Condensed Tannin Content Research Articles

In vitro nutritional quality and antioxidant activity of three weed species as feed additives for sheep in the Central Highlands of Mexico.

Sheep production is traditional for rural communities in Mexico, based on natural grasslands and semi-stabled feeding. Quality forages are necessary to improve productivity in these systems. Weeds are an alternative to feed ruminants and to manage crops. Also, many plants have secondary metabolites beneficial for livestock. The objective was to assess the nutritive value in vitro and the antioxidant activity of three weeds (Tithonia tubiformis, Cosmos bipinnatus, and Tagetes lucida) and four treatments (T0 = control diet, T1 = diet + 5% T. tubiformis, T2 = diet + 5% C. bipinnatus, and T3 = diet + 5% T. lucida). Nutritive value was determined from chemical composition by standard methods and mineral contents by inductively coupled plasma analyses. Secondary compounds, total phenols (TP), total tannins (TT), condensed tannins (CT), and phenolic compounds, were determined by high-performance liquid chromatography, and total antioxidant activity was determined by measuring the oxygen radical absorbance capacity. Rumen fermentation kinetics and in vitro digestibility of dry matter (IVDMD), organic matter (IVOMD), and neutral detergent fibre (IVNDFD) were determined per species and treatment by in vitro gas production. T. tubiformis had the highest CP and TP contents (P < 0.05), and C. bipinnatus had the highest fibre and CT contents (P < 0.05). Inclusion of T. lucida in the diet resulted in an 18% increase in TP content and a 30% increase in antioxidant activity in comparison to the control diet. No significant differences (P > 0.05) were found in rumen kinetics parameters, IVDMD, IVOMD, IVNDFD, or metabolizable energy, indicating that the tested weeds can be used as additives to increase antioxidant activity in sheep diets without negative effects.

The condensed tannin chemistry and astringency properties of fifteen Vitis davidii Foex grapes and wines

This study sought to determine the effects of variety on the astringency and chemistry of condensed tannins of spine grapes and wines. Fifteen varieties of red spine grape (Vitis davidii Foex) were used. Condensed tannin content, composition, and wine astringency were determined. The condensed tannin profiles were assessed by high-performance liquid chromatography coupled with diode array detector (HPLC-DAD). The condensed tannin content highly depended on the variety ranging from 0.30 mg/g to 7.80 mg/g (in skins), from 3.12 mg/g to 8.82 mg/g (in seeds), and from 62.60 mg/L to 225.90 mg/L (in wines). There were significant differences in proportions of certain constitutive subunits (as mole%) and mean degree of polymerization (mDp) among the varieties. Correlation analysis revealed that condensed tannin concentration and composition had a significant effect on the sensory evaluation and quantitative analysis of astringency. A positive correlation between mDp and astringency was also observed. The present results expand knowledge of the characterization of spine grape and wine condensed tannin chemistry and astringency.

Factors Affecting Foliar Oregonin and Condensed Tannin in Red Alder (Alnus rubra Bong.): Phytochemicals Implicated In Defense Against Western Tent Caterpillar (Malacosoma californicum Packard).

Past work shows a significant negative correlation between foliar oregonin concentration and western tent caterpillar (Malacosoma californicum Packard) feeding on red alder (Alnus rubra Bong.). Above an oregonin threshold of 20% leaf dry weight, little feeding by caterpillars is observed. Concentrations of defensive chemicals are influenced by plant genotype, environmental conditions, insect feeding, and the interactions of these factors. Our objective was to measure the effects of nitrogen (N) availability and wounding on foliar oregonin and condensed tannin concentrations in red alder genotypes. One-year-old seedlings from 100 half-sib red alder families were treated with two levels of ammonium nitrate (NH4NO3) for two growing seasons in a common garden. In the second year, leaves from 50 families from the fertilization experiment were used in a bioassay feeding experiment to determine the effects of N fertilization and genotype on WTC damage, and to identify a subset of 20 families with a range of damage to analyze for phytochemical composition. In separate experiments, wound-induction treatments were conducted outdoors and, in a greenhouse using the N treated trees in their third and fourth year, respectively. Foliar condensed tannin, oregonin and N concentrations were measured and ranked among the plant genotypes, and between the two N treatments and two wounding treatments. Results showed that oregonin and condensed tannin concentrations varied among the alder genotypes. Leaf N concentration was negatively correlated with concentration of oregonin. Neither of the measured phenolic compounds responded to wounding. The results suggest that red alder foliar oregonin and condensed tannin are likely constitutive defenses that are largely determined by genotype, and that the negative correlation of defense compounds with plant internal N status holds in this N-fixing tree.

Chemical Analysis and Anthelmintic Activity Against Teladorsagia Circumcincta of Nordic Bark Extracts In vitro.

Helminth parasitic infections are common in small ruminants in Norway; infection is usually treated with anthelmintic drugs, but anthelmintic resistance is an increasing problem. It is necessary to identify strategies to reduce the use of anthelmintic drugs and mitigate the impact of anthelmintic resistance. Condensed tannin (CT)-rich forages have been shown to reduce the helminth burden in small ruminants, but these forages have limited cultivation potential in Scandinavia. A good source for CT in cold climatic regions may be the bark of several commercially utilized tree species. In the present study, we determined the content and characterized the type of CT in bark extracts of pine (Pinus sylvestris L.), spruce (Picea abies L.), and birch (Betula pubescens). Extracts of selected bark samples were tested for their anthelmintic efficacy against the ovine infectious nematode Teladorsagia circumcincta. Total CT content was higher in the bark from younger (10–40 years old) pine and spruce trees; it decreased with tree age in pine, whereas it remained relatively stable in the bark of spruce and birch. Pine trees consisted of 100% procyanidins, whereas prodelphinins were present in most spruce (4–17%) and all birch samples (5–34%). Our studies clearly showed that there is variation in the anthelmintic activity of water and acetone extracts of bark samples collected from various sites around Norway, as this was measured with two independent in vitro assays, the egg hatch and larvae motility assays. The anthelmintic activity of some extracts was consistent between the two assays; for example, extracts from the three samples with the highest CT content showed very high activity in both assays, whereas the extract from the sample with the lowest CT content showed the lowest activity in both assays. For other extracts, activity was not consistent across the assays, which could be attributed to the susceptibility of the different stages of the parasitic life cycle. We demonstrated that bark extracts from commercially used trees in Scandinavia have the potential to be used as alternatives to anthelmintics. Further work should focus on refining the associations between bark extracts and anthelmintic activity to identify the best strategies to reduce the input of anthelmintic drugs in livestock production systems.

Condensed tannin content and antioxidant activity of Hungarian sorghum varieties grown at Research Institute in Karcag

Cereal-based products are one of our main energy sources, and are consumed on a daily basis. One of the weaknesses of wheat based products is their low antioxidant content. Sorghum is a minor cereal, mostly consumed in Africa and Asia. Amongst other phenolic components it contains tannins, which are potent antioxidants and have other positive effect on human health, for example anti-tumor, anti-inflammatory and anti-viral/bacterial effect. We evaluated the tannin content (vanillin-HCL) and antioxidant capacity (DPPH) of sorghum varieties (Alföldi1, Zádor, Foehn, Albita, Albanus) grown in Hungary, with two type of agronomy technology.. Red varieties especially Alföldi1 and Zádor had higher tannin contents than white varieties. The highest condensed tannin content was 1470±73 mg 100g-1 (Control, Alföldi1), 1810±154 mg 100g-1 (Fertilized, Alföldi1), and the highest total antioxidant capacity was 2099±19 mg 100g-1 (Control, Alföldi1) and 2117±26 mg 100g-1 (Fertilized, Alföldi) We found that sorghum type, variety and color influence their tannin and antioxidant contents in general.

Phytochemical Screening, Total Phenolics Contents and in vitro Antioxidant Activity of Salvia officinalis, Satureja calamintha, Mentha pulegium and Marrubium vulgare

This study was designed to evaluate the antioxidant activity of phenolic compounds of for Lamiaceae: Salvia officinalis, Satureja calamintha, Mentha pulegium and Marubium vulgare using ferric reducing power (FRAP) and radical scavenging method (DPPH). Preliminary phytochemical analysis shows that the major constituents of crude extracts (Hydromethanolic, hydroacetonic) are tannins, saponins, quinones, flavonoids, terpenoids and reducing compounds in the four plants. In quantitative analysis, variable polyphenols, flavonoids and condensed tannins content are recorded. The highest polyphenols content is that of the aqueous/methanol crude extract of Salvia officinalis (188.92 ± 1.19 mg GAE/ gE), followed by aqueous/acetone crude extract of Mentha pulegium (176.55 ± 2.49 mg GAE/gE). Flavonoids and condensed tannins content of crude extract showing a high content in aqueous/methanol extract of Mentha pulegium and Satureja calamintha (93.64 ± 0.26mg EQC/gE and 25.44 ± 0.71 mg EQC/gE), respectively. Scavenging activity of the free radical DPPH, revealed that the aqueous/methanol extract of Salvia officinalis shown a relatively high antioxidant activity (IC50 = 1.07 μg/ml) compared with ascorbic acid (IC50 = 0.91 μg/ml). FRAP method revealed that the extracts of Mentha pulegium showed the highest power to reduce iron (EC50 = 0.147 mg/ml), but lower than that of ascorbic acid (EC50 = 0.057 mg/mL).

Replacing Alfalfa with Paper Mulberry in Total Mixed Ration Silages: Effects on Ensiling Characteristics, Protein Degradation, and In Vitro Digestibility.

Simple SummaryThe usage of alfalfa (Medicago sativa L.) as a dietary protein source for ruminants in China is limited by forage quality and planting scale. Paper mulberry (Broussonetia papyrifera L., RY) has emerged as a new and representative high-protein woody forage resource for ruminants. However, information is less available regarding how substituting RY for alfalfa affect the fermentation and protein quality in total mixed ration (TMR) silages. This study evaluated ensiling characteristics, protein quality, and in vitro digestibility in TMR silages by mixing RY with alfalfa at different rations. The TMR were made with alfalfa and RY mixtures (36.0%), maize meal (35.0%), oat grass (10.0%), soybean meal (7.5%), brewers’ grain (5.0%), wheat bran (5.0%), premix (1.0%), and salt (0.5%) on a dry matter basis, respectively. The alfalfa and RY mixtures were made in the following ratios of dry matter: 36:0 (RY0), 27:9 (RY9), 18:18 (RY18), 9:27 (RY27), and 0:36 (RY36). The results showed that RY substitution had no adverse effect on fermentation quality and nutritional composition, but inhibited true protein degradation, while decreasing in vitro dry matter and crude protein digestibility. Therefore, RY and alfalfa mixtures at a ratio of 18:18 is suitable for silage-based TMR.To develop an alternative high-protein forage resource to alleviate ruminant feed shortages, we investigated the effects of replacing alfalfa (Medicago sativa L.) with different ratios of paper mulberry (Broussonetia papyrifera L., RY) on fermentation quality, protein degradation, and in vitro digestibility of total mixed ration (TMR) silage. The TMR were made with alfalfa and RY mixtures (36.0%), maize meal (35.0%), oat grass (10.0%), soybean meal (7.5%), brewers’ grain (5.0%), wheat bran (5.0%), premix (1.0%), and salt (0.5%) on a dry matter basis, respectively. The alfalfa and RY mixtures were made in the following ratios of dry matter: 36:0 (RY0), 27:9 (RY9), 18:18 (RY18), 9:27 (RY27), and 0:36 (RY36). After ensiling for 7, 14, 28, and 56 days, fermentation quality, protein degradation, and microbial counts were examined, and chemical composition and in vitro digestibility were analyzed after 56 days of ensiling. All TMR silages, irrespective of the substitution level of RY, were well preserved with low pH and ammonia nitrogen content, high lactic acid content, and undetectable butyric acid. After ensiling, the condensed tannin content for RY18 silages was higher than the control, but non-protein nitrogen, peptide nitrogen, and free amino acid nitrogen contents was lower, while the fraction B1 (buffer-soluble protein) was not different among all the silages. Dry matter and crude protein digestibility for RY27 and RY36 silages was lower than the control, but there was no difference between control and RY18 silages. This study suggested that ensiling RY with alfalfa inhibited true protein degradation, but decreased in vitro dry matter and crude protein digestibility of TMR silages, and that 18:18 is the optimal ratio.

Enhanced Recovery of Phenolic and Tocopherolic Compounds from Walnut (Juglans Regia L.) Male Flowers Based on Process Optimization of Ultrasonic Assisted-Extraction: Phytochemical Profile and Biological Activities.

The extraction of bioactive compounds present in walnut (Juglans regia L.) male flowers (WMFs) was performed based on an experimental design using ultrasonic-assisted extraction. Solvent nature, extraction time, and water content were selected as experimental variables, and phenolic, flavonoidic, and condensed tannins contents and antioxidant properties were evaluated. Acetone was the solvent with the highest extraction performance, with the extracts obtained using this solvent displaying an increased concentration of bioactive compounds and increased antioxidant activities. For several extracts with high bioactive content, individual polyphenolic and tocopherolic compounds were evaluated by means of LC-MS and LC-MS/MS. The best extraction conditions for polyphenolic (2.86 mg gallic acid equivalents/g WMF) and tocopherolic compounds (29.4 µg/g WMF) were acetone with 40% water content (N20) and acetone with 20% water content (N15), respectively. Although the total tocopherol concentrations were lower than in other Juglans regia parts, most of the total tocopherol quantity was provided by the highly biologically active δ-tocopherol (84%). Significant quantities of quercetin (101.9 µg/g), hyperoside (2662.9 µg/g), quercitrin (405.7 µg/g), and isoquercitrin (1293.7 µg/g) were determined in WMF (N20). Both extracts inhibited the enzymatic activity of α-glucosidase and tyrosinase; however, an increased inhibition was observed for N20, the extract with the higher polyphenolic content. Conversely, N15 had higher anticancerous activity on the cell lines used, with a moderate selectivity towards the cancerous phenotype being observed for both extracts. At non-cytotoxic concentrations, both extracts displayed good antioxidant activities in cellular cultures, decreasing basal and H2O2-induced oxidative stress. This is the first characterization of both hydrophilic and lipophilic phytochemicals in WMF extracts. The outcomes of our study reveal that walnut male flowers have strong biological activities, thus justifying further research to demonstrate their usefulness in the food, pharmaceutical, and/or cosmetic industries.

Estimation of proximate and chemical composition of locally available tropical tree leaves

Present study was carried out to analyse the proximate and chemical composition of five tropical tree leaves which are locally available in and around Krishna District. The trees selected for analysis were Psidium guajava, Musa paradisiaca, Acacia nilotica,Moringa oleifera, Azadirachta indica. Among the analysed samples Moringa oleifera leaves have highest CP content (20.15%) where as Psidium guajava have lowest CP content (6.92%) on dry matter basis. Phenol, tannin and condensed tannin content of all the leaves were analysed in the present study. Phenol content was ranged from 6.93 to 17.51% in the estimated samples. Among all the tree leaves Psidium guajava leaves have highest condensed tannin (10.7%) content, while Musa paradisiaca has lowest condensed tannin (4.2%) content. From the study it was concluded that these tree leaves were not only rich in crude protein also have high concentrations of secondary metabolites (phenols, tannins, CT) which help in improvement of growth when they are included in the animal diet.

The Total Antioxidant Capacity and the Total Phenolic Content of Rice Using Water as a Solvent

Background The present study evaluates the antioxidant properties of some Sri Lankan red rice varieties using water extracts. Methods Water extracts of rice varieties Attakkari, Bg2907, and Bg407 were used in this study. The total antioxidant capacity was measured by ferric reducing antioxidant power (FRAP), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, and reducing power assays. The total phenolic content (TPC), total flavonoid content (TFC), monomeric anthocyanin, and condensed tannin contents were measured by Folin-Ciocalteu, aluminium chloride, pH differential, and vanillin assays, respectively. Results It was observed that mean FRAP, DPPH, reducing power, TPC, TFC, monomeric anthocyanin content, and condensed tannin content were in the range of 0.561 ± 0.113 to 0.695 ± 0.077 mmol/100 g fresh weight (FW), 26.07 ± 3.08 to 53.66 ± 7.61 mg/mL FW, 33.49 ± 4.105.14 to 40.81 ± 3.65 mg/mL, 0.676 ± 0.078 to 0.900 ± 0.057 mg tannic acid equivalent (TAE)/g, 5.36 ± 0.75 to 6.38 ± 0.82 mg TAE/g FW, 0.0202 ± 0.005 to 0.0292 ± 0.009 mg/g FW, and 0.078 ± 0.015 to 0.104 ± 0.017 mg TAE/g FW, respectively. Significant differences were observed in DPPH, reducing power, and TPC among rice varieties (p < 0.05). Rice variety Attakkari had the highest total antioxidant capacity (TAC), scavenging activity, reducing power, TPC, TFC, monomeric anthocyanin content, and condensed tannin content followed by Bg2907 and Bg406. Conclusion Total phenolic compounds, total flavonoid, and condensed tannin are the major antioxidants in all three varieties of rice while the monomeric anthocyanin is only a minor antioxidant.

Identification of Methylxanthines and Phenolic Compounds by UPLC-DAD-ESI-MS OTOF and Antioxidant Capacities of Beans and Dark Chocolate Bars from Three Trinitario×Forastero Cocoa (Theobroma cacao L.) Hybrids

Interest on Trinitario cocoa has continuously increased due to the fact that some genotypes of this group had inherited some characters of vigorosity from Forastero and the flavor grade of Criollo. The pronounced incompatibility between Trinitario clones orientates research on the crossing of Trinitario clones with other varieties of cocoa in order to increase productivity and cocoa beans quality. Polyphenols and methylxanthines are bioactive compounds responsible for the health benefits of cocoa and cocoa based products. Cocoa is a crop with a high content of bioactive compounds in the plant kingdom. This study aims at correlating genotypes, methylxanthines and polyphenols as well as antioxidant activity of beans and dark chocolate derived from Trinitario&amp;times;Forastero hybrids. Total polyphenol content and total condensed tannin contents were determined by spectrophotometric methods. Individual bioactive compounds were identified by UPLC-DAD-ESI(+)-MS both in beans and dark chocolate bar. Results showed differences within beans of dark chocolate and between beans and dark chocolate. Beans from the hybrid (♀)SNK10&amp;times;(♂)IMC67 recorded the highest polyphenol content (49.18&amp;plusmn;1.55mg CatE/g) considering the two matrices. The highest concentration of condensed tannins (22.81&amp;plusmn;0.69 mgCatE/g) was recorded in beans obtained from the hybrid (♀)ICS40&amp;times;(♂)UPA134. Dark chocolate bar from beans of the hybrid (♀)ICS40&amp;times;(♂)UPA134 was the richest in condensed tannins (18.25&amp;plusmn;0.71 mg CatE/g). The total polyphenol and total condensed tannin contents, the chemical composition as well as the antioxidant activity could be genotype-dependent and were affected negatively during roasting. In fact, roasting decreased the polyphenol content and consequently the antioxidant activity. (-)-epicatechin, theobromine, ferulic and chlorogenic acids and their derivatives, procyanidin C1, caffeine and salicylic acid 3-O-glucose/galactose were identified in beans and/or dark chocolate.

Root Secondary Metabolites in Populus tremuloides: Effects of Simulated Climate Warming, Defoliation, and Genotype.

Climate warming can influence interactions between plants and associated organisms by altering levels of plant secondary metabolites. In contrast to studies of elevated temperature on aboveground phytochemistry, the consequences of warming on root chemistry have received little attention. Herein, we investigated the effects of elevated temperature, defoliation, and genotype on root biomass and phenolic compounds in trembling aspen (Populus tremuloides). We grew saplings of three aspen genotypes under ambient or elevated temperatures (+4-6°C), and defoliated (by 75%) half of the trees in each treatment. After 4months, we harvested roots and determined their condensed tannin and salicinoid (phenolic glycoside) concentrations. Defoliation reduced root biomass, with a slightly larger impact under elevated, relative to ambient, temperature. Elevated temperature decreased condensed tannin concentrations by 21-43% across the various treatment combinations. Warming alone did not alter salicinoid concentrations but eliminated a small negative impact of defoliation on those compounds. Graphical vector analysis suggests that effects of warming and defoliation on condensed tannins and salicinoids were predominantly due to reduced biosynthesis of these metabolites in roots, rather than to changes in root biomass. In general, genotypes did not differ in their responses to temperature or temperature by defoliation interactions. Collectively, our results suggest that future climate warming will alter root phytochemistry, and that effects will vary among different classes of secondary metabolites and be influenced by concurrent ecological interactions such as herbivory. Temperature- and herbivory-mediated changes in root chemistry have the potential to influence belowground trophic interactions and soil nutrient dynamics.

Feed Evaluation Based on in Vitro Gas Production of Tropical Forages with Addition of Different Polyethylene Glycol (Peg) Level

This study aimed to determine the chemical composition and gas production based on fermentation in the rumen of nine types of forage tropical feed commonly used in Indonesia. The forages used in this study were: mahogany leaves (Swietenia mahagoni L. Jacq.), tayuman leaves (Bauhinia purpurea), bamboo leaves (Bambusa arundinaceae), canary leaves (Canarium indicum L.), tea leaves (Camellia sinensis), ketapang leaves (Terminalia catapa L.), lamtoro leaves (Leucaena leucocephala), tehtehan leaves (Duranta repens), and turi leaves (Sesbania grandiflora). Measurements of in vitro gas production were carried out at 10 observation points (2, 4, 6, 8, 12, 16, 24, 36, 48, 72 hour). Tannin activity was measured for each sample at observation points using measurements of gas production divided into three groups with modified levels of polyethylene glycol (PEG), ie samples without PEG (P1); sample + PEG in the amount of 200 mgDM (P2); and PEG + samples of tannins contained in each forage based on literature studies (P3). Data were analyzed for a variance by following the factorial completely randomized design (CRD) pattern. Statistical analyzes were performed on all data by following the general linear procedure in PROC GLM from SAS. The data obtained were analyzed for variance at the 5% significance level. The results of gas production calculations showed that crude protein (CP) from each forage ranges from 5.75 - 22.37% where the highest CP was owned by turi leaves (S. grandiflora). The content of crude fiber (CF) ranged from 5.30 - 20.93%. The most optimal measurement of gas production was in the sample given PEG in the amount of 200mg/kg with a significant difference (P&lt;0.05). The higher of the tannin content contained in the forage, the lower of gas produced. Measurement of tannin content showed that condensed tannin content varied from turi leaves by 0.20% to the highest in mahogany leaves by 8.60%. The addition of 200 mg/100mgDM of PEG optimizes the rate of forage gas production, especially for grass plants (gramineae).

Antioxidant activity and laxative effects of tannin-enriched extract of Ecklonia cava in loperamide-induced constipation of SD rats.

To investigate the role of tannin-enriched extracts of Ecklonia cava (TEE) on the regulation of oxidative balance and laxative activity in chronic constipation, we investigated alterations after exposure to TEE, on constipation phenotypes, muscarinic cholinergic regulation, and oxidative stress responses in the transverse colons of SD rats with loperamide (Lop)-induced constipation. This extract contains high levels of total condensed tannin content (326.5 mg/g), and exhibited high inhibitory activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals. TEE treatment induced significant improvements in reactive oxygen species (ROS) production, superoxide dismutase (SOD) expression and nuclear factor erythroid 2-related factor 2 (Nrf2) phosphorylation in primary smooth muscles of rat intestine cells (pRISMCs) and transverse colon of constipation model. Also, Lop+TEE treated groups showed alleviated outcomes for the following: most stool parameters, gastrointestinal transit, and intestine length were remarkably recovered; a similar recovery pattern was observed in the histopathological structure, mucin secretion, water channel expression and gastrointestinal hormones secretion in the transverse colon; expressions of muscarinic acetylcholine receptors M2/M3 (mAChR M2/M3) and their mediators on muscarinic cholinergic regulation were significantly recovered. Taken together, these results provide the first evidence that TEE stimulates oxidative stress modulation and muscarinic cholinergic regulation when exerting its laxative effects in chronic constipation models.

Effects of Large-Scale Nitrogen Fertilization on Insect–Plant Interactions in the Canopy of Tall Alder Trees with N2-Fixing Traits in a Cool Temperate Forest

Nitrogen (N) deposition is expected to influence forests. The effects of large-scale N fertilization on canopy layer insect–plant interactions in stands of tall, atmospheric nitrogen (N2)-fixing tree species have never been assessed. We conducted a large-scale fertilization experiment (100 kg N ha−1 year−1 applied to approximately 9 ha) over three years (2012–2014) in a cool temperate forest in northern Japan. Our goal was to evaluate relational responses between alder (Alnus hirsuta [Turcz.]) and their insect herbivores to N deposition. Specifically, we assessed leaf traits (N concentration, C:N ratio, condensed tannin concentration, and leaf mass per unit area (LMA)) and herbivory by three feeding guilds (leaf damage by chewers and the densities of gallers and miners) between the fertilized site and an unfertilized control. Fertilization led to increased galler density in spring 2013 and increased leaf damage by chewers in late summer 2014. For leaf traits, the LMA decreased in spring 2013 and late summer 2014, and the C:N ratio decreased in late summer 2013. The N and condensed tannin concentrations remained unchanged throughout the study period. There was a negative correlation between LMA and leaf damage by chewers, but LMA was not correlated with galler density. These results show that large-scale N fertilization had a positive plant-mediated (i.e., indirect) effect on leaf damage by chewers via a decrease in LMA in the canopy layer. Changes in physical defenses in canopy leaves may be a mechanism by which N fertilization affects the herbivory in tall N2-fixing trees.

Correlation of Total Polyphenolic Content with Antioxidant Activity of Hydromethanolic Extract and Their Fractions of the Salvia officinalis Leaves from Different Regions of Morocco

The purpose of this study is to determine the total content of phenols, flavonoids, and condensed tannins, as well as on the antioxidant activity of the extract, and their fractions were measured by 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP), phosphomolybdate reduction (or total antioxidant capacity), and cyclic voltammetry (CV). The hydromethanolic extract of Salvia officinalis showed the highest values of total phenolic (176 mgGAE/g of extract) and condensed tannins (162.53 mgEC/g of extract) from the Boulemane and Khenifra regions, respectively. The results showed that the best DPPH assay was found in the ethyl acetate fraction of Salvia officinalis leaves of the Boulemane region (IC50 = 0.002 mg/ml). For the ethyl acetate and butanolic fractions of Salvia officinalis leaves, those collected from different regions have a better reducing capacity (EC50 = 0.021 mg/ml, respectively). For the total antioxidant capacity, the best activity was found in the aqueous fraction of Salvia officinalis leaves of the Boulemane region (108 mgGAE/g of extract). By the cyclic voltammetry method, hydromethanolic extract of Salvia officinalis leaves from the Boulemane region showed an important result (288.8 mgGAE/g). There was a positive correlation between total phenol content (TPC), condensed tannin content (TCT), and total antioxidant capacity (TAC) (r = 0.932, r = 0.896, respectively). The main compounds that have been identified in the hydromethanolic extract of Salvia officinalis are ascorbic acid, gallic acid, 4-hydroxybenzoic acid, tannic acid, and rutin. Due to their antioxidant property, the leaf extracts from Salvia officinalis are used as natural preservative ingredients in food and/or pharmaceutical industries.

Rapid tannin profiling of tree fodders using untargeted mid-infrared spectroscopy and partial least squares regression

BackgroundThe presence of condensed tannins (CT) in tree fodders entails a series of productive, health and ecological benefits for ruminant nutrition. Current wet analytical methods employed for full CT characterisation are time and resource-consuming, thus limiting its applicability for silvopastoral systems. The development of quick, safe and robust analytical techniques to monitor CT’s full profile is crucial to suitably understand CT variability and biological activity, which would help to develop efficient evidence-based decision-making to maximise CT-derived benefits. The present study investigates the suitability of Fourier-transformed mid-infrared spectroscopy (MIR: 4000–550 cm−1) combined with multivariate analysis to determine CT concentration and structure (mean degree of polymerization—mDP, procyanidins:prodelphidins ratio—PC:PD and cis:trans ratio) in oak, field maple and goat willow foliage, using HCl:Butanol:Acetone:Iron (HBAI) and thiolysis-HPLC as reference methods.ResultsThe MIR spectra obtained were explored firstly using Principal Component Analysis, whereas multivariate calibration models were developed based on partial least-squares regression. MIR showed an excellent prediction capacity for the determination of PC:PD [coefficient of determination for prediction (R2P) = 0.96; ratio of prediction to deviation (RPD) = 5.26, range error ratio (RER) = 14.1] and cis:trans ratio (R2P = 0.95; RPD = 4.24; RER = 13.3); modest for CT quantification (HBAI: R2P = 0.92; RPD = 3.71; RER = 13.1; Thiolysis: R2P = 0.88; RPD = 2.80; RER = 11.5); and weak for mDP (R2P = 0.66; RPD = 1.86; RER = 7.16).ConclusionsMIR combined with chemometrics allowed to characterize the full CT profile of tree foliage rapidly, which would help to assess better plant ecology variability and to improve the nutritional management of ruminant livestock.

Condensed tannins in the diet of folivorous diademed sifakas and the gap between crude and available protein.

Tannins, a type of plant secondary metabolite, are well-known for their ability to precipitate proteins and thereby reduce the protein available to consumers. Most primate studies have focused on condensed tannins (CTs) as they were thought to be the most effective type of tannin at preventing protein acquisition, but there is growing recognition that other types of tannins can bind to proteins, suggesting the division among tannin types is not as clear-cut as previously thought. Although previous studies have documented the presence of CTs in primate diets and primates' behavioral responses to them, our understanding of tannins remains limited because few researchers have used Sephadex column purification to accurately determine tannin concentrations, and few have used in vitro assays to determine available protein content and the tannins' effectiveness in binding protein. In this study, we documented diademed sifaka (Propithecus diadema) diet from June to August 2018 at Tsinjoarivo, Madagascar (in two forests with varying degrees of habitat disturbance) and quantified CT concentration and actual available protein in foods. Eleven of the fourteen top foods tested contained CTs (concentrations: 4.8%-39.3% dry matter). An in vitro assay showed available protein was strikingly low in six of the eleven top foods (e.g., little to no apparent available protein, despite high crude protein). Overall, our findings suggest sifakas acquire less protein than previously recognized and probably have adaptations to counteract tannins. Such studies of available protein are critical in understanding dietary constraints on sifaka populations and the evolution of their diet choice strategies; despite the conventional wisdom that leaves are protein-rich, folivorous primates may indeed be protein-limited. However, further studies are necessary to determine if sifakas have counter-adaptations to tannins, and if they absorb more protein than our analyses suggest, perhaps receiving protein that we were unable to detect with the current techniques (e.g., pollen).

Roasting temperature impact on bioactive compounds and PAHs in Carob powder (Ceratonia siliqua L.).

The impact of roasting temperatures (100, 120, 150 and 180° for 25min) on the bioactive compounds, sensory and physicochemical properties of carob pods powder as well as the polycyclic aromatic hydrocarbons content (PAHs) were studied. The study also investigated whether roasting the dried carob pods (PO) or dried carob powder (CPW) is better used in the food industry. Increasing roasting temperatures resulted in several changes in the chemical composition of carob pods powder, as evidenced by significantly lower water content, protein, fat, total sugar and pH values. This increase also was accompanied by a significant increase in ash, fibers, total polyphenols, total flavonoids, and condensed tannins contents. Raw carob powder and roasted powder at 180°C showed the least acceptable organoleptic properties while roasting powders at 120 and 150°C showed the best results in terms of taste, color, odor, texture, and overall acceptability. PAHs ranged from 3.37 to 22.59µg/kg, and carcinogenic PAHs ranged from 1.38 to 10.16µg/kg of roasted carob powder. The difference among the detected levels in different roasting degrees was significant (P ≤ 0.5). Carob powder roasted at 180°C had a total PAHs content higher than other samples roasted at lower temperatures. Roasting at higher temperatures was not acceptable and not applicable due to the occurred partial carbonization and undesired sensorial characteristics formation.

Phytochemical profile and antioxidant properties of leaves extracts from Posidonia oceanica (L.) Delile and their allelopathic potential on terrestrial plant species

Dichloromethane, chloroform, ethyl acetate and ethanol extracts obtained from Posidonia oceanica (L.) leaves, were examined in order to determine their total phenolic, flavonoid, flavonol, anthocyanin and condensed tannins contents as well as their antioxidant and allelopathic activities. The qualitative phytochemical analysis of crude extracts confirmed the presence of coumarins in dichloromethane, chloroform and ethyl acetate extracts. The antioxidant activity estimated using the DPPH assay was significantly more pronounced for the ethyl acetate extract (IC50 = 1.19±0.018 mg/mL) than that of the other extracts. The allelopathic effect against the seeds of Carum carvi (L.) and Foeniculum vulgare (Mill.) indicated that, depending on concentration, the extracts from the leaves of P. oceanic (L.) inhibited or stimulated at different concentrations the germination, shoot and root elongation of seedlings growth. The results of this study suggest that P. oceanica (L.) extracts could be useful as a natural source of health-promoting effects and herbicides.&#x0D; &#x0D; KEY WORDS: Posidonia oceanic (L.), Phytochemical profile, Phenolic compounds, Antioxidant activity, Carum carvi (L.), Foeniculum vulgare (Mill)&#x0D; &#x0D; Bull. Chem. Soc. Ethiop. 2020, 34(3), 437-447.&#x0D; DOI: https://dx.doi.org/10.4314/bcse.v34i3.1