Antioxidant activity, total phenolics and flavonoids contents: Should we ban in vitro screening methods?

Phenolic composition and encapsulation of Brazilian grape seed extracts: evaluating color stabilizing capacity in grape juices

The color of grape juice is an important acceptance attribute by consumers, but it suffers losses during storage. The use of commercial antioxidants has limitations because the concept of a "100% natural drink" of Brazilian legislation. This work characterized Brazilian grape seeds, and the cultivar extract with the greatest potential was encapsulated in arabic-gum (encapsulated extract-EE) to evaluate the color stabilizing capacity. The EE used in the grape juice was compared with the commercial antioxidants sulphite and enological tannin during storage (150 days). The BRS Magna and BRS Violeta grape seeds had the highest phenolic content, and the EE showed high catechin (4108 mg/kg), epicatechin (1161 mg/kg) and procyanidin-B2 (905 mg/kg) values. Sulfite was found to be the best color stabilizer. The use of EE (0.5 g/L) in grape juice improved color stability and anthocyanin stability. It was demonstrated that encapsulated grape seed extract has color stabilizing potential and that Brazilian grape seeds are a raw material of high technological value.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-024-05956-8.

Novel assaying method for the accurate and rapid analysis of antioxidant total capacity based on hexachloroiridate(IV)

We introduce a novel method, namely IrRAC, for assessing total antioxidant capacity utilizing the single electron oxidant hexachloroiridate(IV). This method leverages the 488 nm absorption band of [IrCl6]2- largely reducing interferences from antioxidants and their oxidation products. [IrCl6]2- is stable 6 h in phosphate-buffered saline (PBS) ensuring consistent and reproducible absorbance readings and rendering spectrophotometric determinations under physiological neutrality. Individual assessments of 23 antioxidants reveal a linear correlation between decreasing absorbance and increasing antioxidant concentration. When the IrRAC assay was compared with several established water-based methods, strong correlations were found. Importantly, [IrCl6]2- shows a minimal oxidation of non-antioxidative substances. Moreover, IrRAC performs well with synthetic antioxidant mixtures and real samples, highlighting that the nature of antioxidants dominates the assay without much disturbance. Commercial availability of K2[IrCl6] eliminates the need of pretreatment of the oxidant. Undoubtedly, the new method confers a compelling and cost-effective alternative to the existing electron transfer-based methodologies.

How lignocellulose degradation can promote the quality and function of dietary fiber from bamboo shoot residue by Inonotus obliquus fermentation

Lignocellulose constitutes the primary component of dietary fiber. We assessed how fermenting bamboo shoot residue with the medicinal white-rot fungus Inonotus obliquus affected the yield, composition, and functional attributes of dietary fiber by altering bamboo shoot residue lignocellulose's spatial structure and composition. I. obliquus secretes lignocellulolytic enzymes, which effectively enhance the degradation of holocellulose and lignin by 87.8% and 25.5%, respectively. Fermentation led to a more porous structure and reduced crystallinity. The yield of soluble dietary fiber increased from 5.1 g/100 g raw BSR to 7.1 g/100 g 9-day-fermented bamboo shoot residue. The total soluble sugar content of dietary fiber significantly increased from 9.2% to 13.8%, which improved the hydration, oil holding capacity, in vitro cholesterol, sodium cholate, and nitrite adsorption properties of dietary fiber from bamboo shoot residue. These findings confirm that I. obliquus biotransformation is promising for enhancing dietary fiber yield and quality.

Influences of superfine-grinding and enzymolysis separately assisted with carboxymethylation and acetylation on the in vitro hypoglycemic and antioxidant activities of oil palm kernel expeller fibre

The synergistic effects of ultrafine grinding and enzymolysis (cellulase and Laccase hydrolysis) alone or combined with carboxymethylation or acetylation on the hypoglycemic and antioxidant activities of oil palm kernel fibre (OPKEF) were studied for the first time. After these synergistic modifications, the microstructure of OPKEF became more porous, and its soluble fibre and total polyphenols contents, and surface area were all improved (P < 0.05). Superfine-grinding and enzymolysis combined with carboxymethylation treated OPKEF exhibited the highest viscosity (13.9 mPa∙s), inhibition ability to glucose diffusion (38.18%), and water-expansion volume (3.58 mL∙g-1). OPKEF treated with superfine-grinding and enzymolysis combined with acetylation showed the highest surface hydrophobicity (50.93) and glucose adsorption capacity (4.53 μmol∙g-1), but a lower α-amylase-inhibition ability. Moreover, OPKEF modified by superfine-grinding and enzymolysis had the highest inhibiting activity against α-amylase (25.78%). Additionally, superfine-grinding and enzymolysis combined with carboxymethylation or acetylation both improved the content and antioxidant activity of OPEKF's bounding polyphenols (P < 0.05).

Development of a tamarind-based functional beverage with partially-hydrolyzed agave syrup and the health effects of its consumption in C57BL/6 mice

Excess consumption of sweetened beverages is associated with a global rise in metabolic diseases. Tamarind and partially-hydrolyzed agave syrup have potential for developing healthier beverages. Our objective was to develop a functional beverage using these ingredients (PH-AS-B). We also evaluate shelf-life stability (physicochemical, microbiological, and antioxidant properties) and health effects in C57BL/6 mice compared with tamarind beverages sweetened with glucose or fructose. Optimal tamarind extraction conditions were a 1:10 ratio (g pulp/mL water) and boiling for 30 min, and the resulting beverage had a shelf life of two months at 4 °C. Non-volatile metabolites were identified using HPLC/MS. PH-AS-B was associated with decreased blood cholesterol (5%) and triglyceride (20-35%) concentrations in healthy mice as well as lower lipid (82%) concentrations and evidence of protein oxidation (42%) in the liver, compared with glucose- and fructose-sweetened tamarind beverages. In conclusion, PH-AS-B was stable and associated with beneficial metabolic properties in healthy mice.

Exogenous chlorogenic acid inhibits quality deterioration in fresh-cut potato slices

Fresh-cut potatoes are prone to surface browning and physiological degradation. Chlorogenic acid (CGA), a natural phenolic antioxidant, has demonstrated preservative properties in various postharvest products. However, the underlying mechanisms of its application on maintaining quality remain unclear. Therefore, the effect of exogenous CGA treatment on quality deterioration of potato slices and the mechanisms involved were investigated. Results revealed CGA treatment retarded the browning coloration, suppressed microbial growth and inhibited the declines in starch, and ascorbic acid contents in potato slices. Meanwhile, the treatment activated the phenylpropanoid pathway but decreased the activities of phenolic decomposition-related enzymes such as polyphenol oxidase (PPO) and tyrosinase and downregulated StPPO expression. Moreover, the treated slices exhibited reduced accumulation of reactive oxygen species and increased activity of antioxidant enzymes. Additionally, they displayed enhanced 2,2-diphenyl-1-picrylhydrazyl radicals scavenging capacity and higher ATP levels. Therefore, these findings indicated that CGA treatment was effective for quality maintenance and antioxidant capacity enhancement in fresh-cut potatoes, thereby providing potential strategies for the preservation and processing of fresh-cut produce.

Impact of Simulated Human Gastrointestinal Digestion on the Functional Properties of Dietary Fibres Obtained from Broccoli Leaves, Grape Stems, Pomegranate and Tomato Peels

This study aimed to analyse the impact of a simulated human digestion process on the composition and functional properties of dietary fibres derived from pomegranate-peel, tomato-peel, broccoli-stem and grape-stem by-products. For this purpose, a computer-controlled simulated digestion system consisting of three bioreactors (simulating the stomach, small intestine and colon) was utilised. Non-extractable phenols associated with dietary fibre and their influence on antioxidant capacity and antiproliferative activity were investigated throughout the simulated digestive phases. Additionally, the modifications in oligosaccharide composition, the microbiological population and short-chain fatty acids produced within the digestion media were examined. The type and composition of each dietary fibre significantly influenced its functional properties and behaviour during intestinal transit. Notably, the dietary fibre from the pomegranate peel retained its high phenol content throughout colon digestion, potentially enhancing intestinal health due to its strong antioxidant activity. Similarly, the dietary fibre from broccoli stems and pomegranate peel demonstrated anti-proliferative effects in both the small and the large intestines, prompting significant modifications in colonic microbiology. Moreover, these fibre types promoted the growth of bifidobacteria over lactic acid bacteria. Thus, these results suggest that the dietary fibre from pomegranate peel seems to be a promising functional food ingredient for improving human health.

Pt/NiFe-LDH hybrids for quantification and qualification of polyphenols

Polyphenols with antioxidant properties are of significant interest in medical and pharmaceutical applications. Given the diverse range of activities of polyphenols in vivo, accurate detection of these compounds plays a crucial role in nutritional surveillance and pharmaceutical development. Yet, the efficient quantitation of polyphenol contents and qualification of monomer compositions present a notable challenge when studying polyphenol bioavailability. In this study, platinum-modified nickel-iron layered double hydroxide (Pt/NiFe-LDH hybrids) were designed to mimic peroxidases for colorimetric analysis and act as enhanced matrices for laser desorption/ionization mass spectrometry (LDI MS) to quantify and qualify polyphenols. The hybrids exhibited an enzymatic activity of 33.472 U/mg for colorimetric assays, facilitating the rapid and direct quantitation of total tea polyphenols within approximately 1 min. Additionally, the heterogeneous structure and exposed hydroxyl groups on the hybrid surface contributed to photoelectric enhancement and in-situ enrichment of polyphenols in LDI MS. This study introduces an innovative approach to detect polyphenols using advanced materials, potentially inspiring the future development and applications of other photoactive nanomaterials.

Biotransformation of Cynomorium flavan-3-ols in dairy sheep and their effects on inflammation and liver growth retardation

The stems of Cynomorium songaricum are used in traditional Chinese medicine as a tonic and also used locally as a food material and livestock feed. It is known that some of the falvan-3-ol monomers and dimers that entered the milk of dairy sheep fed with C. songaricum stems are biotransformation products of the original flavan-3-ol polymers in C. songaricum stems. This study was performed to investigate the biotransformation process of the flavan-3-ols in dairy sheep and to evaluate the bioactivities. The results showed that procyanidin A2 and epicatechin could be released from the polymeric flavan-3-ols of C. songaricum through rumen microbial metabolism. On traumatic and lipopolysaccharide (LPS)-induced inflammation models of Tg (mpx: EGFP) zebrafish larvae and LPS-induced liver injury models of Tg (fabp10a: DsRed) zebrafish larvae, the milk from sheep fed with C. songaricum stems showed stronger anti-inflammatory and hepatoprotective activities compared to blank milk. The absorbed chemical constituents of C. songaricum stems and the metabolites also exhibited anti-inflammatory and hepatoprotective activities, with the dimeric flavan-3-ols being more effective than the monomers. The milk, the absorbed chemical constituents of C. songaricum stems, and the metabolites alleviated the increased level of reactive oxygen species induced by LPS in zebrafish larvae. PRACTICAL APPLICATION: This study found that C. songaricum stems as livestock feed could produce milk that has a beneficial impact on consumer and livestock health in terms of anti-inflammation and hepatoprotection.

High-throughput synchronous erythrocyte cellular antioxidant activity and protection screening of phenolic-rich extracts: Protocol validation and applications

Oxidative/nitrosative damage takes part in chronic disease development, which generates an urgent need for intervention and better therapies to manage them. The scientific community has demanded easy-to-run, cheap, and reliable methods for cellular antioxidant activity assays. This work standardised and validated an erythrocyte cellular antioxidant activity and membrane protection/injury (HERYCA-P) protocol to study food-derive extracts. The method measures intracellular reactive oxygen species (ROS) generation, lipoperoxidation, and haemolysis induced by 2,2'-azobis(2-amidinopropane) dihydrochloride. Quercetin decreased ROS generation by 50.4% and haemolysis by 2.2%, while ascorbic acid inhibited lipid peroxidation by 40.1%. Total phenolic contents of teas were correlated with decreased ROS generation (r = -0.924), lipoperoxidation (r = -0.951), and haemolysis (r = -0.869). The erythrocyte ROS generation and lipoperoxidation were also associated with CUPRAC (r = -0.925; r = -0.951) and hydroxyl radical scavenging activity (r = -0.936; r = -0.949). The precision rates of antioxidant standards and tea samples were below 15%. HERYCA-P is feasible as a complementary antioxidant assay for food matrices.

Effectiveness of anthocyanin-containing foods and nutraceuticals in mitigating oxidative stress, inflammation, and cardiovascular health-related biomarkers: a systematic review of animal and human interventions

Cardiovascular diseases (CVDs) are a group of chronic health disorders prevalent worldwide that claim millions of lives yearly. Inflammation and oxidative stress are intricately associated with myocardial tissue damage, endothelial dysfunction, and increased odds of heart failure. Thus, dietary strategies aimed at decreasing the odds of CVDs are paramount. In this regard, the consumption of anthocyanins, natural pigments found in edible flowers, fruits, and vegetables, has attracted attention due to their potential to promote cardiovascular health. The main mechanisms of action linked with their protective effects on antioxidant and anti-inflammatory activities, serum lipid profile modulation, and other cardiovascular health parameters are explained and exemplified. However, little is known about the dose-dependency nature of the effects, which anthocyanin has better efficiency, and whether anthocyanin-containing foods display better in vivo efficacy than nutraceuticals (i.e., concentrated extracts containing higher levels of anthocyanins than foods). Thus, this systematic review focused on determining the effects of anthocyanin-containing foods and nutraceuticals on biomarkers associated with CVDs using animal studies and human interventions supported by in vitro mechanistic insights. Overall, the results showed that the regular consumption of anthocyanin-containing foods and nutraceuticals improved vascular function, lipid profile, and antioxidant and anti-inflammatory effects. The daily dosage, the participants' health status, and the duration of the intervention also significantly influenced the results.

Bioprospecting of Artemisia genus: from artemisinin to other potentially bioactive compounds

Species from genus Artemisia are widely distributed throughout temperate regions of the northern hemisphere and many cultures have a long-standing traditional use of these plants as herbal remedies, liquors, cosmetics, spices, etc. Nowadays, the discovery of new plant-derived products to be used as food supplements or drugs has been pushed by the exploitation of bioprospection approaches. Often driven by the knowledge derived from the ethnobotanical use of plants, bioprospection explores the existing biodiversity through integration of modern omics techniques with targeted bioactivity assays. In this work we set up a bioprospection plan to investigate the phytochemical diversity and the potential bioactivity of five Artemisia species with recognized ethnobotanical tradition (A. absinthium, A. alba, A. annua, A. verlotiorum and A. vulgaris), growing wild in the natural areas of the Verona province. We characterized the specialized metabolomes of the species (including sesquiterpenoids from the artemisinin biosynthesis pathway) through an LC-MS based untargeted approach and, in order to identify potential bioactive metabolites, we correlated their composition with the in vitro antioxidant activity. We propose as potential bioactive compounds several isomers of caffeoyl and feruloyl quinic acid esters (e.g. dicaffeoylquinic acids, feruloylquinic acids and caffeoylferuloylquinic acids), which strongly characterize the most antioxidant species A. verlotiorum and A. annua. Morevoer, in this study we report for the first time the occurrence of sesquiterpenoids from the artemisinin biosynthesis pathway in the species A. alba.

Evaluation of Bioactive Effects of Five Plant Extracts with Different Phenolic Compositions against Different Therapeutic Targets

Plant extracts rich in phenolic compounds have been reported to exert different bioactive properties. Despite the fact that there are plant extracts with completely different phenolic compositions, many of them have been reported to have similar beneficial properties. Thus, the structure-bioactivity relationship mechanisms are not yet known in detail for specific classes of phenolic compounds. In this context, this work aims to demonstrate the relationship of extracts with different phenolic compositions versus different bioactive targets. For this purpose, five plant matrices (Theobroma cacao, Hibiscus sabdariffa, Silybum marianum, Lippia citriodora, and Olea europaea) were selected to cover different phenolic compositions, which were confirmed by the phytochemical characterization analysis performed by HPLC-ESI-qTOF-MS. The bioactive targets evaluated were the antioxidant potential, the free radical scavenging potential, and the inhibitory capacity of different enzymes involved in inflammatory processes, skin aging, and neuroprotection. The results showed that despite the different phenolic compositions of the five matrices, they all showed a bioactive positive effect in most of the evaluated assays. In particular, matrices with very different phenolic contents, such as T. cacao and S. marianum, exerted a similar inhibitory power in enzymes involved in inflammatory processes and skin aging. It should also be noted that H. sabdariffa and T. cacao extracts had a low phenolic content but nevertheless stood out for their bioactive antioxidant and anti-radical capacity. Hence, this research highlights the shared bioactive properties among phenolic compounds found in diverse matrices. The abundance of different phenolic compound families highlights their elevated bioactivity against diverse biological targets.

Bioactive compounds of honey from different regions of Brazil: the effect of simulated gastrointestinal digestion on antioxidant and antimicrobial properties

Monofloral and multifloral honey produced in different regions may have different bioactive compounds and antioxidant capacities, resulting in changes in the antimicrobial activity of honey. However, many of these compounds degrade due to the extreme digestion conditions, which may inhibit the antimicrobial activity. Given this context, this study aimed to describe the bioactive compounds of honey produced in Brazil and verify if honey samples from different botanical and geographical origins differ in bioactive compounds, and if honey maintains its antimicrobial activity after digestion simulation. Multivariate analysis was used to identify characteristics that differentiated the honey samples according to the botanical and geographical origin criteria. The amount of the bioactive compounds varied significantly: the total phenolic compound content varied from 20.49 to 101.44 mg GAE per 100 g, flavonoids varied from 1.41 to 13.52 mg QE per 100 g, phenolic acids varied from 13.61 to 56.41 mg CAE per 100 g, and carotenoids varied from 0.66 to 4.27 mg β-carotene per g. Multifloral honey (H22) produced in the dry season of northeastern Brazil presented the highest bioactive compound concentration except for the carotenoid content. HPLC-MS analysis showed the presence of six hydroxybenzoic acids, four hydroxycinnamic acids, eight flavonols, three flavanones, two flavones and two isoflavonoids; Pterodon pubescens monofloral honey (H14) from midwestern Brazil stood out in terms of the carotenoid content. All analyzed honey samples exhibited antimicrobial activity against Staphylococcus aureus and Escherichia coli bacteria before digestive process simulation, and bacteria were inhibited during in vitro digestion; this activity decreased during the simulation of the oral phase, remained in the gastric phase, and disappeared in the intestinal phase.

Exploring Astrodaucus orientalis (L.) Drude: Phytochemical Analysis and its Biological Potential Against Alzheimer's and Diabetes

In current study antioxidant, antidiabetic, antimicrobial, anticholinesterase, and human carbonic anhydrase I, and II (hCA I and II) isoenzymes inhibition activities of Astrodaucus orientalis different parts were investigated. Achetylcholinesterse (AChE) and butyrylcholinesterse (BChE) inhibitory activities of octyl acetate were determined via molecular docking. Quantitative assessment of specific secondary metabolites was conducted using LC-MS/MS. An examination of chemical composition of essential oils was carried out by GC-MS/MS. A thorough exploration of plant's anatomical characteristics was undertaken. The highest phenolics level and DPPH antioxidant capacity were seen in root and fruit. Fruit essential oil demonstrated the highest AChE inhibition (44.13±3.61 %), while root dichloromethane sub-extract had the best inhibition towards BChE (86.13±2.58 %). Cytosolic hCA I, and II isoenzymes were influentially inhibited by root oil with 1.974 and 2.207 μM IC50 values, respectively. The most effective extracts were found to be root all extract/sub-extracts (except water) against C. tropicalis and C. krusei strains with MIC value 160>μg/mL. Sabinene (29.4 %), α-pinene (20.2 %); octyl acetate (54.3 %); myrcene (28.0 %); octyl octanoate (71.3 %) were found principal components of aerial parts, roots, flowers, and fruits, respectively. Flower essential oil, fruit dicloromethane and ethyl acetate exhibited potent α-glucosidase inhibitory activity with 900, 40, and 937 μg/mL IC50 values, respectively.

An Integrated Approach to the Anti-Inflammatory, Antioxidant, and Genotoxic Potential of Portuguese Traditional Preparations from the Bark of Anacardium occidentale L

Anacardium occidentale L. stem bark Traditional Herbal Preparations (AoBTHPs) are widely used in traditional medicine to treat inflammatory conditions, such as diabetes. The present study aims to evaluate the anti-inflammatory, antioxidant, and genotoxic potential of red and white Portuguese AoBTHPs. Using a carrageenan-induced rat paw edema model, a significant anti-edema effect was observed for all tested doses of white AoBTHP (40.2, 71.5, and 127.0 mg/kg) and the two highest doses of red AoB THP (71.5 and 127.0 mg/kg). The anti-edema effect of red AoBTHP's highest dose was much more effective than indomethacin 10 mg/kg, Trolox 30 mg/kg, and Tempol 30 mg/kg. In DPPH, FRAP, and TAC using the phosphomolybdenum method, both types of AoBTHPs showed similar antioxidant activity and no genotoxicity up to 5000 µg/plate in the Ames test. The LC-UV/DAD-ESI/MS fingerprint allowed the identification of gallic and protocatechuic acids as the two main marker compounds and the presence of catechin, epicatechin, epigallocatechin gallate, and ellagic acid in both AoBTHPs. The obtained results support the validation of red and white AoB and their THPs as anti-inflammatory agents and contribute to the possible development of promising new therapeutic options to treat inflammatory conditions.

Exploring the Antioxidant Potential of Blackberry and Raspberry Leaves: Phytochemical Analysis, Scavenging Activity, and In Vitro Polyphenol Bioaccessibility

The goal of this research was nutritional evaluation through the phytochemical analysis of blackberry and raspberry leaves, the screening of their biological activity (antioxidant capacity and inhibition of lipid peroxidation), and the investigation of the effect of in vitro gastrointestinal digestion (GID) of blackberry and raspberry leaves on the bioaccessibility of polyphenol subclasses. The concentrations of the analyzed liposoluble antioxidants were higher (p < 0.05) in blackberry leaves compared to raspberry leaves, while a significant (p < 0.05) higher content of water-soluble antioxidants was registered in raspberry leaves (with a total polyphenol content of 26.2 mg GAE/g DW of which flavonoids accounted for 10.6 mg/g DW). Blackberry leaves had the highest antioxidant capacity inhibition of the superoxide radicals (O2•-), while raspberry leaves registered the highest inhibition of hydroxyl radicals (•OH), suggesting a high biological potency in scavenging-free radicals under in vitro systems. The maximum inhibition percentage of lipid peroxidation was obtained for blackberry leaves (24.86% compared to 4.37% in raspberry leaves), suggesting its potential to limit oxidative reactions. Simulated in vitro digestion showed that hydroxybenzoic acids registered the highest bioaccessibility index in the intestinal phase of both types of leaves, with gallic acid being one of the most bioaccessible phenolics. The outcomes of this investigation reveal that the most significant release of phenolic compounds from blackberry and raspberry leaves occurs either during or after the gastric phase. Knowledge about the bioaccessibility and stability of polyphenol compounds during digestion can provide significant insights into the bioavailability of these molecules and the possible effectiveness of plant metabolites for human health.

Antimicrobial, antioxidant and cytotoxic activities of the leaf and stem extracts of Carissa bispinosa used for dental health care

BACKGROUND

Carissa bispinosa (L.) Desf. ex Brenan is one of the plants used traditionally to treat oral infections. However, there is limited data validating its therapeutic properties and photochemistry. The aim of this study was to investigate the protective efficacy of the leaf and stem extracts of C. bispinosa against oral infections.

METHODS

The phenolic and tannin contents were measured using Folin-Ciocalteau method after extracting with different solvents. The minimum inhibitory concentrations (MIC) of the extracts were assessed using the microdilution method against fungal (Candida albicans and Candida glabrata) and bacterial (Streptococcus pyogenes, Staphylococcus aureus and Enterococcus faecalis) strains. The 2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing power (FRP) models were utilised to assess the antioxidant potential of the extracts. Cytotoxicity of the leaf acetone extract was evaluated using the methylthiazol tetrazolium assay.

RESULTS

The methanol leaf extract had the highest phenolic content (113.20 mg TAE/g), whereas hexane extract displayed the highest tannin composition of 22.98 mg GAE/g. The acetone stem extract had the highest phenolic content (338 mg TAE/g) and the stem extract yielded the highest total tannin content (49.87 mg GAE/g). The methanol leaf extract demonstrated the lowest MIC value (0.31 mg/mL), whereas the stem ethanol extract had the least MIC value of 0.31 mg/mL. The stem methanol extract had the best DPPH free radical scavenging activity (IC50, 72 µg/mL) whereas the stem ethanol extract displayed maximum FRP with absorbance of 1.916. The leaf acetone extract had minimum cytotoxicity with the lethal concentration (LC50) of 0.63 mg/mL.

CONCLUSIONS

The results obtained in this study validated the protective effect of C. bispinosa against oral infections.

Decoding the enhanced antioxidant activities of the combined small berry pomaces by widely targeted metabolomics analysis

Small berry pomaces (SBPs) are poorly utilized as an inexpensive source of bioactive compounds. This study investigated the impact of compounding treatment on nutritional and antioxidant characteristics of combined SBPs, in comparison with single SBP. The results showed that the amounts of protein, minerals, dietary fiber (DF) and anthocyanidins were significantly (p < 0.05) higher in combined SBPs than in combined fruits. Moreover, the combined SBPs were characterized by an elevated abundance of minerals and anthocyanidins (6 kinds, and 5 kinds, respectively), substantiating the effectiveness of compounding treatment on SBP nutrition. A total of 776 secondary phytochemicals were detected in combined SBPs by a widely targeted metabolomics approach. Each SBP contained approximately 100 kinds of unique natural antioxidants. Furthermore, the combined SBPs group had the highest antioxidant activity compared with single SBP. Meanwhile, the antioxidant activities determined in combined SBPs were higher than arithmetic mean value of single SBP. The synergism and interaction of active components in different sources of SBPs play vital role in the high antioxidant capacity of combined SBPs. All the results provide reference for the comprehensive development and utilization of fruit residues. The SBPs should be highly prized for their substantial amount of nutritional and bioactive constituents, including protein, DF, essential minerals and secondary metabolites. These secondary metabolites are positively associated with antioxidant benefits. The present study summarizes the knowledge about bioactive compounds and antioxidant activities of combined SBPs group and discusses the relevant mechanisms. A conclusion can be educed that combined process is an effective way to improve properties of the pomaces.

The Antioxidant Activities In Vitro and In Vivo and Extraction Conditions Optimization of Defatted Walnut Kernel Extract

The objective of this study was to determine the antioxidant activities of defatted walnut kernel extract (DWE) and whole walnut kernel extract (WE) in vitro and in vivo. Three spectrophotometric methods, DPPH, ABTS, and FRAP, were used in in vitro experiments, and mice were used in in vivo experiments. In addition, response surface methodology (RSM) was used to optimize reflux-assisted ethanol extraction of DWE for maximum antioxidant activity and total phenolic content. The results of in vitro experiments showed that both extracts showed antioxidant activity; however, the antioxidant activity of DWE was higher than that of WE. Both extracts improved the mice's oxidative damage status in in vivo studies. An ethanol concentration of 58%, an extraction temperature of 48 °C, and an extraction time of 77 min were the ideal parameters for reflux-assisted ethanol extraction of DWE. The results may provide useful information for further applications of defatted walnut kernels and the development of functional foods.

Next-generation analytical platforms for antioxidant capacity assessment: The urge for realistic and physiologically relevant methods

Bioactive compounds, such as carotenoids, alkaloids, and phenolics, are well known because of their alleged health benefits when consumed regularly in a balanced healthy diet. Some well-documented bioactivities are antioxidant, antihypertensive, antihyperglycemic, antilipidemic, anti-obesity, anti-inflammatory, and antimicrobial capacities. Trying to associate the chemical composition of distinct sources and their bioactivity using in vitro methods, several assays have been developed, implemented, and optimised to recapitulate human physiological conditions. However, in most cases, pitfalls are apparent, and no single test tube-based assay can predict in vivo responses. The need for a more physiologically relevant cell-based method to evaluate the antioxidant capacity of putative antioxidants is apparent. Therefore, in this Review, the current state-of-the-art in food science and nutrition is aligned with cell biology/bioengineering approaches to propose combining in vitro digestion and absorption to obtain a bioavailable fraction containing antioxidants. Overall, human plasma, 2-dimensional human cell lines, such as erythrocytes, lymphocytes, hepatocytes, enterocytes and, ultimately, 3-dimensional spheroids (organoids) could be used as biologically relevant models to assess the antioxidant activity of compounds, foods, and nutraceuticals. This versatile approach is deemed suitable, accurate, reproducible, and physiologically relevant to evaluate the protective effects of antioxidants against ROS-mediated oxidation in vitro.

Sunflower and Palm Kernel Meal Present Bioaccessible Compounds after Digestion with Antioxidant Activity

Sunflower (Helianthus annuus L.) and African palm kernel (Elaeis guineensis Jacq.) are among the most cultivated in the world regarding oil extraction. The oil industry generates a large amount of meal as a by-product, which can be a source of nutrients and bioactive compounds. However, the physiological effects of bioactive compounds in such matrices are only valid if they remain bioavailable and bioactive after simulated gastrointestinal digestion. This study evaluated the chemical composition and antioxidant and prebiotic potential of de-oiled sunflower (DS) and de-oiled palm kernel (DP) meal after in vitro digestion. The DS sample had the highest protein content and the best chemical score, in which lysine was the limiting amino acid. Digested samples showed increased antioxidant activity, measured by in vitro methods. The digested DS sample showed a better antioxidant effect compared to DP. Moreover, both samples managed to preserve DNA supercoiling in the presence of the oxidizing agent. The insoluble fractions after digestion stimulated the growth of prebiotic bacterium, similar to inulin. In conclusion, simulated gastrointestinal digestion promoted in both matrices an increase in protein bioaccessibility and antioxidant capacity, pointing to a metabolic modulation favorable to the organism.

Seasonal Monitoring of Volatiles and Antioxidant Activity of Brown Alga Cladostephus spongiosus

Cladostephus spongiosus was harvested once a month during its growing season (from May to August) from the Adriatic Sea. Algal volatile organic compounds (VOCs) were obtained by headspace solid-phase microextraction (HS-SPME) and hydrodistillation (HD) and analysed by gas chromatography and mass spectrometry (GC-MS). The effects of air drying and growing season on VOCs were determined. Two different extraction methods (ultrasound-assisted extraction (UAE) and microwave-assisted extraction (MAE)) were used to obtain ethanolic extracts of C. spongiosus. In addition, the seasonal antioxidant potential of the extracts was determined, and non-volatile compounds were identified from the most potent antioxidant extract. Aliphatic compounds (e.g., pentadecane) were predominantly found by HS-SPME/GC-MS. Hydrocarbons were more than twice as abundant in the dry samples (except in May). Aliphatic alcohols (e.g., hexan-1-ol, octan-1-ol, and oct-1-en-3-ol) were present in high percentages and were more abundant in the fresh samples. Hexanal, heptanal, nonanal, and tridecanal were also found. Aliphatic ketones (octan-3-one, 6-methylhept-5-en-2-one, and (E,Z)-octa-3,5-dien-2-one) were more abundant in the fresh samples. Benzene derivatives (e.g., benzyl alcohol and benzaldehyde) were dominant in the fresh samples from May and August. (E)-Verbenol and p-cymen-8-ol were the most abundant in dry samples in May. HD revealed aliphatic compounds (e.g., heptadecane, pentadecanal, (E)-heptadec-8-ene, (Z)-heptadec-3-ene), sesquiterpenes (germacrene D, epi-bicyclosesquiphellandrene, gleenol), diterpenes (phytol, pachydictyol A, (E)-geranyl geraniol, cembra-4,7,11,15-tetraen-3-ol), and others. Among them, terpenes were the most abundant (except for July). Seasonal variations in the antioxidant activity of the ethanolic extracts were evaluated via different assays. MAE extracts showed higher peroxyl radical inhibition activity from 55.1 to 74.2 µM TE (Trolox equivalents). The highest reducing activity (293.8 µM TE) was observed for the May sample. Therefore, the May MAE extract was analysed via high-performance liquid chromatography with high-resolution mass spectrometry and electrospray ionisation (UHPLC-ESI-HRMS). In total, 17 fatty acid derivatives, 9 pigments and derivatives, and 2 steroid derivatives were found. The highest content of pheophorbide a and fucoxanthin, as well as the presence of other pigment derivatives, could be related to the observed antioxidant activity.

Apple Pomace Compositional Data Highlighting the Proportional Contribution of Polymeric Procyanidins

Recent years have seen an increase in research focusing on the amelioration of apple pomace waste for use in the food and nutraceutical industries. Much of this work has concentrated on the characterisation of the polyphenol composition of apple pomace materials to determine their role in conferring nutritional and health benefits. Although apples contain substantial quantities of polymeric procyanidins (condensed tannins), this class of compounds has received limited attention in apple research. This study quantified the polymeric procyanidins in apple pomace extracts using a rapid, methyl-cellulose precipitation (MCP) approach for the first time. In addition, a non-targeted metabolomics approach was applied to determine the most abundant phenolic classes present. Polymeric procyanidins were found to be the most abundant type of polyphenol in apple pomace extracts and were generally oligomeric in nature. Multivariate statistical analysis revealed that the ferric-reducing antioxidant power (FRAP) was most strongly correlated with the polymeric procyanidin concentration. Noting that polymeric procyanidins may not cross the cell layer to exert antioxidant activity in vivo, their presence in apple pomace extracts may therefore overestimate the FRAP. This work highlights the importance of polymeric procyanidins in the phenolic diversity of apple pomaces, and it is proposed that in future studies, rapid MCP assays may be used for their quantification.

Optimization of the Green Chemistry-like Extraction of Phenolic Compounds from Grape (Vitis labrusca L.) and Blackberry (Rubus fruticosus L.) Seeds with Concomitant Biological and Antioxidant Activity Assessments

The objective of this work was to determine the phenolic composition, chemical and cellular antioxidant activity, cytotoxicity in human cells, and peroxidative inhibition of the defatted fraction of grape (Vitis labrusca) and blackberry (Rubus fruticosus) seeds. Soxhlet extraction (Sox) was used to extract the fat and obtain the degreased material. A statistical optimization study was developed to maximize the extraction of bioactive compounds and antioxidant activity from defatted grape and blackberry seeds. Simultaneous optimization was applied with a combination of 35.9 min of extraction and a solid-to-solvent ratio of 1 g of defatted grape seed to 61.28 mL of an extracting solvent (60% ethanol) and 62.1 min of extraction and a solid-to-solvent ratio of 1 g of defatted blackberry seed to 64.1 mL of an extracting solvent (60% ethanol). In the cell viability assay, HepG2 cancer cells seemed more sensitive to grape and blackberry extracts, while Ea.hy926 hybrid cells showed more resistance to their effects. In general, the extracts presented low/no cytotoxicity, exhibited a protective effect against H₂O₂-induced ROS production, and demonstrated antioxidant activity and a protective effect on the erythrocytes when subjected to hypotonic and isotonic conditions not presenting hemolytic behavior (5.0 to 10.0 μg GAE/mL). Thus, the results provided a broad assessment of the bioactivity of the extracts obtained using a simple and low-cost process developed by employing non-toxic solvents and with the potential to be used in technological applications.

Biotransformation of white and black mustard grains through germination and enzymatic hydrolysis revealed important metabolites for antioxidant properties and cytotoxic activity against Caco-2 cells

Germination and enzymatic hydrolysis are biological processes with well-recognized positive effects on phenolic composition and antioxidant potential. This study aimed to apply those processes to white (Sinapsis alba) and black (Brassica nigra) mustard grains and to analyze the influences on the total phenolic content (TPC); phenolic and peptide profile determined by ultra-performance liquid chromatography-high resolution mass spectrometry (UPLC-HRMS); antioxidant potential (DPPH, ABTS, and FRAP assays); and cytotoxicity against Caco-2, a human colorectal adenocarcinoma cell line. Enzyme combinations for hydrolysis were different for each mustard grain, but for both species, enzymatic hydrolysis and germination showed a positive effect on antioxidant properties. From UPLC-HRMS analysis and molecular network studies, 14 peptides and 17 phenolic compounds were identified as metabolites released from mustard after processes application, which were strongly correlated with increased antioxidant activity. In addition, enzymatic hydrolysis applied in germinated mustard grains for both mustards increased the cytotoxic activity against Caco-2 human colorectal adenocarcinoma cell line.

Characterization of Phenolic Profile in Milk Obtained by Ewes Fed Grape Pomace: Reflection on Antioxidant and Anti-Inflammatory Status

The aim of the present work was to evaluate if the use of grape pomace (GP) in the feeding of dairy ewes can improve the content of phenolic compounds (PCs) in the milk and affect the anti-inflammatory and antioxidative status of the milk. For this purpose, 46 ewes were randomly assigned to two groups of 23 animals each: a control group (Ctrl) that received a standard diet and an experimental group (GP+), whose diet was been formulated with 10% GP on a dry matter (DM) basis. At the end of the 60 days of the trial, from 10 ewes selected randomly from each group, individual milk samples were collected and analyzed for the identification and the quantification of phenolic compounds through an ultra-high-performance liquid chromatography system, and milk anti-inflammatory and antioxidative status were evaluated by enzyme-linked immunosorbent assay, determining the activity of GPx and CAT and the levels of IL-1 and TNFα. In addition, gelatinolytic activity of Type IV collagenases (MMP-2/MMP-9) was evaluated by the fluorometric method and zymographic approach. The results obtained showed that the diet with GP affects the phenolic profile of milk, inducing milk enrichment of phenolic compounds without, however, having a significant impact on milk antioxidant and inflammatory status. However, a lower activity of MMP-9 was found in GP+ milk. The use of the molecular docking approach showed the ability of luteolin to approach the catalytic pocket of the enzyme, interfering with the recruitment of the substrate, and therefore, slowing down their hydrolytic activity.

Antioxidant Properties Mediate Nephroprotective and Hepatoprotective Activity of Essential Oil and Hydro-Alcoholic Extract of the High-Altitude Plant Skimmia anquetilia

There are many high-altitude plants such as Skimmia anquetilia that are unexplored for their possible medicinal values. The present study was conducted to examine the antioxidant activities of Skimmia anquetilia (SA) using in vitro and in vivo models. The SA hydro-alcoholic extracts were investigated using LC-MS for their chemical constituents. The essential oil and hydro-alcoholic extracts of SA were evaluated for pharmacological properties. The antioxidant properties were evaluated using in vitro DPPH, reducing power, cupric reducing antioxidant power, and metal chelating assays. The anti-hemolytic activity was carried out using a human blood sample. The in vivo antioxidant activities were evaluated using CCL₄-induced hepatotoxicity and nephrotoxicity assay. The in vivo evaluation included histopathological examination, tissue biochemical evaluation such as the kidney function test, catalase activity, reduced glutathione activity, and lipid peroxidation estimation. The phytochemical investigation showed that the hydro-alcoholic extract contains multiple important active constituents such as L-carnosine, acacetin, linoleic acid, leucylleucyl tyrosine, esculin sesquihydrate, etc., similar to the components of SA essential oil reported in a previous study. The high amount of total phenolic content (TPC) and total flavonoid content (TFC) reflect (p < 0.001) a high level of reducing power, cupric reducing, and metal chelating properties. This significantly (p < 0.001) inhibited enlargement of the liver, with a significant reduction in ALT (p < 0.01) and AST (p < 0.001). Highly significant improvement in the functioning of the kidney was noted using the blood urea and creatinine (p < 0.001) levels. Tissue-based activities showed a major rise in catalase, reduced glutathione, and reduced lipid peroxidation activities. We conclude from this study that the occurrence of a high quantity of flavonoid and phenolic contents had strong antioxidant properties, leading to hepatoprotective and nephroprotective activity. Further active constituent-specific activities should be evaluated.

Sanguisorba minor Scop.: An Overview of Its Phytochemistry and Biological Effects

Since ancient times, many plants have been cultivated for their nutritional and medicinal properties. The genus Sanguisorba has been used for medicinal purposes for more than 2000 years. These species are distributed in temperate, arctic, or alpine areas in the Northern Hemisphere. Elongated, imparipinnate leaves and densely clustered flower heads are characteristics of the genus Sanguisorba. While Sanguisorba officinalis L. is mainly known for its significant medicinal applications, Sanguisorba minor Scop. is beginning to attract greater interest for its chemical composition and biological effects. Our research collected extensive information on Sanguisorba minor, including its history, taxonomy, habitat, and distribution, as well as its bioactive components and biological activities. In addition to electron microscopy of plant parts (root, stems, and leaves), which is described for the first time in the literature in the case of S. minor, the study also provides information on potential pests or beneficial insects that may be present. Our goal was to provide important information that will serve as a solid foundation for upcoming research on Sanguisorba minor Scop.

Investigation of soybean lipophilic proteins as carriers for vitamin B12: Focus on interaction mechanism, physicochemical functionality, and digestion characteristics

This study aimed to explore the interaction mechanism between soybean lipophilic protein (LP) and vitamin B₁₂ and the potential of LP as a vitamin B₁₂ carrier. The results of spectroscopy indicated that the interaction between vitamin B₁₂ and LP changed the conformation of LP and exposed hydrophobic groups largely. The results of molecular docking revealed that vitamin B₁₂ interacted with LP through a hydrophobic pocket embedded on the surface of LP. With the enhancement of the interaction between LP and vitamin B₁₂, the particle size of the LP-vitamin B₁₂ complex gradually decreased to 588.31 nm and the absolute value of zeta potential gradually increased to 26.82 mV. Meanwhile, the LP-vitamin B₁₂ complex showed excellent physicochemical properties and digestive characteristics. The present work enriched the means of vitamin B₁₂ protection and provided a theoretical basis for applying the LP-vitamin B₁₂ complex in food systems.

Antioxidant, Antibacterial and Antibiofilm Activity of Nanoemulsion-Based Natural Compound Delivery Systems Compared with Non-Nanoemulsified Versions

This study aimed to develop nanoemulsions with a focus on improving the bioactivity of oregano essential oil (OEO), carvacrol and thymol for possible food applications. Nanoemulsions were prepared with acoustic cavitation using ultrasound. The nanodroplets had average diameters of 54.47, 81.66 and 84.07 nm for OEO, thymol and carvacrol, respectively. The main compound in OEO was carvacrol (74%), and the concentration in the nanoemulsions was 9.46 mg/mL for OEO and the isolated compounds. The effects of droplet size reduction on antioxidant, antibacterial and antibiofilm activity were evaluated. Regarding antioxidant activity, the nanoemulsions performed better at the same concentration, with inhibitions >45% of the DPPH radical and significant differences compared with their non-nanoemulsified versions (p < 0.05). The nanoemulsions' minimum inhibitory concentration (MIC) and non-nanoemulsified compounds were evaluated against foodborne pathogens with inhibition ranges between 0.147 and 2.36 mg/mL. All evaluated pathogens were more sensitive to nanoemulsions, with reductions of up to four times in MIC compared with non-nanoemulsified versions. E. coli and S. Enteritidis were the most sensitive bacteria to the carvacrol nanoemulsion with MICs of 0.147 mg/mL. Concerning antibiofilm activity, nanoemulsions at concentrations up to four times lower than non-nanoemulsified versions showed inhibition of bacterial adhesion >67.2% and removal of adhered cells >57.7%. Overall, the observed effects indicate that droplet size reduction improved the bioactivity of OEO, carvacrol and thymol, suggesting that nanoemulsion-based delivery systems for natural compounds may be alternatives for food applications compared with free natural compounds.

Molecular Docking Revealed the Potential Anti-Oxidative Stress Mechanism of the Walnut Polypeptide on HT22 Cells

The preparation of novel antioxidant peptides from food raw materials is one of the research focuses, but there are fewer studies on the preparation of antioxidant peptides from walnut meal, a by-product of processing walnuts. This study analyzed the antioxidant properties and protective effects of walnut protein hydrolyzed by alkaline protease and trypsin on the oxidative stress of HT22 cells. The peptides were identified by UPLC-MS/MS, and the anti-oxidative peptides were screened based on virtual computer tools. The potential anti-oxidative stress mechanism of the walnut polypeptide on HT22 cells was explored by molecular docking. The results revealed that walnut protein hydrolysates (WPH) with molecular weights of less than 1 kDa had good antioxidant properties and inhibited oxidative damage of HT22 cells by regulating the levels of reactive oxygen species (ROS) and antioxidant enzyme catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px). Six of the ninety identified new peptides showed good solubility, non-toxicity, and bioactivity. The molecular docking results showed that the six peptides could dock with Keap1 successfully, and EYWNR and FQLPR (single-letter forms of peptide writing) could interact with the binding site of Nrf2 in the Keap1-Kelch structural domain through hydrogen bonds with strong binding forces. The results of this study provided important information on the antioxidant molecular mechanism of the walnut polypeptide and provided a basis for further development of walnut antioxidant polypeptide products.

Recovery of Anthocyanins from Hibiscus sabdariffa L. Using a Combination of Supercritical Carbon Dioxide Extraction and Subcritical Water Extraction

Anthocyanins are one of the bioactive compounds in roselle that has many medicinal proposes. Anthocyanins are placed in the inner part of the roselle; therefore, combinations of two methods were applied to extract the anthocyanins. The first stage is employing supercritical carbon dioxide (ScCO2) to break the particle surface or outer layer of the roselle based on the total phenolic compounds (TPC) recovery, and the second step was to apply subcritical water extraction (SWE) for the extraction of anthocyanins. The objective is to determine the best conditions to obtain high yields of total anthocyanins compounds (TAC) from the roselle (Hibiscus sabdariffa) by employing a combination of ScCO2 and SWE. The optimal conditions of ScCO2 (first stage) were 19.13 MPa, 60 °C, and 4.31 mL/min, yielding 18.20%, and 80.34 mg/100 g TPC, respectively. The optimum conditions of SWE (second stage) were 9.48 MPa, 137 °C, and 6.14 mL/min, yielding 86.11% and 1224.61 mg/100 g TAC, respectively. The application of integrated ScCO2 and SWE proved successful in achieving high anthocyanins production and yield as compared to previous extraction methods. This approach may be used to extract the roselle with a greater anthocyanin’s concentration than the prior method.

A novel Stauntonia leucantha fruits arabinogalactan: and structural characterization

Polysaccharides were the key ingredients of many herbal medicines, and were responsible for multiple pharmacological activities. In this study, a novel polysaccharide fraction, named SLP-2, was isolated from Stauntonia leucantha fruits, and purified by DEAE-52 and Sephadex G-100 column chromatography. Furthermore, SLP-2 was identified by congo red, methylation, partial acid hydrolysis and NMR. The results indicated that the backbone of SLP-2 was composed of →4)-β-D-Galp-(1 → 4)-β-D-Galp-(1→ substituted at C-6 with 1,5-linked arabinan. SLP-2 had good anti-oxidation ability in vitro. Surprisingly, we found that reduction of carboxyl groups and methylation of hydroxyl groups enhanced the ability to scavenge 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radicals and inhibit lipid peroxidation, and weakened the activity to scavenge 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals and reduce ferric iron.

Comparative Investigation on the Phytochemicals and Biological Activities of Jackfruit (Artocarpus heterophyllus Lam.) pulp from Five Cultivars

Jackfruit is one of the major tropical fruits, but information on the phytochemicals and biological benefits of its pulp is limited. In this study, the phytochemicals and biological activities including antioxidant, antitumor and anti-inflammatory activities of five jackfruit pulp cultivars (M1, M2, M3, M7 and T5) were comparatively investigated. A total of 11 compounds were identified in all cultivars of jackfruit pulp, among which 4-hydroxybenzoic acid, caffeic acid, ferulic acid and tryptophan N-glucoside were reported for the first time in jackfruit. T5 exhibited the highest total phenolic content (7.69 ± 0.73 mg GAE/g DW), antioxidant capacity (109.8, 96.7 and 207 mg VCE/g DW for DPPH, ABTS and FRAP, respectively), antitumor activity (80.31%) and anti-inflammatory activity (78.44%) among five cultivars. These results can provide a reference for growers to choose jackfruit cultivar and offer an insight into the industrial application of jackfruit pulp derived-products.

Amaranth proteins and peptides: Biological properties and food uses

Amaranthus grains have attracted great attention due to its attractive health benefits. The grains have processing properties (e.g., starch related properties) similar to those of common cereals. Amaranth grains are gluten free and protein is a significant component of these grains. Proteins of the grains have been used in various food applications such as formulations of edible films and emulsions for controlled release of bioactive compounds. The proteins have been hydrolyzed using different enzymes to produce peptides and hydrolysates, which showed a range of biological functions including anti-hypertensive and antioxidant activities among others. They have been formulated into staple foods including breads and pastas for improved nutritional quality. This review summarizes the recent advances of the last 5 years in understanding the biological functions and food applications of proteins, protein hydrolysates and peptides from the grains of different Amaranthus species. Limitations in the studies summarized are critically discussed with an aim to improve the efficiency in amaranth grain protein and peptide research.

Methods for quality evaluation of sweet cherry

Sweet cherry (Prunus avium L.) is a highly valued fruit, whose quality can be evaluated using several objective methodologies, such as calibre, colour, texture, soluble solids content (SSC), titratable acidity (TA), as well as maturity indexes. Functional and nutritional compounds are also frequently determined, in response to consumer demand. The aim of the present review is to clarify and establish quality evaluation parameters and methodologies for the whole cherry supply chain, in order to promote easy and faithful communication among all stakeholders. The use of near-infrared spectroscopy (NIRS) as a non-destructive and expeditious method for assessing some quality parameters is discussed. In this review, the results of a wide survey to assess the most common methodologies for cherry quality evaluation, carried out among cherry researchers and producers within the framework of the COST Action FA1104 'Sustainable production of high-quality cherries for the European market', are also reported. The standardisation of quality evaluation parameters is expected to contribute to the preservation and shelf-life extension of sweet cherries, and the valorisation of the whole supply chain. For future studies on sweet cherry, we put forward a proposal regarding both sample size and the tests chosen to evaluate each parameter. © 2022 Society of Chemical Industry.

Antioxidant, Alpha-Glucosidase Inhibition Activities, In Silico Molecular Docking and Pharmacokinetics Study of Phenolic Compounds from Native Australian Fruits and Spices

Native Australian fruits and spices are enriched with beneficial phytochemicals, especially phenolic compounds, which are not fully elucidated. Therefore, this study aimed to analyze native Australian mountain-pepper berries (Tasmannia lanceolata), rosella (Hibiscus sabdariffa), lemon aspen (Acronychia acidula), and strawberry gum (Eucalyptus olida) for phenolic and non-phenolic metabolites and their antioxidant and alpha-glucosidase inhibition activities. Liquid chromatography-mass spectrometry-electrospray ionization coupled with quadrupole time of flight (LC-ESI-QTOF-MS/MS) was applied to elucidate the composition, identities, and quantities of bioactive phenolic metabolites in Australian native commercial fruits and spices. This study identified 143 phenolic compounds, including 31 phenolic acids, 70 flavonoids, 10 isoflavonoids, 7 tannins, 3 stilbenes, 7 lignans, 10 other compounds, and 5 limonoids. Strawberry gum was found to have the highest total phenolic content (TPC-36.57 ± 1.34 milligram gallic acid equivalent per gram (mg GAE/g), whereas lemon aspen contained the least TPC (4.40 ± 0.38 mg GAE/g). Moreover, strawberry gum and mountain pepper berries were found to have the highest antioxidant and anti-diabetic potential. In silico molecular docking and pharmacokinetics screening were also conducted to predict the potential of the most abundant phenolic compounds in these selected plants. A positive correlation was observed between phenolic contents and biological activities. This study will encourage further research to identify the nutraceutical and phytopharmaceutical potential of these native Australian fruits.

Bioactive Compounds from Fruits as Preservatives

The use of additives with preservative effects is a common practice in the food industry. Although their use is regulated, natural alternatives have gained more attention among researchers and professionals in the food industry in order to supply processed foods with a clean label. Fruits are essential components in a healthy diet and have also been associated with improved health status and a lower risk of developing diseases. This review aims to provide an overview of the main bioactive compounds (polyphenols, betalain, and terpenes) naturally found in fruits, their antioxidant and antimicrobial activity in vitro, and their preservative effect in different foods. Many extracts obtained from the skin (apple, grape, jabuticaba, orange, and pomegranate, for instance), pulp (such as red pitaya), and seeds (guarana, grape, and jabuticaba) of fruits are of great value due to the presence of multiple compounds (punicalagin, catechin, gallic acid, limonene, β-pinene, or γ-terpinene, for instance). In terms of antioxidant activity, some fruits that stand out are date, jabuticaba, grape, and olive, which interact with different radicals and show different mechanisms of action in vitro. Antimicrobial activity is observed for natural extracts and essential oils (especially from citrus fruits) that limit the growth of many microorganisms (Bacillus subtilis, Escherichia coli, Penicillium digitatum, and Pseodomonas aeruginosa, for instance). Studies in foods have revealed that the use of extracts or essential oils as free or encapsulated forms or incorporated into films and coatings can inhibit microbial growth, slow oxidative reactions, reduce the accumulation of degradative products, and also preserve sensory attributes, especially with films and coatings. Future studies could focus on the advances of extracts and essential oils to align their use with the development of healthier foods (especially for meat products) and explore the inhibition of spoilage microorganisms in dairy products, for instance.

Bioaccessibility of phenolic compounds using the standardized INFOGEST protocol: A narrative review

The INFOGEST protocol creation was a watershed for phenolic bioaccessibility studies. Because of this important initiative to standardize bioaccessibility studies, data comparisons between different laboratories are now expedited. It has been eight years since the INFOGEST protocol creation, and three from the latest update. However, the current status in terms of phenolic bioaccessibility and how far different laboratories are from reaching a consensus are still unrevealed. In this sense, this narrative review considered an evaluation of different studies that applied the INFOGEST protocol to investigate the bioaccessibility of phenolic compounds. The central objective was to compile the main findings and consensus and to identify possible gaps and future opportunities. This approach intends to further facilitate the use of this protocol by professionals in the field of food science and technology and related areas, generating a reflection on the actual level of standardization of the method. Despite the differences in phenolic compounds from diverse food matrices, and their peculiar behavior, some trends could be elucidated, in terms of phenolic release, stability, and/or transformation upon in vivo digestion. In contrast, there was no general consensus regarding sample preparation, how to report results and the form to calculate bioaccessibility, making it difficult to compare different studies. There is still a long road to effectively standardize the results obtained for phenolic bioaccessibility using the INFOGEST protocol, which is also an opportunity in terms of food analysis that can impact the food industry, especially for the development of nutraceuticals and functional foods.

Changes in the Phytochemical Profile and Antioxidant Properties of Prunus persica Fruits after the Application of a Commercial Biostimulant Based on Seaweed and Yeast Extract

Plant biostimulants are formulations that are experiencing great success from the perspective of sustainable agriculture. In this work, we evaluated the effect derived from the application of a biostimulant based on algae and yeast extracts (Expando^®) on the agronomic yield and nutraceutical profile of two different cultivars ("Sugar Time" and "West Rose") of Prunus persica (peach). Although, at the agronomic level, significant effects on production yields were not recorded, the biostimulant was able to reduce the ripening time, increase the fruit size, and make the number of harvestable fruits homogeneous. From a nutraceutical point of view, our determinations via spectrophotometric (UV/Vis) and chromatographic (HPLC-DAD-MS/MS) analysis showed that the biostimulant was able to boost the content of bioactive compounds in both the pulp (5.0 L/ha: +17%; 4.0 L/ha: +12%; 2.5 L/ha: +11%) and skin (4.0 L/ha: +38%; 2.5 L/ha: +15%). These changes seem to follow a dose-dependent effect, also producing attractive effects on the antioxidant properties of the fruits harvested from the treated trees. In conclusion, the biostimulant investigated in this work proved to be able to produce more marketable fruit in a shorter time, both from a pomological and a functional point of view.

Effect of in vitro gastrointestinal digestion on the chemical composition and antioxidant properties of Ginkgo biloba leaves decoction and commercial capsules

In this study Ginkgo biloba leaves (GBL) decoction and commercial capsules were digested using an in vitro model. Thirty-six active compounds were identified and quantified by HPLC-ESI-MS analysis based on the MS/MS patterns (precursor ions and product ions) and retention times, in comparison with reference standards. Most compounds in GBL showed a significant decrease during intestinal digestion, with an exception of vanillic acid and biflavonoids. Bioaccessibility values of chemical compositions varied between decoction and capsules samples. Also, significant reductions of total flavonoids and total phenolic content was observed after in vitro digestion. Both, 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazo-line-6-sulfonic acid (ABTS) scavenging capacity decreased after gastric digestion, but increased during intestinal digestion. Nevertheless, different behaviour was observed in reducing antioxidant power (FRAP) assay. Compared to the pH of digestion, the influence of digestive enzymes on the chemical composition and antioxidant activity of GBL was relatively minor. Overall, these results may help provide a valid foundation for further investigations on bioactive compounds and the pharmacodynamics of GBL.

Profile and activity of phenolic antioxidants in chrysanthemum (Huangshan Gongju) as affected by simulated digestions

The phenolics are the main bioactive substances of Huangshan Gongju, a famous chrysanthemum of China, but their digestive characteristics are still unknown. To explore the digestive properties of Huangshan Gongju phenolics, the flower was extracted and subjected to simulated digestions, and their phenolic profile and activity were analyzed. The results indicated that the total phenolics content and antioxidant activity of the extract varied with the simulated digestion steps, and they generally decreased in the oral and small intestine digestions but increased in the gastric digestion, and high correlations were detected between the total phenolics content and antioxidant activity (0.873 < r < 0.979, p < .01). The change of phenolic profile during the simulated digestions was similar to that of total phenolics content, and six individual phenolics were identified and quantified, and three of them, including chlorogenic acid, apigenin-7-O-rutinoside, and apigenin-7-O-6″-acetylglucoside showed higher recovery (>64.29%), implying they may be the main functional phenolics of Huangshan Gongju. PRACTICAL APPLICATIONS: This study proved that most phenolics in Huangshan Gongju were relatively stable during digestion. The finding may guarantee the application of Huangshan Gongju in the field of functional foods.

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.

Seasonal Changes in Chemical Profile and Antioxidant Activity of Padina pavonica Extracts and Their Application in the Development of Bioactive Chitosan/PLA Bilayer Film

Seaweeds are a potentially sustainable source of natural antioxidants that can be used in the food industry and possibly for the development of new sustainable packaging materials with the ability to extend the shelf-life of foods and reduce oxidation. With this in mind, the seasonal variations in the chemical composition and antioxidant activity of brown seaweed (Padina pavonica) extracts were investigated. The highest total phenolic content (TPC) and antioxidant activity (measured by ferric reducing/antioxidant power (FRAP), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, and oxygen radical absorbance capacity (ORAC)) were found for P. pavonica June extract. The TPC of 26.69 ± 1.86 mg gallic acid equivalent/g, FRAP of 352.82 ± 15.41 µmole Trolox equivalent (TE)/L, DPPH of 52.51 ± 2.81% inhibition, and ORAC of 76.45 ± 1.47 µmole TE/L were detected. Therefore, this extract was chosen for the development of bioactive PLA bilayer film, along with chitosan. Primary or quaternary chitosan was used as the first layer on polylactic acid (PLA) films. A suspension of chitosan particles with entrapped P. pavonica extract was used as the second layer. X-ray photoelectron spectroscopy confirmed the presence of layers on the material surface. The highest recorded antioxidant activity of the newly developed films was 63.82% inhibition. The developed functional films exhibited antifogging and antioxidant properties, showing the potential for application in the food industry.

Nutritional anti-nutritional chemical composition and antioxidant activities of the leaves of the sea cliff dwelling species Limonium spathulatum (Desf.) Kuntze

This work explored the nutritional and antioxidant properties of the leaves of the halophytic species Limonium spathulatum (Desf.) Kuntze from Tunisian sea cliffs. Furthermore, the analysis of the total phenolics and flavonoids contents and their individual compounds using high-performance liquid chromatography coupled with electrospray ionization mass spectrometry (HPLC-ESI-MS/MS) were also studied. L. spathulatum leaves had high levels of moisture, ash, neutral detergent fiber, and acid detergent fiber, but low concentrations of crude protein, crude fat and acid detergent lignin. It contained low carbohydrates levels, and low energetic values. The most abundant macroelements were Cl, Na and Ca while the microelements detected in the highest levels were Fe and Zn. No relevant α-amylase inhibition was observed, and no toxic metals (Pb and Cd) and phytic acid were detected. The ethanol and the hydroethanolic extracts had the highest capacity to scavenge free radicals, to chelate iron and copper and to inhibit lipid peroxidation. The same samples were also the most active towards oxidative haemolysis. These extracts contained high total phenolic and flavonoid contents. HPLC analysis, performed on ethanolic extracts identified 58 individual compounds known for their high antioxidant actvitiy including hydroxybenzoic acids (gallic, syringic acids), hydroxycinnamic acids (caffeic, coumaric, ferulic acids) and flavonoids (catechin, epigallocatechin gallate and naringin).In conclusion, the leaves of Tunisian accession of L. spathulatum were good source of minerals and fibers useful in the human diet for attaining nutritional sufficiency. The high in vitro and ex vitro antioxidant activities associated with high favonoids contents and compounds suggest the possibility to use the extracts of L. spathulatum in herbal products with the aim of improving general health and well-being, and/or as food additives for preventing lipid oxidation of lipid-rich foods.