Potential interventions and interactions of bioactive polyphenols and functional polysaccharides to alleviate inflammatory bowel disease - A review.

Inflammatory bowel disease is a multifaceted condition that is influenced by nutritional, microbial, environmental, genetic, psychological, and immunological factors. Polyphenols and polysaccharides have gained recognition for their therapeutic potential. This review emphasizes the biological effects of polyphenols and polysaccharides, and explores their antioxidant, anti-inflammatory, and microbiome-modulating properties in the management of inflammatory bowel disease (IBD). However, polyphenols encounter challenges, such as low stability and low bioavailability in the colon during IBD treatment. Hence, polysaccharide-based encapsulation is a promising solution to achieve targeted delivery, improved bioavailability, reduced toxicity, and enhanced stability. This review also discusses the significance of covalent and non-covalent interactions, and simple and complex encapsulation between polyphenols and polysaccharides. The administration of these compounds in appropriate quantities has proven beneficial in preventing the development of Crohn's disease and ulcerative colitis, ultimately leading to the management of IBD. The use of polyphenols and polysaccharides has been found to reduce histological scores and colon injury associated with IBD, increase the abundance of beneficial microbes, inhibit the development of colitis-associated cancer, promote the production of microbial end-products, such as short-chain fatty acids (SCFAs), and improve anti-inflammatory properties. Despite the combined effects of polyphenols and polysaccharides observed in both in vitro and in vivo studies, further human clinical trials are needed to comprehend their effectiveness on inflammatory bowel disease.

Polyphenol Treatment of Peripheral Blood Mononuclear Cells from Individuals of Different Ages.

Human peripheral blood mononuclear cells (PBMCs) have been largely utilized to assess the cytotoxic, immunomodulatory, and anti-inflammatory properties of both synthetic and natural compounds. Within the latter category, polyphenols from dietary sources have been extensively analyzed. PBMCs represent a feasible in vitro model to study polyphenol hallmarks and activity according to quantitative and qualitative differences in immune responses in individuals of different age. In this chapter, we propose a method for PBMC treatment with polyphenols and analysis designed on age-dependent qualitative and quantitative variability in immune cell performance.

Effect of gelatin edible coating with Aronia melanocarpa pomace polyphenols on the cold storage of chilled pork.

In this research, the Aronia melanocarpa pomace polyphenols (AMPPs) were extracted and purified. The purified AMPPs contained the most abundant chlorogenic acid (CGA) at 36.91 mg/100 mg, followed by chrysin at 8.61 mg/100 mg. At a concentration of 60 µg/mL, the purified AMPPs exhibited stronger scavenging activity against: DPPH radical, hydroxyl radical, ABTS∙+, and also showed greater Fe3+ reducing activity than the VC control group. To solve the problem of easy spoilage of chilled meat during storage, gelatin edible coatings containing Aronia melanocarpa pomace polyphenols, referred to as G/AMPPs, were investigated for their effect on the chilled storage of pork. At a 1:1 volume ratio of 1 % polyphenol solution to 3 % gelatin solution, the G/AMPPs coating effectively curbed pH, TVB-N, TVC, drip loss, and b* value increases in chilled pork, while delaying declines in hardness, adhesion, a* value and L* value; The TVB-N content and TVC values demonstrated that the G/AMPPs coating significantly extended the shelf life of chilled pork by up to 15 days. The results showed that G/AMPPs had good preservative, antibacterial and antioxidant effects on chilled pork and thus development of G/AMPPs based coating shows appeared to offer promise for meat preservation.

Health benefits of fermented olives, olive pomace and their polyphenols: a focus on the role of lactic acid bacteria.

Fermented foods have regained popularity in Western diets for their health-promoting potential, mainly related to the role of lactic acid bacteria (LAB) during the fermentation process. Nowadays, there is an increasing demand for vegetable-based fermented foods, representing an environmentally sustainable options to overcome the limitations of lactose intolerance, vegetarian, or cholesterol-restricted diets. Among them, table olives and their co-products (i.e., olive pomace) represent important plant-origin matrices, whose exploitation is still limited. Olives are an important source of fiber and bioactive molecules such as phenolic compounds with recognized health-promoting effects. Based on that, this minireview offer a brief overview about the potential beneficial role of fermented table olives/olive pomace, with a particular focus on the role of LAB to obtain healthy and/or probiotic-enriched fermented foods.

Phytochemical profiling of oak bark extract: A combined approach using near-infrared spectroscopy and liquid chromatography-mass spectrometry.

The aim of the presented study was to qualitatively and quantitatively determine the chemical composition of oak bark extracts in order to gain insights into the effectiveness as alternative medication for various diseases. The primary emphasis was on developing a near-infrared spectroscopy (NIRS) method for precise quantification of two key polyphenolic compounds, specifically gallic acid and catechin, in form of a fast and non-destructive quality control. A comprehensive dataset consisting of 48 samples from various production batches was analyzed throughout this research. Qualitative analysis was conducted using High Performance Liquid Chromatography coupled with a mass detector (LC-MS) to separate and identify individual components of the oak bark extract. Individual components were identified, confirmed and quantified using existing literature combined with appropriate standard references. Whereas the predominant nature of identified substances was of polyphenolic nature. Furthermore, a semi-quantitative assessment was additionally performed for eight identified constituents to identify their chemical stability or possible occurring transformations during storage, utilizing quantification via internal standard met in order to identify fluctuations and chemical variability within oakbark, five key components were precisely quantified using LC-MS and corresponding standard substances. For this purpose, HPLC measurements coupled to an Ultraviolet/Visible (UV/Vis) detector were utilized as reference method. NIRS measurements were performed on a FT-NIR benchtop device in transmission mode. Partial least squares regression (PLSR) was then applied for model building, after identifying the optimal spectral pretreatment. Model evaluation was performed using leave-one-out-cross validation followed by evaluation of an independent test set. The model proved promising results for the quantification of gallic acid on the benchtop device with a standard error of cross validation (SECV) of 13.41 mg/L and a standard error of prediction (SEP) of 19.33 mg/L, while the absolute concentrations of the different batches analyzed ranged from 126.49 to 332.54 mg/L. For the quantification of catechin the SECV was reported at 23.61 mg/L, the SEP at 32.35 mg/L with sample concentrations falling between 13.50 and 383.72 mg/L. In this study, we introduce various analytical methodologies for both qualitative and quantitative assessment of a complex phytochemical sample, specifically oak bark extract, aimed at identifying and confirming the presence of active compounds within the extract.

Unlocking the in vitro neuroprotection of sloe residues phenolic extracts by bioanalytical and chemometric strategies.

Wild fruits, particularly the underutilized sloe (Prunus spinosa), are gaining interest as natural antioxidants, with residues from liqueur production being a source of bioactive compounds. This study proposes a sustainable approach for valorizing sloe residues, seeds and skins, by employing an innovative green extraction method. HPLC-ESI-QTOF and spectrophotometric techniques were used to explore the phenolic profile, highlighting the predominance of quercetin, 2,3-dihydroxybenzoic and ferulic acids (9.7-57 µg·g-1). In addition, the presence of Cu, Zn and Ca was confirmed by atomic absorption spectroscopy. Simultaneously, their neuroprotective potential against Alzheimer's disease (AD) was studied by exploring the inhibition of beta-amyloid aggregation and oxidative stress cytoprotection in SH-SY5Y cell line, standing out 1 µg·g-1 and 10 µg·g-1 extracts of sloe skin. Phenolic composition was correlated with bioactivities by means of multivariate analysis. These results contributed to highlight the potential of this bio-residue as a neuroprotective agent against AD in pharmaceutical and nutraceutical industries.

Enhancing pediatric attention-deficit hyperactivity disorder treatment: exploring the gut microbiota effects of French maritime pine bark extract and methylphenidate intervention.

Introduction: The pathogenesis of Attention-Deficit Hyperactivity Disorder (ADHD) is thought to be multifactorial, with a potential role for the bidirectional communication between the gut microbiome and brain development and function. Since the "golden-standard" medication therapy with methylphenidate (MPH) is linked to multiple adverse effects, there is a need for alternative treatment options such as dietary polyphenols. These secondary plant metabolites exert antioxidant and anti-inflammatory effects, but much less is known about their impact on the gut microbiota. Since polyphenols are believed to modulate gut microbial composition, interventions might be advantageous in ADHD therapy. Therefore, intervention studies with polyphenols in ADHD therapy investigating the gut microbial composition are highly relevant. Methods: Besides the primary research questions addressed previously, this study explored a potential prebiotic effect of the polyphenol-rich French Maritime Pine Bark Extract (PBE) compared to MPH and a placebo in pediatric ADHD patients by studying their impact on the gut microbiota via amplicon sequencing of the full length 16S rRNA gene ribosomal subunit (V1-V9). Results: One interesting finding was the high relative abundance of Bifidobacteria among all patients in our study cohort. Moreover, our study has identified that treatment (placebo, MPH and PBE) explains 3.94% of the variation in distribution of microbial taxa (adjusted p-value of 0.011). Discussion: Our small sample size (placebo: n = 10; PBE: n = 13 and MPH: n = 14) did not allow to observe clear prebiotic effects in the patients treated with PBE. Notwithstanding this limitation, subtle changes were noticeable and some limited compositional changes could be observed. Clinical Trial Registration: doi: 10.1186/S13063-017-1879-6.

Ellagic acid-enhanced biocompatibility and bioactivity in multilayer core-shell gold nanoparticles for ameliorating myocardial infarction injury.

BACKGROUND: Myocardial infarction (MI) is the main contributor to most cardiovascular diseases (CVDs), and the available post-treatment clinical therapeutic options are limited. The development of nanoscale drug delivery systems carrying natural small molecules provides biotherapies that could potentially offer new treatments for reactive oxygen species (ROS)-induced damage in MI. Considering the stability and reduced toxicity of gold-phenolic core-shell nanoparticles, this study aims to develop ellagic acid-functionalized gold nanoparticles (EA-AuNPs) to overcome these limitations. RESULTS: We have successfully synthesized EA-AuNPs with enhanced biocompatibility and bioactivity. These core-shell gold nanoparticles exhibit excellent ROS-scavenging activity and high dispersion. The results from a label-free imaging method on optically transparent zebrafish larvae models and micro-CT imaging in mice indicated that EA-AuNPs enable a favorable excretion-based metabolism without overburdening other organs. EA-AuNPs were subsequently applied in cellular oxidative stress models and MI mouse models. We found that they effectively inhibit the expression of apoptosis-related proteins and the elevation of cardiac enzyme activities, thereby ameliorating oxidative stress injuries in MI mice. Further investigations of oxylipin profiles indicated that EA-AuNPs might alleviate myocardial injury by inhibiting ROS-induced oxylipin level alterations, restoring the perturbed anti-inflammatory oxylipins. CONCLUSIONS: These findings collectively emphasized the protective role of EA-AuNPs in myocardial injury, which contributes to the development of innovative gold-phenolic nanoparticles and further advances their potential medical applications.

Seaweeds and Their Secondary Metabolites: A Promising Drug Candidate With Novel Mechanisms Against Cancers and Tumor Angiogenesis.

Cancer continually remains a severe threat to public health and requires constant demand for novel therapeutic drug candidates. Due to their multi-target orientation, lesser toxicity, and easy availability, natural compounds attract more attention from current scientific research interest than synthetic drug molecules. The plants and microorganisms produce a huge variety of secondary metabolites because of their physiological diversification, and the seaweeds occupy a prominent position as effective drug resources. Seaweeds comprise microscopic or macroscopic photosynthetic, multicellular, eukaryotic marine algae that commonly inhabit the coastal regions. Several molecules (such as polysaccharides, lipids, proteinaceous fractions, phenolic compounds, and alkaloids) are derived from seaweeds, and those small molecules are well attractive and more effective in cancer research programs. Their structural variation, derivative diversity, and quantity vary with seaweed species and geographical origin. Their smaller molecular weight, unique derivatives, hydrophobicity, and degree of sulfation are reported to be causes of their crucial role against different cancer cells in vitro. Several reports showed that those compounds selectively discriminate between normal and cancer cells based on receptor variations, enzyme deficiency, and structural properties. The present review aimed to give a concise explanation regarding their structural diversity, extractability, and mechanism of action related to their anti-cancer activities based on recently published data.

Apple polyphenols prevent patulin-induced intestinal damage by modulating the gut microbiota and metabolism of the gut-liver axis.

Patulin (PAT), a foodborne toxin, causes severe intestinal damage. To mitigate this health threat, mice were pretreated with apple polyphenols (AP) in their drinking water (0.01 % and 0.05 %) for eight weeks, followed by exposure to PAT during the last two weeks. Subsequently, histopathological and biochemical evaluations of intestinal tissues were conducted, alongside assessments of alterations in gut microbiota, colonic content metabolome, and hepatic metabolome. Consequently, AP alleviated PAT-induced villus and crypt injury, mucus depletion, GSH level decline, GSH-Px and SOD activity reduction, and MPO activity elevation. Notably, AP counteracted PAT-mediated microbiota disruptions and promoted the abundance of beneficial bacteria (Dubosiella, Akkermansia, Lachnospiraceae, and Lactobacillus). Furthermore, AP counteracted PAT-induced metabolic disorders in the colonic contents and liver. Ultimately, AP prevented intestinal injury by regulating the gut microbiota and amino acid, purine, butanoate, and glycerophospholipid metabolism in the gut-liver axis. These results underscore the potential of AP to prevent foodborne toxin-induced intestinal damage.

Microbial catabolism of coffee pulp (poly)phenols during in vitro colonic fermentation.

Coffee pulp is a by-product characterized by its richness in phenolic compounds. This study examined the catabolism of (poly)phenols in digested coffee pulp flour (CPF) and extract (CPE) during in vitro colonic fermentation. After a simulated gastrointestinal digestion, samples were fermented using human microbiota and (poly)phenol transformations were analyzed by UHPLC-ESI-MS/MS. Digested CPF and CPE contained high amounts of phenolic acids, notably 3',4'-dihydroxycinnamic (99.7-240.1 µmol 100 g-1) and 3,4-dihydroxybenzoic acid (174.1-491.4 µmol 100 g-1). During the in vitro fecal fermentation, phenylpropanoic acids (1.5- to 2.6-fold), phenyl-γ-valerolactones (1.3- to 23-fold), phenylvaleric acids (1.1- to 2-fold) and benzene derivatives (1.5-fold) increased; while benzoic and cinnamic acids, cinnamoylquinic derivatives, flavonols, benzaldehydes and diphenylpropan-2-ols decreased. The (poly)phenols in CPF were catabolized more slowly than in CPE, suggesting protection of the fibrous matrix against phenolic degradation. Coffee pulp may be a promising food ingredient rich in (poly)phenols contributing to the prevention of intestinal diseases.

Polyphenol-Mediated Modulation of Non-Coding RNAs: A New Therapeutic Approach for Hypertension - A Review.

Hypertension (HTN) is a leading risk factor for cardiovascular diseases (CVDs) and a major contributor to global morbidity and mortality. Conventional pharmacological treatments have been effective but are often accompanied by side effects and do not address all pathological aspects of the disease. Recent advances in molecular biology have identified non-coding RNAs (ncRNAs), including microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), as key regulators in the pathogenesis of hypertension. These ncRNAs influence various cellular processes, such as gene expression, vascular tone, and inflammation, making them promising targets for therapeutic intervention. This review explores the potential of polyphenols, a diverse group of phytochemicals with potent antioxidant and anti-inflammatory properties, in modulating ncRNA expression and function. We discuss how polyphenols, such as epigallocatechin-3-gallate (EGCG), resveratrol, curcumin, and quercetin impact the regulation of ncRNAs, particularly focusing on their roles in reducing oxidative stress, improving endothelial function, and ameliorating vascular remodeling associated with hypertension. The review synthesizes current evidence from both in vitro and in vivo studies, highlighting significant findings and the mechanisms by which polyphenols exert their effects on ncRNA-mediated pathways. Moreover, we address the challenges of translating these findings into clinical applications, including issues related to bioavailability, dosing, and the complex interactions of polyphenols with other cellular components. Future directions for research are suggested, with an emphasis on the need for comprehensive clinical trials to establish the efficacy of polyphenol-based therapies targeting ncRNAs in hypertension management. By targeting ncRNAs, polyphenols offer a novel therapeutic strategy that could enhance the treatment landscape for hypertension and potentially other cardiovascular conditions.

Metabolite variations in sulla shoots induced by drought stress.

BACKGROUND: Climate change results in an increased occurrence of drought periods, which affect the performance of Mediterranean legumes such as sulla. To evaluate the effects of drought stress on the antioxidant capacity and the accumulation of phytochemicals in sulla shoots, rainfed and drought-stressed plants (RAI) and watered plants with timely vegetative regeneration (STI) were cultivated in parallel in a field experiment and sampled at four different times. RESULTS: Drought stress strongly and positively affected the antioxidant capacity and the accumulation of polyphenols in sulla shoots, with key differences at wintertime. These findings were supported through untargeted and targeted metabolomics of RAI and STI samples, which detailed the accumulation of about 300 secondary metabolites in RAI, mostly polyphenols and saponins. CONCLUSION: This study provided new insights into the changes in secondary metabolites in sulla due to drought stress, which can be used to produce forages or raw plant extracts with enhanced biological effects. © 2024 Society of Chemical Industry.

Hydrolyzable tannins and pectin are glycolipid lowering ingredients in Phyllanthus emblica Linn.: Valid interaction with gut action targets.

Phyllanthus emblica L., a distinctive fruit, is rich in polyphenols and polysaccharide. However, there is a lack of knowledge regarding the role of these compounds as glycolipid lowering ingredients. In this study, the glycolipid lowering ingredients and their effects have been determined by gradually comparing varieties, parts, and components, splitting components, and calculating combined index via their interactions with digestion enzymes, bile acids, cholesterol micelles and probiotics. Results indicated that the glycolipid lowering ingredients were polyphenols and polysaccharide, which located in the pulp, and not influenced by the variety. Pectin with multiple structural domains, and hydrolyzable tannins, i.e. gallic acid, ellagic acid and their derivatives interacted with multiple gut action targets could regulate glycolipid digestion, absorption and metabolism. Polysaccharide and polyphenols demonstrated a synergistic effect in lowering glycolipid by interacting with gut action targets. These findings highlight the potential for further investigation and utilization of glycolipid lowering ingredients in fruits.

Plant-derived compounds normalize platelet bioenergetics and function in hyperglycemia.

Background: Polyphenols have been shown to decrease oxidative stress and modulate glycemic response. Nevertheless, their effect on platelet bioenergetics and clot structure in diabetes and hyperglycemia is unknown. Objectives: To investigate the effect of polyphenols on human platelet bioenergetics and its subsequent effect on clot structure in normoglycemia vs acute hyperglycemia in vitro. Methods: Four polyphenols (resveratrol, hesperetin, epigallocatechin gallate [EGCG], and quercetin) were selected for initial analysis. Healthy volunteers' isolated platelets/platelet-rich plasma were treated with 5 or 25 mM glucose to represent normoglycemia and acute hyperglycemia, respectively. Platelet-derived reactive oxygen species (ROS), citrate synthase activity (mitochondrial density), mitochondrial calcium flux, and mitochondrial respiration were performed following exposure to polyphenols (20 µM, 1 hour) to determine their effects on platelet bioenergetics. Procoagulant platelets (annexin V) and fibrin fiber density (Alexa Fluor-488 fibrinogen; Invitrogen) were analyzed by laser scanning confocal microscopy, while clot porosity was determined using platelet-rich plasma following exposure to polyphenols (20 µM, 20 minutes). Results: Acute hyperglycemia increased ROS, mitochondrial calcium flux, maximal respiration, and procoagulant platelet number. Resveratrol, quercetin, and EGCG reduced platelet ROS in normoglycemic and acute hyperglycemic conditions. Mitochondrial density was decreased by quercetin and EGCG in normoglycemia. Resveratrol and EGCG reduced mitochondrial calcium flux in acute hyperglycemia. Resveratrol also decreased procoagulant platelet number and attenuated oxygen consumption rate in normoglycemia and acute hyperglycemia. No effect of hyperglycemia or polyphenols was observed on fibrin fiber density or clot pore size. Conclusion: Our results suggest polyphenols attenuate increased platelet activity stemming from hyperglycemia and may benefit thrombosis-preventative strategies in patients with diabetes.

Sustainable ruminant nutrition in West Africa by in vitro characterization of cashew apple by-products.

Cashew trees (Anacardium occidentale L.) are planted for primarily their nuts, but they also generate apples which are mostly thrown away due to their astringent taste. The current study aimed to explore the possible utilization of cashew apple by-products (CABP) in West Africa as an alternative feedstuff for small ruminants' nutrition. To achieve this aim, five parts of cashew apple by-products (whole, up, down and middle part, and pomace) of two cashew varieties (red and yellow) were collected in two different agroecological zones (Sudanian Zone, SZ and Sudano-Guinea Zone, SZ) to be characterized for the chemical composition, including polyphenols and sugars, and the in vitro fermentation pattern. In general, the results showed that CABP characteristics depend more on sampling area than on variety. The dry matter (DM) in SZ and SGZ varied from 12.76 to 26.10 % and 7.41-22.9 %, respectively. The pomace showed the highest crude protein, lipids, and neutral detergent fiber (NDF) content (SZ: 9.48, 3.94 and 31.66 % DM; SGZ: 14.03, 4.94 and 34.12 % DM, respectively) but the lowest nonstructural carbohydrate (NSC) and sugar for both zones. Regarding the in vitro fermentation, the organic matter degradability (dOM) was higher in the middle part (73.73 %) and whole apple (61.62 %) of SZ and SGZ, respectively. In contrast, the pomace from both zones showed the lowest in vitro fermentation parameters. The total polyphenols were more concentrated in the CABP from SZ (whole: 2736 µg/g DW; pomace: 3813 µg/g DW) compared to those from SGZ (whole: 1755 µg/g DW; pomace: 1374 µg/g DW). Results suggest that CABP should be collected in each cultivation zone regardless of variety, separating pomace from other by-products and may be used as alternative feedstuff for small ruminants during the dry season in the West Africa region.

Effects of starch-tea polyphenol complexes on the structure features of reconstituted doughs and oil absorption of potato crisps.

The structural features of reconstituted doughs play a crucial role in determining the oil uptake properties of fried potato crisps. Wheat starch (WS), corn starch (CS), potato starch (PS), or tapioca starch (TS) and tea polyphenols (TPs) complexes were prepared, and their effects on the physicochemical and structural properties of reconstituted dough and oil uptake of potato crisps were investigated. A denser and consistent network structure was observed in the reconstituted dough produced by PS-TPs and TS-TPs complexes. Thus, the reconstituted dough prepared using PS-TPs and TS-TPs complexes displayed slower water evaporation and less matrix swelling during frying, leading to a denser matrix and limited oil uptake of potato crisps. The potato crisps with PS-TPs and TS-TPs complexes had 20.83 % and 10.15 % lower oil content. Consequently, the starch-TPs complexes can be used to improve the properties of reconstituted doughs and produce fried snacks with lower oil content.

Effect and Mechanism of Apple Polyphenols in Regulating Intestinal Flora and Inhibiting the TLR4/NF-κB/TGF-ß Signaling Pathway to Alleviate Alcoholic Liver Fibrosis.

Apple polyphenols (APs) have gained attention for their various bioactivities, while no studies on anti-liver fibrosis activity are reported. This study evaluated the protective effect of APs on liver fibrosis using LPS-treated activated HSC-T6 cells and alcohol-treated liver fibrosis (ALF) mice. The results indicated that APs inhibited HSC-T6 cells activation in vitro and reduced the level of serum hyaluronic acid (HA) (p < 0.05), decreased fibrogenesis marker expression (p < 0.05), thereby alleviating ALF. In addition, APs (800 mg/kg b.w.) decreased the Firmicutes/Bacteroidetes ratio (p < 0.05) in ALF mice, inhibited LPS accumulation in the liver tissue and serum (p < 0.05), and significantly inhibited the TLR4/NF-κB/TGF-ß signaling in mice liver. In conclusion, APs markedly ameliorated ALF, possibly by improving gut microbiota homeostasis, decreasing the translocation of bacterial endotoxins to the blood, and suppressing the TLR4/NF-κB/TGF-ß signaling pathway, indicating its potential as lead compounds for functional foods and/or drugs against ALF.

Valorization of grape pomace extracts against cranberry, elderberry, rose hip berry, goji berry and raisin extracts: Phytochemical profile and in vitro biological activity.

The circular economy is gaining attention around the world as a sustainable approach to tackling environmental problems, promoting more responsible management of resources. The aim of this work is the valorization of grape pomace as a waste product of agrifood chain. We prepared decoction (DC), ultrasound-assisted and microwave-assisted extracts (UAE and MAE respectively) of grape pomace, determining their phytochemical profile (using HPLC-ESI-Q-TOF-MS), antioxidant activity and enzyme inhibitory effects. Then, the results were compared with those of raisins and several edible berries already present in the market. Grape pomace extracts presented the highest total phenolic content (62-68 mg gallic acid equivalents/g; mg GAE/g), whereas the concentrations in the other berries were 4-43 mg GAE/g. These results were in agreement with the higher antioxidant activity and tyrosinase inhibition observed in grape pomace compared with the other berries, except for the metal chelating activity. The main compounds in grape pomace extracts were flavonoids (particularly quercetin glycosides), followed by organic acids (citric, isocitric and gallic acids). These results open new perspectives in the development of food supplements and nutraceuticals based on grape pomace extracts.

Biopolymer-polyphenol conjugates: Novel multifunctional materials for active packaging.

The development of natural active packaging materials and coatings presents a promising alternative to petroleum-based packaging solutions. These materials are engineered by incorporating functional ingredients with preservative capabilities. Concurrently, research has highlighted the diverse physicochemical, functional, and health-promoting properties of protein-polyphenol, polysaccharide-polyphenol, and protein-polysaccharide-polyphenol conjugates within various food formulations. However, a critical gap exists regarding the exploration of these biopolymers as active packaging materials. In contrast to conventional approaches for developing active packaging materials, this review presents a novel perspective by focusing on biopolymer-polyphenol conjugates. In this work, we delve into the realm of active packaging materials and coatings constructed from these conjugates, highlighting their potential as multifunctional active components in food packaging and preservation. This review comprehensively investigates the physicochemical properties, functionalities, and health-promoting activities associated with biopolymer-polyphenol conjugates. Their emulsification, antioxidant, and antimicrobial activities, coupled with enhancements in mechanical strength and permeability properties, contribute to their multifunctional nature. Furthermore, we explore the potential advantages and limitations of utilizing these conjugates in active packaging applications. Finally, the review concludes by proposing crucial research avenues for further exploration of biopolymer-polyphenol conjugates within the domain of active food packaging.