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In ruminant nutrition, the use of protein sources with low ruminal degradability is one of the ways to increase the efficiency of the use of dietary nitrogen and the supply of metabolizable protein to the animal. Among the promising strategies to reduce ruminal protein degradation of the foods usually used, are the thermal processing of food and the use of vegetable tannin extracts. This study aimed to evaluate the effect of inclusion levels of Acácia mearnsii tannin extract (SETA S/A, Estância Velha/RS) in soybean meal associated with different heat treatments on fermentation and in vitro digestion parameters. Three levels of inclusion of the tannin extract (0, 2.5 or 5.0% of dry matter) were tested in the soybean meal, three processing temperatures (environment (Control), 110°C or 120°C) and three times of heat treatment (without thermal treatment (Control), 15 or 30 minutes), in a 3×3×3 factorial design, with the moisture content of the mixture fixed at 20%. The material was incubated in vitro and the parameters analyzed were gas production and ammoniacal N concentration at 24, 36 and 48 hours of incubation. Additionally, the samples were incubated in situ for 16 hours and then the residue was subjected to in vitro hydrolysis with proteases in order to measure the ruminal degradability (DR), intestinal digestibility (DI) and total digestibility (DT) of the compounds nitrogenous. Three tests were carried out for each variable, each test being considered a replicate. There was no significant interaction between tannins and temperature for the variables. After 48 hours of in vitro fermentation, gas production was on average 2.8 and 7.0% lower by the inclusion of 2.5 and 5.0% of tannin extract, respectively. The heat treatment at 110ºC resulted in gas production 3.5% higher compared to room temperature or 120ºC, while the time of exposure to the heat treatment did not significantly affect the volume of gases. Ammonia release in the incubation medium was reduced 22% by the addition of 5% tannin extract and 8% by heat treatment at 120ºC. The heat treatment time or the treatment at 110ºC, as well as the addition of 2.5% tannin extract in soybean meal, did not affect the ammonia release in the incubation medium. The ruminal degradability of soybean meal was not affected by the addition of tannins or by the heat treatment time, but reduced 15% by the treatment at 120ºC. As for PNDR intestinal digestibility, the inclusion of tannins affected negatively, reducing it. There was no effect of time or temperature. The total N digestibility was affected only by the inclusion of tannins, decreasing it. Treatment with 5% tannin at 120ºC for 30 minutes has greater effect on reducing gas production and ammonia concentration, resulting in lower DR and minimal impact on DI and DT. Na nutrição de ruminantes, a utilização de fontes proteicas com baixa degradabilidade ruminal constitui uma das formas de aumentar a eficiência do uso do nitrogênio alimentar e o aporte de proteína metabolizável para o animal. Dentre as estratégias promissoras para reduzir a degradação proteica ruminal dos alimentos usualmente utilizados, estão o processamento térmico de alimentos e o uso de extratos taníferos vegetais. O presente trabalho teve como objetivo avaliar o efeito de níveis de inclusão de extrato tanífero de Acacia mearnsii (SETA S/A, Estância Velha/RS) no farelo de soja associado a diferentes tratamentos térmicos sobre parâmetros de fermentação e digestão in vitro. Foram testados três níveis de inclusão do extrato tanífero (0, 2,5 ou 5,0% da matéria seca) no farelo de soja, três temperaturas de processamento (ambiente (Controle), 110°C ou 120°C) e três tempos de tratamento térmico (sem tratamento térmico (Controle), 15 ou 30 minutos), em um delineamento fatorial 3×3×3, com umidade da mistura fixada em 20%. O material foi incubado in vitro e os parâmetros analisados foram produção de gases e concentração de N amoniacal em 24, 36 e 48 horas de incubação. Adicionalmente, as amostras foram incubadas in situ durante 16 horas e posteriormente o resíduo foi submetido à hidrólise in vitro com proteases com o objetivo de medir a degradabilidade ruminal (DR), a digestibilidade intestinal (DI) e a digestibilidade total (DT) dos compostos nitrogenados. Foram realizados três ensaios para cada variável sendo cada ensaio considerado uma replicata. Não houve interação significativa entre taninos e temperatura para as variáveis. Após 48 horas de fermentação in vitro a produção de gases foi em média 5 e 9,1% menor pela inclusão de 2,5 e 5,0% de extrato tanífero, respectivamente. O tratamento térmico a 110ºC resultou em produção de gases 2,5% maior comparado à temperatura ambiente ou 120ºC, enquanto que o tempo de exposição ao tratamento térmico não interferiu significativamente no volume de gases. A liberação de amônia no meio de incubação foi reduzida 24,5% pela adição de 5% de extrato tanífero e 9,2% pelo tratamento térmico a 120ºC. O tempo de tratamento térmico ou o tratamento a 110ºC, assim como a adição de 2,5% de extrato tanífero no farelo de soja, não afetaram a liberação de amônia no meio de incubação. A degradabilidade ruminal do farelo de soja não foi afetada pela adição de taninos e nem pelo tempo de tratamento térmico, mas reduziu 16,3% pelo tratamento a 120ºC. Quanto a digestibilidade intestinal da PNDR, a inclusão de taninos afetou negativamente, reduzindo-a. Não houve efeito de tempo ou temperatura. A digestibilidade total do N foi afetada apenas pela inclusão de taninos, diminuindo-a. O tratamento com 5% de tanino, a 120ºC durante 30 minutos, tem maior efeito na redução da produção de gás e concentração de amônia, resulta em menor DR e mínimo impacto na DI e DT.

The objective of this study is to evaluate the fit of Artificial Neural Networks (ANN) for height estimation and evaluation of the effects of consortium in a mixed-species plantation of Eucalyptus globulus (E) and Acacia mearnsii (A). The experiment was installed in 2005, on two farms in the municipality of Piratini - RS, where was planted the species Eucalyptus globulus (E) and Acacia mearnsii (A), in monoculture and mixed in simple lines (50%E:50%A - SL), and double lines (50%E:50%A - DL). The training and evaluation of the networks were made in R-project with the package neuralnet. All ANNs, from the simplest to the most complex, showed high values for Rŷy and low for Syx, BIAS and RMSE, with superior results in ANN 3, 4, and 6, which demonstrates that the information of DBHmin, DBHmean, and DBHmax were important stand attributes. Furthermore, the ANNs were able to capture the different growth patterns shown by the species in the different forms of consortiums, therefore is indicated for the height estimation in monocultures and mixed plantations of Eucalyptus globulus and Acacia mearnsii, and only one ANN would be necessary to represent the entire population.

The development of a sustainable wood energy chain is an essential part of ecological and energy transition in Reunion Island (Indian Ocean), where Acacia mearnsii is the main potential wood energy resource identified to date. In order to assess future wood biomass supply chain strategies, a major first issue is to gain knowledge of the spatial distribution of this species forest stands.In this study, we assessed the potential of very high spatial resolution multispectral imagery for mapping the main forest stands in a study area located the Western Highlands region, where Acacia mearnsii expands alongside Acacia heterophylla, an endemic forest species and Cryptomeria japonica, an exotic forest stand. A reference database including 150 samples of seven classes (Acacia mearnsii (mature and non-mature), Acacia heterophylla (mature and non-mature), Cryptomeria japonica, ‘herbaceous areas’, and ‘bare soils’) was used to classify a Pleiades image acquired in May 2020. Spectral and textural indices were used in an incremental classification procedure using a random classifier.The best results (Kappa = 0.84, global accuracy = 84%) were obtained for the classification using all spectral and textural bands. The resulting map enables analyzing the spatial distribution of the different forest stands.

Abstract In the present study, the tannins from stem and root barks of Tessmannia burttii Harms (Caesalpiniaceae), a plant species abundantly growing in Tanzania and other parts of Africa, were investigated for their suitability in hides tanning. Tannin powder was extracted at selected temperatures (30, 50 and 80 °C) and the influence of each temperature on the crosslinking capacity was evaluated. The interaction mechanism between hide powder collagen and the tannins was studied by Differential Scanning Calorimetry (DSC), trinitrobenzensulfonic (TNBS) acid assay and amino acid hydrolysis methods. Extraction temperatures showed low influence on crosslinking capacity of the tannins. However, extract obtained at 50 °C exhibited best performance in terms of gap size between Tonset and Tpeak. The stem bark extract yield was higher than that from the root bark, but both were within the recommended ranges. The tannin content (61%) of T. burttii stem bark extract was above recommended value (10%), whereas its total phenolic content and total flavonoic content were found to be above that of commercial Acacia mearnsii tannin. The study of cross-linking parameters as a function of pH showed cross-linking to occur via a covalent mechanism at the basic amino groups. However, the bonds were not resistant to acid hydrolysis. The observed interaction mechanism indicated that tannins from stem and root barks of T. burttii belong to the condensed tannin, similar to A. mearnsii (black wattle), a commercial tannin source that was used in this study as a reference. Findings from this study depict that T. burttii extracts are auspicious eco-friendly alternative source of vegetable tannins to overcome the use of chromium salts in the leather industry. Graphical abstract

Quantity of water is a major concern, but the quality is of more urgent concern due to heavy metal pollution. In this study, the focus was to develop adsorbents (tannin resin (TR) and iron-doped tannin resin (Fe-TR)) from invasive Acacia mearnsii for Pb2+ and Ni2+ in solution. The developed TR and Fe-TR were prepared directly by crosslinking and iron-grafting; respectively with thermal stable at ≤ 350 °C. Surface functionality analysis revealed the presence of chelating groups at ≈ 1688 and 3661 cm−1. The crystallite sizes of the adsorbents were smaller compared to tannin; however, the % carbon and nitrogen were significantly higher. Also, the Brunauer–Emmet–Teller study revealed that iron-grafting of tannin after crosslinking increases the surface area, pore volume and pore size. Furthermore, the surface morphology of adsorbents indicated a well-defined structure with the formation of a whitish deposit and rough lump-like after ion uptake. Both adsorbents showed a type II isotherm with adsorption capacities of 40.650 mg/g and 13.763 mg/g for Pb2+and 120.63 mg/g and 110.74 for Ni2+ ion by TR and Fe-TR; respectively. The absorbate-adsorbent interactions were observed to be endothermic with negative and positive Gibb's free energy values for the adsorption of Pb2+ and Ni2+; respectively. The adsorption kinetics of Ni2+ is governed by several models; however, Pb2+ interaction is regulated by Pseudo-second-order model. Furthermore, the data generated offered the possibility of both chemisorption and physisorption processes; highlighting the flexibility and multifunctionality of tannin traps for the erasure of ion impurities in wastewater.

The acacia bark extract derived from Acacia mearnsii De Wild is rich in proanthocyanidins, whose constituent units are robinetinidol, fisetinidol, catechin, and gallocatechin. In this study, we examined the effect of proanthocyanidins on obesity and diabetes using KKAy mice, a type 2 diabetes model. KKAy mice were fed either a low-fat diet, a high-fat diet, or a high-fat diet mixed with an acacia bark extract, a proanthocyanidins fraction, and other fraction for 7 weeks. Monitoring the changes in the body weight revealed that acacia bark extract and proanthocyanidins fraction could prevent excessive weight gain resulting from a high-fat diet. In addition, increases in the fasting blood glucose level due to high-fat diet intake were found to be suppressed by acacia bark extract and proanthocyanidins fraction. Furthermore, proanthocyanidins derived from acacia bark were found to increase the expression of adiponectin in white adipose tissue, which enhances the action of insulin. In addition, acacia bark-derived proanthocyanidins suppressed gluconeogenesis and fatty acid synthesis in the liver, as well as suppressing the decrease in energy production under pathological conditions in skeletal muscle. In addition, acacia bark-derived proanthocyanidins showed AMPK activation and DPP-4 inhibitory action. Therefore, it was suggested that acacia bark-derived proanthocyanidins lowered fasting blood glucose levels through the above mechanism. These results suggest that proanthocyanidins derived from acacia bark are the active ingredients of the anti-obesity and anti-diabetic effects of acacia bark extract.

Made available in DSpace on 2021-06-25T12:36:51Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-02-07 Clarification of sugarcane juice is one of the most important steps in the sugar manufacturing process, considering that an efficient clarification may result in highly beneficial effects on the quality and yield of the final product, crystal or refined sugar. Currently, depending on the industrial plant and intended product, the use of calcium hydroxide, phosphoric acid and sulfur dioxide as auxiliary agents for clarification has been consolidated, the latter being questioned for causing adverse health reactions. In this context, the present study evaluated the performance of the natural black Acacia (Acacia mearnsii) tannin extract as an alternative for the sugarcane juice clarification. The results showed that tannin dosages between 300 and 500 ppm along with liming applied at pH 7.3 and 3 ppm of anionic flocculant provided the best performance, resulting in 32-34% of color removal and 89-93% of turbidity removal. Under these conditions, starch and dextran removal increased, 90 and 98%, as compared to 69% and 96%, obtained with conventional treatment. The performance of the tannin also reduced the calcium hardness of clarified juice by up to 18% compared to the conventional treatment, which in turn may prevent fouling in the subsequent steps. Sao Paulo State Univ, Dept Food Engn & Technol, Sao Jose Do Rio Preto, SP, Brazil Sao Paulo State Univ, Dept Food Engn & Technol, Sao Jose Do Rio Preto, SP, Brazil

Invasive alien species (IAS) threaten tropical grasslands and native biodiversity and impact ecosystem service delivery, ecosystem function, and associated human livelihoods. Tropical grasslands have been dramatically and disproportionately lost to invasion by trees. The invasion continues to move rapidly into the remaining fragmented grasslands impacting various native grassland-dependent species and water streamflow in tropical montane habitats. The Shola Sky Islands of the Western Ghats host a mosaic of native grasslands and forests; of which the grasslands have been lost to exotic tree invasion (Acacias, Eucalyptus and Pines) since the 1950s. The invasion intensities, however, differ between these species wherein Acacia mearnsii and Pinus patula are highly invasive in contrast to Eucalyptus globulus. These disparities necessitate distinguishing these species for effective grassland restoration. Further, these invasive alien trees are highly intermixed with native species, thus requiring high discrimination abilities to native species apart from the non-native species.Here we assess the accuracy of various satellite and airborne remote sensing sensors and machine learning classification algorithms to identify the spatial extent of native habitats and invasive trees. Specifically, we test Sentinel-1 SAR and Sentinel-2 multispectral data and assess high spatial and spectral resolution AVIRIS-NG imagery identifying invasive species across this landscape. Sensor combinations thus include hyperspectral, multispectral and radar data and present tradeoffs in associated costs and ease of procurement. Classification methods tested include Support Vector Machine (SVM), Classification and Regression Trees (CART) and Random Forest (RF) algorithms implemented on the Google Earth Engine platform. Results indicate that AVIRIS-NG data in combination with SVM recover the highest classification skill (Overall −98%, Kappa-0.98); while CART and RF yielded < 90% accuracy. Fused Sentinel-1 and Sentinel-2 produce 91% accuracy, while Sentinel-2 alone yielded 91% accuracy with RF and SVM classification; but only with higher coverage of ground control points. AVIRIS-NG imagery was able to accurately (97%) demarcate the Acacia invasion front while Sentinel-1 and Sentinel-2 data failed. Our results suggest that Sentinel-2 images could be useful for detecting the native and non-native forests with more ground truth points, but hyperspectral data (AVIRIS-NG) permits distinguishing, native and non-native tree species and recent invasions with high precision using limited ground truth points. We suspect that large areas will have to be mapped and assessed in the coming years by conservation managers, NGOs to plan restoration, or to assess the success of restoration activities, and several data procurement and analysis steps may have to be simplified.

Due to their natural origin and broad availability, industrial tannin extracts are extending their application field from the classical, and still principal, application in tannery, to oenology, pharmacy, adhesives and material science. Despite the growing interest, not much is known about the thermal valorization of these biomolecules. In this article we present the thermal properties of the eight most common commercial tannin extracts and their elemental chemical composition to shed light on the end-life of the bio-materials based on these polyphenols. Results have shown that hydrolysable tannins can be managed similarly to wood, while condensed tannins have higher heating values but also generally higher chlorine content. Sumac and gambier leaf extracts registered contained heating values and significant amounts of ashes rich in calcium and sulfur. The high chlorine content observed for the extracts of mimosa (Acacia Mearnsii) does not hinder the combustion of its derived products which can still be thermally valorized. Mimosa tannin-based materials can also be added up to 2% to wood pellets and briquettes without significantly affecting the overall quality of the biofuels according to the in-force standards.

Tannins are compounds able to form complexes with proteins limiting their ruminal degradation and thus the synthesis of some odour-active compounds may be inhibited. Tannins are broadly divided in condensed tannins (CT) and hydrolysable tannins (HT). The study aimed to assess the influence of dietary inclusion of three commercial tannin extracts, namely mimosa (Acacia mearnsii; CT), chestnut (Castanea sativa; HT) or tara (Caesalpinia spinosa; HT) on volatile profile and flavour of meat and kidney fat from lambs. Comisana male lambs were divided into four groups (n = 9 each) and fed for 75 days with a concentrate-based diet (CON) or CON supplemented with 4% of one of the tannin extracts. Tannins reduced “pastoral” odour in perirenal fat of lambs the meat of which was characterized by a very low perception of this attribute. It may be assumed that p-cresol and 8-methylnonanoic acid mostly contributed to “pastoral” odour expression in the diet without condensed or hydrolysable tannins.

The objective of this study was to determine the optimum level of condensed tannins (CTs), delivered as Acacia mearnsii extract, for inclusion in the diet of goats for enhancing growth, commercial cuts, the physicochemical composition and fatty acid (FA) profile of the meat and meat sensory attributes. Thirty-two castrated crossbreed Boer goats with a mean age of four months and a mean body weight (BW) of 19.7 ± 2.05 kg were distributed in a completely randomized design. The diets varied in level of CTs [0, 16, 32 and 48 g/kg dry matter (DM)] from an Acacia mearnsii extract. Final BW; acid detergent fiber (ADF); shoulder, neck and rib weight; and loin yield increased quadratically (P ≤ 0.05) with the amount of CTs in the diet. Except for a trend of a quadratic reduction in luminosity color (P = 0.07) and a linear reduction in collagen deposition (P = 0.03) with increasing level of dietary CTs, the meat physicochemical parameters were unaffected by CTs inclusion. With increasing amount of CTs from Acacia mearnsii extract in the diet, the concentrations of C17:1 and C18:1 cis-9 in the longissimus lumborum of goats linearly decreased, whereas those of C18:0, C18:2 cis-9, cis-12 and C18:3 cis-9, cis-12, cis-15 (P ≤ 0.05) linearly increased. In addition, the values of total saturated FA (ΣSFA), polyunsaturated FA (ΣPUFA), ratio of ΣPUFA:ΣSFA and ΣPUFA:monounsaturated FA (ΣMUFA) increased (P ≤ 0.05) with increasing CTs level; in contrast, ΣMUFA and the ΣMUFA/ΣSFA ratio decreased. Other FA sums and ratios were not affected by the inclusion of CTs in the diet. The inclusion of dietary CTs tended to unfavorably reduce the FA index and enzymatic activity of Δ9-desaturase C16 (P ≤ 0.10). However, there was a linear decrease (P ≤ 0.05) in Δ9-desaturase C18 and elongase enzymatic activities and the hypocholesterolemic to hypercholesterolemic FA ratio (h:H) index with increasing level of dietary CTs, and the atherogenicity index (AI) tended to increase as the CTs level increased (P = 0.06). The dietary inclusion of the Acacia mearnsii extract improved the flavor, aroma, softness and overall acceptance of goat kid meat (P ≤ 0.05). Linear response plateau (LRP) analysis demonstrated that Acacia mearnsii levels of 16 and 32 g/kg DM had similar effects and increased growth performance and carcass cut weights (P

With A. mearnsii being one of the most successful invaders globally, its management has become a large part of invasive alien species management programs, especially in South Africa, where a significant investment of about 561.9 million rands has been made to eliminate it. Despite this huge investment, there is still no sign that the spread of this species has diminished. To ensure that the damage caused by A. mearnsii is halted, professionals must understand how it spreads and persists. Accurate data on the spatial distribution of A. mearnsii might help to develop useful and successful management techniques for savannah environments, particularly in protected mountainous grasslands. This study, therefore, developed a GIS model for predicting the potential spatial spread of A. mearnsii in a protected mountainous grassland ecosystem using spatiotemporal data derived from Landsat and Sentinel-2 imageries. The study used environmental factors like slope aspect, elevation, distance from streams, and soil type and rainfall. Other climatic variables like land surface temperature derived from the thermal band of Landsat images were included in the environmental factors. The influence of species interactions with fire severity and animal populations was also included as indicator variables. The species' AUC of 0.83 is estimated, and the model fit is a sign of a successful model. The study showed that the spread of A. mearnsii was influenced primarily by the following factors: The average Land surface temperature, aspect, changes in land surface temperature, and rain from 2000 to the present, and distance to the river. The species increased in areas where there was a reduction in both land surface temperature and rainfall. The predicted circumstances of decreasing temperature and rainfall events may lead to widespread invasion by A. mearnsii while nevertheless changing community structure, composition, hydrological properties, and other essential ecosystem services in the examined region.

Although the effects of invasive alien plants on natural ecosystems are widely acknowledged, the effects of specific plant species can be context dependent. The study examined changes in native vegetation diversity and composition following Lantana camara invasion at different cover conditions in the Vhembe Biosphere Reserve, Limpopo Province of South Africa. Using a comparative approach, native vegetation diversity, cover, and composition were compared in L. camara high and low cover and uninvaded conditions, on three replicated sites, each with five 10 × 10 m plots. Results show that vegetation diversity (species richness, Shannon-Wiener, and evenness index) were significantly higher in the uninvaded condition than in the L. camara high and low invasion conditions. Species relative cover was significantly higher in uninvaded condition than in L. camara high and low invasion conditions, though it decreased gradually along the invasion cover gradient for trees and shrubs as well as forbs. Analysis of similarities showed significant separations in vegetation composition among the three invasion conditions for all the growth forms, with most woody alien plants, e.g. Acacia mearnsii, Rubus rigidus, and Caesalpinia decapetala being associated with L. camara high and low invasion conditions. The study concludes that invasion by L. camara was associated with changes in native vegetation diversity, cover, and composition, with observed changes being more visible under L. camara high as compared to low invasion condition. The presence of L. camara at high cover condition significantly decreased native species diversity and composition, an indication that impacts of L. camara invasion are cover dependent. From a management standpoint, the study suggests the removal of L. camara, however such removal should consider protecting the co-occurring native species. This study offers a baseline for further research to determine mechanisms responsible for native vegetation change associated with L. camara invasion.

Background: The most commonly used method for extracting DNA from plant leaf tissue involves cetyl trimethylammonium bromide but some species, such as Acacia mearnsii, contain high levels of secondary metabolites and polysaccharides that interfere with this process. Various modifications have been proposed for effective removal of these biomolecules but these methods can be time consuming. Therefore, this study was initiated to optimise the cetyl-trimethylammonium bromide protocol for the extraction of high-quality genomic DNA and to develop a fingerprinting tool using cross species transferable simple sequence repeat markers for genetic diversity studies in A. mearnsii. Methods: Five CTAB-based modification were examined and 49 cross-species microsatellite markers, developed for several Acacia species, were tested in four multiplex panels of A. mearnsii populations. Results: The modified protocol yields high quantity and quality DNA from A. mearnsii leaves using high concentration of NaCl to remove polysaccharides and polyvinylpolypyrrolidone (PVPP) to eliminate polyphenols during DNA purification. In addition, omitting the selective precipitation and NaCl gradient steps in the extraction protocol, enabled us to extract DNA 10–20 min faster than the normal protocol. Of the tested microsatellite loci, 11 were successful in amplifying sharp and high-intensity bands in all the four multiplex panels and were polymorphic. The level of polymorphism ranged from 0.115 to 0.794, with a mean 0.50 and mean number of alleles varied from 2 to 10, with overall mean of 6 alleles per locus. The mean observed and expected heterozygosity ranged from 0.058 to 0.970 and 0.102 to 0.796, respectively. The 11 microsatellite loci that were effectively amplified from A. mearnsii DNA were adequate in detecting genetic variation among the tested populations. Conclusions: These PCR-based, multi-allelic, co-dominant microsatellite markers provide a powerful tool for genetic, breeding and conservation studies in A. mearnsii.

The aim of this study was to evaluate the effect of the dietary inclusion of Acacia mearnsii tannin extract (TA) on nutrients intake and digestibility, and nitrogen (N) retention by sheep given a tropical grass-based diet. The trial was conducted with six castrated male sheep in a cross-over design in two 21-days experimental periods. The sheep were housed in metabolic cages and offered Tifton 85 hay (Cynodon dactylon) ad libitum plus concentrate at a rate of 12 g of dry matter (DM)/kg body weight (BW). The treatments were concentrate without (Control) or with 10 g TA/kg DM (Tannin). Concentration of TA in the diet was 3.8 g/kg DM and did not affect the feed intake or apparent digestibility. The TA decreased the true digestibility of n compounds (P

Acacia mearnsii gum is not commercially exploited, being characterized as residue from A. mearnsii cultivation. This work investigated the A. mearnsii gum polysaccharide composition, its cytotoxicity and the technological effect as a stabilizer in ice cream. A. mearnsii gum showed a similar chemical structure to commercial gum Arabic and did not decrease the viability and proliferation of fibroblast cells (Balb/3T3) and hepatocarcinoma (HepG2). Rheological tests showed that the ice cream stabilized by the A. mearnsii gum had a more structured system (more interactions between the mixture components) and the same melting characteristics as the ice cream samples made with commercial gum Arabic. The results showed that A. mearnsii gum, which is actually an agro-industrial residue from tannin production for industry, is a potential stabilizing gum for the food industry, contributing to the economic development of the exploitation chain of A. mearnsii products and by-products.

In South Africa the invasion of riparian forests by alien trees has the potential to affect the country's limited water resources. Tree water-use measurements have therefore become an important component of recent hydrological studies. It is difficult for South African government initiatives, such as the Working for Water (WfW) alien clearing programme, to justify alien tree removal and implement rehabilitation unless hydrological benefits are known. The objective of this study was to investigate the water use (transpiration rates) of a selection of introduced and indigenous tree species and quantify the hydrological benefit that could be achieved through a suitable rehabilitation programme. Consequently water use within a riparian forest in the upper Mgeni catchment of KwaZulu-Natal in South Africa was monitored over a 2-year period. The site consisted of an indigenous stand of eastern mistbelt forest that had been invaded by Acacia mearnsii, Eucalyptus nitens and Solanum mauritianum. The heat ratio method of the heat pulse velocity (HPV) sap flow technique and the stem steady state (SSS) techniques were used to measure the sap flow of a selection of indigenous and introduced species. The indigenous trees at New Forest, South Africa, showed clear seasonal trends in the daily sap flow rates varying from 8 to 25 L day−1 in summer (sap flow being directly proportional to tree size). In the winter periods this was reduced to between 3 and 6 L day−1 when limited energy flux was available to drive the transpiration process. The water use in the A. mearnsii and E. grandis trees showed a slight seasonal trend, with a high flow during the winter months in contrast to the indigenous species. The water use in the understorey indicated that multi-stemmed species used up to 12 L day−1. Small alien trees (A. mearnsii and S. mauritianum used up to 4 L day−1 each. The total accumulated sap flow per year for the three individual A. mearnsii and E. grandis trees was 6548 and 7405 L a−1 respectively. In contrast, the indigenous species averaged 2934 L a−1, clearly demonstrating the higher water use of the introduced species. After spatial upscaling, it was concluded that, at the current state of invasion (21 % of the stand being alien species), the stand used 40 % more water per unit area than if the stand were in a pristine state. If the stand were to be heavily invaded at the same stem density of the indigenous forest, a 100 % increase in water use would occur over an average rainfall year.

This study investigated the effects of proanthocyanidins derived from Acacia (Acacia mearnsii) bark extract in healthy Japanese adult subjects experiencing uncomfortable skin symptoms. All subjects were randomly allocated into two groups (n = 33 each) using a computerized random-number generator. The subjects received either Acacia bark extract tablets or placebo for 8 weeks. Evaluations included water content in the stratum corneum, transepidermal water loss (TEWL), Skindex-16, dermatology life quality index (DLQI), visual analog scale for desire to scratch, and blood tests. At 4 weeks, the symptom/feeling score of DLQI, subjective symptoms related to uncomfortable skin, and the desire to scratch were significantly reduced in the intervention group than in the placebo group. At 8 weeks, the intervention group exhibited significantly lower TEWL on facial skin than that in the placebo group. In conclusion, the intake of Acacia bark extract tablets reduced TEWL and improved dry and uncomfortable skin.

International audience; Key messageAcacia longifoliaandAcacia mearnsiiexhibit different reproductive behavior (viability, germination, and dormancy) in relation to fire and seed maturation. The potential of invasion ofA. longifoliais stronger than that ofA. mearnsii.A. longifoliagerminates abundantly between fires and after fires, whileA. mearnsiionly germinates after fire and needs higher thermal thresholds to break dormancy.ContextFire affects environments through the modification of biological processes such as seed viability, dormancy, and germination. Seed maturation stage can modulate seed response to fire. Invasive alien species could be enhanced by forest fires.AimsTo analyze the viability, germination, and dormancy of two invasive alien species (Acacia longifolia and Acacia mearnsii) in relation to fire and seed maturation.MethodsViability of seeds was obtained performing a tetrazolium test. Additionally, we obtained germination and dormancy in mature and fresh seeds simulating fire conditions through different levels of fire factors (smoke, ash, charcoal, and heat).ResultsControl viability of seeds was 100% in the two Acacia species and maturation stages and severe heat reduced it to zero. Germination of A. longifolia varied depending on the maturation stage, being higher in fresh seeds. In A. mearnsii, germination did not change with maturation. In both species, heat stimulated germination by breaking seed dormancy. Seed maturation stage and fire factors affect the germination speed of each species differently.ConclusionFire reduces viability, stimulates germination, and breaks dormancy of the two species. Seed maturity exerts notable effects on A. longifolia reproductive behavior.

The objective of this study was to evaluate the effect of inclusion of condensed tannins (CT) from black wattle (Acacia mearnsii) on feed intake, ruminal protozoa population, ruminal fermentation, and nutrient digestibility in Jersey steers. Five ruminally-cannulated steers were used in a 5x5 Latin square design, with five periods of 20 days each (14 days for diet adaptation and six days for sample collection per period). Treatments were composed of dietary inclusion levels of condensed tannins at 0, 5, 10, 15, and 20 g/kg of diet dry matter. Intakes of dry matter, organic matter, ether extract, crude protein, neutral detergent fiber, and total digestible nutrients were not affected by condensed tannins. The ruminal pH was reduced linearly with tannin levels. Ruminal ammonia nitrogen concentration was not affected by tannins. Tannins reduced the molar proportion of acetate and did not affect the ruminal protozoal population, which might be related to the low doses used. Digestibilities of dry matter, organic matter, and neutral detergent fiber were not altered, however, there was a linear reduction in crude protein digestibility. Based on these results, CT extracts from black wattle are not recommended for improving nutrient utilization in steers at the tested levels.

Rooting media were evaluated to identify problems contributing to poor rooting. Seven media combinations of coir and perlite were investigated, including two sources of coir (‘CG’ and ‘GS’). Final ...