Natural Active Substances Research Articles

Recent Progress in Microencapsulation of Active Peptides—Wall Material, Preparation, and Application: A Review

Being a natural active substance with a wide variety of sources, easy access, significant curative effect, and high safety, active peptides have gradually become one of the new research directions in food, medicine, agriculture, and other fields in recent years. The technology associated with active peptides is constantly evolving. There are obvious difficulties in the preservation, delivery, and slow release of exposed peptides. Microencapsulation technology can effectively solve these difficulties and improve the utilization rate of active peptides. In this paper, the commonly used materials for embedding active peptides (natural polymer materials, modified polymer materials, and synthetic polymer materials) and embedding technologies are reviewed, with emphasis on four new technologies (microfluidics, microjets, layer-by-layer self-assembly, and yeast cells). Compared with natural materials, modified materials and synthetic polymer materials show higher embedding rates and mechanical strength. The new technology improves the preparation efficiency and embedding rate of microencapsulated peptides and makes the microencapsulated particle size tend to be controllable. In addition, the current application of peptide microcapsules in different fields was also introduced. Selecting active peptides with different functions, using appropriate materials and efficient preparation technology to achieve targeted delivery and slow release of active peptides in the application system, will become the focus of future research.

Preparation of Cod Skin Collagen Peptides/Chitosan-Based Temperature-Sensitive Gel and Its Anti-Photoaging Effect in Skin.

Photoaging decreases quality of life and increases the risk of skin cancer, underscoring the urgent need to explore natural, high-efficacy, anti-skin photoaging (SP) active substances. In this study, a gel (CS/CSCPs/β-GP gel) was prepared using chitosan (CS) and sodium β-glycerophosphate (β-GP) through crosslinking with small molecular CSCPs as the carried drug. We evaluated its structural characteristics and properties. The effect of CS/CSCPs/β-GP gel on the degree of ultraviolet (UV)-induced skin aging of mice was investigated through comparative analysis of skin damage, the integrity of collagen tissues and elastic fibers, levels of reactive oxygen species (ROS) and key inflammatory factors (tumor necrosis factor [TNF]-α and interleukin [IL]-1β, IL-6, and IL-10), and tissue expression of matrix metalloproteinase-3 (MMP-3) after repeated UV irradiation in a nude mice SP model. The results showed that CS/CSCPs/β-GP gel was successfully prepared and had the desired characteristics. Compared with CSCPs alone, the CS/CSCPs/β-GP gel more evidently improved typical photoaging characteristics on mouse dorsal skin. It also increased the moisture content, causing the skin to become glossy and elastic. Pathological skin analysis revealed that this peptide-carrying gel can effectively inhibit epidermal thickening, reduce tissue inflammatory infiltration, suppress collagen fiber degradation, increase the collagen content, alleviate structural elastic fiber damage, and significantly inhibit abnormal MMP-3 expression. In addition, biochemical analysis showed that the CS/CSCPs/β-GP gel can effectively inhibit the elevated expressions of ROS and key proinflammatory factors (TNF-α, IL-1β, IL-6) in photoaging skin tissues and promote expression of the anti-inflammatory factor IL-10. SP can cause many clinical skin diseases, such as solar freckle-like nevus, solar keratosis, cutaneous melanoma, and squamous cell carcinoma. CSCPs are a high-efficacy anti-SP natural active substance and CS/CSCPs/β-GP gel can synergistically enhance the CSCPs' anti-SP effect. The mechanism is likely related to the inhibited activation of ROS/nuclear transcription factor-κB signaling and the expression of downstream inflammatory factors.

Construction and Activity Study of a Natural Antibacterial Patch Based on Natural Active Substance-Green Porous Structures.

Bacterial infections are a serious threat to human health, and the rapid emergence of bacterial resistance caused by the abuse of antibiotics exacerbates the seriousness of this problem. Effectively utilizing natural products to construct new antimicrobial strategies is regarded as a promising way to suppress the rapid development of bacterial resistance. In this paper, we fabricated a new type of natural antibacterial patch by using a natural active substance (allicin) as an antibacterial agent and the porous structure of the white pulp of pomelo peel as a scaffold. The antibacterial activity and mechanisms were systematically investigated by using various technologies, including the bacteriostatic circle, plate counting, fluorescence staining, and a scanning electron microscope. Both gram-positive and negative bacteria can be effectively killed by this patch. Moreover, this natural antibacterial patch also showed significant anti-skin infection activity. This study provides a green approach for constructing efficient antibacterial patches.

The Mechanism of Two Benzaldehydes from Aspergillus terreus C23-3 Improve Neuroinflammatory and Neuronal Damage to Delay the Progression of Alzheimer's Disease.

Alzheimer's disease (AD), a neurodegenerative disease, is the most common cause of dementia in humans worldwide. Although more in-depth research has been carried out on AD, the therapeutic effect of AD is not as expected, and natural active substances are increasingly sought after by scientists. In the present study, we evaluated two benzaldehydes from a coral-derived Aspergillus terreus strain C23-3, their anti-neuroinflammatory activity in microglia (BV-2), and their neuroprotective activity and mechanisms in hippocampal neuronal cells (HT-22). These include the protein expression of iNOS, COX-2, MAPKs pathways, Tau protein-related pathways, caspases family-related signaling pathways. They also include the levels of TNF-α, IL-6, IL-18 and ROS, as well as the level of mitochondrial oxidative stress and neuronal cell apoptosis. The results showed that both benzaldehydes were effective in reducing the secretion of various inflammatory mediators, as well as pro-inflammatory factors. Among these, benzaldehyde 2 inhibited mitochondrial oxidative stress and blocked neuronal cell apoptosis through Tau protein-related pathways and caspases family-related signaling pathways, thereby inhibiting β-amyloid (Aβ)-induced neurological damage. This study reveals that benzaldehyde 2 has potential as a therapeutic agent for Alzheimer's disease, and offers a new approach to the high-value use of marine natural products.

Screening for in vitro inhibiting Nrf2 of some Vietnamese medicinal plants

Nuclear factor erythroid 2–related factor 2 (Nrf2) is vital in regulating cellular defenses against oxidative or environmental aggressors. Some studies reveal that increasing Nrf2 activity affects chemotherapy drug resistance in cancer; thus, Nrf2 has become an attractive target in cancer therapeutics research. Our study screened the effects of 52 methanol extracts from different parts of 24 medicinal plants used in traditional and folk medicine to evaluate the ability to inhibit Nrf2 and the cell viability by an in vitro model of Huh7 liver cancer cells at the crude extract concentration of 100 µg/mL. The study has successfully suggested a screening model for Nrf2 expression based on luciferase fluorescence assay of Huh7 cells transfected with the Nrf2 gene. The results of our study show that the Piper sarmentosum roots can inhibit nearly 90% of Nrf2 activity in cancer cells. We also found that the extracts of Vernonia amygdalina leaves, Phyllanthus amarus leaves, Zingiber zerumbet leaves, Hyptis suaveolens leaves and roots, Curcuma zedoaria leaves and roots, Luvunga scandens leaves, Helicteres hirsuta leaves, Oroxylum indicum stem and leaves, Lasia spinosa fruits and Crotalaria pallida leaves inhibited more than 60% of Nrf2 expression levels. Furthermore, the extracts from the leaves of Luvunga scandens and Curcuma zedoaria can cause toxicity on cancer cell of more than 70% at 100 µg/mL. From the study, we have the basis for further studies on natural active substances that have the effect of drug resistance by inhibiting the expression of Nrf2 on cancer cells.

Isolation, identification and molecular docking of anti-inflammatory peptides from walnut (Juglans regia L.) meal hydrolysates.

The oil extraction residue of walnuts is rich in proteins and has been employed in the formulation of various functional food products. In this study, alcalase and neutrase were used to hydrolyze defatted walnut meal protein to obtain anti-inflammatory peptides. After separation by ultrafiltration and by using Sephadex G-25, the fraction with the highest anti-inflammatory activity was identified using liquid chromatography-tandem mass spectrometry (LC-MS/MS), and 579 peptides were obtained. Then, four of the most stable binding tripeptides with the sequences Trp-Pro-Leu (WPL, MW: 414.2 Da), Trp-Ser-Leu (WSL, MW: 404.2 Da), Phe-Pro-Leu (FPL, MW: 375.2 Da) and Phe-Pro-Tyr (FPY, MW: 425.2 Da) were successfully identified by virtual screening. The anti-inflammatory activity determination of the synthetic peptide assay indicated that FPL (200 μM) exhibited excellent anti-inflammatory activity with inhibitory rates of 63.65 ± 2.64%, 68.25 ± 2.19%, 42.52 ± 2.01% and 59.39 ± 2.21% in terms of four inflammatory mediators (NO, TNF-α, IL-6 and IL-1β), respectively. It was speculated that the anti-inflammatory activity of walnut peptides might be related to hydrophobic amino acids and aromatic amino acids. By molecular docking, further insight into the theoretical interaction mechanism of binding revealed that hydrophobic interactions and hydrogen bonds turned out to be the main interaction forces between the four peptides and iNOS. These results indicated that FPL screened in this study could be expected to be used as a natural anti-inflammatory active substance in the functional food and pharmaceutical industries.

Protective Effect of Tea Saponins on Alcohol-Induced Gastric Mucosal Injury in Mice.

Excessive alcohol consumption harms the human body, particularly the digestive system, by causing damage to the gastric mucosa. Tea saponin is a natural active substance extracted from tea tree seeds that has gastroprotective potential against alcohol-induced mucosal damage. However, the protective mechanism of tea saponins is not fully understood. The current study aimed to explore the protective mechanism of tea saponins against alcohol-induced gastric mucosal injury in mice. Histopathological changes, immunohistochemistry, immunoblotting, and gastric mucosa-related cytokine levels were analyzed in three groups of male mice: model, control, and tea saponin-treated. Compared to the model group, the tea saponin group prominently ameliorated alcohol-induced gastric mucosal injury by improving cell necrosis, inflammatory cell infiltration, and edema. Downregulation of inflammation-related factors cluster of differentiation 68 (CD68), myeloperoxidase (MPO), tumor necrosis factor-α (TNF-α), and interleukin-1β (IL-1β) was also found in the tea saponin group. These results suggest that tea saponins have a protective effect against alcohol-induced gastric mucosal damage in mice. Therefore, tea saponin may serve as a food additive for gastric mucosal protection.

Research Progress of Natural Active Substances with Uric-Acid-Reducing Activity.

Hyperuricemia is a metabolic disease caused by the accumulation of uric acid in the body. Allopurinol, benzbromarone, and febuxostat, which are available in the market, have reduced the circulating urate levels; however, they exhibit serious side effects. Therefore, it is reasonable to develop a new active antihyperuricemia drug with few side effects. With the deepening of research, numerous kinds of literature have shown that natural active substances are effective in the treatment of hyperuricemia with a variety of sources and few side effects, which have become the focus of research in recent years. This review focuses on natural active substances with uric-acid-reducing activity and discusses their pharmacological effects. More specifically, the bioactive compounds of natural active substances are divided into five categories: natural extracts, monomer compounds extracted from plants, natural protease hydrolysates, peptides, and probiotic bacteria. In addition, the mechanisms by which these bioactive compounds exhibit hypouricemic effects can be divided into four classes: inhibition of key enzyme activities, promotion of uric acid excretion and inhibition of reabsorption in the kidney, promotion of decomposing uric acid precursors, and promotion of decomposing uric acid. Overall, this current and comprehensive review examines the role of natural active substances in the treatment of hyperuricemia.

Toxicological Comparison of Pesticide Active Substances Approved for Conventional vs. Organic Agriculture in Europe.

There is much debate about whether the (mostly synthetic) pesticide active substances (AS) in conventional agriculture have different non-target effects than the natural AS in organic agriculture. We evaluated the official EU pesticide database to compare 256 AS that may only be used on conventional farmland with 134 AS that are permitted on organic farmland. As a benchmark, we used (i) the hazard classifications of the Globally Harmonized System (GHS), and (ii) the dietary and occupational health-based guidance values, which were established in the authorization procedure. Our comparison showed that 55% of the AS used only in conventional agriculture contained health or environmental hazard statements, but only 3% did of the AS authorized for organic agriculture. Warnings about possible harm to the unborn child, suspected carcinogenicity, or acute lethal effects were found in 16% of the AS used in conventional agriculture, but none were found in organic agriculture. Furthermore, the establishment of health-based guidance values for dietary and non-dietary exposures were relevant by the European authorities for 93% of conventional AS, but only for 7% of organic AS. We, therefore, encourage policies and strategies to reduce the use and risk of pesticides, and to strengthen organic farming in order to protect biodiversity and maintain food security.

The effects of natural active substances in food on the toxicity of patulin

Patulin (PAT) is a mycotoxin, a secondary metabolite mainly produced by fungi of the generaAspergillus, Byssochlamys, andPenicillium. Many studies have looked into the potential impacts of this mycotoxin due to its high risk. Researchers are currently doing a more in-depth investigation of and employing physical, chemical, and biological ways to remove PAT. However, existing technology cannot completely remove it, and the residual PAT will continue to pose a threat to human health. As a result, substances capable of reducing PAT toxicity need be discovered. According to previous studies, natural components in food could reduce the toxicity of PAT. This article will review the different types of active compounds and discus the detoxification processes, as well as give recommendations for decreasing the toxicity of PAT and future research directions.

Non-coding RNA-related antitumor mechanisms of marine-derived agents.

In the last two decades, natural active substances have attracted great attention in developing new antitumor drugs, especially in the marine environment. A series of marine-derived compounds or derivatives with potential antitumor effects have been discovered and developed, but their mechanisms of action are not well understood. Emerging studies have found that several tumor-related signaling pathways and molecules are involved in the antitumor mechanisms of marine-derived agents, including noncoding RNAs (ncRNAs). In this review, we provide an update on the regulation of marine-derived agents associated with ncRNAs on tumor cell proliferation, apoptosis, cell cycle, invasion, migration, drug sensitivity and resistance. Herein, we also describe recent advances in marine food-derived ncRNAs as antitumor agents that modulate cross-species gene expression. A better understanding of the antitumor mechanisms of marine-derived agents mediated, regulated, or sourced by ncRNAs will provide new biomarkers or targets for potential antitumor drugs from preclinical discovery and development to clinical application.

A Bioactive Substance Derived from Brown Seaweeds: Phlorotannins.

Phlorotannins are a type of natural active substance extracted from brown algae, which belong to a type of important plant polyphenol. Phloroglucinol is the basic unit in its structure. Phlorotannins have a wide range of biological activities, such as antioxidant, antibacterial, antiviral, anti-tumor, anti-hypertensive, hypoglycemic, whitening, anti-allergic and anti-inflammatory, etc. Phlorotannins are mainly used in the fields of medicine, food and cosmetics. This paper reviews the research progress of extraction, separation technology and biological activity of phlorotannins, which will help the scientific community investigate the greater biological significance of phlorotannins.

A new green alternative solvent for extracting echinacoside and acteoside from Cistanche deserticola based on ternary natural deep eutectic solvent

Echinacoside and acteoside, the representative constituents of Cistanche deserticola Y. C. Ma (C. deserticola), are known for its many important biological activities. In this study, a novel ternary natural deep eutectic solvent (NADES) (citric acid, fructose and glucose in a 1:2:1 molar ratio, 30 % water content) was obtained through the adjustment and optimization of single-factor experiments. And through the Box-Behnken design optimization, the optimal extraction conditions were obtained, at the moment, the yields of echinacoside and acteoside were 6.16 and 2.13 mg/g, respectively. In addition, through computer molecular simulation, it was found that there are strong hydrogen bonds and interactions between the molecules of NADES, and the hydrogen bonds, van der Waals forces and π-π interactions played an important role in the extraction of echinacoside and acteoside from C. deserticola by NADES. Finally, compared with the traditional method, NADES ultrasound-assisted extraction of echinacoside and acteoside has a shorter time (15 min), the maximum extraction yield is 1.54–2.86 times and 1.26–2.52 times than that of traditional extraction methods for echinacoside and acteoside, respectively. This study demonstrates that NADES can provides a new direction for developing new sustainable alternatives, improving green extraction process and efficiency for extracting natural active substances.

Potential application of natural bioactive compounds as skin-whitening agents: A review.

Melanin is a skin pigment that gives color to the skin, hair, and eyes. The accumulation or over production of melanin can lead to aesthetic problems as well as serious diseases associated with hyperpigmentation. Skin lightening is described as the procedure of using natural or synthetic products to lighten the skin tone or provide an even skin complexion by reducing the amount of melanin in the skin; therefore, skin lightening products help people to treat their skin problems. Ingredients such as hydroquinone, ascorbic acid, and retinoic acid were used as whitening agents to lighten the skin. However, they have many adverse effects on the skin and body health, such as skin irritation. In this review, firstly, discuss on the directly/indirectly target melanogenesis-related signal pathways. Secondly, summarize potential natural bioactive ingredients with skin lightening properties from plants, marine organisms, microorganisms. Finally, the remaining problems and future challenges are also discussed. For relevant literature, a literature search was conducted using Google Scholar and Web of Science. Natural bioactive compounds, tyrosinase inhibitors, and other related topics were researched and evaluated. Natural products isolated from plant and animal resources are potential active cosmetic candidates for lightening the skin tone and skin whitening and protection against UV irradiation. Natural bioactive ingredients as cosmetic whitening additives have attracted increasingly attention due to their safety and cost effectiveness, with few side effects. Although natural active substances have been advocated for use in whitening cosmetics in recent years, there are still many challenges due to the fact that traditional inhibitors are used perennial in cosmetics which cannot be easily changed and the research on natural active substances is still in its infancy. In the future, by improving the extraction technique of natural extracts, it is achieved to give a qualitative and quantitative analysis of the active ingredients of the extracts, to determine the effect of the active components of action, and to find the substances that have the best possible whitening effect in natural organisms.

Isolation of a New Polysaccharide from Dandelion Leaves and Evaluation of Its Antioxidant, Antibacterial, and Anticancer Activities.

Dandelion, in China, has a long history as a medicinal and edible plant, and possesses high nutritional and medical value. The present study aimed to isolate a new polysaccharide (DLP-3) from dandelion leaves and to evaluate its antioxidant, antibacterial, and anticancer activities. The structure of DLP-3 was analyzed using HPLC, FT-IR, SEM, GC-MS, and NMR spectroscopy. DLP-3 mainly consisted of Man, Rha, GlcA, Glc, Gal, and Ara with molar ratios of 2.32, 0.87, 1.21, 3.84, 1.00, and 1.05, respectively, with a molecular weight of 43.2 kDa. The main linkages of DLP-3 contained (1→4)-α-d-Glc, (1→4,6)-α-d-Glc, (1→6)-α-d-Gal, (1→2)-α-d-Man, (1→4)-α-d-Man, β-l-Ara-(1→, and α-l-Rha-(1→. DLP-3 exhibited a smooth surface, purely flake-like structure, and a triple helix conformation. Moreover, DLP-3 presented obvious antioxidant and antibacterial activities in a concentration-dependent manner. DLP-3 showed significant anticancer activities by inhibiting tumor cell proliferation. These findings provide a theoretical basis for the application of DLP-3 as a natural functional active substance in functional foods.

Variability in metabolites produced by Talaromyces pinophilus SPJ22 cultured on different substrates

BackgroundSeveral metabolites released by fungal species are an essential source of biologically active natural substances. Gas chromatography high resolution time-of-flight mass spectrometry (GC-HRTOF-MS) is one of the techniques used in profiling the metabolites produced by microorganisms, including Talaromyces pinophilus. However, there is limited information regarding differential substrates’ impacts on this fungal strain’s metabolite profiling. This study examined the metabolite profile of T. pinophilus strain SPJ22 cultured on three different media, including solid czapek yeast extract agar (CYA), malt extract agar (MEA) and potato dextrose agar (PDA) using GC-HRTOF-MS. The mycelia including the media were plugged and dissolved in 5 different organic solvents with varying polarities viz.: acetonitrile, dichloromethane, hexane, 80% methanol and water, and extracts analysed on GC-HRTOF-MS.ResultsThe study revealed the presence of different classes of metabolites, such as fatty acids (2.13%), amides (4.26%), alkanes (34.04%), furan (2.13%), ketones (4.26%), alcohols (14.89%), aromatic compounds (6.38%), and other miscellaneous compounds (17.02%). Significant metabolites such as acetic acid, 9-octadecenamide, undecanoic acid methyl ester, hydrazine, hexadecane, nonadecane, eicosane, and other compounds reported in this study have been widely documented to have plant growth promoting, antimicrobial, anti-inflammatory, antioxidant, and biofuel properties. Furthermore, T. pinophilus grown on PDA and MEA produced more than twice as many compounds as that grown on CYA.ConclusionThus, our result showed that the production of essential metabolites from T. pinophilus is substrate dependent, with many of these metabolites known to have beneficial characteristics, and as such, this organism can be utilised as a sustainable and natural source for these useful organic molecules.

Integrated strategy of derivatization and separation for sensitive analysis of salvianolic acids using capillary electrophoresis with laser-induced fluorescence detection

Salvianolic acids (SAs) are a class of natural active substances that have been widely used in clinical treatment and food adjuvant therapy. In this work, we found that SAs could form the ternary complex with borax and 2-hydroxypropyl-β-cyclodextrin (HP-β-CD), thereby sensitizing their weak intrinsic fluorescence to maximized 92-fold for salvianolic acid B (SAB). The formation of ternary complex was dynamic and could complete once mixed, and the fluorescence intensity remained stable within 3 h. On this basis, an integrated strategy of derivatization and separation was proposed for the sensitive analysis of SAs using capillary electrophoresis (CE) with laser-induced fluorescence (LIF) detection. After the systematic investigation, a solution consisting of 20 mM borax and 20 mM HP-β-CD (pH 8.5) was selected as the running buffer. By the direct injection of SAs, the dynamic derivatization was realized in the capillary, and the baseline separation was achieved within 6 min, with the detection limits of 1.2-21.2 nM for four SAs (S/N=3). Then, the developed CE-LIF method was successfully applied to the quantitative analysis of SAs in four traditional ginsengs, including Salvia miltiorrhiza, Codonopsis pilosula, Panax quinquefolius and Panax ginseng with the recoveries ranging from 95.2% to 110.7%. Except for four target SAs, a large number of unknown electrophoretic peaks had also been observed in four ginsengs, and then were utilized for the identification of ginseng species via principal component analysis. Furthermore, a hypoxia/reoxygenation model was constructed using Rat cardiomyocyte H9c2 cells, and subsequently, the developed method was applied to continuously monitor the consumption of SAB in cell culture medium after its intervention.

Simple and efficient enzymatic procedure for p-coumaric acid synthesis: Complete bioconversion and biocatalyst recycling under alkaline condition

p-Coumaric acid (para-hydroxycinnamic acid, p-HCA), as a kind of natural active substance from plant cell walls, is widely used in medicine, food, and cosmetics with its antioxidant, anticancer, and other properties. Biological production of p-HCA can be achieved via one-step deamination of the L-tyrosine by tyrosine ammonia-lyase (TAL). Here, a new highly active TAL (Fc-TAL) from Flavobacterium columnare was identified via gene mining and heterologous expression. The purified Fc-TAL completely converts 22 mM L-tyrosine to p-HCA under alkaline condition (pH 9.5–10.0) at 55 °C. To increase enzymatic recyclability and reduce the bioproduction cost, Fc-TAL was immobilized on a silica nanospheres through silica-binding peptides (SiBP2) at pH 10. In comparison to free enzyme, the immobilized TALSiBP2 exhibited higher stability, over 50% activity was retained even after 10 consecutive catalytic cycles. Further experiments revealed that an aliquot of immobilized enzyme (about 200 mg TAL) can transform 20 g L-tyrosine into17.8 g p-HCA with 96% yields and 98% purity through 5 consecutive reaction cycles. Our studies not only provided a strategy for enzyme immobilization in alkaline condition, but also developed a green process for p-coumaric acid biosynthesis with the highest conversion rate and yield reported to date.

Evaluation of the antibacterial mechanism and biofilm removal effect of eugenol on Vibrio vulnificus and its application in fresh oysters

Eugenol is a natural active substance with high antibacterial activity, but its antibacterial activity against Vibrio vulnificus has not been extensively studied. The purpose of this study was to investigate the antibacterial and biofilm-clearing abilities and potential mechanisms of eugenol against V. vulnificus, and to provide knowledge for the use of eugenol to prevent oyster contamination. It was found that eugenol had an encouraging antibacterial effect on V. vulnificus with a minimum inhibitory concentration (MIC) of 0.2 mg/mL. The accumulation of reactive oxygen species (ROS) and the increase of malondialdehyde (MDA) content suggest that oxidative stress is involved in the bactericidal mechanism. Moreover, cell membrane hyperpolarization, changes in cell membrane integrity and morphology suggest that eugenol can reduce the permeability and integrity of cell membranes in V. vulnificus. In addition, eugenol produced a significant biofilm clearance effect on V. vulnificus, as evidenced by the reduced amount of biofilm and the reduction of polysaccharides and viable cells in the biofilm. Finally, eugenol was able to effectively inhibit the activity of V. vulnificus in artificially contaminated oyster at 4 °C and 25 °C. But sensory analysis showed that 0.10% eugenol was most acceptable to trained panelists. All of these highlight the great promise of eugenol as a natural bacteriostatic agent for the food industry.

Effects of different deodorization methods on the oxidation of sterol components in rice bran oil

Rice bran oil contains a significant quantity of phytosterols that have various active functions and are natural active substances beneficial to humans. It is well known that deodorization during refining affects the quality of rice bran oil. However, changes in phytosterols fraction caused by stripping with nitrogen compared to water vapor remain unexplored. We measured phytosterols in rice bran oil after deodorization with nitrogen and water vapor. The variations in sitosterol fraction, which accounts for the highest percentage of phytosterols in rice bran oil, were analyzed by Gas chromatography (GC), Fourier transform infrared spectrometer (FTIR), and Nuclear magnetic resonance (NMR). Results showed that using nitrogen as the stripping gas was more suitable for deodorization. It promoted the formation of phytosterol esters, reduced the production of phytosterol oxidation products and improved the oil quality. This study provides a theoretical basis for improving the industrial production quality of rice bran oil.