Evolution of food antioxidants as a core topic of food science for a century

Unravelling the effect of droplet size on lipid oxidation in O/W emulsions by using microfluidics

Lipid oxidation in emulsions is hypothesised to increase with decreasing droplet size, as this increases the specific oil-water interfacial area, where lipid oxidation is expected to be initiated. In literature, however, contradictory results have been reported, which can be caused by confounding factors such as the oil droplet polydispersity and the distribution of components between the available phases. In this work, monodisperse surfactant-stabilised emulsions with highly controlled droplet sizes of 4.7, 9.1, and 26 µm were produced by microfluidic emulsification. We show that lipid oxidation increases with decreasing droplet size, which we ascribe to the increased contact area between lipids and continuous phase prooxidants. Besides, a significant amount of oxygen was consumed by oxidation of the surfactant itself (Tween 20), an effect that also increased with decreasing droplet size. These insights substantiate the importance of controlling droplet size for improving the oxidative stability of emulsions.

The power of the QUENCHER method in measuring total antioxidant capacity of foods: Importance of interactions between different forms of antioxidants

Antioxidants play a crucial role in maintaining human health by counteracting oxidative stress and regulating redox balance within the body. The mixture of various antioxidant compounds in different forms (i.e., free, bound, insoluble) in food creates a redox active environment both in the human body and in the food system. Acting as both electron donors and acceptors while interacting with each other can either result in antagonism through pro-oxidative effects, or synergism through regeneration of one antioxidant by another. During the antioxidant capacity measurement, besides the individual antioxidant effects of the antioxidant components, these effects that occur because of their interaction with each other should be also considered. Classical antioxidant capacity measurement methods mostly concentrate on the fractions of foods that can be extracted with either water, alcohol, lipid, or acid/alkaline solutions. Antioxidants that cannot be extracted with any solvent are mostly ignored in these methods. On the other hand, the QUENCHER method, which allows direct measurement of antioxidant capacity foods without extraction, offers a rational solution to the limitations of traditional extraction-based methods. This approach considers the antioxidant capacity and interactions of all antioxidant forms that can be found in a food matrix, at the same time. This review provides detailed insights into the advantages of QUENCHER as a holistic approach for the accurate measurement of the antioxidant capacity of foods.

Plant-Based Antioxidants in Gluten-Free Bread Production: Sources, Technological and Sensory Aspects, Enhancing Strategies and Constraints

The recognized contribution of antioxidant compounds to overall health maintenance and spotted deficiencies in celiac patients' diets has driven more intensive research regarding antioxidant compounds' inclusion in gluten-free bread (GFB) production during the last decade. The presented review gathered information that provided insights into plant-based antioxidant sources which are applicable in GFB production through the resulting changes in the technological, sensory, and nutritional quality of the resulting antioxidant-enriched GFB. The influence of the bread-making process on the antioxidant compounds' content alteration and applied methods for their quantification in GFB matrices were also discussed, together with strategies for enhancing the antioxidant compounds' content, their bioaccessibility, and their bioavailability, highlighting the existing contradictions and constraints. The addition of plant-based antioxidant compounds generally improved the antioxidant content and activity of GFB, without a profound detrimental effect on its technological quality and sensory acceptability, and with the extent of the improvement being dependent on the source richness and the amount added. The determination of a pertinent amount and source of plant-based antioxidant material that will result in the production of GFB with desirable nutritional, sensory, and technological quality, as well as biological activity, remains a challenge to be combated by elucidation of the potential mechanism of action and by the standardization of quantification methods for antioxidant compounds.

Natural Enzyme-Inspired Design of the Single-Atom Cu Nanozyme as Dual-Enzyme Mimics for Distinguishing Total Antioxidant Capacity and the Ascorbic Acid Level

Although various oxidase mimetic or peroxidase (POD) mimetic nanozymes have been extensively studied, their poor substrate selectivity significantly inhibits their practical applications. Nanozymes with specific biomolecules as substrates, especially ascorbic acid oxidase (AAO) mimetic nanozymes with ascorbic acid (AA) as a substrate, have scarcely been studied. Herein, inspired by the multi-Cu atom sites and the redox electron transfer pathway of Cu2+/Cu+ in the natural AAO, atomically dispersed Cu sites immobilized on N-doped porous carbon (Cu-N/C) are artificially designed to simulate the function of natural AAO. Compared with their natural counterparts, the Cu-N/C catalysts exhibited higher catalytic efficiency and superior stability. Combined theoretical calculation and experimental characterizations reveal that the Cu-N/C nanozymes could catalyze the AA oxidation through a 2e- oxygen reduction pathway with H2O2 as the product. Moreover, the Cu-N/C nanozymes also possess high POD activity. As a proof-of-concept application, Cu-N/C can simultaneously realize AA detection in fluorescent mode based on its AAO activity and total antioxidant capacity detection in colorimetric mode utilizing its POD activity.

A Review of Foods of Plant Origin as Sources of Vitamins with Proven Activity in Oxidative Stress Prevention according to EFSA Scientific Evidence

Beyond their nutritional benefits, vitamins could decrease the risk of chronic diseases due to their potent antioxidant capacity. The present work is aimed at reviewing the state of the art regarding (1) the vitamins involved in oxidative stress prevention in accordance with the requirements established by the European Food Safety Authority (EFSA) and (2) the foods of plant origin that are sources of those vitamins and have potential benefits against oxidative stress in humans. According to the European regulations based on EFSA scientific evidence, riboflavin, vitamin C, and vitamin E are those vitamins subjected to the approved health claim "contribute to the protection of cells from oxidative stress". Scientific studies conducted in humans with some natural food sources of riboflavin (almonds, wheat germ, mushrooms, oat bran), vitamin C (guava, kale, black currant, Brussels sprouts, broccoli, orange), and vitamin E (hazelnuts, almonds, peanuts, pistachio nuts, extra virgin olive oil, dates, rye) have been performed and published in the literature. However, no food of plant origin has obtained a favorable EFSA opinion to substantiate the approval of health claims related to its potential properties related to oxidative stress prevention. Further studies (concretely, well-controlled human intervention studies) must be carried out in accordance with EFSA requirements to provide the highest level of scientific evidence that could demonstrate the potential relationship between foods of plant origin and antioxidant capacity. This review could be useful for the scientific community to study the application of health claims referring to the antioxidant capacity potentially exerted by foods of plant origin.

Lactobacillus co-fermentation of Cerasus humilis juice alters chemical properties, enhances antioxidant activity, and improves gut microbiota

Fermentation with Lactobacillus has been shown to improve the nutritional value of juice. In this study, Cerasus humilis juice was fermented using two commercial probiotics, namely, Lactobacillus acidophilus and Lactobacillus plantarum. The total antioxidant capacity (TAOC), viable count, chemical properties, antioxidant activity after in vitro digestion, and alterations in the gut microbiota composition of the fermented juice were investigated. After fermentation, the TAOC increased from 107.66 U mL-1 to 126.72 U mL-1; viable count increased from 5.85 lg (CFU mL-1) to 8.17 lg (CFU mL-1); and the contents of total phenols, total flavonoids, proanthocyanins, four organic acids, and 29 amino acids had changed. Overall, 47 compounds were identified in the juice, 20 of which were enriched after fermentation. Furthermore, Lactobacillus co-fermentation improved the antioxidant properties of the juice after in vitro digestion and increased the abundance of probiotics to regulate the gut microbiota. These findings illustrate the potential use of Lactobacillus acidophilus and Lactobacillus plantarum in the co-fermentation of C. humilis juice to enhance its nutritional and functional properties.

From Plants to Psycho-Neurology: Unravelling the Therapeutic Benefits of Bioactive Compounds in Brain Disorders

The brain's sensitivity to oxidative stress and neuronal cell death requires effective pharmacotherapy approaches. Current pharmacological therapies are frequently ineffective and display negative side effects. Bioactive chemicals found in plants may provide a potential alternative due to their antioxidant and neuroprotective properties and can be used in therapy and the management of a variety of neuropsychiatric, neurodevelopmental, and neurodegenerative illnesses. Several natural products, including vitamin C, Cammelia sinensis polyphenols, Hypericum perforatum, and Crocus sativus have shown promise in lowering oxidative stress and treating symptoms of major depressive disorder (MDD). Similarly, bioactive compounds such as curcumin, luteolin, resveratrol, quercetin, and plants like Acorus gramineus, Rhodiola rosea, and Ginkgo biloba are associated with neuroprotective effects and symptom improvement in neurodevelopmental disorders such as autism spectrum disorder (ASD) and attention deficit/hyperactivity disorder (ADHD). Furthermore, in neurodegenerative diseases, natural compounds from Rhodiola rosea, Morinda lucida, and Glutinous rehmannia provide neurological improvement. Further study in clinical samples is required to thoroughly investigate the therapeutic advantages of these bioactive substances for persons suffering from these illnesses.

Utilization of different by-products to produce nutritionally rich gelled products

Yellow corn cooking water with yerba mate (Ilex paraguariensis) extract, obtained as a by-product of snack manufacture, was combined with whey protein concentrate (7 g/100 g), flaxseed (Linum usitatissimum L.) flour (2 g/100 g), and honey (8 g/100 g) to obtain different gelled products. The effect of the composition on the physicochemical parameters was analyzed. Flaxseed flour was added directly or with a previous pre-heating, and, in both cases, it increased the solid behavior of gels. On the contrary, honey increased the gel liquid-like behavior, and both ingredients modified the color of the gels. Elastic and loss modulus decreased after storage for 7 and 14 days. Some of the textural parameters also changed during storage. Principal component analysis and cluster analysis revealed three groups of formulations according to their composition, and those samples containing only flaxseed flour were best described with the textural and rheological parameters. Yerba mate extract, mainly, flaxseed flour, and honey increased the phenolic composition of gels but decreased the sensory acceptability, despite the sweetness of honey. A variety of gelled products with different textures and flavors was obtained using by-products of the food industry. These gels could be used either for dessert formulations or as a matrix for gelled products.

Potential of Syzygnium polyanthum as Natural Food Preservative: A Review

Food preservation is one of the strategies taken to maintain the level of public health. Oxidation activity and microbial contamination are the primary causes of food spoilage. For health reasons, people prefer natural preservatives over synthetic ones. Syzygnium polyanthum is widely spread throughout Asia and is utilized as a spice by the community. S. polyanthum has been found to be rich in phenols, hydroquinones, tannins, and flavonoids, which are potential antioxidants and antimicrobial agents. Consequently, S. polyanthum presents a tremendous opportunity as a natural preservative. This paper reviews recent articles about S. polyanthum dating back to the year 2000. This review summarizes the findings of natural compounds presented in S. polyanthum and their functional properties as antioxidants, antimicrobial agents, and natural preservatives in various types of food.

Sustainable production of astaxanthin from Dilocarcinus pagei crab and optimisation of its extraction with edible oils

Dilocarcinus pagei is a South American crab commonly found in fishponds. As crabs are a source of astaxanthin (AST) and food inputs, this preliminary research aimed at studying the composition of females and males of this species to assess its potential for commercial applications, and at optimising the extraction of AST with edible oils to promote its use as an ingredient for the nutraceutical, pharmaceutical and feed industries. The chemical composition differed between males and females only in moisture, and the values obtained were: 65.4 ± 1.0% and 72.5 ± 3.1% moisture, 45.7-40.3% d.m. minerals, 22.0-24.1% d.m. fibres, 18.2-17.4% d.m. proteins, and 10.4-11.1% d.m. lipids. The Box-Behnken design was applied and validated for extraction with soya bean and sunflower oils, adjusting the oil:crab ratio, temperature, and extraction time. The optimal conditions found consisted of 140 mL/g, 90 °C and 170 min for soya bean oil, reaching an accumulation of AST of 50 ± 5 μg/g crab d.m. For sunflower oil, the conditions were 60 mL/g, 90 °C and 161 min, reaching 31 ± 3 μg/g crab d.m. Finally, the amounts of AST obtained using soya bean oil were higher than those obtained using sunflower oil; thus, soya bean oil would be recommended as a solvent to extract the pigment.

A Physicochemical Study of the Antioxidant Activity of Corn Silk Extracts

Corn silk (CS) extracts are reported to contain flavonoids (appx. 59.65 mg quercetin/g), polysaccharides (appx. 58.75 w.%), steroids (appx. 38.3 × 10^-3 to 368.9 × 10^-3 mg/mL), polyphenols (appx. 77.89 mg/GAE/g) and other functional biological substances. This study investigated the antioxidant activity of corn silk extracts related to their functional compounds. The radical scavenging effect of corn silk extracts was evaluated by the spin-trapping electron paramagnetic resonance (EPR) technique, 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzo-thiazoline-6-sulfonate) (ABTS^•+) free radical measurement, ferric ion-reducing antioxidant power, and copper ion reductive capacity. It was found that the maturity stage of CS plant materials and the applied extraction procedure of their bioactive compounds have a profound effect on the radical scavenging capacity. Differences in the antioxidant activity of the studied corn silk samples based on their maturity were also confirmed. The strongest DPPH radical scavenging effect was observed for the corn silk mature stage (CS-M)stage (CS-MS) (65.20 ± 0.90)%, followed by the silky stage (CS-S) (59.33 ± 0.61)% and the milky stage (CS-M) (59.20 ± 0.92)%, respectively. In general, the final maturity stage (CS-MS) provided the most potent antioxidant effect, followed by the earliest maturity stage (CS-S) and the second maturity stage (CS-M).

Influence of Different Rootstocks on Fruit Quality and Primary and Secondary Metabolites Content of Blood Oranges Cultivars

Blood oranges have high concentrations of bioactive compounds that are beneficial to health. In Europe, the cultivation of blood oranges is increasing due to their excellent nutritional properties. In Citrus crops, rootstocks play an important role in juice and can increase the content of bioactive compounds. The morphological, qualitative and nutritional parameters were analyzed in cultivars 'Tarocco Ippolito', 'Tarocco Lempso', 'Tarocco Tapi' and 'Tarocco Fondaconuovo' grafted onto Citrus macrophylla and Citrus reshni. 'Tarocco Lempso' grafted onto Citrus macrophylla obtained the highest values of weight (275.78 g), caliber (81.37 mm and 76.79 mm) and juice content (162.11 g). 'Tarocco Tapi' grafted onto Citrus reshni obtained the most interesting qualitative parameters (15.40 °Brix; 12.0 MI). 'Tarocco Lempso' grafted onto Citrus reshni obtained the most intense red juice (a* = 9.61). Overall, the highest concentrations of primary metabolites were in proline, aspartate, citric acid, and sucrose. The results showed that 'Tarocco Ippolito' juice grafted onto Citrus reshni had the highest levels of total hydroxycinnamic acids (263.33 mg L^-1), total flavones (449.74 mg L^-1) and total anthocyanins (650.42 mg L^-1). To conclude, 'Tarocco Lempso' grafted onto Citrus macrophylla obtained the best values of agronomic parameters, and the cultivars grafted onto Citrus reshni obtained significantly higher concentrations in primary and secondary metabolites.

A Novel Strategy to Enhance Antioxidant Content in Saccharomyces Cerevisiae Based on Oxygen Pressure

Antioxidant foods represent a potent lever to improve diets while creating value. Yet, their cultivation is often tied to a specific area and climate, limiting availability and increasing market cost. Therefore, microorganism-based antioxidant production emerges as a promising technology to solve these problems. In this view, a novel process was investigated for antioxidant accumulation in yeast culture. S. cerevisiae cells were exposed to various hyperbaric air conditions from 1 to 9 bar (A). Yeast cultures exhibited an increased reactive oxygen species content, which induced oxidative defense expression. After a few hours, reactive oxygen species levels decreased while antioxidant contents remained high, leading to a net increase in antioxidant power. At 6 bar (A), yeast achieved the highest net antioxidant power (phenolics content +48.3 ± 18.6 %, reducing power +120 ± 11.4 %) with an acceptable growth rate (0.27 h^-1). Regarding time evolution, a 2 h exposure seems to be the optimum: cells have the lowest reactive oxygen species level while their antioxidant power is increased. From a biotechnological perspective, this finding highlights air pressure as an antioxidant-manipulating stress strategy. Moreover, the proposed process led to a patent that could potentially reduce energy and chemical consumption in such antioxidant accumulation processes.

Application of Doehlert Experimental Design for Optimization of a New-Based Hydrophilic Interaction Solid-Phase Extraction of Phenolic Acids from Olive Oils

In this work, a rapid, precise, and cost-valuable method has been established to quantify phenolic compounds in olive oil using new-based hydrophilic interaction solid-phase extraction (SPE). Boehlert's experimental design applied the determination of the optimal operating conditions. An investigation into the effects of the methanol composition (50-100%), the volume of eluent (1-12 mL), and pH (1-3) on the extraction of phenols acids and total phenols from Tunisian olive oils was performed. The results showed that the extraction conditions had a significant effect on the extraction efficiency. The experiment showed that the greatest conditions for the SPE of phenolic acids were the methanol composition at 90.3%, pH at 2.9, and volume at 7.5 mL, respectively. The optimal conditions were applied to different types of olive oils, and it could be concluded that larger concentrations of polyphenols were found in extra virgin olive oil (89.15-218), whereas the lowest levels of these compounds (66.8 and 5.1) were found in cold-pressed crude olive oil and olive pomace oil, respectively.

The antioxidant properties of resveratrol on sperm parameters, testicular tissue, antioxidant capacity, and lipid peroxidation in isoflurane-induced toxicity in mice

This study explores whether resveratrol effectively protects the reproductive system against isoflurane-induced toxicity in testicular tissue. In this experiment, we randomly divided 60 adult male C57BL/6 mice into six groups (n = 10). Five consecutive days per week, mice were exposed to 1.5% isoflurane for 1 h/day and were given 50 and 100 mg/kg resveratrol. After 35 days (the completion of the mouse spermatogenesis period), the left testis was removed for histomorphometric evaluations, while the right testis was used to determine the Capacity of total antioxidants and lipid peroxidation. To analyze the Parameters of sperm, chromatin maturation, and DNA fragmentation, the left caudal epididymis was used. Based on a one-way analysis of variance (ANOVA), we considered a difference in means of 0.05 to be significant (P0.05). Compared to the control group, the isoflurane group showed a significant decrease in testicular weight, volume, sperm parameters, and tissue histomorphometry. Comparatively, to the control group, malondialdehyde levels increased, and the total antioxidant capacity decreased significantly. Resveratrol improved all of the above parameters in the simultaneous treatment groups compared to the isoflurane group. It did not, however, reach the level of the control group in all cases. It has been demonstrated that resveratrol, with its powerful antioxidant properties, reduces the reproductive toxicity of isoflurane by inhibiting free radicals and increasing the testicular tissue's antioxidant capacity.

Phenolic Profile and Antioxidant Properties in Extracts of Developing Açaí (Euterpe oleracea Mart.) Seeds

We investigated changes in the phenolic profile and antioxidant properties in the extracts of developing seeds of açaí (Euterpe oleracea). Four developmental stages were evaluated, with earlier stages displaying higher antioxidant activity and polyphenols content, while mass spectrometry analysis identified procyanidins (PCs) as the major components of the extracts in all stages. B-type PCs varied from dimers to decamers, with A-type linkages in a smaller number. Extracted PCs decreased in average length from 20.5 to 10.1 along seed development. PC composition indicated that (-)-epicatechin corresponded to over 95% of extension units in all stages, while (+)-catechin presence as the starter unit increased from 42 to 78.8% during seed development. This variation was correlated to the abundance of key enzymes for PC biosynthesis during seed development. This study is the first to report PC content and composition variations during açaí seed development, which can contribute to studies on the plant's physiology and biotechnological applications.

Oxidative Stress and Antioxidants-A Critical Review on In Vitro Antioxidant Assays

Antioxidants have been widely studied in the fields of biology, medicine, food, and nutrition sciences. There has been extensive work on developing assays for foods and biological systems. The scientific communities have well-accepted the effectiveness of endogenous antioxidants generated in the body. However, the health efficacy and the possible action of exogenous dietary antioxidants are still questionable. This may be attributed to several factors, including a lack of basic understanding of the interaction of exogenous antioxidants in the body, the lack of agreement of the different antioxidant assays, and the lack of specificity of the assays, which leads to an inability to relate specific dietary antioxidants to health outcomes. Hence, there is significant doubt regarding the relationship between dietary antioxidants to human health. In this review, we documented the variations in the current methodologies, their mechanisms, and the highly varying values for six common food substrates (fruits, vegetables, processed foods, grains, legumes, milk, and dairy-related products). Finally, we discuss the strengths and weaknesses of the antioxidant assays and examine the challenges in correlating the antioxidant activity of foods to human health.

Apple Polyphenol Diet Extends Lifespan, Slows down Mitotic Rate and Reduces Morphometric Parameters in Drosophila Melanogaster: A Comparison between Three Different Apple Cultivars

Plant-derived polyphenols exhibit beneficial effects on physiological and pathological processes, including cancer and neurodegenerative disorders, mainly because of their antioxidant activity. Apples are highly enriched in these compounds, mainly in their peel. The Tuscia Red (TR) apple variety exhibits the peculiar characteristic of depositing high quantities of polyphenols in the pulp, the edible part of the fruit. Since polyphenols, as any natural product, cannot be considered a panacea per se, in this paper, we propose to assess the biological effects of TR flesh extracts, in comparison with two commercial varieties, in a model system, the insect Drosophila melanogaster, largely recognized as a reliable system to test the in vivo effects of natural and synthetic compounds. We performed a comparative, qualitative and quantitative analysis of the polyphenol compositions of the three cultivars and found that TR flesh shows the highest content of polyphenols, and markedly, anthocyanins. Then, we focused on their effects on a panel of physiological, morphometrical, cellular and behavioral phenotypes in wild-type D. melanogaster. We found that all the apple polyphenol extracts showed dose-dependent effects on most of the phenotypes we considered. Remarkably, all the varieties induced a strong relenting of the cell division rate.

Food-Borne Chemical Carcinogens and the Evidence for Human Cancer Risk

Commonly consumed foods and beverages can contain chemicals with reported carcinogenic activity in rodent models. Moreover, exposures to some of these substances have been associated with increased cancer risks in humans. Food-borne carcinogens span a range of chemical classes and can arise from natural or anthropogenic sources, as well as form endogenously. Important considerations include the mechanism(s) of action (MoA), their relevance to human biology, and the level of exposure in diet. The MoAs of carcinogens have been classified as either DNA-reactive (genotoxic), involving covalent reaction with nuclear DNA, or epigenetic, involving molecular and cellular effects other than DNA reactivity. Carcinogens are generally present in food at low levels, resulting in low daily intakes, although there are some exceptions. Carcinogens of the DNA-reactive type produce effects at lower dosages than epigenetic carcinogens. Several food-related DNA-reactive carcinogens, including aflatoxins, aristolochic acid, benzene, benzo[a]pyrene and ethylene oxide, are recognized by the International Agency for Research on Cancer (IARC) as causes of human cancer. Of the epigenetic type, the only carcinogen considered to be associated with increased cancer in humans, although not from low-level food exposure, is dioxin (TCDD). Thus, DNA-reactive carcinogens in food represent a much greater risk than epigenetic carcinogens.

Electrochemical Methodologies for Investigating the Antioxidant Potential of Plant and Fruit Extracts: A Review

In recent years, the growing research interests in the applications of plant and fruit extracts (synthetic/stabilization materials for the nanomaterials, medicinal applications, functional foods, and nutraceuticals) have led to the development of new analytical techniques to be utilized for identifying numerous properties of these extracts. One of the main properties essential for the applicability of these plant extracts is the antioxidant capacity (AOC) that is conventionally determined by spectrophotometric techniques. Nowadays, electrochemical methodologies are emerging as alternative tools for quantifying this particular property of the extract. These methodologies address numerous drawbacks of the conventional spectroscopic approach, such as the utilization of expensive and hazardous solvents, extensive sample pre-treatment requirements, long reaction times, low sensitivity, etc. The electrochemical methodologies discussed in this review include cyclic voltammetry (CV), square wave voltammetry (SWV), differential pulse voltammetry (DPV), and chronoamperometry (CAP). This review presents a critical comparison between both the conventional and electrochemical approaches for the quantification of the parameter of AOC and discusses the numerous applications of the obtained bioextracts based on the AOC parameter.

Advances in drying techniques for retention of antioxidants in agro produces

Antioxidants are compounds that are essential for the human body which prevents cell from disease causing free radicals. Antioxidants are present in a wide range of fruits, vegetables, and spices. However, a considerable amount of antioxidants is lost during the post-harvest drying operation of agro produces for their shelf-life enhancement. Hence, retention of antioxidants becomes utmost importance in preserving the nutritional aspects of fruits and vegetables. Compared to conventional hot air drying, methods like freeze drying, vacuum drying, and dehumidified drying helps in the retention of antioxidants. However, the drawbacks prevalent in current drying practices, such as high-power consumption and high capital cost, could be eliminated by adopting novel drying mechanisms. This review focuses on various pretreatment methods like ultra-sonication, high pressure processing, pulsed electric field and ethanol treatment prior to drying operation helps in enhancing the drying efficiency with maximum retention of antioxidants. In addition, hybrid drying technologies such as microwave assisted drying, IR-radiated drying and electro-magnetic assisted drying methods also could significantly improve the retention of antioxidants.HIGHLIGHTSDrying is the most commonly adopted unit operation for enhancing the shelf life of perishable agro produces.However, drying is accompanied by loss of bioactive, color, texture, and sensory attributes.Compared to conventional drying techniques like hot air drying, methods like freeze drying, vacuum drying and dehumidified drying helps in the retention of antioxidants present in agro/food produces.Pretreatment methods like Ozonation, ultra-sonication, and UV radiation prior to drying are also found to improve the drying performance with good retention of antioxidants.Recent developments like microwave-assisted and IR-assisted drying methods perform well in the retention of antioxidants with less energy consumption.

Natural Antioxidant Evaluation: A Review of Detection Methods

Antioxidants have drawn the attention of the scientific community due to being related to the prevention of various degenerative diseases. The antioxidant capacity has been extensively studied in vitro, and different methods have been used to assess its activity. However, the main issues related to studying natural antioxidants are evaluating whether these antioxidants demonstrate a key role in the biological system and assessing their bioavailability in the organism. The majority of outcomes in the literature are controversial due to a lack of method standardization and their proper application. Therefore, this study aims to compile the main issues concerning the natural antioxidant field of study, comparing the most common in vitro methods to evaluate the antioxidant activity of natural compounds, demonstrating the antioxidant activity in biological systems and the role of the main antioxidant enzymes of redox cellular signaling and explaining how the bioavailability of bioactive compounds is evaluated in animal models and human clinical trials.

Supplementation with kaempferol relieves oxidative stress and enhances development of early bovine embryos in vitro

Oxidative stress (OS) has been considered the principle cause of developmental failure of early embryos cultured in vitro; therefore, the addition of antioxidants is very important for improving in vitro culture (IVC) systems. Various antioxidants have been tested for IVC systems, but most have exhibited some side effects. Kaempferol (3,5,7-trihydroxy-2-(4-hydroxyphenyl)-4h-1-benzopyran-4-one, KAE) is a flavonoid with strong antioxidant activity and no obvious side effects. This study explored the effect of KAE on antioxidant capacity and developmental competence of bovine embryos after fertilization. KAE was added to bovine IVC medium and significantly reduced reactive oxygen species (ROS) in 2-, 4- and 8-cell stage embryos and increased blastocyst formation. In addition, the level of H3K9ac was increased, the apoptotic index was reduced, and total cell numbers and trophectoderm cell numbers in day 7 blastocysts were increased significantly in KAE-treated embryos compared to control. Expression of the apoptotic gene, Bcl-2, was higher in blastocysts after KAE treatment, while expression of the endoplasmic reticulum (ER) stress genes, Bip and HDAC1, and the pro-apoptotic gene, Bax, were significantly lower in the KAE group. Thus, KAE significantly reduced ROS damage and improved development of IVC bovine embryos.

Lycium barbarum polysaccharide inhibits lipid oxidation and protein degradation in Tan sheep meatballs during frozen storage

The aim of the present study was to evaluate the effectiveness of Lycium barbarum polysaccharide (LBP) on lipid oxidation and protein degradation in Tan sheep meatballs during the frozen period. The meatballs were treated with LBP at 0.01%, 0.02%, and 0.03% and stored at –18±1°C for 0, 3, 6, 9, and 12 weeks. The effects of LBP treatment were investigated using the contents of total volatile basic nitrogen (TVB-N), texture profile (TP), thiobarbituric acid reactive substances (TBARS), colour, and pH values, compared with 0.02% butylated hydroxytoluene treatment and the blank control. The results showed that LBP treatment significantly decreased TBARS content compared with the control, which confirmed LBP to be a highly effective component in preventing lipid oxidation of Tan sheep meatballs during frozen storage, and protein degradation in Tan sheep meatballs had a significant inhibition effect because of TVB-N value reduction. In addition, the colour, TP and pH values of meatballs treated with LBP were improved dramatically. To further determine the quality changes of the blank control and all treated groups during storage, the comprehensive score evaluation equation based on principal component analysis was obtained: Y=0.51632Y₁+0.29589Y₂ (cumulative contribution rate=81.221%), and the 0.02% LBP-treated group had a higher comprehensive score than the other groups, and the quality of LBP-treated meatballs was better as well. In summary, LBP may reduce or inhibit lipid oxidation and protein degradation, and enhance overall quality and shelf-life in prepared meat products.

Bioactive compounds, antioxidant activity and fruit quality evaluation of eleven blood orange cultivars

BACKGROUND

Blood oranges are grown increasingly in Europe for fresh consumption because of their special taste and excellent nutraceutical properties that confer the status of a functional food. The health benefits are associated with the range of additional bioactive compounds that they contain with respect to blonde oranges.

RESULTS

We analysed the physicochemical properties and the levels of organic acids, sugars and antioxidants in 11 blood orange cultivars representing the most representative cultivars of blood oranges widespread in the Mediterranean basin. In particular, we examined the levels of phenols, flavonoids and anthocyanins present in these cultivars at harvest maturity. The physicochemical, antioxidant and colour properties differ significantly among these cultivars. The deepest red peel and juice was found in Sanguinelli, followed by Tarocco Rosso and Moro. High-performance liquid chromatography with refractive index detector analysis revealed sucrose as the main sugar in all these cultivars, followed by fructose and glucose. Citric acid was the dominant organic acid, followed by malic acid and ascorbic acid. Moro showed the greatest levels of antioxidant activity. Regarding the phenolic composition, we found p-coumaric acid to be the main hydroxycinnamic acid in all cultivars, with maximum amounts in Moro and Sanguinelli. The highest amounts of cyanidin-3-O-glucoside and cyanidin-3-(6''-malonyl)-glucoside were found in Moro, for which the juice was of the deepest red colour.

CONCLUSION

The phenolic composition and antioxidant activity of the 11 cultivars was assessed. The results showed that Moro was the cultivar with the highest content of polyphenols and levels of antioxidant activity, followed by Sanguinelli. © 2021 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Copper(ii) complexes with terpene derivatives of ethylenediamine: synthesis, and antibacterial, antifungal and antioxidant activity

The synthesis of new chiral copper(ii) complexes with terpene derivatives of ethylenediamine and the results of studying their antibacterial, antifungal and antioxidant activity in vitro are discussed. All studied copper complexes (1–4) showed significantly higher antifungal activity against the strains of C. albicans, S. salmonicolor and P. notatum compared to the activity of the clinical antifungal drug amphotericin. High antibacterial activity of copper complexes with terpene derivatives of ethylenediamine was revealed against the S. aureus (MRSA) strain, which is resistant to the reference antibiotic ciprofloxacin. Using various test systems, a comparative assessment of the antioxidant activity (AOA) of the synthesized copper complexes and the ligands was carried out. The salen-type complex 4, which has the highest AOA in the model of initiated oxidation of a substrate containing animal lipids, was superior to other copper complexes in the ability to protect erythrocytes under conditions of H₂O₂-induced hemolysis.

The synthesis of new chiral copper(ii) complexes with terpene derivatives of ethylenediamine and the results of studying their antibacterial, antifungal and antioxidant activity in vitro are discussed.

Gold Nanomaterials-Based Electrochemical Sensors and Biosensors for Phenolic Antioxidants Detection: Recent Advances

Antioxidants play a central role in the development and production of food, cosmetics, and pharmaceuticals, to reduce oxidative processes in the human body. Among them, phenolic antioxidants are considered even more efficient than other antioxidants. They are divided into natural and synthetic. The natural antioxidants are generally found in plants and their synthetic counterparts are generally added as preventing agents of lipid oxidation during the processing and storage of fats, oils, and lipid-containing foods: All of them can exhibit different effects on human health, which are not always beneficial. Because of their relevant bioactivity and importance in several sectors, such as agro-food, pharmaceutical, and cosmetic, it is crucial to have fast and reliable analysis Rmethods available. In this review, different examples of gold nanomaterial-based electrochemical (bio)sensors used for the rapid and selective detection of phenolic compounds are analyzed and discussed, evidencing the important role of gold nanomaterials, and including systems with or without specific recognition elements, such as biomolecules, enzymes, etc. Moreover, a selection of gold nanomaterials involved in the designing of this kind of (bio)sensor is reported and critically analyzed. Finally, advantages, limitations, and potentialities for practical applications of gold nanomaterial-based electrochemical (bio)sensors for detecting phenolic antioxidants are discussed.

The effect of resveratrol on advanced glycation end products in diabetes mellitus: a systematic review

Advanced glycation end products (AGEs) lead to chronic oxidative stress and inflammation, which in turn augment diabetes complications. Resveratrol plays a potential role in relation to diabetes due to improving of hyperglycemia, oxidative stress, and inflammation. The aim of this review was to evaluate the scientific literature to identify the impacts of resveratrol on the accumulation of AGEs. The literature was searched in the online databases, viz. PubMed, SCOPUS, Embase, ProQuest, and Google Scholar until May 2019. From a total of 338 retrieved articles, 10 papers were eligible for the present analysis. Except one clinical trial, all studies were conducted on animals. All the included studies, except one, showed inhibitory effects of resveratrol on the accumulation of AGE or receptor for AGEs. The findings indicate that resveratrol is a potential protective agent against the accumulation of AGEs. There is, however, the need for future studies to investigate this effect on human.

Exercise, Diet and Sleeping as Regenerative Medicine Adjuvants: Obesity and Ageing as Illustrations

Regenerative medicine uses the biological and medical knowledge on how the cells and tissue regenerate and evolve in order to develop novel therapies. Health conditions such as ageing, obesity and cancer lead to an impaired regeneration ability. Exercise, diet choices and sleeping pattern have significant impacts on regeneration biology via diverse pathways including reducing the inflammatory and oxidative components. Thus, exercise, diet and sleeping management can be optimized towards therapeutic applications in regenerative medicine. It could allow to prevent degeneration, optimize the biological regeneration and also provide adjuvants for regenerative medicine.

Core-Shell Iron-Nickel Hexacyanoferrate Nanoparticle-Based Sensors for Hydrogen Peroxide Scavenging Activity

To access hydrogen peroxide scavenging activity, we propose a sensor based on core-shell iron-nickel hexacyanoferrate nanoparticles. On the one hand, the sensor preparation procedure is simple: syringing the nanoparticles suspension with subsequent annealing. On the other hand, the sensor demonstrates a stable response to 0.05 mM of H2O2 within one hour, which is sufficient for the evaluation of antioxidant activity (AO). The analytical performance characteristics of the sensor (0.5–0.6 A M−1 cm−2, detection limit 1.5 × 10−7 M and linear dynamic range 1–1000 µM) are leads to advantages over the sensor based on Prussian Blue films. The pseudo-first-order constant of hydrogen peroxide scavenging was chosen as a characteristic value of AO. The latter for trolox (standard antioxidant) was found to be linearly dependent on its concentration, thus allowing for the evaluation of antioxidant activity in trolox equivalents. The approach was validated by analyzing real beverage samples. Both the simplicity of sensor preparation and an expressiveness of analytical procedure would obviously provide a wide use of the proposed approach in the evaluation of antioxidant activity.

Fortified Fermented Rice-Acid Can Regulate the Gut Microbiota in Mice and Improve the Antioxidant Capacity

The study aimed to explore the effects of fortified fermented rice-acid on the antioxidant capacity of mouse serum and the gut microbiota. Hair characteristics, body mass index, intestinal villus height, intestinal crypt depth, serum antioxidant capacity, and gut microbiota of mice were first measured and the correlation between the antioxidant capacity of mouse serum and the gut microbiota was then explored. The mice in the lactic acid bacteria group (L-group), the mixed bacteria group (LY-group), and the rice soup group (R-group) kept their weight well and had better digestion. The mice in the L-group had the better hair quality (dense), but the hair quality in the R-group and the yeast group (Y-group) was relatively poor (sparse). In addition, the inoculation of Lactobacillus paracasei H4-11 (L. paracasei H4-11) and Kluyveromyces marxianus L1-1 (K. marxianus L1-1) increased the villus height/crypt depth of the mice (3.043 ± 0.406) compared to the non-inoculation group (R-group) (2.258 ± 0.248). The inoculation of L. paracasei H4-11 and K. marxianus L1-1 in fermented rice-acid enhanced the blood antioxidant capacity of mouse serum (glutathione 29.503 ± 6.604 umol/L, malonaldehyde 0.687 ± 0.125 mmol/L, catalase 15.644 ± 4.618 U/mL, superoxide dismutase 2.292 ± 0.201 U/mL). In the gut microbiota of L-group and LY-group, beneficial microorganisms (Lactobacillus and Blautia) increased, but harmful microorganisms (Candidatus Arthromitus and Erysipelotrichales) decreased. L. paracasei H4-11 and K. marxianus L1-1 might have a certain synergistic effect on the improvement in antibacterial function since they reduced harmful microorganisms in the gut microbiota of mice. The study provides the basis for the development of fortified fermented rice-acid products for regulating the gut microbiota and improving the antioxidant capacity.

Lycium Barbarum Polysaccharide-Iron (III) Chelate as Peroxidase Mimics for Total Antioxidant Capacity Assay of Fruit and Vegetable Food

Quantitative evaluation of the antioxidant capacity of foods is of great significance for estimating food’s nutritional value and preventing oxidative changes in food. Herein, we demonstrated an easy and selective colorimetric method for the total antioxidant capacity (TAC) assay based on 3,3’,5,5’-tetramethyl-benzidine (TMB), hydrogen peroxide (H₂O₂) and synthetic Lycium barbarum polysaccharide-iron (III) chelate (LBPIC) with high peroxidase (POD)-like activity. The results of steady-state kinetics study showed that the K_m values of LBPIC toward H₂O₂ and TMB were 5.54 mM and 0.16 mM, respectively. The detection parameters were optimized, and the linear interval and limit of detection (LOD) were determined to be 2–100 μM and 1.51 μM, respectively. Additionally, a subsequent study of the determination of TAC in six commercial fruit and vegetable beverages using the established method was successfully carried out. The results implied an expanded application of polysaccharide-iron (III) chelates with enzymatic activity in food antioxidant analysis and other biosensing fields.

A validated Folin-Ciocalteu method for total phenolics quantification of condensed tannin-rich açaí (Euterpe oleracea Mart.) seeds extract

ABSTRACT

The widely used methodology to quantify polyphenols-the Folin-Ciocalteu (FC) method-cannot be applied indiscriminately since different matrices may impair the assay's accuracy. Thus, this study aimed to adapt the FC method for the açaí seed extract, a tannin-rich extract with potential applications for various therapies. Firstly, a pre-method standardization was established to determine parameters such as reading wavelength (765 nm), reaction time (30 min), and the reference substance (pyrogallol). In the validation step, the adapted method responded linearly to the analyte (R² = 0.9910), ensuring its selectivity (linearity and selectivity curves statistically parallel) and accuracy (99.18-101.43%). Furthermore, the method proved to be precise (RSD ≤ 2.63%) at the two levels assessed (repeatability and intermediate precision) and robust (RSD ≤ 4.45%) concerning variation on the Na₂CO₃ concentration and the reaction time. The limits of detection and quantification were also calculated (9.9 µg/mL and 33.1 µg/mL, respectively). An additional step for tannins quantification based on its reported selective precipitation by complexing agents was also evaluated; however, unspecific precipitation was observed, reducing the results' accuracy. Our work successfully adapted and validated a method for total phenolics quantification of açaí seed extract, resulting in 38 g of pyrogallol equivalent/100 g of extract.

GRAPHIC ABSTRACT

Evaluation of Antioxidant, Antibacterial and Enhancement of Antibiotic Action by Punica granatum Leaves Crude Extract and Enriched Fraction against Multidrug-Resistant Bacteria

The aim of this study was to evaluate the phytochemical composition, antioxidant, and antimicrobial potential of crude extract and fractions of Punica granatum leaves. The extract was produced by turbo extraction, after which hexanic, ethyl acetate, and aqueous fractions were obtained by partitioning. The chemical analyses were performed by thin layer chromatography and high-performance liquid chromatography, and the antioxidant activities were assayed by DPPH^. and ABTS^.+ . Minimal inhibitory and bactericidal concentrations (MIC/MBC) were applied to twenty-two bacteria. Most strains susceptible to extract/fractions and resistant to antibiotics were selected, and ampicillin, azithromycin, ciprofloxacin, and gentamicin were associated with the ethyl acetate fraction (EAF) against multidrug-resistant strains in modulatory and checkboard models. The data from chromatographic analyses showed flavonoids and tannins in the extract, as well as the enrichment of EAF in phenols, mainly flavonoids. The flavonoids were connected to the electron transfer activity demonstrated in the DPPH^. and ABTS^.+ assays. Gram-positive strains are more susceptible to EAF. The subinhibitory concentrations of P. granatum enhanced the antimicrobial activity of the agents and reduced the EAF individual MIC, and the combination of EAF and antibiotics demonstrated a synergistic effect. These results present a promising approach for developing a therapy in which antioxidant extracts and fractions can be used in combination with antibiotics.

Application of a Biosurfactant Produced by Bacillus cereus UCP 1615 from Waste Frying Oil as an Emulsifier in a Cookie Formulation

Biosurfactants have attracted increasing interest from the food industry due to their emulsifying, foaming and solubilizing properties. However, the industrial use of microbial biosurfactants has been hampered by the high production costs related mainly to the use of expensive substrates. The search for low-cost alternative substrates is one of the strategies adopted to overcome this problem. In the present study, a biosurfactant produced by Bacillus cereus UCP1615 by fermentation in a medium supplemented with waste frying soybean oil as a low-cost substrate was evaluated as a bioemulsifier for the production of cookies. The biosurfactant was evaluated for its emulsifying capacity against different vegetable oils, antioxidant activity and toxicity, demonstrating favorable results for use in food. In particular, it showed satisfactory antioxidant activity at the tested concentrations and no cytotoxicity to the L929 (mouse fibroblast) and Vero (monkey kidney epithelial) cell lines using the MTT assay. The biosurfactant was then added at different concentrations (0.25%, 0.5% and 1%) to a standard cookie dough formulation to evaluate the physicochemical characteristics of the product. Cookies formulated with the biosurfactant exhibited similar energy and physical characteristics to those obtained with the standard formulation but with a lower moisture content. The biosurfactant also ensured a good preservation of the cookie texture after 45 days of storage. These results suggest that the biosurfactant has a potential application as a green emulsifier in accordance with the demands of the current market for biocompatible products.

Spectroscopy NIR and MIR toward predicting simultaneous phenolic contents and antioxidant in red propolis by multivariate analysis

Conventional methods for determining phenolics and their bioactive properties are expensive, time-consuming, and laborious. This hinders the quality control of red propolis, recognized for having different types of phenolic constituents with different bioactive properties, for example, its antioxidant properties. In this sense, we present a new application of near and medium infrared spectroscopy to predict phenolic constituents, total flavonoids, gallic acid, kaempferol, pyrocatechin, quercetin, and different antioxidant tests (DPPH radical, reducing power and protection of the β-carotene: linoleic acid system) of red propolis using chemometry. The optimized models showed good predictive capacity with a minimum correlation coefficient of 0.70, low associated error, and figures of merit that indicate the good predictive capacity in the validation of the models. These data show infrared spectroscopy as efficient to simultaneously predict nine quality analyzes of red propolis quickly and simply. This also avoids tedious procedures for traditional chromatographic and spectrophotometric tests.

Bioactive Ingredients from Nitraria tangutorun Bobr. Protect Against Cerebral Ischemia/Reperfusion Injury Through Attenuation of Oxidative Stress and the Inflammatory Response

Nitraria tangutorun Bobr. has been used for thousands of years as a native folk medicine to alleviate dizziness and neurasthenia due to oxygen. In our previous study, natural antioxidant components (namely, NJBE) were isolated from industrial N. tangutorun Bobr. juice byproducts (NJBE) from the Qinghai-Tibet plateau. The current investigation assessed the effects of NJBE on ischemic stroke in mice and the potential mechanisms. C57BL/6 mice received NJBE (25, 50, or 100 mg/Kg) by gavage for 14 days and then stroke was induced by the middle cerebral artery occlusion (MCAO) model, followed by reperfusion for 72 h. The evaluation of brain infarct size, behavioral tests, and functional assessments was conducted to assess the effects of NJBE after MCAO. Our results suggested that NJBE significantly decreases infarct size, improves neurological deficits, as well as reduces the number of GFAP⁺ and Iba-1⁺ cells after MCAO. NJBE inhibited nitric oxide and malondialdehyde production in the ischemic brain. Meanwhile, it attenuated the expressions of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx). Also, NJBE significantly attenuated the expression levels of proinflammatory indicators, including TNF-α, IL-1β, IL-6, and IL-12. This process was accompanied by the downregulation of TLR4, TRAF6, pIκB/pIκB, and MMP9 expression and the upregulation of claudin-5 expression. NJBE induced improvements in brain injury. The neuroprotective effect of NJBE provides evidence for its potential application in stroke treatment.

Nutritional, Physiochemical, and Biological Value of Muffins Enriched with Edible Insects Flour

Edible insects are gaining attention as a novel food; however, studies with their use in food are still limited. This study aimed to determine the chemical composition, physical parameters, sensory acceptance, and biological properties of muffins enriched with different levels of cricket (Gryllodes sigillatus) and mealworm (Tenebrio molitor) flours. The approximate composition was analyzed, along with the physical and textural properties, color, and consumer acceptance. Moreover, the antioxidant properties, starch digestibility, and glycemic index were determined in vitro. As we expected, the protein content in muffins supplemented with insect flour increased, while the carbohydrates content decreased. Moreover, the total phenolic content and antioxidant capacity against ABTS·⁺ and DPPH· increased correspondingly as the percentage of insect flour in the muffins increased. The estimated glycemic index was lower for the fortified muffins than the control (p < 0.05). Additionally, enriched muffins were accepted by consumers, and their taste positively surprised respondents (p < 0.05). Therefore, the results obtained are satisfactory as regards the use of insects for the supplementation of traditional products, and further research into the addition of insects to other nutrient matrices is needed. Furthermore, examining the effect of insect addition on in vivo food biological activity is highly desirable.