Thermal treatment alternatives for enzymes inactivation in fruit juices: Recent breakthroughs and advancements.

Fruit juices (FJs) are frequently taken owing to their nutritious benefits, appealing flavour, and vibrant colour. The colours of the FJs are critical indicators of the qualitative features that influence the consumer's attention. Although FJs' intrinsic acidity serves as a barrier to bacterial growth, their enzymatic stability remains an issue for their shelf life. Inactivation of enzymes is critical during FJ processing, and selective inactivation is the primary focus of enzyme inactivation. The merchants, on the other hand, want the FJs to stay stable. The most prevalent technique of processing FJ is by conventional heat treatment, which degrades its nutritive value and appearance. The FJ processing industry has undergone a dramatic transformation from thermal treatments to nonthermal treatments (NTTs) during the past two decades to meet the requirements for microbiological and enzymatic stability. The manufacturers want safe and stable FJs, while buyers want high-quality FJs. According to the past investigation, NTTs have the potential to manufacture microbiologically safe and enzymatically stable FJs with low loss of bioactive components. Furthermore, it has been demonstrated that different NTTs combined with or without other NTTs or mild heating as a hurdle technology increase the synergistic effect for microbiological safety and stability of FJs. Concise information about the variables that affect NTTs' action mode has also been addressed. Primary inactivates enzymes by modifying the protein structure and active site conformation. NTTs may increase enzyme activity depending on the nature of the enzyme contained in FJs, the applied pressure, pH, temperature, and treatment period. This is due to the release of membrane-bound enzymes as well as changes in protein structure and active sites that allow substrate interaction. Additionally, the combination of several NTTs as a hurdle technology, as well as temperature and treatment periods, resulted in increased enzyme inactivation in FJs. Therefore, a combination of thermal and non-thermal technologies is suggested to increase the effectiveness of the process as well as preserve the juice quality.

Global Metabolomics Reveals That Vibrio natriegens Enhances the Growth and Paramylon Synthesis of Euglena gracilis.

The microalga Euglena gracilis is utilized in the food, medicinal, and supplement industries. However, its mass production is currently limited by its low production efficiency and high risk of microbial contamination. In this study, physiological and biochemical parameters of E. gracilis co-cultivated with the bacteria Vibrio natriegens were investigated. A previous study reports the benefits of E. gracilis and V. natriegens co-cultivation; however, no bacterium growth and molecular mechanisms were further investigated. Our results show that this co-cultivation positively increased total chlorophyll, microalgal growth, dry weight, and storage sugar paramylon content of E. gracilis compared to the pure culture without V. natriegens. This analysis represents the first comprehensive metabolomic study of microalgae-bacterial co-cultivation, with 339 metabolites identified. This co-cultivation system was shown to have synergistic metabolic interactions between microalgal and bacterial cells, with a significant increase in methyl carbamate, ectoine, choline, methyl N-methylanthranilate, gentiatibetine, 4R-aminopentanoic acid, and glu-val compared to the cultivation of E. gracilis alone. Taken together, these results fill significant gaps in the current understanding of microalgae-bacteria co-cultivation systems and provide novel insights into potential improvements for mass production and industrial applications of E. gracilis.

ACT001 modulates the NF-κB/MnSOD/ROS axis by targeting IKKß to inhibit glioblastoma cell growth.

Glioblastomas are high-grade brain tumors with poor prognoses, and new therapeutic approaches for these tumors are critically needed. This study revealed the underlying mechanisms of a new orphan drug, ACT001, that is currently in clinical trials for the treatment of advanced glioblastoma in Australia and China. ACT001 significantly suppressed glioma cell proliferation and induced apoptosis and cell cycle arrest in vitro, as determined by Cell Counting Kit-8 assays and flow cytometry. In addition, U-118 MG cells with high expression of p-IKKß were sensitive to ACT001. Changes in the oxidative stress pathway in U-118 MG cells were detected with the isobaric tags for relative and absolute quantitation (iTRAQ) method. We further verified that ACT001 elevated the levels of reactive oxygen species (ROS) by regulating NF-κB-targeted MnSOD. ACT001 markedly inhibited NF-κB activation by directly binding IKKß and inhibiting its phosphorylation. Overexpression of IKKß markedly attenuated the changes in MnSOD and NOX1, indicating that ACT001 increased the levels of ROS by reducing the protein expression of p-IKKß. Furthermore, ACT001 reduced cyclin B1/CDC2 expression and triggered G2/M phase arrest by increasing ROS production. ACT001 also upregulated the expression of Bax and Bim and induced apoptosis in a ROS-dependent manner. ACT001 effectively suppressed the growth of U-118 MG tumors in BALB/c nude mice and GL-261-luciferase tumors in C57BL/6 J mice. Finally, ACT001 downregulated the expression of p-p65, MnSOD, cyclin B1, CDC2, and Ki67 in U-118 MG tumor tissues. Patients with activated NF-κB signaling should thus be given priority for enrollment in future phase II clinical trials. KEY MESSAGES: ACT001 directly bind to IKKß and inhibited its phosphorylation. The inhibition of p-IKKß induced the generation of ROS. ACT001 promoted the generation of ROS by regulating MnSOD expression to induce G2/M phase arrest.

Chitin/chitosan derivatives and their interactions with microorganisms: a comprehensive review and future perspectives.

Chitosan, obtained as a result of the deacetylation of chitin, one of the most important naturally occurring polymers, has antimicrobial properties against fungi, and bacteria. It is also useful in other fields, including: food, biomedicine, biotechnology, agriculture, and the pharmaceutical industries. A literature survey shows that its antimicrobial activity depends upon several factors such as: the pH, temperature, molecular weight, ability to chelate metals, degree of deacetylation, source of chitosan, and the type of microorganism involved. This review will focus on the in vitro and in vivo antimicrobial properties of chitosan and its derivatives, along with a discussion on its mechanism of action during the treatment of infectious animal diseases, as well as its importance in food safety. We conclude with a summary of the challenges associated with the uses of chitosan and its derivatives.

Fatty acid and metabolomic profiling approaches differentiate heterotrophic and mixotrophic culture conditions in a microalgal food supplement 'Euglena'.

BACKGROUND: Microalgae have been recognized as a good food source of natural biologically active ingredients. Among them, the green microalga Euglena is a very promising food and nutritional supplements, providing high value-added poly-unsaturated fatty acids, paramylon and proteins. Different culture conditions could affect the chemical composition and food quality of microalgal cells. However, little information is available for distinguishing the different cellular changes especially the active ingredients including poly-saturated fatty acids and other metabolites under different culture conditions, such as light and dark. RESULTS: In this study, together with fatty acid profiling, we applied a gas chromatography-mass spectrometry (GC-MS)-based metabolomics to differentiate hetrotrophic and mixotrophic culture conditions. CONCLUSIONS: This study suggests metabolomics can shed light on understanding metabolomic changes under different culture conditions and provides a theoretical basis for industrial applications of microalgae, as food with better high-quality active ingredients.

Thermal Degradation and Isomerization of ß-Carotene in Oil-in-Water Nanoemulsions Supplemented with Natural Antioxidants.

The goal of this study was to see the impact on the retention and isomerization of encapsulated ß-carotene (BC) in nanoemulsions fortified with natural antioxidants (α-tocopherol (AT) and l-ascorbic acid (AA)). The physical stability of nanoemulsion, oxidative stability, and isomerization of all-trans-ß-carotene (BC) in oil-in-water (O/W) nanoemulsions were determined in the presence or absence of natural antioxidants at 25 and 50 °C at certain intervals of time by high-performance liquid chromatography (HPLC). Sodium caseinate was used as the emulsifier, and corn oil (CO) was more protective than medium-chain triglycerides (MCT) and used for isomerization studies. Mean diameters of control (without antioxidants) and AA- and AT-fortified particles were similar. Mean particle diameter of nanoemulsions increased from 10 to 25 nm at 25 °C and from 40 to 50 nm at 50 °C during 30 days of storage. The isomerization from all-trans-BC to cis-BC isomers was inhibited by antioxidants. The isomerization rates were in the following order: 13-cis-BC > 15-cis-BC > 9-cis-BC. AT had better antioxidant activities than AA in inhibiting BC degradation in O/W nanoemulsions. The results indicated that BC encapsulated in nanoemulsions supplemented with antioxidants could significantly improve BC's chemical stability.

Effects of Lipids on in Vitro Release and Cellular Uptake of ß-Carotene in Nanoemulsion-Based Delivery Systems.

ß-Carotene (BC) nanoemulsions were successfully prepared by microfluidization. BC micellarization was significantly affected by bile salts and pancreatin concentration. Positive and linear correlation was observed between BC release and bile salts concentration. Pancreatin facilitated BC's release in simulated digestion. Compared to the control (bulk oil) (4.6%), nanoemulsion delivery systems significantly improved the micellarization of BC (70.9%). The amount of BC partitioned into micelles was positively proportional to the length of carrier oils. Unsaturated fatty acid (UFA)-rich oils were better than saturated fatty acid (SFA)-rich oils in transferring BC (p < 0.05). No significant difference was observed between monounsaturated fatty acid (MUFA)-rich oils and polyunsaturated fatty acid (PUFA)-rich oils (p > 0.05). A positive and linear relationship between the degree of lipolysis and the release of BC in vitro digestion was observed. Bile salts showed cytotoxicity to Caco-2 cells below 20 times dilution. BC uptake by Caco-2 cells was not affected by fatty acid (FA) compositions in micelles, but BC uptake was proportional to its concentration in the diluted micelle fraction. The results obtained are beneficial to encapsulate and deliver BC or other bioactive lipophilic carotenoids in a wide range of commercial products.

Treatment of allergic inflammation and hyperresponsiveness by a simple compound, Bavachinin, isolated from Chinese herbs.

Asthmatic inflammation is mediated by a type 2 helper T cell (Th2) cytokine response, and blocking Th2 cytokine production is proven to have a potent therapeutic effect against asthmatic inflammation. Using IL-4-green fluorescent protein (GFP) reporter mice, we demonstrated that Bavachinin, a single compound isolated from a Chinese herb, significantly inhibited Th2 cytokine production, including IL-4, IL-5 and IL-13. Notably, this compound almost completely blocked inflammation in the ovalbumin (OVA)-sensitized animal asthma model. Furthermore, we demonstrated that this chemical selectively affects the level of GATA-3, most likely by affecting the stability of GATA-3 mRNA. Our results demonstrate, for the first time, the potential therapeutic value of this single compound derived from Chinese herbs.

Three new flavonoids from the active extract of Fallopia convolvulus.

Five solvent extracts (ethanol, petroleum ether, EtOAC, n-butanol, and water) from Fallopia convolvulus (L.) Love were separated and their inhibitory effects on nitric oxide production in lipopolysaccharide-activated macrophages were evaluated. Three new flavonoids, falloconvolin A (1), falloconvolin B (2), and quercetin-3-O-(2-E-sinapoxyl)-glucopyranoside (3), together with 17 known phenolic compounds, were isolated from the active EtOAC extract, and their structures were elucidated on the basis of spectroscopic analysis and literature data.

[Cloning and expression of cDNA for maize nonspecific lipid transfer protein as well as calmodulin-binding activity analysis of the expression product].

Maize nonspecific lipid transfer protein (Zm-nsLTP) was cloned and expressed to investigate its CaM-binding activity. The cDNA of Zm-nsLTP was amplified using RT-PCR (Fig.1), and then inserted into the vector pET32a(+). The recombinant vector pET-Zm-nsLTP was expressed in E. coli BL21(DE3)trxB(-). Results of CaM-gel overlay assays (Fig.2) and CaM-sepharose pull-down experiments (Fig.3) indicated that recombinant Zm-nsLTP was bound to CaM in a Ca(2+)-independent manner, which is in accordance with the way that CaMBP-10 and Arabidopsis non-specific lipid transfer protein-1 (At-nsLTP1) are bound to CaM. The CaM-binding domain in Zm-nsLTP was mapped to the region of 47-60 amino acids (Fig.3), and online sequence analysis using Predict Protein program predicted that it has a BAA structure (Fig.4,5).

Bioconversion of isoeugenol into vanillin by crude enzyme extracted from soybean.

Crude enzyme extracted from soybean was used to convert isoeugenol into vanillin. The effects of several factors on the bioconversion were studied. Conversion was affected by the amount of substrate and was also improved by the addition of absorbents, among which powdered activated carbon was the best. The effect of H2O2 concentration on the conversion was also studied. The optimum concentration of H2O2 was 1% (v/v). With 10 g/L of powdered activated carbon and 0.1% H2O2 added, vanillin reached a maximum concentration of 2.46 g/L after 36 h, corresponding to a molar yield of 13.3%.