Chemical Characterization and Release of Polyphenols from Pecan Nut Shell [<Emphasis Type="Italic">Carya illinoinensis</Emphasis> (Wangenh) C. Koch] in Zein Microparticles for Bioactive Applications

The pecan nut [Carya illinoinensis (Wangenh) C. Koch] is a natural source of polyphenols with antioxidant properties. In this study, the encapsulation of aqueous and hydroalcoholic extracts of pecan nut shell were evaluated for the release of bioactive compounds and antioxidant potential in order to explore food applications using zein as encapsulating agent. The extracts showed high contents of total phenolics, condensed tannins and high antioxidant activity. Concentrations of proanthocyanidins were 9-fold higher in hydroalcoholic extracts. The LC-DAD analysis showed that catechins were the major phenolic compounds in samples, with epigallocatechin levels up to 138.62 mg mL^?1. Zein microparticles loaded with aqueous extract released 2.3 times more phenolic compounds than the hydroalcoholic extracts and the DSC thermograms showed that extracts of pecan nut shell remained thermally stable up to 240 °C. The zein microcapsules obtained in this study were efficiently encapsulated and represent an interesting additive due its high antioxidant capacity, physicochemical characteristics and morphology. The use of zein microparticles combined with natural extracts constitute a step forward in the improvement of current technology for delivering phenolic compounds with applications in functional foods and nutraceuticals.     

Condensed tannins extraction from grape pomace: Characterization and utilization as wood adhesives for wood particleboard

The extraction of condensed tannins from grape pomace was examined using water medium in the presence of NaOH, Na₂CO₃, NaHCO₃ eventually in the presence of Na₂SO₃. The tannin fractions reactivity towards formaldehyde was studied by gel time analysis and thermomechanical analysis in bending and it was demonstrated that despite of their lower phenolic contents, some of these extracts displayed promising properties for adhesive applications. A resin formulation in which the total content of tannin is 75% of the total resin solids content gave good results and was employed for the elaboration of the first grape pomace based-wood particleboard which passed relevant international standard specifications for interior-grade panels.     

Prediction of total phenols,condensed tannins,and 3-deoxyanthocyanidins in sorghum grain using near-infrared (NIR) spectroscopy

The reported high phenolic levels in sorghum have led an interest from sorghum breeding programs in developing and identifying germplasms with high phenolic levels, which require screening a large number of samples to find those with the highest levels. Since wet chemistry screening methods are slow, expensive, and destructive, the use of NIR calibration curves could be an alternative. The objectives of this project were to determine the variation range in total phenols, condensed tannins, and 3-deoxyanthocyanidin levels in a diverse set of sorghum genotypes and to assess the predictive value of NIR curves to estimate these compounds in sorghum. A calibration curve to estimate each compound was developed and validated with an independent validation set. Calibration curve correlations for total phenols, condensed tannins, and 3-deoxyanthocyanidins were r = 0.98, 0.97, and 0.99, respectively. Correlations between NIR-predicted values and reference values in the validation set were significant for total phenols (r = 0.93), condensed tannins (r = 0.81) and 3-deoxyanthocyanidin (r = 0.82). These indicated that sufficient variation for these compounds existed within sorghum and that NIR calibration curves could be used to rapidly and non-destructively predict total phenols, condensed tannins, and 3-deoxyanthocyanidins concentrations in whole grain sorghum.     

Evaluation of the Relationship Between Bioactive Components in Seaweeds and Advanced Glycation End-Products Inhibitory Activities Using Principal Component Analysis

This study comprehensively presents the relationship between the bioactive substance of 70% (v/v) aqueous ethanol extract of 38 species of seaweeds (SWEs), and anti-glycation activities. The contents of bioactive substance of SWEs, such as total phenolic, total flavonoid and condensed tannins, were determined through a colorimetric analysis. Among the tested species, Ecklonia bicyclis, Ishige foliacea, and Cladophora urightiana var. minor had the highest amount of total phenolic (255.75 mg GAE/g DW), total condensed tannins (63.36 mg CE/g DW), and total flavonoid content (85.26 mg CE/g DW), respectively. Anti-glycation properties of SWEs were evaluated through advanced glycation end-products (AGEs) formation, AGEs-collagen cross-link formation, and AGEs-collagen cross-link breaking assay. Brown algae species exhibited a more prominent inhibitory activity on AGEs formation and AGEs-collagen cross-links, and the breaking of AGEs-collagen cross-links compared to that exhibited by aminoguanidine and ALT-711 (positive controls). Using principal component analysis, we confirmed that the AGEs formation inhibitory property and AGEs-collagen cross-links breaking activity were closely correlated with total phenolic and the condensed tannin contents contained in SWEs. Therefore, the bioactive substances such as phenolics and condensed tannins in seaweeds can be used as predictive indices in selecting compounds for the development of a therapeutic agent that prevents diabetic complications related to the AGEs. In addition, our results suggest that brown algae species, which contains more bioactive substances than green and red algae species, can be utilized as a promising natural resource for the prevention and alleviation of AGEs-related diabetic complications as AGE inhibitor and cross-links breaker.

     

Tannin contents and protein digestibility of black grams (Vigna mungo) after soaking and cooking

The objective of this research was to ascertain the effects of soaking black grams (Cultivar AARI-5732)in different salt solutions at different temperatures and different timeperiods, and different methods of cooking on the tannin content and proteindigestibility. Tannin content of black grams was reduced to variousextents by soaking at 30^° and 100 ^°C for different timeperiods. However, soaking at 100 ^°C increased the rate ofextraction and reduced the extraction time of tannins. Soaking black gramsin water at 100 ^°C reduced tannins by 22.14% in 45 minuteswhereas about 2.5 times more tannin was reduced after soaking in sodiumbicarbonate solution with or without sodium chloride. Maximumimprovement in protein digestibility was also observed after soaking blackgrams in sodium bicarbonate solution. Tannin contents were furtherreduced along with improvement in protein digestibility as a result ofcooking.     

Efficacy of Lawsonia inermis leaves extract and its phenolic compounds against olive knot and crown gall diseases

This study was undertaken to determine the antibacterial efficacy of the leaves extracts of Lawsonia inermis in vitro and in vivo, against the phytopathogenic bacteria Pseudomonas savastanoi pv savastanoi IVIA 1628 and Agrobacterium tumefaciens. The hydroalcoholic extract of L. inermis was fractionated by liquid–liquid partition using hexane, chloroform, ethyl acetate and butanol. Among the tested fractions, the ethyl acetate (EtOAcF) and chloroform (CHCl₃F) extracts exhibited high inhibition against all tested plant pathogens. The extracts exerted a bactericidal activity against both P. savastanoi and A. tumefaciens with MIC values ranging from 1.25 to 2.5 mg/ml. In planta experiments, the EtOAcF, tested at four concentrations (0.4, 0.2, 0.1 and 0.05 mg/wounds), completely inhibited the formation of knots on twigs of olive and tomato plants inoculated with pathogenic strains of P. savastanoi and A. tumefaciens (strains B6 and C58). The phytochemical screening revealed that the L. inermis fractions contain flavonoids, quinones, tannins and terpenoids. The qualitative analysis of the EtOAcF by LC–DAD–ELSD–ESI/MSⁿ showed the presence of eight identified phenolic and phenolic glycoside compounds. These results suggest that L. inermis extracts could be used to control plant bacterial diseases caused by P. savastanoi and A. tumefaciens.     

Assessment of nematicidal properties and phytochemical screening of neem seed formulations using Radopholus similis, parasitic nematode of plantain in Cameroon

Phytoparasitic nematodes of banana and plantain make one of the major constraints to sustainable banana and plantain production. The burrowing nematode, Radopholus similis, common in Cameroon is of particular importance where most smallholder farmers are unaware of this “hidden enemy”. In intensive plantain plantations, nematicides are often used as a primary means of control. Despite their efficacy, chemical pesticides are harmful to the environment and human health. The objective of this study was to assess the nematicidal properties of four neem seed formulations (raw neem seed powder (NSP); organic, watery and essential oil extracts) and to determine the phytochemical properties of these extracts. Alkaloids, saponins, triterpens and steroids were found in all three extracts, tannins in the organic and essential oils extracts and phenols only in the essential oils extract. Using five different concentrations of each of the three extracts as well as NSP, the nematicidal properties of all four formulations was confirmed. The NSP killed 100% of all nematodes at the lowest concentration tested, 10 μg ml⁻¹, after 48 h. The in vivo test using two plantain varieties, Essong and Big Ebanga showed that all neem seed formulations increased plant growth and reduced nematode populations significantly when compared with the control. Since NSP seems to perform as well or even better than the extracts, it could provide farmers with a simple, low cost alternative for the control of banana and plantain nematodes.     

Tannin-based rigid foams: Characterization and modification

Tannin-based rigid foams are networked structures obtained by polycondensations of polyflavonoid tannins and furfuryl alcohol. They present a wide range of characteristics. Thus, there is the need to characterise the different kinds of tannin foams to better understand their physical behaviour and their chemical composition. Mimosa tannin, pine tannin and quebracho tannin bark extracts were used as building blocks. Foams modified by the addition of hydroxymethylated lignin, polyurethane and an industrial surfactant were also characterised. Water absorption, compression resistance, direct flame behaviour and foam cells dimensions were measured for each foam sample. The foams were characterised also by ¹³C NMR analysis. Tannin-based rigid foams appear suitable for a wide range of applications.     

Antioxidant Activities of Four Edible Seaweeds from the Southern Coast of Thailand

The aqueous extracts of four marine algae, Caulerpa racemosa var. macrophysa, Gracilaria tenuistipitata var. tenuistipitata, Sargassum sp., and Ulva lactuca, from the coastal areas in Southern Thailand, were prepared by boiling dried seaweed powder in water for 3 h, and by autoclaving each sample at 120 °C for 3 h. They were then freeze-dried and evaluated for their antioxidant activities using DPPH (1, 1-diphenyl-2-picrylhydrazyl), hydroxyl radical (OH^•) and superoxide anion (O₂^•−) scavenging assays. Boiling extracts of the seaweeds, except C. racemosa, were found to have higher total phenolic contents (TPC) than those obtained from the autoclave method. The antioxidant results also showed that O₂^•− scavenging activity existed only in the boiling extracts of C. racemosa, G. tenuistipitata, and U. lactuca. In DPPH and OH^• assays, however, almost all the boiling extracts were less active than the autoclave ones. Among the four alga species, Sargassum sp. was the most active. Both extracts of this seaweed had the highest TPC and also displayed the strongest DPPH^• and OH^• inhibitory activities. A strong positive-correlation between the antioxidant potency and TPC of the autoclave extracts was found, while for the boiling extracts such relation was very weak. This result thus reflected that in addition to the phenolic compounds, there might be some other active components present in these extracts involved in the antioxidant activity.     

Sorghum and millet phenols and antioxidants

Sorghum is a good source of phenolic compounds with a variety of genetically dependent types and levels including phenolic acids, flavonoids, and condensed tannins. Most sorghums do not contain condensed tannins, but all contain phenolic acids. Pigmented sorghums contain unique anthocyanins that could be potential food colorants. Some sorghums have a prominent pigmented testa that contains condensed tannins composed of flavan-3-ols with variable length. Flavan-3-ols of up to 8–10 units have been separated and quantitatively analyzed. These tannin sorghums are excellent antioxidants, which slow hydrolysis in foods, produce naturally dark-colored products and increase the dietary fiber levels of food products. Sorghums have high concentration of 3-deoxyanthocyanins (i.e. luteolinidin and apigenidin) that give stable pigments at high pH. Pigmented and tannin sorghum varieties have high antioxidant levels that are comparable to fruits and vegetables. Finger millet has tannins in some varieties that contain a red testa. There are limited data on the phenolic compounds in millets; only phenolic acids and flavones have been identified.     

Temporal aspects of onion-induced antiplatelet activity

Organosulfur compounds in onion extracts are formed following thelysis of the S-alk(en)yl-L-cysteine sulfoxides by alliinase. Thesecompounds inhibit the aggregation of human blood platelets and offer thepotential for positive cardiovascular health benefits. An experiment wasdesigned to examine temporal and temperature effects on onion-inducedantiplatelet activity. Platelet aggregation is induced by various agonists,including ADP, collagen, and thrombin. Unexpectedly, all freshly-juicedonion extracts (ca. 5 minutes post-juicing) appeared to exhibit both anagonist-free aggregation peak (AFP) and a platelet inhibitory peak (PIP)characteristic of inhibition of platelet aggregation. The AFP was minimalby 30 minutes and dissipated in all treatments by 120 minutes, whilethe PIP increased as onion extracts aged and did not change after 30minutes at 25 ^°C. This finding confirms the observation that the in vitro platelet inhibitory activity of onion organosulfur compounds istime dependent. Freshly-prepared onion extracts were incubated with theADP scavenger enzyme apyrase (E.C. 3.6.1.5). AFPs were abolished inapyrase-treated extracts, suggesting that this response may have been dueto free ADP in onion extracts, although an amount of ADP required togenerate such a response would be unexpected in onion extracts. Inaddition, platelet aggregates were not observed in the AFP, suggesting thisresponse may be associated with changes in light transmission throughplatelet rich plasma that are not associated with platelet aggregation.Artifacts of analysis are, therefore, possible when assessing onion-inducedantiplatelet activity with freshly-juiced extracts. Temporal formation ofplatelet-inhibiting organosulfur compounds should be taken into accountduring both in vitro and in vivo assessment of onion-inducedantiplatelet activity.     

Comparative assessment of antioxidant and cholinesterase inhibitory properties of the marigold extracts from Calendula arvensis L. and Calendula officinalis L.

Calendula sp. is an important medicinal and industrial plant with various bioactivities. In this study, we examined enzyme inhibitory effects of the n-hexane, dichloromethane, acetone, ethyl acetate, methanol, and water extracts of the leaf and flowers of Calendula arvensis L. and C. officinalis L. against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). The extracts were screened for their antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric ion-chelating capacity and ferric-reducing antioxidant power (FRAP) assays at 250, 500, and 1000 μg mL⁻¹. Total phenol and flavonoid quantification of the extracts was achieved using Folin-Ciocalteau and AlCl₃ reagents, respectively. The ethyl acetate extract of C. arvensis flowers was the most active in AChE inhibition assay (31.24 ± 1.29%), while the n-hexane extract of C. officinalis leaves exerted the highest ferric ion-chelating capacity (74.27 ± 2.25%). Thin layer chromatographic analysis indicated presence of flavonoid and triterpene derivatives mainly in the extracts.     

Physicochemical assessment and bioactive properties of condensed distillers solubles,a by-product from the sorghum bio-fuel industry

Large volumes of condensed distillers solubles (CDS) are generated as by-products, from the sorghum bioethanol industry. The objective was to assess the physico-chemical and bioactive properties of CDS. The unfractionated CDS showed the highest content of phenolic compounds (16 mg GAE/g), antioxidant (522 μM Trolox/g) and antimicrobial activity (MIC 1%(w/v) against Campylobacter spp.) compared to its extracts. The water and methanol extracts also showed high levels of phenolic compounds and antioxidant activity (11.6 and 9.2 mg GAE/g and 349 and 409 μM Trolox/g respectively), followed by ethanol and acetone extractions (7.5 and 6.6 mg GAE/g; 337 and 346 μM Trolox/g respectively). A positive correlation was revealed between total phenol and antioxidant activity. The main phenolic compounds found in the extracts were protocatechuic acid, 4-hydroxybenzoic acid, taxifolin, ferulic acid, cinnamic acid and p-coumaric acid. This study indicates the potential of using CDS as a functional ingredient for other food and feed applications.     

Yield, persistency and chemical composition of Lotus species and varieties (birdsfoot trefoil and greater birdsfoot trefoil) when harvested for silage in the UK

The yield and chemical composition of thirteen Lotus corniculatus varieties and one Lotus uliginosus variety, when grown and ensiled in the UK, were investigated. Replicate plots of each variety were established in a randomized block design. Dry‐matter (DM) yield was measured over two harvest years. At cuts 1 and 2 of the first harvest year, 1 kg of each variety was ensiled and sub‐sampled for chemical analysis. At cut 2 of the second harvest year, sub‐samples of forage were analysed for condensed tannins. Two L. corniculatus varieties, Oberhaunstaedter and Lotar, had higher DM yields (with Oberhaunstaedter having the highest DM yield at cut 3) in both harvest years compared with other varieties (P < 0·001). Chemical analyses showed differences among silages of varieties of L. corniculatus (P < 0·001) and that the ammonia‐N concentration of L. uliginosus silage was higher than that of L. corniculatus (P < 0·001), despite its lactic acid concentrations being within the range observed for L. corniculatus (17 g kg^?1 DM vs. 13–19 g kg^?1 DM). Differences (P < 0·001) in HCl/Butanol test absorbance units were found among varieties of L. corniculatus, indicating possible differences in concentrations of condensed tannins. Overall, the variety Oberhaunstaedter was found to be the most suitable variety for silage production. Based on its agronomic performance, L. corniculatus does not compare well with other legumes such as red clover.     

Effects of Pressurized Low Polarity Water Extraction Parameters on Antioxidant Properties and Composition of Cow Cockle Seed Extracts

Antioxidant activity of pressurized low polarity water (PLPW) extracts of cow cockle seed and extraction residues were determined using DPPH, ABTS, and FRAP assays. The effect of extraction conditions (temperature (125, 150 and 175 °C) and time) on the antioxidant activity and the relationship amongst the antioxidant activity and extract composition (total phenolics and saponin content) were determined. The antioxidant activity of PLPW extracts increased with extraction temperature. Increasing activity with time was also observed at 175 °C. PLPW extraction residues had the highest activity suggesting antioxidant compounds were not completely extracted by PLPW. Antioxidant activity correlated well with total phenolics content of samples (R ² ≥ 0.94), however no correlation was observed with the saponin content. A strong correlation was observed between the antioxidant activity values obtained using different methods (R ² ≥ 0.94). These results point to the potential of PLPW extraction as a method to modify the activity of biological materials for the production of customized extracts.     

In vitro fermentation patterns and methane production of sainfoin (Onobrychis viciifolia Scop.) hay with different condensed tannin contents

Sainfoin (Onobrychis viciifolia Scop.) is a perennial legume recently reappraised for some positive characteristics leading to highly satisfactory animal performance. Sainfoin’s characteristics may be partly explained by the presence of moderate levels of condensed tannins (CTs) able to protect dietary protein from microbial degradation in the rumen. Decreased CH₄ emissions have been reported for ruminants consuming CT‐containing forage. The aim of this study was to evaluate the effects of CT content on the in vitro fermentation characteristics and kinetics and methane production of four samples of O. viciifolia cut at different phenological stages. Sainfoin hays and one sample of alfalfa hay were incubated at 39°C in anaerobiosis using the in vitro gas production technique. The chemical composition, tannin content and fermentation characteristics and kinetics of sainfoin samples were significantly affected by phenological stage. After 48 h, the CH₄ production in sainfoin hays showed a tendency to increase with the advancement of phenological stage [from 38·6 to 49·8 mL g⁻¹ of degraded organic matter (OM)]. The best period to cut sainfoin for hay making is between early and late flowering, when the forage combines high OM digestibility, low CH₄ production and more efficient microbial fermentation.     

Anti-nutritive constituents in oilseed crops from Italy

Eight different oilseed crops (Brassica carinata, Camelina sativa, Coriandrum sativum, Euphorbia lagascae, Lepidium sativum, Lesquerella fendleri, Madia sativa, Vernonia galamensis) grown in Italy were investigated regarding anti-nutritive compounds, such as glucosinolates, sinapine, inositol phosphates and condensed tannins, which can adversely affect the nutritional value of residues from the oilseed processing. In all seeds at least one anti-nutritive compound was found, which possibly could lower the nutritive value, but in most cases a real negative effect is not to be expected. The existence and the concentration of the different anti-nutritive components varied in the different seeds. Glucosinolates and sinapine were found only in seeds of B. carinata, L. sativum, C. sativa and L. fendleri, whereas condensed tannins and inositol phosphates appeared in all seeds. In the different seeds the amount ranged from 0.2 mg/g (L. fendleri) to 13.1 mg/g (L. sativum) for sinapine, from 0.4 mg/g (E. lagascae) to 19.6 mg/g (L. fendleri) for condensed tannins, from 6.6 mg/g (E. lagascae) to 23.1 mg/g (B. carinata) for inositol hexa-phosphate as well as from 18.7 μmol/g (C. sativa) to 164.6 μmol/g (L. sativum) for glucosinolates.     

Antioxidant properties of wheat and rye bran extracts obtained by pressurized liquid extraction with different solvents

Rye and wheat brans are valuable sources of bioactive compounds, which could be used for the development and commercialization of high added value functional ingredients such as dietary antioxidants. The aim of this study was to evaluate antioxidant potential of rye and wheat bran using different polarity solvents. Cereal brans were ground to four different particle size fractions and extracted at 10.3 MPa pressure and 80 °C temperature by consecutive application of hexane, acetone and methanol:water (80:20%). The highest extract yield was obtained from rye bran using methanol-water; particle size in most cases had a significant effect. Antioxidant potential of extracts was assessed by ABTS^+•, DPPH^• scavenging, ORAC and total phenols content (TPC) assays. Extraction solvent had a major influence on TPC and antioxidant activity of the extracts. The most active extracts were obtained using methanol:water; rye bran extracts, in general, were stronger antioxidants than wheat bran extracts. For the majority of assays, reduction of particle size resulted in higher antioxidant activity values. However, ABTS^+• scavenging was found to decrease by decreasing particle size of rye bran used for extraction.     

Evaluation of phenolics and antioxidant activity of black sorghum hybrids

Black sorghums possess very high levels of the rare 3-deoxyanthocyanidins which can be used as natural food colorants with health benefits. However, these sorghum genotypes have undesirable agronomic properties (i.e. high height, low yield, increased weathering). Black sorghum hybrids with improved agronomic properties were developed and their phenolic profiles and antioxidant activity were compared with black sorghum lines. Black sorghum hybrids were significantly lighter in colour than the lines (P < 0.001). All hybrids had a pigmented testa which was indicated by the presence of condensed tannins, which significantly increased total phenol levels and antioxidant activity. The 3-deoxyanthocyanidin, flavan-4-ol, and flavone levels were significantly lower in the hybrids (P < 0.001) and were strongly correlated to pericarp colour (P < 0.001). Flavanone levels were not significantly different among the lines and hybrids (P > 0.05) and pericarp colour did not affect their levels (P > 0.05). Even though the 3-deoxyanthocyanidin levels were lower in black sorghum hybrids than in the lines, the presence of condensed tannins in the hybrids significantly increased their antioxidant activity. Since 3-deoxyanthocanidin levels were dependent on pericarp colour, hybrids with increased blackness intensity should be developed to increase the stable 3-deoxyanthocyanidins.     

Evaluation of grape stalks as a bioresource

The compositional characteristics of grape stalk in terms of lignin, sugars, ash, extractives and tannins contents were established. The biomass composition of grape stalk is 34% lignin, 36% cellulose, 24% hemicellulose and 6% tannins. The tannins, analysed by solution ¹³C NMR, were essentially of procyanidin type and the dichloromethane extractives fraction, characterized by GC-MS, was mainly composed of fatty acids. Different processes for the pretreatment of grape stalk were compared. Due to the high content of lignin and tannins, dilute sulfuric acid and ethanol organosolv pretreatments resulted in a low degree of delignification. However, a wet oxidation process permitted a significant reduction of the Klason lignin content of the pulp with a good carbohydrate recovery and improved enzymatic digestibility.