Research Advances on Organic Acid Degradation Process and Its Effects on Flavor of Fermented Alcohol Beverage

Moderate organic acids can make fermented alcohol beverage produce comfortable flavor and delicate taste, but during the fermentation process, the content of organic acids in fermented alcohol beverage is unstable. Too high can easily result in astringent and bitter taste and poor flavor, while too low can make the wine bland and tasteless. The type of organic acid also has important influence on the flavor of fermented alcohol beverage. Some methods of acid degradation are frequently used to accurately reduce the level of the primary organic acids in fermented alcohol beverage in order to improve its flavor and quality. This helps to better maintain the volatile flavor components in fermented alcohol beverage and control its flavor. In order to provide a theoretical foundation for improving the quality of fermented alcohol beverage and optimizing the brew processing, and promoting the large-scale sustainable development of fermented alcohol beverage industry, this paper describes the main acid degradation processes and their principles in fermented alcohol beverage, analyzes the benefits, drawbacks, and limitation of various processes, discusses the effects of acid degradation processes on the types of flavor substances in fermented alcohol beverage, and offers an outlook on future research for flavor regulation of fermented alcohol beverage

Nanoparticle Emulsions Enhance the Inhibition of NLRP3

Antibacterial delivery emulsions are potential materials for treating bacterial infections. Few studies have focused on the role and mechanism of emulsions in inflammation relief. Therefore, based on our previous analysis, in which the novel and natural Pickering emulsions stabilized by antimicrobial peptide nanoparticles were prepared, the regulation effect of emulsion on inflammasome was explored in silico, in vitro and in vivo. Firstly, the interactions between inflammasome components and parasin I or Pickering emulsion were predicted by molecular docking. Then, the inflammasome stimulation by different doses of the emulsion was tested in RAW 264.7 and THP-1 cells. Finally, in Kunming mice with peritonitis, NLRP3 and IL-1β expression in the peritoneum were evaluated. The results showed that the Pickering emulsion could combine with ALK, casp-1, NEK7, or NLRP3 to affect the assembly of the NLRP3 and further relieve inflammation. LPNE showed a dose–dependent inhibition effect on the release of IL-1β and casp-1. With the concentration of parasin I increased from 1.5 mg/mL to 3 mg/mL, the LDH activity decreased in the chitosan peptide-embedded nanoparticles emulsion (CPENE) and lipid/peptide nanoparticles emulsion (LPNE) groups. However, from 1.5 to 6 mg/mL, LPNE had a dose–dependent effect on the release of casp-1. The CPENE and parasin I-conjugated chitosan nanoparticles emulsion (PCNE) may decrease the release of potassium and chloride ions. Therefore, it can be concluded that the LPNE may inhibit the activation of the inflammasome by decreasing LDH activity, potassium and chloride ions through binding with compositions of NLRP3

Viscoelastic and Functional Properties of Cod-Bone Gelatin in the Presence of Xylitol and Stevioside

The physical, rheological, structural and functional properties of cod bone gelatin (CBG) with various concentrations (0, 2, 4, 6, 10, and 15%) of low-calorie sweeteners [xylitol (X) and stevioside (S)] to form gels were investigated. The gel strength of CBGX increased with increased xylitol due presumably to hydrogen bonds between xylitol and gelatin, but with CBGS the highest gel strength occurred when S concentration was 4%. Viscosity of CBGS samples were higher than CBGX due to S's high molecular mass. The viscoelasticity (G′ and G′′), foaming capacity and fat binding capacity of CBGX were higher while foam stability was lower. The emulsion activity and emulsion stability of CBGX were a little lower than CBGS at the same concentration. The structure of X is linear making it easier to form a dense three-dimensional network structure, while the complex cyclic structure of S had more difficulty forming a network structure with cod bone gelatin. Therefore, X may be a better choice for sweetening gelatin gels

Ultrastructure characteristics and quality changes of low-moisture Chilgoza pine nut (Pinus gerardiana) during the near-freezing-temperature storage

The effects of thermal treatment on the ultrastructure and quality of Chilgoza pine nuts stored at near-freezing temperature were investigated. The moisture content of pine nuts was adjusted to 13.3%, compared to the initial 17.3% moisture content. Thermal treatment improved the storage stability. The hydrolysis of lipids was delayed in low-moisture pine nuts, resulting in a significant inhibition of free fatty acid accumulation in pine nuts. Low-moisture pine nuts also showed lower peroxide and thiobarbituric acid (TBA)​ values compared with the control. Ultrastructure characterization revealed that thermal treatment maintained the cell integrity, deferred the degradation of the plasmalemma and protected the internal lipid droplet. Thermal treatment better retained the antioxidant components, including total phenolics and vitamin E, and reduced the activities of lipase and lipoxygenase in pine nuts. These results indicated that thermal treatment could retard the senescence and deterioration of quality in pine nuts stored at a near-freezing temperature.Se investigaron los efectos del tratamiento térmico en la ultrastructura y la calidad del piñón de pino Chilgoza almacenado a una temperatura cercana a congelación. El contenido de humedad de los piñones de este pino fue de 13,3%, en comparación con el contenido de humedad inicial de 17,3%. El tratamiento térmico mejoró la estabilidad de almacenamiento. La hidrólisis de los lípidos se retardó en los piñones de pino de baja humedad, resultando en una inhibición significativa de la acumulación de ácidos grasos libres en los piñones. Los piñones de pino de baja humedad también mostraron unos índices bajos de peróxido y TBA en comparación con la muestra control. La caracterización de la ultrastructura reveló que el tratamiento térmico mantuvo la integridad de las células, atrasó la degradación de la plasmalema y protegió la gota lipídica interna. El tratamiento térmico retuvo de forma más favorable los componentes antioxidantes, como el total fenólico y la vitamina E, además redujo la actividad de la lipasa y la lipoxigenasa en los piñones. Estos resultados indicaron que el tratamiento térmico podría retardar la senescencia y la deterioración de la calidad de los piñones almacenados a una temperatura cercana a la congelación

Effects of Pinus masoniana and Saxifraga stolonifera (L.) Meerb. Essential Oils Preservative Treatment on the Storage Quality of Shine Muscat Grapes

In this work, Pinus masoniana and Saxifraga stolonifera (L.) Meerb. essential oils were employed to develop preservative materials (i.e., preservative paper and preservative tablet), and effects of the preservative material treatments on Shine Muscat grapes under different temperatures (room temperature and low temperature) were also investigated. The results showed that the preservative paper was more effective than the preservative tablet to maintain the quality of the Shine Muscat in storage time. In addition, grapes treated with the preservative paper under low-temperature storage exhibited the optimum quality among all. Pinus masoniana-Saxifraga stolonifera (L.) Meerb. essential oils preservative paper effectively inhibited the weight loss rate, maintained the color and hardness, slowed down the decrease of total soluble solids, acidity and reducing sugar. After storage for 5 weeks under low temperature with the preservative paper, the weight loss rate of the grapes was 0.36%, significantly lower than that of the control group (0.81%, P<0.05), the total soluble solids and acidity were 1.65% and 0.13% significantly higher than those of the control group (P<0.05), respectively. In addition, the increase of the activities of polyphenol oxidase, peroxidase and malondialdehyde content in grapes were effectively inhibited by the preservative paper, the malondialdehyde content was 0.88 nmol/g, significantly lower than that in the control group (3.25 nmol/g, P<0.05). In conclusion, Pinus masoniana and Saxifraga stolonifera (L.) Meerb. essential oils preservative paper plays the role of maintaining the quality of the Shine Muscat during storage. Besides, preservative paper is convenient to use and has the prospect of industrialization

The accumulation of active ingredients of Polygonatum cyrtonema Hua is associated with soil characteristics and bacterial community

IntroductionWith the increasing demand for health products derived from Polygonati rhizoma (PR), people begin to artificially plant Polygonatum cyrtonema Hua (P. cyrtonema) in the middle and lower reaches of the Yangtze River. To promote P. cyrtonema cultivation and increase farmers’ income, efforts are needed to understand the ways to obtain high-quality PR under artificial cultivation conditions.MethodsRhizomes of artificial planting P. cyrtonema and rhizosphere soils were collected across five regions in Zhejiang Province, China. Subsequently, the contents of the main active ingredients of P. cyrtonema and soil properties were analyzed, and both rhizosphere and endophytic bacteria of P. cyrtonema were detected by 16S rDNA sequencing. The relationship between the active ingredients and soil properties, and the dominant bacteria were investigated by correlation analysis.ResultsThe content of active ingredients of P. cyrtonema from the five regions varied significantly, especially polysaccharides and saponins. High-throughput sequencing demonstrated that Proteobacteria was the dominant bacterial phylum in all samples, and Burkholderia-Caballeronia-Paraburkholderia was the main endophytic bacterial genus in rhizome. In addition, the bacterial diversity and richness of rhizosphere soil samples were higher than those of rhizome samples. Soil physicochemical properties and enzyme activities were significantly different across regions, leading to notable variations in the community structures of rhizosphere and endophytic bacteria. Redundancy analysis (RDA) displayed that pH and urease (UE) were the major factors altering shifting rhizosphere bacteria community structure. Moreover, the composition and diversity of rhizome endophytic bacteria were principally affected by both soil physicochemical properties and soil enzyme activities. Soil properties and bacteria from rhizosphere soil and rhizome had a considerable impact on certain active ingredients in P. cyrtonema under artificial cultivation conditions after Pearson correlation analysis. Polysaccharides were significantly correlated with nutrient-rich soil and endophytic bacteria, such as Burkholderia-Caballeronia-Paraburkholderia, Pseudomonas, Ralstonia, and Bacillus. However, flavonoids were associated with nutrient-poor soil. Saponins were positively correlated with OM and available phosphorous (AP) and were significantly negatively affected by rhizosphere bacterial communities.ConclusionThe study demonstrated that bacterial microorganisms were involved in the accumulation of active ingredients of P. cyrtonema together with soil physicochemical properties and enzyme activities, which provided a theoretical basis for the scientific and effective artificial cultivation of high-quality P. cyrtonema

Texture characteristics of chilled prepared Mandarin fish (Siniperca chuatsi) during storage

Mandarin fish that have been prepared and chilled have a shelf life of 4 days at 4°C storage, according to the total volatile basic nitrogen values. During the storage process, we observed that the texture characteristics of these fish significantly deteriorated. Certain low-abundance proteins were degraded during the shelf life, which resulted in changes in protein conformation and protein–water interaction patterns. The water-holding capacity of the fish decreased during 4°C storage; nuclear magnetic resonance analysis showed that the binding of water in fish was weakened as shelf storage prolonged and a portion of the free water was also “squeezed” to the surface of the fish in the later stages of storage. A correlation analysis showed that a decrease in the immobilized water content and mobility was associated with quality deterioration of the fish, which may be a result of increase in hydrophobic interaction and disulfide bonds in the fish during storage