Protein Precipitable Phenolics Research Articles

Ticktrefoil (Desmodium) species as a nutraceutical forage resource for animals

AbstractTicktrefoil (Desmodium) species from the USDA, ARS, Plant Genetic Resources Conservation Unit (PGRCU) germplasm collection in Griffin, GA, were evaluated for their potential livestock nutraceutical (nutritional + pharmaceutical) value in a field small plot study at the Fort Valley State University (FVSU) Agricultural Research Station, Fort Valley, GA. Horse marmalade (Desmodium discolor Vogel), greenleaf ticktrefoil (Desmodium intortum [Mill.] Urb.), panicledleaf ticktrefoil (Desmodium paniculatum [L.] DC.), Hawaii ticktrefoil (Desmodium sandwicense E. May) and twisted ticktrefoil (Desmodium tortuosum [Sw.] DC.) were established in a greenhouse and transplanted to field plots, with plant material from each species harvested, freeze‐dried, ground and analyzed for nutrient content and bioactivity. Crude protein (CP) levels in D. discolor and D. tortuosum averaged 233 g/kg, whereas CP in D. intortum, D. paniculatum and D. sandwicense ranged from 99 to 157 g/kg. The Desmodium species had in vitro true digestibility values of 755 to 878 g/kg. There were no detectable condensed tannins in D. discolor and D. tortuosum, whereas D. intortum, D. paniculatum and D. sandwicense averaged 88, 89 and 73 g/kg total condensed tannin, respectively. There were species differences in flavonoid content (p < .01), with the highest delphinidin and cyanidin concentrations in D. sandwicense and D. paniculatum, respectively. There were no detectable levels of delphinidin or cyanidin for D. discolor or D. tortuosum. Quercitin and kaempferol concentrations were highest in D. intortum and D. paniculatum, respectively, whereas D. discolor and D. tortuosum had the lowest values. The highest protein precipitable phenolics and total phenolic concentrations were for D. paniculatum. Desmodium species have potential as nutraceutical forage for livestock and warrant further investigation.

259 Screening of Lespedeza germplasm for forage quality and bioactivity

Abstract Interest in the condensed tannin-containing legume sericea lespedeza (Lespedeza cuneata) as a nutraceutical (bioactive) forage for livestock has been increasing in the United States but other Lespedeza species have not been adequately evaluated. A study was completed to determine the nutritional and bioactivity potential of Lespedeza species obtained from the USDA Plant Genetic Resources Conservation Unit in Griffin, GA. Accessions from 15 Lespedeza species were planted in small plots at Fort Valley State University in Fort Valley, GA. After establishment, forage was harvested, freeze-dried, ground and analyzed for neutral detergent fiber (NDF), acid detergent fiber (ADF), in vitro true digestibility (IVTD), total phenolics (TP), and protein precipitable phenolics (PPP). Species differences were significant (P < 0.01) for all parameters measured. Lespedeza cuneata accessions, including “AUGrazer,” the cultivar most commonly used as an anti-parasitic crop in the United States had NDF, ADF, and IVTD values of 35.7±0.4%, 26.8±0.4%, and 74.3±1.2%, while L. virginica, a native species, had 34.9±3.0%, 26.0±2.5%, and 74.9±4.2%, respectively. The L. cuneata accessions averaged 179.6±4.3 and 133.6±3.5 mg/g of forage material for TP and PPP, while L. virginica averaged 564.2±24.6 and 306.5±19.9 mg/g, respectively. Other species varied from 30.5±3.0 to 47.4±4.2% NDF, 22.9±1.6 to 36.4±3.6% ADF, 55.2±5.9 to 81.6±3.4% IVTD, and 107.7±17.4 to 283.5±34.7 and 55.2±14.0 to 139.4±28.1 mg/g of forage for TP and PPP, respectively. Based upon these results, Lespedeza species tested in this study, particularly L. virginica, have potential as nutraceutical forages for livestock production systems. As L. cuneata accessions established and grew much better than other Lespedeza species in this study, agronomic testing of this germplasm collection in other environments is warranted. In addition, determining potential anti-parasitic properties of these species using in vitro and in vivo testing would be beneficial.

Leaf functional trait responses to changes in water status differ among three oak (Quercus) species

We monitored differences in rates of foliar carbon-compound increases with progressive drought as an indicator of sink limitation status and subsequent drought tolerance. We postulate that species which increase foliar carbohydrates and protein-precipitable phenolics (PPP) more quickly than related species over the same time period and drought conditions have stronger sink limitations and are therefore less drought tolerant. Quercus macrocarpa, Q. shumardii, and Q. virginiana saplings were subjected to two treatments for approximately 3.5 months: (1) watered, which received the equivalent of average weekly precipitation for College Station, TX, USA, and (2) droughted, in which precipitation was reduced by 100%. Q. virginiana’s photosynthesis (A) and stomatal conductance (gs) were 44 and 54% greater, respectively, than the other species in the drought treatment. Q. virginiana’s gs also increased more dramatically with watering and subsequent increases in predawn leaf water potential. This plasticity suggests Q. virginiana is best equipped to deal with sporadic rainfall events and soil moisture changes, at least in the short term. Results indicate that the three species allocate carbon from photosynthate in different ways. Q. shumardii had the most soluble sugar in its foliage but had the least PPP, while Q. virginiana and macrocarpa had more PPP and less sugar than Q. shumardii. Diameter:height growth rate was greatest in Q. shumardii. Foliar protein-precipitable phenolic content appears to be more affected by factors other than drought. Differences in species’ physiological responses to drought may result in stand composition shifts with future climate alterations.

Molecular weight and protein-precipitating ability of condensed tannins from warm-season perennial legumes

The beneficial effects of forages containing condensed tannins (CTs) on ruminants are well documented, but the chemical features of CT that yield benefits have not been defined. Some evaluations of limited numbers of highly purified compounds have resulted in positive correlations between CT molecular weight (MW) and biological activity, while others have failed to show a correlation. The objectives of this study were to determine if MW of CT could predict biological activity relative to protein precipitability. MW of condensed tannin, protein-precipitable phenolics (PPP), and the amount of protein bound (PB) were determined for nine species of warm-season perennial legumes. There was no correlation between PPP or PB and MW (R2 0.11 and R2 0.02, respectively). However, CT concentration did correlate with PPP and PB (R2 0.81 and R2 0.69, respectively). It was concluded that CT MW does not explain the variation in protein precipitation by CT from the forage legumes surveyed.

Effects of phenolic compounds in three oak species on in vitro gas production using inoculums of two breeds of indigenous Iranian goats

The capabilities of rumen fluid (RF) from two indigenous Iranian goats (i.e., Markhoz, Alamout) to ferment tanniniferous (i.e., oak leaves) and non-tanniniferous (i.e., a mixture of lucerne hay and barley grain) feeds were studied. Five air dried samples from each of three oak species (i.e., Quercus persica, Quercus infectoria, and Quercus libani) were used to determine their chemical composition, phenolic compounds and protein precipitable phenolics (PPP). In three runs of in vitro gas production, the influence of non-tannin containing substrate incubated with either RF (i.e., Markhoz or Alamout) was assessed. Gas production (GP) was recorded from 1 to 96h of incubation. Effects of tannins on in vitro gas production, in vitro organic matter disappearance (IVOMD) and estimated metabolisable energy (ME) were assessed by a polyethylene glycol (PEG) tannin bioassay. There were no differences in gas production and IVOMD for a non-tannin substrate incubated with RF from either breed of goat. However, RF from Markhoz goats produced consistently more gas than RF from Alamout goats among oak species. The PEG treatment improved (P<0.01) the IVOMD in RF and estimated ME from both breeds of goats for all oak species. The RF from Markhoz goats fermented oak leaves more effectively than RF from Alamout goats, possibly due to the presence of tannin-degrading bacteria.

Caution against Determining Tannins in Soil using the Protein Precipitable Phenolics Assay

The aim of this study was to assess the use of the protein precipitable phenolics assay as a method for estimating tannin in soil samples. This method is more selective than general methods such as Folin assays and is used to differentiate tannin from other phenolics in plant extracts. We evaluated the role of the protein as an agent that separated tannin from nontannin phenolics in soil by running the assay in the normal mode, with protein present, and in a modified format without the protein. We tested the method using native soils and soils amended with tannic acid. We found that this assay is not suitable for determining tannin in soil samples, because the protein precipitation step is incompatible with solid soil samples. We also assessed the background color of soil samples in the assay and established that background color is so high that reliable absorbance readings cannot be obtained.

Nutritive Value of Oak Leaves in Sheep

Oak (Quercus sp.) leaves and branches is an important source of forage in the north-west of Iran, during winter season, when the pasture herbages are not available, but the nutritive value of this forage is not well known. In this study nutritive value of three species of oak tree leaves: Quercus persica, Q. infectoria and Q. libani were assessed by chemical analysis and in situ method. The chemical composition (g/kg DM basis) of the above species, respectively were as follow; 951, 927, 946, Organic Matter (OM); 115, 92, 123, Crude Protein (CP); 532, 540, 512, Neutral Detergent Fiber (NDF); 317, 300, 331, Acid Detergent Fiber (ADF); 98, 103, 95, lignin (ADL); 78, 115, 104, total phenols; 73, 109, 100, Total Tannins (TT); 14, 15, 12, Condensed Tannin (CT) and 46, 87, 62, Hydrolysable Tannin (HT). Protein Precipitable Phenolics (PPP) were respectively 160, 190 and 230 (g/kg total phenols). Rumen liquor taken from three male Ghezel sheep was used to measure the in situ degradability characteristics of oak leaf. The soluble component (a), insoluble but fermentable fraction (b), the potential degradability (a+b) and the Effective Degradability (ED) were higher in Q. persica (p Q. libani > Q. infectoria.

Effects of ensiling, air-drying and addition of polyethylene glycol on in vitro gas production of pistachio by-products

The objective of this study was to determine effects of freeze-drying, sun-drying, ensiling and addition of polyethylene glycol (PEG) on deactivation of tannins in pistachio by-products (PB) by assessing changes in the chemical composition and phenolics levels of freeze-dried, sun-dried and ensiled PB for 30 or 60 days. In vitro gas production for 24 h (IVGP), estimated organic matter digestibility (OMD) and metabolisable energy, with or without PEG addition, were determined. Ensiling decreased the content of water soluble carbohydrates (WSC), neutral detergent fiber (NDFom) and acid detergent fiber (ADFom) as well as condensed tannins, hydrolysable tannins, protein-precipitable phenolics, IVGP and OMD (P<0.05). Adding PEG to freeze-dried, sun-dried and ensiled PB increased (P<0.05) IVGP and OMD demonstrating the positive influence of PEG, but not sun-drying or ensiling, on inactivation of tannins in PB.

Characteriztion of Quercus persica, Quercus infectoria and Quercus libani as ruminant feeds

The nutritive value of three species of oak trees leaves was assessed by chemical analysis as well as by an in situ and in vitro gas production method. The chemical composition (g/kg DM basis) of three species, Quercus persica, Q. infectoria and Q. libani were 951, 927, 946 organic matter (OM); 115, 92, 123 crude protein (CP); 532, 540, 512 neutral detergent fiber (NDFom); 317, 300, 331 acid detergent fiber (ADFom); 98, 103, 95 lignin (lignin(sa)); 8.9, 11.7, 19.2 water soluble carbohydrates (WSC); 78, 115, 104 total phenols; 73, 109, 100 total tannins (TT); 14, 15, 12 condensed tannin (CT); and 46, 87, 62 hydrolysable tannin (HT). Protein precipitable phenolics (PPP) were respectively 160, 190 and 230 (g/kg total phenols). Effects of tannins on in vitro gas production, in vitro organic matter digestibility (OMD), metabolisable energy (ME) and effective DM digestibility (ED) were assessed by polyethylene glycol (PEG) tannin bioassay. Among species, Q. Libani had the highest gas production. This species also had the highest (P<0.05) increase in gas production, OMD and ME due to the addition of PEG. Using this in situ method the soluble component (A), insoluble but fermentable component (B), the degradation rate of B (c), the potential degradability (A + B) and the effective degradability (ED) of the oak leaves were influenced (P<0.05) by species, PEG treatment and interaction of species and PEG treatment. Adding PEG to Quercus species suggests that these feeds have potential as small ruminant feeds.

Tannins and nitrogen dynamics in mangrove leaves at different age and decay stages (Jiulong River Estuary, China)

Changes in the total phenolics, condensed tannins (CT), protein-precipitable phenolics content and protein precipitation capacity were determined on mangrove leaves representing a range of maturation and senescence in the Jiulong River Estuary, Fujian, China. The results showed that the total phenolics, extractable condensed tannins, total condensed tannins, protein-precipitable phenolics content and protein precipitation capacity in young leaves were higher than those in mature and senescent leaves. With leaf maturation and senescence, total pehnolics decreased. The rapid loss of phenolics observed following senescence and abscission can be ascribed to leaching and degradation. Protein-bound CT and fibre-bound CT tended to increase with leaf maturity, and decreased with senescence. Protein-bound CT and fibre-bound CT increased with leaf decomposition, with CT binding more strongly to protein than to fibre. The increases in nitrogen contents and ash free caloric values, and declines in total phenolics and total condensed tannins of mangrove leaf litter suggests that partially decomposed mangrove detritus is a palatable heterotrophic substrate, and thus may be an important source of matter and energy for the estuarine food web.

Effect of Tannins in Acacia nilotica, Albizia procera and Sesbania acculeata Foliage Determined In vitro, In sacco, and In vivo

The nutritive value and the effect of tannins on the utilization of foliage from three commonly used legumes, Acacia nilotica, Albizia procera, and Sesbania acculeata, were determined. Three mature rumen-fistulated bullocks were used to study in sacco degradability and twelve adult sheep were randomly allocated on the basis of live weight to 4 groups of 3 in each to study the in vivo digestibility of the foliages. In all foliages, the contents of crude protein (17 to 24% of DM) were high. Fibre was especially high in Albizia (NDF 58.8% of DM vs. 21% in Sesbania and 15.4% in Acacia). Contents of both hydrolysable (4.4 to 0.05%) and condensed tannins (1.2 to 0.04%) varied from medium to low in the foliages. Acacia contained the highest level of total phenolics (20.1%), protein precipitable phenolics (13.2%) and had the highest capacity to precipitate protein (14.7%). Drying in shade reduced the tannin content in Acacia and Albizia by 48.6 and 69.3% respectively. The foliages ranked similarly for each of the different methods used to estimate tannin content and activity. Acacia and Sesbania foliage was highly degradable (85-87% potential degradability of DM in sacco), compared to Albizia (52%), indicating a minimal effect of tannins in Acacia and Sesbania. Yet, in vitro, the tannins in the Acacia inhibited microbial activity more than those in Albizia and Sesbania. Following the addition of polyethylene glycol to neutralise the tannins, gas production and microbial growth increased by 59% and 0.09 mg RNA equiv./dg microbial yield respectively in the Acacia, compared to 16-17% and 0.06 mg RNA equiv./dg microbial yield in the other foliages. There was a trend for low in vivo apparent digestibility of N in the Acacia (43.2%) and Albizia (44.2%) compared to the Sesbania (54.5%) supplemented groups. This was likely to be due to presence of tannins. Consistent with this was the low N retention (0.22 and 0.19 g N/g NI) in sheep supplemented with Acacia and Albizia compared to that for the Sesbania (0.32). Similarly, a trend for poor microbial N yield was observed in sheep fed these foliages. Across the foliages tested, an increase in tannin content was associated with a reduction in ruminal fermentation, N digestibility and N retention. For overall nutritive value, Sesbania proved to be the superior forage of the three tested.

Effects of ensiling grape pomace and addition of polyethylene glycol on in vitro gas production and microbial biomass yield

Due to a shortage of ruminant feeds, co-products such as grape pomace (GP) which contain tannins, represent alternative ruminant feed resources. The aim of the current study was to assess effects of ensiling and addition of polyethylene glycol (PEG) on deactivation of tannins in the grape pomace by changes in the chemical composition and phenolics levels of fresh and ensiled GP for 5, 10 or 30 days. In vitro gas production (IVGP), estimated organic matter digestibility (OMD), ammonia concentration and microbial biomass yield (MB) of each treatment, with or without PEG addition were measured. Increasing the duration of ensilage decreased the content of WSC and pH (P<0.01). Ensiling decreased (P<0.01) total phenolics (TP), total tannin (TT), soluble condensed tannins (SCT), protein precipitable phenolics (PPP), and IVGP, OMD and MB. Adding PEG to ensiled GP, however, increased (P<0.01) IVGP, OMD, ammonia and MB. The increment in gas production at 24 h for fresh and ensiled GP due to addition of PEG illustrates the positive influence of PEG addition, but not ensiling, on inactivation of tannins.

Tannin Dynamics of Propagules and Leaves of Kandelia candel and Bruguiera gymnorrhiza in the Jiulong River Estuary, Fujian, China

Changes in the total phenolics, condensed tannins (CT), protein-precipitable phenolics content and protein precipitation capacity were determined on a series of mangrove leaves from two true viviparous mangrove species (Kandelia candel and Bruguiera gymnorrhiza) at various stages of development and decomposition in the Jiulong River Estuary, Fujian, China. Similar measurements were also done for the propagules at different developmental stages. The results showed that the total phenolics, extractable condensed tannins, total condensed tannins, protein-precipitable phenolics content and protein precipitation capacity in young leaves were higher than those in mature and senescent leaves. Tannin dynamics during leaf decomposition varied with species, and the rapid loss of phenolics observed during decomposition can be ascribed to leaching and degradation. Protein-bound CT and fibre-bound CT tended to increase with leaf decomposition, with CT binding more strongly to protein than to fibre. Protein-bound CT was higher than fibre-bound CT with the exception of mature leaves. Total phenolics, extractable CT and protein-precipitable phenolics contents in flower tissues were relatively lower than those in hypocotyls at different developmental stages. Protein precipitation capacity fluctuated with the development of propagules. Increases in nitrogen in decaying litter, and declines in contents of total phenolics and total condensed tannins of detritus support the general conclusion that decomposing mangrove detritus can be a more palatable heterotrophic substrate than living leaves.

Tannins and Partial Consumption of Acorns: Implications for Dispersal of Oaks by Seed Predators

-A common assumption in studies of seed predation is that seeds survive attack and are dispersed only 'when animals fail to find seeds, drop undamaged seeds or fail to recover seeds after they are cached. This study, however, suggests that many acorn consumers consistently eat only a portion of the cotyledon of several species of acorns and thereby permit embryo survival. Several vertebrates [gray squirrels (Sciurus carolinensis), common grackles (Quiscalus quiscula) and blue jays (Cyanocita cristata)] were observed to consume only 30-60% of the cotyledon from the basal portion (cap end) of willow oak (Quercus phellos) acorns. Gray squirrels exhibited a similar preference for the basal end of acorns of several other species of red oaks (Q. rubra, Q. laevis, Q. nigra, Q. palustris and Q. coccinea) from a wide geographic region. In addition, acorn weevil larvae (Curculio sp.) were observed significantly (>35%) more often in the basal portion than in the apical end of Q. alba acorns. Chemical analyses of acorns from two tree species revealed that the concentration of protein-precipitable phenolics (primarily tannins) was 12.5% (Q. phellos) and 84.2% (Q. laevis) higher in the apical portion of the seeds where the embryo is located. Moreover, germination experiments revealed equal or greater germination frequencies for partially consumed acorns than for intact acorns. We suggest that the higher tannin levels may render the apical portion less palatable, and thereby increase the probability of embryo survival after attack by seed consumers.

Tannin levels in leaves of some oak species at different stages of maturity

AbstractTotal phenolics, condensed tannins, degree of polymerisation, protein precipitation capacity, protein precipitable phenolics and specific activity (protein bound per unit tannins) were determined in the leaves of four oak species at different stages of maturation (4 days old to 1 year old). The content of total extractable phenols was higher in younger leaves in Quercus ilex Linn, Quercus semecarpifolia Sm and Quercus serrata Roxb, whereas in Quercus glauca Thumb the content was higher in the mature leaves. In all species studied, condensed tannins increased with maturation. Protein precipitation capacity had a trend similar to that of total phenols. In Q serrate and Q semecarpifolia the apparent degree of polymerisation increased, and the content of protein precipitable phenolics and specific activity decreased as the leaves matured. The decrease in protein precipitation capacity with maturation in these two species may be explained by both the decrease in the content and the change in the nature of phenols capable of binding proteins. Protein precipitation capacity was not detectable in Q ilex leaves. Protein precipitation capacity in the mature leaves decreased in the order of Q serrata &gt; Q semecarpifolia &gt; Q glauca &gt; Q ilex.

Tannin levels and their degree of polymerisation and specific activity in some agro-industrial by-products

Tannins were determined by various chemical and biological methods in 15 agro-industrial by-products. Tannins in terms of total phenols (TP), condensed tannins (CT) and protein-precipitation capacity (PPC) were very high in Acacia nilotica and Theobroma cacao pods, Mangifera indica seed kernel, Panicum miliaceum polish and cakes of Madhuca indica seed and Garcinia indica. The correlation coefficients of PPC (measure of biological activity) with TP (0·81), degree of polymerisation (−0·83) and protein-precipitable phenolics (0·96) were significant ( P < 0·05), but that with CT (0·34) was not significant. It is inferred that TP rather than CT contribute significantly towards PPC and that highly-polymerised tannins do not bind proteins as efficiently as the lesser-polymerised ones. The TP and CT were low in pods of Prosopis juliflora and Pithecolobium saman, Cassia tora seeds, cakes of Guizotia abyssinica, Pongamia glabra, Schleichera oleosa, Hevea brasiliensis and Hibiscus cannabinus and Panicum miliaceum bran. The PPC could not be detected in these by-products, suggesting that these nine by-products can be considered safe for incorporation in livestock feed, subject to absence of other deleterious factors.

Total phenolics, condensed tannins, and protein-precipitable phenolics in young and mature leaves of oak species

Total phenolics, condensed tannins, and protein-precipitable phenolics in young and mature leaves of oak species