Complex Polyphenols Research Articles

THE CHEMICAL COMPOSITION AND NUTRITIONAL VALUE OF BLACKBERRIES GROWING IN THE REPUBLIC OF AZERBAIJAN AND THEIR DEPENDENCE ON THE SPECIES AND REGION OF GROWTH

The work shows the biological and nutritional value of Rubus, which grows in Azerbaijan. It was found that the highest content of sugars is the wild blackberry of the Rubus sanguineus Friv species (8.75±0.19%), while it contains little sucrose, glucose (from 3.10±0.12 to 4.87±0.16%) and fructose (from 3.08±0.28 to 3.40±0.09%) predominate. The content of the mass fraction of organic acids is greater in the species Rubus caucasicus forche (1.94±0.10%) than in the species Rubus caesius and Rubus sanguineus Friv (1.85±0.15 and 1.62±0.12%, respectively). The content of pectin substances in blackberries ranges from 0.26±0.01 to 0.30±0.04%, and the mass fraction of ash from 0.42±0.08 to 0.58±0.11%. In terms of vitamin C content, the species Rubus sanguineus Friv is superior (32.1±1.20 mg/100 g) to the species Rubus caesius and Rubus caucasicus forche (23.76±0.58 mg/100 g and 29.35±0.47 mg/100 g, respectively). In the polyphenol complex of blackberries of the species Rubus sanguineus Friv, Rubus caucasicus forche and Rubus caesius, catechins and anthocyanins are present with a clear predominance of the latter. The results of the studies show that the main indicators of the chemical composition of blackberries depend on the type of raw materials and on the soil-climatic and ecological-geographical conditions of the growing region. The biological and nutritional value of blackberries of various types allows us to consider them as an additional source of physiologically active substances and raw materials for the production of various soft drinks based on them, including tonic energy drinks.

Polyphenol nanoparticles of millet, rice and wheat: extraction, identification, functional and morphological characteristics

SummaryPolyphenols complexes were extracted from Common millet (CM), Long‐grain rice (LGR) and Huaihe wheat (HW), purification method, components and functional characteristics were studied. Higher phenol content (18.7 in CM, 12.9 in LGR and 22.3 mg g−1 in HW) was obtained by the high‐speed shear, with high antioxidants (DPPH 89.2% in HW, ABTS 81.6% in LGR, FRAP 0.83 in HW) after purified. Thirteen typical polyphenol complexes were identified from 21 peaks by UHPLC‐LTQ‐Orbitrap‐MS/MS. Gingerenone A was first detected in CM, HW and LGR; (+/−)‐Gingerol was first detected in CM and HW. Morphology by TEM displayed a rough spherical structure with 200–500 nm. Peculiarly contained hydroxyl polyphenol (5‐(3,4‐Dihydroxyphenyl) valeric acid, Apigenin‐8‐C‐xylosyl‐6‐C‐glucoside), polyphenols with B‐rings (Trans‐cinnamic acid, Gingerenone A) and the highest contents (+/−)‐Gingerol with hydroxyl and Sinapinic acid with B‐rings, CM had a higher α‐amylase inhibition rate (80.5%) than LGR and HW, which providing a foundation for the development of hypoglycaemic drugs.

Anti-Inflammatory Effects Induced by a Polyphenolic Granular Complex from Olive (Olea europaea, Mainly Cultivar coratina): Results from In Vivo and Ex Vivo Studies in a Model of Inflammation and MIA-Induced Osteoarthritis.

MOMAST® GR25 is a polyphenolic granular complex from olive pressing juice with high total content in polyphenols. In this work, we evaluated the possible anti-inflammatory effects of MOMAST® GR25 in both acute and chronic inflammatory models. MOMAST® GR25 decreased the levels of prostaglandin (PG) E2 and 8-iso-PGF2α in isolated rat colon, liver, and heart specimens stimulated with lipopolysaccharide (LPS). In vivo, compared to controls, rats treated with MOMAST® GR25 (100 mg/kg to 1 g/kg) showed a significant reduction in both licking/biting time in the formalin test. In a rat model of osteoarthritis by monoiodoacetate (MIA) injection, MOMAST® GR25 showed pain-relieving properties when acutely administered, reducing mechanical hyperalgesia and spontaneous pain. Moreover, a repeated daily treatment with MOMAST® GR25 (300 mg/kg) fully counteracted osteoarticular pain without the development of tolerance to the antinociceptive effect. Taken together, our present findings showed that MOMAST® GR25 could represent a potential strategy for the treatment of inflammation and pain.

Interactions between the protein-epigallocatechin gallate complex and nanocrystalline cellulose: A systematic study

In this work, the noncovalent interactions between the protein-epigallocatechin gallate (protein-EGCG) complex and nanocrystalline cellulose (NCC) were systematically investigated. Rheological properties, including large amplitude oscillation shear (LAOS), transient rheology, and conventional rheology of the mixture were also evaluated. As obtained, flexible myofibrillar protein-epigallocatechin gallate (MP-EGCG) and rigid ovalbumin-epigallocatechin gallate (Ova-EGCG) follow different rules in the stability of the regulatory system because of the difference in noncovalent interactions, triggering different rheological responses of the complexes. Additionally, MP-EGCG/NCC showed an obvious strain overshoot during LAOS flow, which could not be obtained in Ova-EGCG/NCC. Notably, the fibrous MP-EGCG network was the factor that dominated the formation of a more stable suspension system with strong hydrogen bonding, dipole–dipole interactions and/or van der Waals forces. This study can provide some ideas for the future study of the interaction between protein–polyphenol complexes and polysaccharides.

INVESTIGATION OF SUPERCRITICAL CO2-EXTRACTS OF WILD LEDUM PALUSTRE L. (RHODODENDRON TO-MENTOSUM HARMAJA) AND IDENTIFICATION OF ITS METABOLITES BY TANDEM MASS SPECTROMETRY

The purpose of this research is to investigate and identify polyphenolic complexes and other biologically active compounds by tandem mass spectrometry, presented in the leaves and stems of Ledum palustre L. Carbon dioxide, compressed to a supercritical state, was used for the most environmentally friendly extraction of polyphenolic complexes and other biologically active compounds of Ledum palustre L. The most effective extraction characteristics (pressure 350 bar; temperature 60 °С; extraction time 1-hour, co-solvent MeOH 3.5%) supercritical CO2-extraction of L. palustre were obtained empirically. To identify target analytes in supercritical extracts, High Performance Liquid Chromatography (HPLC) was used in combination with a BRUKER DALTONIKS ion trap. The results showed the presence of 61 biologically active compounds corresponding to the rhododendron species, of which 32 were identified for the first time in L. palustre. These are flavanols dihydrokaempferol, quercetin arabinoside, myricetin galactoside; flavones: diosmetin, nevadensin, cirsimaritin; flavanone naringenin; anthocyanins delphinidin, petunidin, cyanidin pentoside, delphinidin pentoside, peonidin 3-(6-O-acetyl) glucoside, peonidin-3-O-malonylglucoside, cyanidin-3-rutinoside, peonidin 3-O-glucoside; ellagic acid; lignan medioresinol; a type A procyanidin dimer; sterols fucosterol and avenasterol, etc.

Mechanistic insight into the one step green synthesis of hybrid rGO/Fe NPs

Recently, the green synthesis of iron nanoparticles and associated hybrids using plant extracts has attracted much attention due to its low cost, simplicity and environmental friendliness. However, the exact formation mechanism is still unclear. In this study, the one step green synthesis of hybrid rGO/Fe NPs by a tea extract was examined using a response surface methodology (RSM) to obtain a high activity of rGO/Fe NPs. The results showed that the best conditions for synthesis were an extract concentration = 35 g/L, pH = 7, and temperature = 30 °C. The optimized hybrid produced could remove 99.9% of mitoxantrone (MTX) compared to only 78.9% when unoptimized. To better understand the formation process, characterizations by SEM, TEM, AFM, FTIR, XRD, Raman, and XPS were performed. Theses characterizations showed that the Fe NPs produced had a particle size of 25 nm which were deposited randomly across the rGO nanosheet with a thickness of approximately 1.5 nm, indicating that stable hybrid rGO/Fe NPs were successfully synthesized, where the green tea extract exhibited both reducing and capping/stabilizing behavior. Furthermore, the specific biomolecules in the green tea extract responsible for bio-reduction and stabilization were identified by GC-MS and LC-MS, which showed that catechins were the main reducing agents, while alkaloids, amino acids and phenolic acids were the main capping/stabilizing agents. Finally, a mechanism for synthesizing rGO/Fe NPs was proposed, where the polyphenols successfully reduced GO and complexed with iron ions to form amorphous ferric (and ferrous) polyphenol complex nanoparticles.

THE STUDY OF NETTLE HERB (URTICA DIOICA L.) GROWING IN SOME AREAS OF THE EUROPEAN RUSSIA AND SIBERIA

The report presents the results of the study of the chemical composition of nettle herb, 40%, 70% extracts, and extracts of polyphenolic complexes (PPC). Nettle herb were collected by the authors in June-July 2007–2020 in the territories of Tomsk, Kemerovo, Kursk, Novosibirsk, Moscow, Kirov, Tver regions, Altai and Krasnoyarsk Krai; Altai Republic. Extracts, polyphenolic and polysaccharide complexes were obtained from the herb. The studies was conducted using PC, TLC, UV-spectroscopy, HPLC, titrimetry, neutron activation. Reverse-phase HPLC were carried out on a chromatograph «Dionex Ultimate 3000» with UV-detector in the wave length range from 254 to 330 nm. Separation was performed by a column with reversed-phase sorbent «Restek Pinnacle IIC18» (150×4.6 mm, particle size 5 µm), flow rate of mobile phase is 1 ml/min; temperature is 20 °C, mobile phase (50 ml of acetonitrile, 50 ml of 0.1% trifluoroacetic acid) were carried out on. The study showed that nettle herb, 40%, 70% extracts and PPC contain phenolic compounds: phenolcarbonic acids, flavonoids, catechins, tannins; vitamin C and pigments. Baicalein, chrysoeriol, scutellarin identified for the first time. One of the dominant groups is hydroxycinnamic acids. The composition of flavonoids, phenolic carboxylic acids, catechins, hydroxycinnamic acids, including chlorogenic acid, chlorophyll, the sum of phenolic compounds, catechins are similar in 70% extract and its PPC. Additional information was obtained on the elements contained in nettle herb and its extracts.

Fabrication and characterization of oil-in-water emulsions stabilized by whey protein isolate/phloridzin/sodium alginate ternary complex

Whey protein isolate (WPI) is an important food supplement and natural surfactant. Emulsion systems based on WPI and WPI–polyphenol complex have been the focus of food delivery research. However, these emulsions are pH-sensitive, which limits their application. In this study, an emulsion stabilized by the WPI–phloridzin (PHL)–sodium alginate (SA) ternary complex was constructed for the first time, and its physicochemical properties were characterized. The results indicated that at pH 5.0, the ternary complex possessed higher stability than the WPI–PHL complex. Moreover, the ternary complex significantly enhanced the ABTS radical scavenging ability of PHL at pH 5.0. The emulsion stability increased with increasing SA proportion in the complex. The antioxidant activity and β-carotene retention capacity of the emulsion were also positively correlated with SA concentration. The results suggest that the emulsion stabilized by the WPI–PHL–SA ternary complex is a promising food delivery system.

Enhanced bioavailability and anti-hyperglycemic activity of young apple polyphenols by complexation with whey protein isolates.

This study aims to evaluate the effects of complexation of whey protein isolate (WPI) and young apple polyphenols (YAP) on the bioavailability and anti-hyperglycemic activity of YAP. Two types of WPI-YAP complexes were fabricated by mixing WPI with YAP at 25℃ (WPI-YAP) and 90℃ (WPI-YAP-H), respectively. The intermolecular interactions between WPI and YAP were investigated by fluorescence spectroscopy and circular dichroism analyses. The in vitro bioaccessibility and bioavailability of YAP were determined using a simulated gastrointestinal digestion and human Caco-2 cells model. It was found that the total polyphenols transport efficiency was improved from 39.8% (YAP) to 48.2% (WPI-YAP) and 56.1% (WPI-YAP-H), indicating that the bioavailability of YAP was improved by complexation with WPI. Besides, after complexation with WPI, YAP displayed an improved in vivo effect on alleviating the increase in postprandial blood glucose level than the pure YAP, with WPI-YAP-H showing a better effect. This finding indicates that co-complexation of YAP with WPI is an effective way to improve the functionality of YAP, and the WPI-YAP complexes are also expected to have potential application in designing YAP-containing functional foods. PRACTICAL APPLICATION: The research provided a method to improve the bioavavibility of polyphenols, and the WPI-YAP complex can be developed in designing polyphenols related functional foods.

Ferulic acid and EGCG alter the structural characteristics of ovalbumin and its application in mineral loading

SummaryThis study aims to fabricate mineral‐loading nanocarriers using natural materials. The interaction patterns between ovalbumin (OVA) and four water‐soluble polyphenols, namely ferulic acid (FA), (‐)‐Epigallo‐catechin 3‐gallate (EGCG), gallic acid (GA) and epicatechin (EC), were investigated. Results showed that the optimised conditions for preparing stable OVA–polyphenol complexes are at the OVA–polyphenol ratio of 4:1 at pH 6, under which OVA–FA and OVA–EGCG showed the highest stability and mineral‐loading capacity among four OVA–polyphenol complexes. The fluorescence results indicated that the addition of EGCG and FA induced a significant fluorescence quenching to OVA. The interaction between OVA and polyphenols involved hydrogen bonding, hydrophobic interaction and electrostatic interaction. Fourier transform infrared spectroscopy (FTIR) analysis suggested that both FA and EGCG enhanced the stability and orderliness of the structure of OVA. The transmission electron microscopy images also exhibited the spherical structure of OVA after the addition of FA and EGCG. Furthermore, scanning electron microscope–energy dispersive X‐ray spectrum results suggested that OVA–FA and OVA–EGCG complexes were better mineral carriers than OVA–GA and OVA–EC. This study may serve as the theoretical support for the promising application of OVA in the fabrication of mineral‐loading nanocarriers in functional food and pharmaceutic.

Imparting reusable and SARS-CoV-2 inhibition properties to standard masks through metal-organic nanocoatings

Face masks are effective response to address this havoc pandemic caused by respiratory infection virus, but they are lack of reusable, antibacterial, and antiviral abilities due to their simple filtration mechanism, bringing to a supply shortage and severe plastic pollution globally. Herein, we designed reusable, antiviral, and antibacterial masks (referred to as R2A masks) that transformed from commonly-used standard masks and household fabrics based on the polyphenol-based surface functionalization. R2A nanocoatings are mainly composed of supramolecular complexation of natural polyphenols and metal ions, possessing a high performance of antibacterial property and comprehensive recyclability. Interfacial interaction of R2A nanocoating can effectively capture the spreading of particulate matters and aerosols containing virus-mimic nanoparticles even after 10 recycles. Moreover, R2A masks exist antibacteria and antivirus for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Collectively, this simple functional enhancement of masks provides a sustainable and strategic preparation for combating the infectious respiratory diseases.

The Technology and Composition of Functional Food Ingredients Obtained by Sorption of the Polyphenolic Compounds From Cranberry on Coagulated Egg Albumen

The technologies for developing food products for people with type 2 diabetes involve enrichment with polyphenolic compounds that have hypoglycemic and/or hypolipidemic properties. The production of ingredients for introduction into such food products should involve the techniques of concentration of natural polyphenols on certain food-grade protein matrices. In this study, a technology was developed for the production of a functional food ingredient, which was a complex of polyphenols (mostly anthocyans) from cranberries with coagulated egg albumen. The optimal parameters of sorption of anthocyans from cranberry juice on the albumen during the coagulation of the latter were determined. The contents and profile of anthocyans within the resulting food ingredient were assessed. The concentration of total anthocyans (recalculated to equivalents of cyanidin-3-glucoside) was determined by pH-differential spectrophotometry; the profile of individual anthocyans was determined by highperformance liquid chromatography. Sensory evaluation of the resulting ingredient (through a taste panel test) evidenced the possibility of including the product in the functional foodstuffs. The technology developed can be used in the design of functional food ingredients for subsequent introduction into anti-diabetic food products.
 Keywords: coagulated egg albumen, cranberry juice, anthocyans, functional food ingredients

Hypoglycemic Effects of Polyphenol Complexes from Bilberry Leaves and Fruits Sorbed on Brown Buckwheat Flour -- Experimental Evaluation and Prospects of Use

The effects of plant polyphenols on carbohydrate and/or lipid metabolism disorders have wide experimental and clinical justification; however, their effects are limited due to low bioavailability. Thus, the development of technological approaches enhancing their effectiveness and stability is relevant.The aim of this work was to evaluatein vivothe effects of polyphenols from bilberry leaves and fruits, sorbed on the brown buckwheat flour, on C57Bl/6c mice with carbohydrate and lipid metabolism disorders. We assessed in vivothe effect of a food matrix (FM1: bilberry leaf polyphenols sorbed on brown buckwheat flour) on C57Bl/6c mice with induced carbohydrate and lipid metabolism disorders. The aim of the second experiment was to evaluate the effectiveness of prolonged prophylactic consumption of another food matrix (FM2: billberry fruit polyphenols, sorbed on brown buckwheat flour) by C57Bl/6c micewith induced carbohydrate and lipid metabolism disorders. Technological approaches were developed and pilot batches of the food matrices FM1 and FM2were obtained. According to the in vivo testing, a significant decrease in the glucose levels and normalization of glucose tolerance and insulin sensitivity were found in animals treated with FM1. When assessing the in vivo effects of FM2, the hypoglycemic effect of bilberry fruit polyphenols in the composition of the matrix was established. The results of these studies can be used to justify the testing of the developed matrices in a clinical setting and using them as functional food ingredients for preventative nutrition in cases of carbohydrate metabolism disorders.
 Keywords: polyphenols, food matrix, functional food ingredient, carbohydrate metabolism, lipid metabolism

Vibrational Study (Raman, SERS, and IR) of Plant Gallnut Polyphenols Related to the Fabrication of Iron Gall Inks.

FT-Raman, FTIR, and SERS spectra of the structurally related gallnut polyphenols tannic acid, gallic acid, pyrogallol, and syringic acid are reported in this work aiming at performing a comparative assignation of the bands and finding specific marker features that can identify these compounds in complex polyphenol mixtures. Tannic and gallic acids are the principal components in oak gallnuts, and they can be found in iron gall inks. The different functional groups existing in these molecules and their spatial distribution lead to slight changes of the vibrations. The Raman spectra are dominated by bands corresponding to the ring vibrations, but the substituents in the ring strongly affect these vibrations. In contrast, the FTIR spectra of these molecules are dominated by the peripheral oxygen-containing substituents of the aromatic ring and afford complementary information. SERS spectroscopy can be used to analyze trace amounts of these compounds, but the spectra of these polyphenols show strong changes in comparison with the Raman spectra, indicating a strong interaction with the metal. The most significant modification observed in the SERS spectra of these compounds is the weakening of the benzene 8a ring vibration and the subsequent intensification of the 19a mode of the benzene ring. This mode is also more intense in the FTIR spectra, and its intensification in the SERS spectra could be related to a drastic change in the molecular polarizability associated with the interaction of the polyphenol with the metal in Ag NPs.

Споживчі та біологічно активні показники якості сублімованих плодів і ягід

The article shows the effect of freeze-drying on consumer and biologically valuable indicators of product quality. An important place in the food industry is occupied by drying processes, one of them is sublimation, which is recommended for products containing heat-sensitive antioxidant components such as ascorbic acid and phenolic substances. The article describes in detail the technological process of lyophilization and the stages of which it consists, namely: product preparation, freezing, sublimation, which is divided into primary and secondary drying, and packaging of the dried product. During the theoretical study of the question of the influence of sublimation on the quality of products, the ambiguity of the data was established, which contributes to further, more detailed study, taking into account varietal and weather factors. For example, a number of scientists Pérez-Gregorio, Robles-Sánchez R.M., Patthamakanokporn O., Pérez-Gregorio M.R., Pérez-Gregorio M.R., Rodrigues A.S., Que F., Mao L., Wojdylo A., Figiel A., Wojdylo A., Figiel A., Skrovankova S., Sumczynski D., Wojdyło A., Figiel A. note that post-harvest processes, including various types of fruit drying, negatively affect their chemical composition, in particular, the content of vitamin C, polyphenols and their antioxidant activity. The claim of a high percentage of ascorbic acid retention in freeze-dried fruits was confirmed by Dario Donno, Rupasinghe H.V., Fernandes F.A.N., Hawlader M.N.A. Studies on the effect of lyophilization on changes in the polyphenolic complex and bioactivity of fruits are quite controversial. Researchers Scheuermann E. et all proved that phenolic content and antioxidant activity increased during sublimation, while Kaya, Skrovankova S., Değirmencioğlu N. reported that drying fruits during the production of snacks does not significantly change their qualitative polyphenolic profile. The fact of an increase in the polyphenolic complex in freeze-dried blueberries was proven by the American researcher Esteban I. Other data contradicting the above data were obtained in the course of their research by researchers Paes J., Dotta R., who note that lyophilization reduces the amount of phenolic compounds.

Potential effects of mung bean protein and a mung bean protein-polyphenol complex on oxidative stress levels and intestinal microflora in aging mice.

This study investigated the effects of mung bean protein (MPI) and a MPI-polyphenol complex on oxidative stress levels and intestinal microflora in a D-galactose-induced aging mouse model. MPI and MPI-polyphenol complex intervention significantly increased activity of superoxide dismutase (SOD) and catalase and other antioxidant enzymes, improved the abundance and diversity of intestinal flora, and decreased the Firmicutes to Bacteroidetes ratio. Among them, the complex was more conducive to the improvement of the activity of antioxidant enzymes. The addition of MPI and the MPI-polyphenol complex can help the proliferation of Bacteroidetes, Bifidobacterium and Roseburia in the intestinal tract of aging mice, and inhibit the growth of Firmicutes and Ruminococcus, and the proliferation effect of the complex on Bifidobacterium was better than that of MPI. MPI significantly upregulated five pathways related to lipid and energy metabolism. Roseburia and Muribaculaceae were negatively correlated with malondialdehyde levels and positively correlated with SOD and other antioxidant enzyme indices. Our findings showed that MPI and MPI-polyphenol complexes can delay aging in mice by reducing oxidative damage and regulating intestinal flora. We also found a strong relationship between the abundance of intestinal flora and the levels of oxidative stress-related enzymes. This study provides theoretical support for the health and anti-aging benefits of mung bean food products.

Gastroprotective effect of Berberis vulgaris on ethanol-induced gastric mucosal injury: Histopathological evaluations.

Objective:Modern treatment of peptic ulcers includes antibacterial and gastroprotective medications. However, current anti-ulcer drugs possess severe side effects. Therefore, all attempts to find new effective medications free from side effects are justified. Though Berberis vulgaris is a medicinal plant commonly used for the treatment of numerous disorders, gastroprotective effect of its leaf extract was not investigated before. Materials and Methods:Gastric ulcer was modelled in Sprague-Dawley rats after treatment with B. vulgaris leaf extract containing 0.07% of alkaloids, 0.48% of flavonoids and 8.05% of tanning substances, 10 or 50 mg of dry extract/kg, changes in the stomach mucosa were assessed semi-quantitatively, and the gastric wall was evaluated for prostaglandin E2 level using ELISA and assessed histologically by calculation of the lesion index.Results: B. vulgaris leaf extract at the dose of 50 mg/kg reduced the macroscopic ulcer score and the microscopic lesion index, increased prostaglandin E2 concentration in the gastric wall significantly higher than atropine and B. vulgaris leaf extract 10 mg/kg.Conclusion:The gastroprotective effect of the high dose of B. vulgaris leaf extract may be due to stimulation of prostaglandin E2 secretion in the stomach, and anti-oxidative and anti-inflammatory properties of polyphenolic complex of flavonoids and tannins present in the leaves of this plant.

Improving foam performance using colloidal protein–polyphenol complexes: Lactoferrin and tannic acid

In this study, colloidal complexes were prepared from bovine lactoferrin (BLF) and tannic acid (TA) and then their ability to form and stabilize foams was characterized. The molecular interactions between BLF and TA were studied using fluorescence and molecular docking analysis, which suggested that hydrophobic forces were primarily involved in holding the complexes together. The production of colloidal BLF-TA complexes was supported by increases in turbidity and mean particle diameter, quenching of intrinsic fluorescence, decrease in surface hydrophobicity, and change in conformation. When used alone, BLF exhibited good foam formation but poor foam stability properties. In contrast, BLF-TA complexes exhibited good foam stability but poor foamability properties. The change in foaming properties of the proteins was closely related to their interactions with the polyphenols. These findings may be useful for the development of novel functional ingredients to construct food foams with good physicochemical and nutritional attributes.

Making Protein-Based Adhesives Water Resistant: Role of Protein Water Solubility, Galloyl Modification, and Complexation

There has been an ongoing interest in using proteins as more environmentally friendly substitutes for the existing synthetic adhesives. Poor water resistance is a particular shortcoming of protein-based adhesives, which negatively affects their outdoor functionality. In this study, we systematically investigated if water solubility of the protein, addition of a phenolic compound such as tannic acid, and protein–polyphenol complexation could improve the water resistance of protein-based adhesives. It was found that the synergetic effects of these parameters can yield commercial-level water resistance.

Haze in Beer: Its Formation and Alleviating Strategies, from a Protein-Polyphenol Complex Angle.

Beer is one of the oldest and most widely consumed alcoholic beverages. Haze formation in beer is a serious quality problem, as it largely shortens the shelf life and flavor of beer. This paper reviews the factors affecting haze formation and strategies for reducing haze. Haze formation is mainly associated with specific chemical components in malt barley grains, such as proteins. The main factor causing haze formation is a cross-linking of haze active (HA) proteins and HA polyphenols. Many HA proteins and their editing genes or loci have been identified by proteomics and quantitative trait locus (QTL) analysis, respectively. Although some technical approaches have been available for reducing haze formation in beer, including silica and polyvinylpolypyrrolidone (PVPP) adsorbent treatments, the cost of beer production will increase and some flavor will be lost due to reduced relevant polyphenols and proteins. Therefore, breeding the malt barley cultivar with lower HA protein and/or HA polyphenols is the most efficient approach for controlling haze formation. Owing to the completion of barley whole genome sequencing and the rapid development of modern molecular breeding technology, several candidate genes controlling haze formation have been identified, providing a new solution for reducing beer haze.