The safety and antitumor activity of NPPA-PTX@PEG were confirmed in our in vitro and in vivo experiments. The NPPA-PTX@PEG NPs developed in this study could offer a new way of preparing bioreductive prodrug, self-assembled NPs suitable for antitumor therapy.

A case of lepromatous leprosy complicated by hemophagocytosis misdiagnosed as hemophagocytic lymphohistiocytosis.

Leprosy is an infectious chronic granulomatous disease caused by Mycobacterium leprae. The disease mainly affects the skin, peripheral nerves, mucosa, and viscera. The World Health Organization has reported that most countries with high endemicity have reached the goal of eliminating leprosy (defined as reaching a prevalence of <1 leprosy case per 10 000 population) at the national level, after years of proactive control campaigns. The incidence of leprosy has been decreasing across the globe year by year. However, misdiagnosis happens occasionally due to the complexity of clinical manifestations and lack of physician awareness of this disease. We report a case of lepromatous leprosy complicated by hemophagocytosis misdiagnosed as hemophagocytic lymphohistiocytosis.