In vitro antioxidant extracts evaluation from the residue of the Hevea brasiliensis seed

The antioxidants used in the food industry are essential to inhibit the formation of free radicals, preserving the existing properties in the different matrices. However, the insecurity of the synthetic antioxidants regarding human health propels search for natural substrates with potential antioxidant activity as an alternative to synthetic compounds. In this way, the work had as objective obtaining extracts from the seed pomace of the Hevea brasiliensis (rubber tree), relating the contents of flavonoids and total phenols in the application as an antioxidant. The methodology consisted of the extraction using four solvents, varying extractive methods, time, and seed concentrations. The antioxidant activity in vitro was evaluated by capturing the DPPH (2,2-diphenyl-1-picryl-hydrazil) radical. The optimized results demonstrate that the aqueous extracts produced in the Soxhlet in the concentrations of 85 g L−1 and retention time of 4 h reached 37.73 ± 1.69% in the antioxidant tests of the free radical DPPH capture, 1405.15 mg EAC 100 g−1 in the quantification of phenolic compounds and 223.34 mg 100 g−1 of total flavonoids. Thus, this work may contribute to the realization of studies and future research for characterization and identification concerning which phenolic compounds and flavonoids attribute the antioxidant characteristic to the extracts produced, enabling the discovery of products with high added value in the production chain. In addition, because the water used as a solvent showed greater antioxidant potential between the extracts, the non-toxic and environmentally friendly character is highlighted, allowing a wide variety of applications in the food industry.

Phytochemical Properties and Diverse Beneficial Roles of Eucalyptus globulus Labill.: A Review

Eucalyptus globulus Labill. is one of the most widely utilized medicinal plants throughout the world due to its wide spectrum of interesting biological activities that are mainly attributed to the diversity of phytochemical constituents in the plant parts. The emerging crisis of pathogen resistance for conventional antibiotics is considered a global concern for the diminishing effectiveness of antibiotics; hence, there is an urgent need to explore new antimicrobial ingredients from botanical sources, among which the most promising sources are medicinal plants. Moreover, the growing limitation toward synthetic antioxidants motivated the scientific community all over the world to identify plant-acquired antioxidants and antimicrobials. This is a huge global challenge, because of the increasing public health awareness and reliance on natural compounds, as these compounds are safer alternatives. Moreover, the undesirable impacts of synthetic pharmaceuticals can be avoided. Furthermore, plant extracts and their oil could be used as eco-friendly plant-based products for insects, weeds, and plant pathogen control, which will diminish the dependence on synthetic chemicals. Thus, this review is to highlight the richness of the E. globulus plant, with precious bioactive constituents, antioxidants, antimicrobials, and phytoremediation, and herbicidal activities, which will pave the way to the development of new pharmaceuticals and agrochemicals, as well as food preservatives. They may also provide potential commercial applications to counteract the limitations of synthetic antioxidants.

Development of Electrochemical Sensors/Biosensors to Detect Natural and Synthetic Compounds Related to Agroalimentary, Environmental and Health Systems in Argentina. A Review of the Last Decade

Electrochemical sensors and biosensors are analytical tools, which are in continuous development with the aim of generating new analytical devices which are more reliable, cheaper, faster, sensitive, selective, and robust than others. In matrices related to agroalimentary, environmental, or health systems, natural or synthetic compounds occur which fulfil specific roles; some of them (such as mycotoxins or herbicides) may possess harmful properties, and others (such as antioxidants) beneficial ones. This imposes a challenge to develop new tools and analytical methodologies for their detection and quantification. This review summarises different aspects related to the development of electrochemical sensors and biosensors carried out in Argentina in the last ten years for application in agroalimentary, environmental, and health fields. The discussion focuses on the construction and development of electroanalytical methodologies for the determination of mycotoxins, herbicides, and natural and synthetic antioxidants. Studies based on the use of different electrode materials modified with micro/nanostructures, functional groups, and biomolecules, complemented by the use of chemometric tools, are explored. Results of the latest reports from research groups in Argentina are presented. The main goals are highlighted.

The antioxidant activity of Lactic acid bacteria and probiotics: a review

Probiotics and Lactic Acid Bacteria play important roles such as the production of antimicrobial compounds and other metabolites. So they have positive effects on human health. When reactive oxygen species generated in excess or cellular defenses are deficient, biomolecules can be damaged by the oxidative stress process. Various studies have shown that the best way to protect the human body from the effects of oxidation reactions is to avoid them, which can be accomplished by using antioxidants. Due to the damages of synthetic antioxidants, their usage has been discussed. Nowadays natural antioxidants derived from bio-resources have recently gained a lot of attention as a potential replacement for synthetic antioxidants. Probiotic bacteria are thought to defend against oxidative stress by restoring the gut microbiota, according to hypothesis of some scientists. This type of microorganisms indicated their antioxidant activity by producing and increasing antioxidant enzymes, production of secondary metabolites, small hydrolyzed peptides in food, resistance to the presence of hydrogen peroxide, and production of intracellular and extracellular compounds such as Exopolysaccharides. Also, they have shown their positive effect on in vivo models. In conclusion, according to the results of studies, lactic acid bacteria and probiotics are significant sources of natural antioxidants. Therefore, they have important research value and market development potential. Also, it should be noted that the mechanism of antioxidant activity of this group of microorganisms has not been fully investigated, this requires further research.

THE ANTIOXIDANT COMPONENTS AND UMAMI MOLECULES IN MUSHROOMS: A REVIEW

Mushrooms possess several therapeutic properties such as antioxidant, antifungal, antimicrobial, anticancer, antineoplastic, antidiabetic, anti-inflammatory, antibacterial, cholesterol-lowering, and immune-stimulating effects. Antioxidants are defined as the molecules which occur in our food and helps in the prevention or reduction of oxidative stress. Antioxidants are known for elevating good health and minimizes the risk of cardiovascular diseases, certain types of cancers, diabetes, cirrhosis, and stroke. The antioxidants are categorized into natural antioxidants and synthetic antioxidants. Various ingredients (like polyols, free amino acids, soluble sugars, and 5?-nucleotides) are present. The common flavor present in mushrooms is named umami taste, also known as the perception of satisfaction which is produced by MSG (Monosodium glutamate). MSG present in the mushroom is responsible for its rich, brothy, or meaty taste

Preservation of meat products with natural antioxidants from rosemary

Oxidative reactions can reduce the quality of meat products. Synthetic antioxidants can delay the formation of oxidation products but their use in muscle foods has been reconsidered among modern consumers willing to purchase clean label products. Rosemary is a relevant source of antioxidants that can be explored as natural additive in muscle foods. This review aims to provide an overview of the protective effect of rosemary active against the oxidative decay in meat products. The use of rosemary essential oil or extract can slow the progression of oxidative reactions and preserve redness, reduce the accumulation of primary and secondary lipid oxidation and protein oxidation products, and slow the increase of perceived rancidity in sensory analysis. These effects were reported during the storage of patties, burgers, meatballs, sausages, and nuggets. In this sense, rosemary extracts and essential oil can be explored as natural antioxidant in meat products.

Antioxidant Compounds from Microalgae: A Review

The demand for natural products isolated from microalgae has increased over the last decade and has drawn the attention from the food, cosmetic and nutraceutical industries. Among these natural products, the demand for natural antioxidants as an alternative to synthetic antioxidants has increased. In addition, microalgae combine several advantages for the development of biotechnological applications: high biodiversity, photosynthetic yield, growth, productivity and a metabolic plasticity that can be orientated using culture conditions. Regarding the wide diversity of antioxidant compounds and mode of action combined with the diversity of reactive oxygen species (ROS), this review covers a brief presentation of antioxidant molecules with their role and mode of action, to summarize and evaluate common and recent assays used to assess antioxidant activity of microalgae. The aim is to improve our ability to choose the right assay to assess microalgae antioxidant activity regarding the antioxidant molecules studied.

In vitro antioxidant properties of 2-(4-(2-hydroxybenzylideneamino)benzylideneamino)benzoic acid

In recent years, it has attracted great attention to determine and appraise synthetic antioxidants with high free radical scavenging capacity associated with various disorders. Because synthetic antioxidants are widely used in place of native antioxidants as they are influential and less expensive. In this study, the antioxidant activity of the newly synthesized asymmetric diimine Schiff base was determined by using DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging, ferrous ion chelation (FIC) activity and total antioxidant activity (Phosphomolybdenum assay) methods. The effective concentration (IC50) values were calculated for the Schiff base and standards. According to the results of DPPH radical scavenging, ferrous ion chelation and total antioxidant methods, Schiff base showed a well antioxidant activity. It was determined that Schiff base is reactive towards DPPH radicals (IC50, 180.0 μM) and especially Fe+2 ions (IC50, 76.3 μM). It was also found that it actively reduces the Mo(VI) ion to the Mo(V) form (IC50, 121.5 μM). The our results indicate Schiff base, may be a fine candidate as a source of synthetic antioxidants and possibly strong drug.