Combination of entropy weighting and global stability index provides a potential strategy for monitoring the shelf-life of Litopenaeus vannamei during cold storage

Monitoring the quality degradation of shrimp during cold storage is a tough task due to the involvement of multi-biological process and the accurate kinetic model is extremely necessary to optimize the storage management. Here, the entropy weighting and global stability index (GSI) were combined to establish the model monitoring the shelf-life of Litopenaeus vannamei during storage at –23, –5, 0, 4 and 9 °C, respectively. The typically quality-related indicators including sensorial score, total aerobic count, total volatile base nitrogen, and activity of protease and polyphenol oxidase was selected to reflect the quality degradation. After systematical calculation, the weighting factors of these indicators were determined, respectively. Subsequently, the zero-order reaction model reflecting the overall quality degradation process was satisfactorily described based on GSI, in which the activation energy (Ea) and reaction rate constant (k0) were calculated to be (64.78 ± 0.75) kJ/mol and (3.47 ± 0.54) × 1011, respectively. As a consequence, the GSI model was established as following: GSI = 1 – 3.47 × 1011t × exp (–64.78 × 103/RT), with the relative error of less than 15%. Therefore, the established GSI model could be applied to monitor the quality deterioration of L. vannamei during cold storage and is helpful for distributors and consumers to determine the storing time

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

Effect of Mustard Essential Oil Combined 1-Methylcyclopropene Preservation Treatment on the Quality of Broccoli during Refrigerated Storage

The experiment took the broccoli (Brassica oleracea var. italica) as the research object, 1-methylcyclopropene (1-MCP), mustard essential oil (MEO) and 1-MCP combined MEO (1-MCP+MEO) were used to treat fresh green broccoli. The effects of physiological and biochemical indexes such as sensory quality, relative conductivity, chlorophyll, vitamin C and malondialdehyde (MDA) content on the quality of broccoli were investigated during storage. The result showed that with the increase of storage time, all groups of preservative treatments could effectively maintain the quality of broccoli during storage, among which 1-MCP+MEO treatment had the best storage effect on broccoli, effectively maintained the appearance of broccoli, avoided yellows and mildew, and slowed down the chlorophyll content and vitamin C degradation rate and made the chlorophyll content of broccoli always higher than that of other treatment groups. 1-MCP+MEO inhibited the increase of relative conductivity and MDA content in broccoli. On the 28th day of storage, the relative conductivity and MDA of the combined treatment group were 14.94% and 9.1 μmol/g, respectively, which were 43.1% and 27.6% lower than that of the control group respectively, and there was a significant difference (P<0.05), so that the cell integrity of the broccoli was maintained and the senescence of the broccoli was inhibited. After 28 days of storage, 1-MCP+MEO treatment group could effectively reduce the decrease of total phenol and total flavonoid contents, and combined treatment was 51.9% higher than that of control group, and total flavonoid content was 38.4% higher than that of control group. In addition, the activity of polyphenoloxidase (PPO) and peroxidase (POD) related to enzymatic browning was significantly inhibited, and the activity of PPO and POD were 23.6% and 48.1% lower than that of control group, respectively. Significantly lowered than control group (P<0.05). This study aims to provide a theoretical basis for the development of broccoli preservation technology and a new idea for the research and development of preservatives

Progress on the Anti-inflammatory, Anti-cancer Activities and Mechanism of Action of Fucoxanthin

Fucoxanthin is a carotenoid, reddish-brown in color, which is mainly derived from marine organisms such as brown algae and diatoms, and has aroused extensive scientific interest due to its unique chemical structure and abundant biological activities. Studies have shown that fucoxanthin processes significant anti-inflammatory and anti-cancer activities. Its anti-inflammatory mechanisms primarily include inhibiting oxidative stress, regulating inflammatory factors, inducting cell autophagy, and resisting cell apoptosis, etc. The main mechanism of anti-cancer activity includes inducing cell autophagy and apoptosis mechanisms, regulating the cell cycle, inhibiting cell migration, and suppressing cell invasion, among other aspects. In this paper, the research progress of anti-inflammatory and anti-cancer activities and related mechanisms of action of fucoxanthin is briefly summarized, which provides the theoretical basis and reference for further research and development of fucoxanthin

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

Thawing of Frozen Hairtail (<i>Trichiurus lepturus</i>) with Graphene Nanoparticles Combined with Radio Frequency: Variations in Protein Aggregation, Structural Characteristics, and Stability

Efficient thawing can preserve the quality of frozen hairtail (Trichiurus lepturus) close to that of fresh hairtail. In contrast to air thawing (AT) and radio-frequency thawing (RT), this study looked at how graphene oxide (GO) and graphene magnetic (GM) nanoparticles paired with RT affect the microstructure and protein conformation of hairtails after thawing. The results suggested that GM-RT can reduce the myofibrillar protein (MP) damage and be more effective than other thawing treatments, like AT, RT, and GO-RT, in maintaining the microstructure of hairtail. The particle size and zeta potential showed that GM-RT could reduce the aggregation of MP during the thawing process compared to other thawing methods. Moreover, the texture of the hairtail after GM-RT exhibited higher hardness (1185.25 g), elasticity (2.25 mm), and chewiness (5.75 mJ) values compared to other thawing treatments. Especially compared with RT, the GM-RT treatment displayed significant improvements in hardness (27.24%), a considerable increase in springiness (92.23%), and an increase in chewiness (57.96%). GO-RT and GM-RT significantly reduced the centrifugal loss. The scanning electron microscopy results demonstrated that the effect of GM-RT was more akin to that of a fresh sample (FS) and characterized by a well-organized microstructure. In conclusion, GM-RT effectively diminished the MP aggregation and improved the texture of thawed fish. It can be regarded as a viable alternative thawing technique to enhance MP stability, which is vital for preserving meat quality