Incorporation Of Polyphenols Research Articles

An Improved pH-Driven Method for Upcycling Polyphenols from Plants or Byproducts into Foods

The incorporation of polyphenols into food systems provides various health benefits, yet their stability and bioactivity are often compromised by processing conditions. In this study, we advanced the pH-driven method for processing highly pH-sensitive polyphenols, such as quercetin, by optimizing operating conditions, including minimizing oxygen exposure and reducing operating times. As a result, an improved post-pH-driven (PPD) method was developed to encapsulate pH-sensitive quercetin into nanoemulsions with an encapsulation efficiency exceeding 95%, indicating that this method could be broadly applicable for incorporating various polyphenols. For example, it has been successfully applied to upcycle plant polyphenols from peanut skin into nanoemulsions, serving as a representative food model. The PPD method demonstrated superior performance compared to a conventional water-based method, achieving 1.8 times higher remaining percentage of total polyphenolic content. Additionally, the PPD-based nanoemulsions exhibited significantly enhanced antioxidant properties, with DPPH and ABTS radical scavenging activities increasing by 3.7 and 2.8 times, respectively, compared to the water-based method. These findings underscore the potential of the PPD method as a versatile and efficient approach for developing polyphenol-powered foods by upcycling plant byproducts and improving processing efficiency.

Improving the Properties of Polysaccharide-Based Films by Incorporation of Polyphenols Through Free Radical Grafting: A Review

The increasing demand for sustainable materials has propelled research into polysaccharide modifications for various applications, particularly in active packaging. This review aims to explore the incorporation of bioactive compounds such as polyphenols into polysaccharides, focusing on chemical modification through free radical grafting techniques. The methods examined include enzymatic, physical, and chemical grafting techniques, highlighting their effectiveness in enhancing the properties of polysaccharide-based films. Recent studies have demonstrated that free radical grafting can significantly improve the mechanical, barrier, and antimicrobial properties of these films, extending their applicability in the food and pharmaceutical industries. However, challenges such as the stability of polyphenols and the understanding of grafting mechanisms remain critical areas for further investigation. This review discusses these advancements and outlines future research directions, emphasizing the potential of polysaccharide modifications to create innovative materials that meet the evolving needs of consumers and industries alike.

Effects of polyphenols from Tasmannia lanceolata on structural, emulsifying, and antioxidant properties of pea protein

The effects of polyphenols from Tasmanian pepper (Tasmannia Lanceolata) leaf and berry on the functional properties of pea protein were investigated in flaxseed oil-in-water emulsions. Phenolic acids and flavonols in Tasmanian pepper leaf with smaller molecular weights led to stronger non-covalent interactions with pea protein, while anthocyanins from Tasmanian pepper berry induced protein aggregation under acidic condition and co-existed with proteins in neutral and alkaline conditions. The total phenolic content was significantly increased with incorporation of polyphenols from Tasmanian pepper leaf (334.94–445.92 μg/mL) and berry (72.89–153.03 μg/mL) to pea protein (4.19–15.59 μg/mL). The oxidative stability of emulsions at pH 3 and 7 was enhanced, reducing TBARS value from 1.54 to 2.68 mg MDA/kg in pea protein to 0.56–0.85 mg MDA/kg after 2 weeks storage. These findings illustrated the distinct interactions between pea protein and different polyphenols from Tasmanian pepper leaf and berry to enhance the antioxidant capacity of pea protein.

A self-healing crosslinked-xanthan gum/soy protein based film containing halloysite nanotube and propolis with antibacterial and antioxidant activity for wound healing

Traumatic multidrug-resistant bacterial infections are the most threat to wound healing. Lower extremity wounds under diabetic conditions display a significant delay during the healing process. To overcome these challenges, the utilization of protein-based nanocomposite dressings is crucial in implementing a successful regenerative medicine approach. These dressings hold significant potential as polymer scaffolds, allowing them to mimic the properties of the extracellular matrix (ECM). So, the objective of this study was to develop a nanocomposite film using dialdehyde-xanthan gum/soy protein isolate incorporated with propolis (PP) and halloysite nanotubes (HNTs) (DXG-SPI/PP/HNTs). In this protein-polysaccharide hybrid system, the self-healing capability was demonstrated through Schiff bonds, providing a favorable environment for cell encapsulation in the field of tissue engineering. To improve the properties of the DXG-SPI film, the incorporation of polyphenols found in PP, particularly flavonoids, is proposed. The synthesized films were subjected to investigations regarding degradation, degree of swelling, and mechanical characteristics. Additionally, halloysite nanotubes (HNTs) were introduced into the DXG-SPI/PP nanocomposite films as a reinforcing filler with varying concentrations of 3 %, 5 %, and 7 % by weight. The scanning electron microscope (SEM) analysis confirmed the proper embedding and dispersion of HNTs onto the DXG-SPI/PP nanocomposite films, leading to functional interfacial interactions. The structure and crystallinity of the synthesized nanocomposite films were characterized using Fourier Transform Infrared Spectrometry (FTIR) and X-ray diffraction (XRD), respectively.Moreover, the developed DXG-SPI/PP/HNTs nanocomposite films significantly improved cell growth of NIH-3T3 fibroblast cells in the presence of PP and HNTs, indicating their cytocompatibility. The antibacterial activity of the nanocomposite was evaluated against Escherichia coli (E. Coli) and Staphylococcus aureus (S. Aureus), which are commonly associated with wound infections. Overall, our findings suggest that the synthesis of DXG-SPI/PP/HNTs nanocomposite scaffolds holds great promise as a clinically relevant biomaterial and exhibits strong potential for numerous challenging biomedical applications.

Preparation, structure characterization, and in vitro bioactivity of yam starch-polyphenol complex

Abstract Background Chinese yam (Dioscorea opposita Thunb.), with medicinal and edible properties, holds a significant position in both traditional medicine and food in China. It is rich in resistant starch (RS), which imparts various beneficial effects, including anticonstipation, regulation of blood lipids, and prevention of gastric ulcers. However, the resistance of native yam starch to digestion diminishes during cooking, necessitating suitable modifications. Objective In this article, yam starch was complexed with five different polyphenols to create RS5. The goal was to explore how these diverse polyphenols influence the physicochemical characteristics and bioactivities associated with yam RS. Method Yam starch-polyphenol complexes, involving five different polyphenols, namely, magnolol (MAG), ferulic acid (FA), resveratrol (RES), apple polyphenols (APs), and green tea polyphenols (GTPs), were prepared. The investigation encompassed the assessment of physicochemical properties, structural traits, in vitro cholate binding capacity, and in vitro antidigestive effects of these complexes. Results The results highlight the pronounced affinity of MAG for yam starch, followed by FA. Fourier transform infrared spectroscopy reveals that starch-polyphenol binding primarily involves noncovalent interactions. X-ray diffraction analysis discloses V-type crystal structures in YS-MAG, YS-APs, and YS-GTPs complexes. The incorporation of polyphenols reduces the thermal stability of starch while enhancing its in vitro cholate binding capacity, restraining starch digestion, and elevating RS content. Notably, YS-FA exhibits an impressive RS content of up to 54.15%. In addition, YS-MAG and YS-FA significantly enhance the production of short-chain fatty acids. These findings deepen our comprehension of the interplay between yam starch and polyphenols, offering valuable insights for the development of novel food products with enhanced health benefits.

A review of food preservation based on zein: The perspective from application types of coating and film.

The application of zein in food preservation was discussed from a unique perspective of application types, including coating and film. For the study of coating, edibility is considered because the coating adheres to the surface of food directly. For the study of film, plasticizers improve their mechanical properties, while barrier performance and antibacterial performance are achieved by nanoparticles; the incorporation of polyphenols is mainly due to their antibacterial and antioxidant properties; other biopolymers realize the complementarity between zein and biopolymers within films. In the future, the interaction between the edible coating and food matrix needs to be concerned. The mechanism of various exogenous additives and zein in the film should be noticed. Importantly, food safety and the possibility of large-scale application should be followed. Additionally, the intelligent response is one of the key development directions of zein-based film in the future.

Polyphenolic compounds affect the long-term degradation behaviour of polymer and composite materials based on PCL, PLGA, and bioactive glass

In recent years, the modification of biodegradable aliphatic polyesters with bioactive ceramics and plant-derived active agents has gained much attention in biomedical applications. They provide significant improvement in biological functionality of synthetic polymers. However, they simultaneously affect numerous physicochemical properties. In this work, for the first time, effect of incorporation of polyphenols (PPh) extracted from sage and sol-gel-derived bioactive glass (BG) particles, either alone or in combination, into poly(ε-caprolactone) (PCL) and poly(lactic-co-glycolide) (PLGA) was evaluated. BG particles were shown to accelerate degradation of materials based on slowly degrading polymer - PCL, while degradation of materials based on fast degrading polymer – PLGA was retarded. For PLGA-based composites, the formation of apatite layer and dissolution of alkaline ions from BG appear to have pivotal role in controlling degradation by providing protection from direct exposition to aqueous environment and neutralizing acidic by-products. PPh were shown to accelerate degradation of all studied materials. The following PPh-related factors can be involved in this process: wettability improvement, acid catalysis, plasticizing effect, and porosity formation. Our results highlighted the importance of considering the effect of commonly used polymeric modifiers on one of the most important properties of biomaterials used in tissue engineering and drug delivery - degradation.

Liposomes loading grape seed extract: A nanotechnological solution to reduce wine-making waste and obtain health-promoting products

Liposomes with grape marc seed extract were developed as a promising solution to reuse the wine industry's waste and develop nanotechnological products with high added value for human health. Thus, a hydroalcoholic extract rich in phenolic compounds, such as flavan-3-ols and proanthocyanidins, was obtained from seeds isolated from the bagasse of the cultivar Merlot. This extract was nanoincorporated in liposomal vesicles, which reached a size of 238.6 nm, polydispersity index of 0.252, the zeta potential of -14.66 mV, pH 5.71, and catechin content of 0.75%. The liposomes remained stable for 30 days under refrigeration. Corona protein formation was not found when vesicles were added to the culture media, due to the fact that they did not change the physico-chemical properties in the culture media. The liposomes were viable in human fibroblasts (HFF-1). They were also capable of neutralizing the basal production of reactive oxygen species (ROS), which are produced during the normal cell metabolism and cell culture procedures, not being cytotoxic to the cells, demonstrating antioxidant potential. The analytical method for the quantification of catechins was shown to be linear (r= 0.9994), precise (RSD < 4.0), and specific to determine the catechin without the interference of the constituents from liposomes. It has been proved that the incorporation of polyphenols contained in grape seeds, resulting from vinification residues, in liposomal vesicles are effective, as they improve the stability and bioavailability of these compounds and can be used as a promising technological solution to obtain beneficial products, such as new food ingredients and sustainable packaging, taking advantage of the wine industry's waste.

Antibacterial ability and osteogenic activity of polyphenol-tailored calcium silicate bone cement.

Calcium silicate-based cement (CSC) has attracted much interest because of its favourable osteogenic effect that supports its clinical use. Although CSC has antibacterial activity, this activity still needs to be improved when used in an infected bone defect. Natural polyphenols have been considered antimicrobial reagents. To this end, three different types of polyphenols (gallic acid (GA), pyrogallol (PG) and tannic acid (TA)) with different concentrations as a liquid phase were mixed with bioactive calcium silicate to enhance the antibacterial activity of CSC. The setting time, antibacterial activity, and osteogenic activity of CSC were studied. Evaluation of antibacterial ability and reactive oxygen species (ROS) was performed using Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus) bacteria, while a human osteoblast-like cell line (MG63) was used to examine osteogenic activity. The experimental results showed that the addition of polyphenols did not remarkably affect the phase composition and morphology of CSC, but changed the setting time and diametral tensile strength. At the same concentration of 1 wt%, the setting time of TA (21 min) was significantly shorter than that of PG (26 min) and GA (68 min), and was indistinguishable from the control cement (20 min). GA had a significantly higher antioxidant activity than PG and TA. As expected, higher concentrations of polyphenols had a more positive impact on ROS generation. More importantly, the incorporation of polyphenols greatly enhanced the antibacterial activity of CSC against E. coli and S. aureus, but had little effect on the in vitro osteogenic activity of MG63 cells and the cytotoxicity of L929 cells. It was concluded that among the three phenolic compounds, the optimal concentration of the liquid phase in the hybrid cement was 5 wt% TA in terms of setting time, strength, antibacterial activity and in vitro osteogenic activity.

Development of extra virgin olive and olive pomace oil nanoemulsions (o/w and w/o) enriched with surface‐active phenolic compounds

AbstractThe present study explored the potential use and the effectiveness of extra virgin olive oil (EVOO) and olive pomace oil (OPO) for water in oil (w/o) and oil in water (o/w) nanoemulsion preparations. Nonionic food grade emulsifiers were examined in the formulation of the nanoemulsions and the incorporation of polyphenols extracted from olive kernel on their physicochemical properties was also investigated. The effect of the dispersed phase and the incorporated bioactive compounds was evaluated based on the mean droplet diameter (MDD) and polydispersity index (PDI), turbidity and viscosity, MDD growth, surface tension, and total phenolic content of the nanoemulsions during storage. Results were statistically evaluated using analysis of variance and Duncan's test was performed where applicable. The most effective type and the optimum ratio of the emulsifier was determined in each system (o/w–w/o, EVOO–OPO). The nanoemulsions produced presented desirable properties, in terms of kinetic stability, MDD, PDI, and viscosity and they demonstrated satisfactory physical and chemical stability during storage. MDD and PDI values were minimum in the case of o/w nanoemulsion prepared with 4% Tween 40. The stability of the nanoemulsion was enhanced by polyphenols while their retention reached ~80% being higher in o/w nanoemulsions. It was concluded that it is possible to prepare fine o/w and w/o nanoemulsions using both EVOO and OPO. The incorporation of bioactive compounds can significantly affect the nanoemulsions' properties, improving their kinetic and chemical stability.Practical ApplicationsAlthough olive oil has been thoroughly studied for nanoemulsion preparations, there is still limited study on olive pomace oil applications. Hence, this present study was designed to compare the effectiveness of extra virgin olive oil and olive pomace oil on the formation of o/w and w/o nanoemulsion enriched with phenolic compounds extracted from the olive kernel. The novelty of work is highlighted in the following: both extra virgin olive and olive pomace oil can be suitable for the preparation of o/w and w/o nanoemulsions with good physical stability and without excessive droplet growth upon storage. These nanoemulsions can be used as a suitable means for the incorporation and protection of bioactive ingredients, such as polyphenolic compounds, and serve as an excellent delivery system as they exhibit satisfactory retention during storage.

The effect of green tea polyphenols addition on the physicochemical, microbiological and bioactive characteristics of yogurt

PurposeThe purpose of this paper is to evaluate the effect of green tea polyphenols addition on physicochemical, microbiological and bioactive characteristics of yogurt.Design/methodology/approachTwo incorporation methods of polyphenols were evaluated: direct addition or incorporated within protein particles of whey protein concentrate and gelatin. During yogurt’s shelf life, structure characteristics (water holding capacity, textural and rheological parameters), lactic acid bacteria (LAB) viability and polyphenols antioxidant activity were analyzed. Also, polyphenol bioaccesibility afterin vitrodigestion was evaluated.FindingsPolyphenols addition (by the two methods used) did not affect the dynamics of the fermentation process, nor the LAB viability during storage. The color parametera* for the yogurts with the highest polyphenol concentrations showed positive values (tending to red), but not visible to the naked eye. Because of the ability of polyphenols to interact with milk proteins, yogurts with polyphenols presented higher values in firmness and cohesiveness with respect to the control. Additionally, the incorporation of polyphenols in protein particles increased even more these parameters because of the higher protein content of these formulations. After simulated digestion, a high polyphenol bioaccesibility was observed, and the antioxidant activity was retained, which could be explained by the “protector” effect of the milk matrix.Practical implicationsYogurt supplementation with green tea polyphenols is feasible for the development of functional food. However, the use of protein particles would not provide an extra benefit because milk proteins already act as protective molecules of polyphenols.Originality/valueThis study shows not only the physico-chemical implications of including polyphenols in yogurt but also their bioaccesibility after anin vitrodigestion, revealing a suitable manner for delivery of antioxidants in a dairy product like yogurt.

Incorporation of polyphenols in baked products.

Bakery foods, including breads, cakes, cookies, muffins, rolls, buns, crumpets, pancakes, doughnuts, waffles, and bagels, etc., have been an important diet of humans for thousands of years. As the nutraceuticals with various biological activities, polyphenols, especially polyphenol-enriched products are widely used in bakery foods. The polyphenol-enriched products are mainly from fruits and vegetables, including fruits in whole, juice, puree, jam, and the powder of dried fruits, pomace, and peels. Incorporation of these products not only provide polyphenols, but also supply other nutrients, especially dietary fibers for bakery products. This chapter discussed the thermal stability of different types of polyphenols during baking, and the effect of polyphenols on the sensory attributes of baked foods. Moreover, their role in mitigation of reactive carbonyl species and the subsequent formation of advanced glycation end products, antioxidant and antimicrobial activities have been also discussed. Since polyphenols are subjected to high temperature for dozens of minutes during baking, future works need to focus on the chemical interactions of polyphenols and their oxidized products (quinones) with other food components, and the safety consequence of these interactions.

Exploring the Use of Bryophyllum as Natural Source of Bioactive Compounds with Antioxidant Activity to Prevent Lipid Oxidation of Fish Oil-In-Water Emulsions.

The current industrial requirements for food naturalness are forcing the development of new strategies to achieve the production of healthier foods by replacing the use of synthetic additives with bioactive compounds from natural sources. Here, we investigate the use of plant tissue culture as a biotechnological solution to produce plant-derived bioactive compounds with antioxidant activity and their application to protect fish oil-in-water emulsions against lipid peroxidation. The total phenolic content of Bryophyllum plant extracts ranges from 3.4 to 5.9 mM, expressed as gallic acid equivalents (GAE). The addition of Bryophyllum extracts to 4:6 fish oil-in-water emulsions results in a sharp (eight-fold) increase in the antioxidant efficiency due to the incorporation of polyphenols to the interfacial region. In the emulsions, the antioxidant efficiency of extracts increased linearly with concentration and levelled off at 500 μM GAE, reaching a plateau region. The antioxidant efficiency increases modestly (12%) upon increasing the pH from 3.0 to 5.0, while an increase in temperature from 10 to 30 °C causes a six-fold decrease in the antioxidant efficiency. Overall, results show that Bryophyllum plant-derived extracts are promising sources of bioactive compounds with antioxidant activity that can be eventually be used to control lipid oxidation in food emulsions containing (poly)unsaturated fatty acids.

Black Chokeberry Fruit Polyphenols: A Valuable Addition to Reduce Lipid Oxidation of Muffins Containing Xylitol.

The study aimed at assessing effects of black chokeberry polyphenol extract (ChPE) added (0.025–0.075%) to xylitol-containing muffins to reduce lipid oxidation, especially in preventing degradation of hydroperoxides throughout the storage period. Among polyphenolic compounds (3092 mg/100 g in total) in ChPE, polymeric procyanidins were the most abundant (1564 mg/100 g). ChPE addition resulted in a significantly increased capacity of scavenging free radicals and markedly inhibited hydroperoxides decomposition, as reflected by low anisidine values (AnV: 3.25–7.52) throughout the storage. On the other hand, sucrose-containing muffins had increased amounts of primary lipid oxidation products and differed significantly from other samples in conjugated diene hydroperoxides (CD values), which was in accordance with the decrease of C18:2 9c12c in those muffins after storage. In addition, sucrose-containing muffins were found to be those with the highest level of contamination with toxic carbonyl lipid oxidation products. Throughout the storage, no yeast or moulds contamination were found in higher enriched muffins. The incorporation of polyphenols to xylitol-containing muffins resulted in preventing decomposition of polyunsaturated fatty acids (PUFAs), and in reducing the content of some toxic aldehydes. ChPE could be regarded as a possible solution to xylitol-containing muffins to extend their shelf life. The results support the use of xylitol in muffin manufacture as being favourable in terms of suitability for diabetics.

Improvement of the Physical Properties of Guided Bone Regeneration Membrane from Porcine Pericardium by Polyphenols-Rich Pomace Extract.

To achieve optimal performances, guided bone regeneration membranes should have several properties, in particular, proper stiffness and tear resistance for space maintenance, appropriate resorption time, and non-cytotoxic effect. In this work, polyphenol-rich pomace extract (PRPE), from a selected grape variety (Nebbiolo), rich in proanthocyanidins and flavonols (e.g., quercetin), was used as a rich source of polyphenols, natural collagen crosslinkers, to improve the physical properties of the porcine pericardium membrane. The incorporation of polyphenols in the collagen network of the membrane was clearly identified by infra-red spectroscopy through the presence of a specific peak between 1360–1380 cm−1. Polyphenols incorporated into the pericardium membrane bind to collagen with high affinity and reduce enzymatic degradation by 20% compared to the native pericardium. The release study shows a release of active molecules from the membrane, suggesting a possible use in patients affected by periodontitis, considering the role of polyphenols in the control of this pathology. Mechanical stiffness is increased making the membrane easier to handle. Young’s modulus of pericardium treated with PRPE was three-fold higher than the one measured on native pericardium. Tear and suture retention strength measurement suggest favorable properties in the light of clinical practice requirements.

Effect of different grape residues polyphenols impregnation techniques in mango

The objective of this work was to evaluate the effect of the incorporation of grape residue polyphenols in mango using different impregnation methods. Experiments were performed at atmospheric pressure or vacuum, and with or without performing osmotic treatment and ultrasound. The samples were evaluated after the different impregnation techniques in terms of carotenoids, phenolic compounds, ascorbic acid, energy consumption, color, and firmness. The osmotic dehydration assisted impregnation showed positive results in relation to the incorporation of polyphenols in the mango (3.22–3.34 mg GAE/g DM), but negative in relation to carotenoids (27.37–32.71 μg/g DM) and ascorbic acid (11.90–16.22 mg/100 g DM), while the use of ultrasound showed results satisfactory in all evaluated parameters. The combination of ultrasound and osmotic dehydration in the impregnation resulted in samples with higher losses of carotenoids (28.8–29.38 μg/g DM), small incorporation of phenolic compounds (2.21–2.54 mg GAE/g DM) and retention of ascorbic acid (21.34–22.32 mg/100 g DM). Although the total energy expenditure was higher (0.05–0.09 kWh), the vacuum impregnation and ultrasound-assisted vacuum impregnation assays presented the best performance in relation to the retention of carotenoids (33.07–34.53 μg/g DM) and ascorbic acid (28.29–40.97 mg/100 g DM), greater incorporation of polyphenols from the grape residue by mango (6.29–7.74 mg GAE/g DM), greater color change due to the presence of grape residue extract, and softer texture when compared to untreated samples.

Bioinspired Metal⁻Polyphenol Materials: Self-Healing and Beyond.

The blue mussel incorporates the polyphenolic amino acid l-3,4-dihydroxyphenylalanine (DOPA) to achieve self-healing, pH-responsiveness, and impressive underwater adhesion in the byssus threads that ensure the survival of the animal. This is achieved by a pH-dependent and versatile reaction chemistry of polyphenols, including both physical interactions as well as reversible and irreversible chemical bonding. With a short introduction to the biological background, we here review the latest advances in the development of smart materials based on the metal-chelating capabilities of polyphenols. We focus on new ways of utilizing the polyphenolic properties, including studies on the modifications of the nearby chemical environment (on and near the polyphenolic moiety) and on the incorporation of polyphenols into untraditional materials.

Study of the interactions between rosmarinic acid and bovine milk whey protein α-Lactalbumin, β-Lactoglobulin and Lactoferrin

Incorporation of polyphenols in dairy food is being considered as way to develop oral nutraceutical formulation due to their antioxidant and anti-inflammatory activities. However, polyphenols can interact with proteins, which gives rise to a significant loss of their biological properties. The objective of this research was to study the interactions of rosmarinic acid (RA) and bovine milk whey protein (i.e. α-Lactalbumin, β-Lactoglobulin and Lactoferrin). Radical quenching assay (ABTS), optical density, liquid chromatography (HPLC and FPLC), dynamic light scattering (DLS) and zeta-potential, Fourier transform infrared spectroscopy (FTIR), and differential scanning calorimetry (DSC) were used for the screening of the interactions at 0, 3, and 24h of storage at 4°C. Interactions were assessed both at neutral pH of the complexes in water and acidic pH3 and 4.5. Results show the occurrence of non-covalent interactions between RA and whey proteins, such as hydrophobic, hydrogen bonding, and dipole–dipole type. Radical quenching activity of RA decreased in the presence of milk proteins yet at the initial time especially in the case of α-Lactalbumin, meaning that the amount of free polyphenol diminished. Complex dimension was different depending on pH, and on primary and secondary structures of proteins. Interactions showed to be favored at the lowest pH, and reversible in all cases; nonetheless, complex RA–proteins were more stable than proteins alone.

The effect of the incorporation of grape marc powder in fettuccini pasta properties

Several studies have been conducted to evaluate the potentiality of grape residues to be used in the food industry. In the present work, the incorporation of 25, 50 and 75 g/kg of grape marc powder in fettuccini pasta preparation was evaluated over its cooking, nutraceutical and sensory properties. The results show that the incorporation of the dried by-product did not interfere in the water absorption and in the solid loss of the pasta after cooking. The addition of grape marc powder increased the total phenolic, condensed tannins, monomeric anthocyanin and compounds antioxidant capacity concentration in the cooked pasta due to the incorporation of polyphenols stemmed from grape. Sensory analysis showed that the incorporation of grape marc powder reduced the acceptance of aroma, aftertaste, flavor and appearance, regardless of the concentration of the dried residue added. Furthermore, the incorporation of 25 g/kg of grape marc powder presented the best overall acceptance, with lower changes of color, according to the CIELAB method. Based on the results, the addition of grape marc powder to pasta is an interesting alternative of use of this by-product, potentially reflecting on final product costs and representing an environmentally friendly way to manage industrial waste.

Evaluation of the effect of Uncaria tomentosa extracts on the size and shape of human erythrocytes (in vitro)

In this study, we continued our investigations concerning the interaction of Uncaria tomentosa extracts with the human erythrocytes. The analysis of the size and shape of the erythrocytes by means of flow cytometry and phase contrast microscopy was performed. We executed our experiments using ethanolic and aqueous extracts from the leaves and bark of U. tomentosa. Disturbances were observed in the size and shape of the erythrocytes incubated with ethanolic and aqueous extracts at the concentrations of 100μg/mL and 250μg/mL, respectively. The observed changes were probably related to the entry of polyphenolic compounds contained in U. tomentosa extracts into erythrocyte membrane. Externalization of phosphatidylserine on the erythrocytic surfaces was also noticed during incubation with extracts at concentration of 250μg/mL. We concluded that all of the extracts examined induced changes in the erythrocyte membrane properties, whereas ethanolic extracts from bark induced the most significant changes. The possible binding of polyphenols to the erythrocyte surface may have accounted for the protective properties of extracts against haemolysis of RBCs, which was observed in our previous study (Bors et al., 2011), but considerable incorporation of polyphenols into cell membranes can result in disturbance of phosphatidylserine transport and changes in erythrocyte shape. Nevertheless the results of the investigations showed that considerable morphological changes appear only as a result of erythrocyte exposure to high concentrations (50ppm and 100ppm) of the extracts studied, thus they should not lead to clinical erythrocytic damage if recommended doses of U. tomentosa preparations are administrated.