Toksikologi Pakan: Tannins

Outline
Toksikologi Pakan: Tannins
A.
B.
C.
D.
E.
F.
Introduction
Structure
Interaction
Analytical methods
Biological effects
Treatments/processing methods
Anuraga Jayanegara
Department of Nutrition and Feed Technology
A. Introduction
Plant secondary compounds
- Do not function in primary metabolism such as biosynthesis,
biodegradation and other energy conversions of intermediary
metabolism
- Do have diverse biological activities ranging from toxicity to hormonal
mimicry
- May play a role in protecting plants from herbivory and disease
- Examples: alkaloids, terpenes, phenolics
Classification
Condensed tannin (CT, proanthocyanidins): oligomers of two or more
flavan-3-ols such as catechin, epicatechin, or gallocatechin.
Hydrolysable tannin (HT): consisting of a central core of carbohydrate to
which phenolic carboxylic acids are bound by ester linkage.
Tannins, definition
Water-soluble phenolic compounds that have ability to precipitate
proteins
Department of Nutrition and Feed Technology
Department of Nutrition and Feed Technology
Why plants produce phenolics?
A strategy adopted by plants to deter attack by microorganisms,
insects and higher animals.
Factors affecting tannin levels:
- Nutrient stress (N, P, K, S deficiencies)
- High light intensity
- High temperature
- Severe drought
- Tissue damage
Department of Nutrition and Feed Technology
Department of Nutrition and Feed Technology
B. Structure
Diversity of tannin structures
Hydrolysable tannin (HT)
Condensed tannin (CT)
Department of Nutrition and Feed Technology
Source: Mueller-Harvey (2006)
J. Sci. Food Agric. 86, 2010-2037.
Department of Nutrition and Feed Technology
Increase tannin
levels
C. Interaction
Illustration of protein precipitation by tannins
Multiple hydroxyl groups: enable phenolics to form complexes
with proteins, polysachharides and minerals.
Tannin-protein complex:
1. Hydrogen bonds: free phenolic hydroxyl groups
2. Hydrophobic bonds: aromatic ring structures
3. Covalent bonds: polymerization reactions due to heating,
exposure to UV radiation and the action of polyphenol
oxidase
Marangon et al. (2010)
Analytica Chimica Acta 660, 110-118
Department of Nutrition and Feed Technology
Department of Nutrition and Feed Technology
D. Analytical methods
- Categorized into: (1) chemical methods, (2) protein precipitation
methods, (3) gravimetric assays, (4) tannin bioassay, (5) Others.
- Chemical assays:
- Total phenols and total tannins: Folin-Ciocalteu (oxidation-reduction),
ferric chloride (metal-complexing property of phenolics)
- Condensed tannins: vanilin assay, butanol-HCl assay
- Hydrolysable tannins: rhodanine method, HPLC
- Protein precipitation assays: ninhydrin assay, BSA method, radial
diffusion assay
- Gravimetric methods: ytterbium acetate, PVPP
- Tannin bioassay: in vitro gas production + PEG (e.g. Jayanegara &
Sofyan, 2008)
E. Biological effects
Negative effects:
- Decreasing nutrient utilization, in particular protein utilization
- Decreasing feed intake
- Toxicity and death of animals
Positive effects:
- Prevention of bloat
- Protection of protein from rumen degradation
- Mitigating methane emission
- Modulation of PUFA biohydrogenation in the rumen
- Controling of gastro-intestinal nematode parasites
More detailed methods ....
Department of Nutrition and Feed Technology
Department of Nutrition and Feed Technology
Decreasing nutrient utilization
Toxicity problems
Department of Nutrition and Feed Technology
Department of Nutrition and Feed Technology
Prevention of bloat
Protection of
protein from
rumen
degradation
Department of Nutrition and Feed Technology
Department of Nutrition and Feed Technology
Mitigating methane emission
• Global warming
• Loss of energy
Evidences:
- Jayanegara et al. (2009), Animal Feed Science and Technology 150, 230237
- Jayanegara et al. (2009), Media Peternakan 32, 120-129
- Jayanegara et al. (2010), Sustainable Improvement of Animal Production
and Health (Odongo, N.E., Garcia, M., Viljoen, G.J. (Eds.)), FAO, Rome,
pp. 151-157
- Jayanegara et al. (2011), Animal Feed Science and Technology 163, 231243
- Jayanegara et al. (2012), Journal of Animal Physiology and Animal
Nutrition 96, 365-375
- Jayanegara et al. (online first), British Journal of Nutrition
Source: Morgavi et al. (2010)
Animal 4, 1024-1036
Department of Nutrition and Feed Technology
Department of Nutrition and Feed Technology
Ruminal methanogens attached to protozoal
species interspecies H transfer
Protozoa-associated methanogens contribute
up to 37% of total rumen methane emissions
Removal of protozoa from the rumen
(defaunation) may ↓ CH4 emission
Source: Bhatta et al. (2009)
J. Dairy Sci. 92, 5512-5522
Department of Nutrition and Feed Technology
Phenolics and microbial population
Protozoa colonized by
methanogens
Department of Nutrition and Feed Technology
Modulation of PUFA biohydrogenation
• Reduce the risk of
α-Linolenic acid
cardiovascular disease
• Lowering plasma
cholesterol level
Linoleic acid
Rumenic acid
Vaccenic acid
• Prevent cancer
proliferation
• Decrease atherosclerosis
• Improve immune system
Stearic acid
Source: Chilliard et al. (2007)
Eur. J. Lipid Sci. Technol. 109, 828-855
Department of Nutrition and Feed Technology
Condensed tannins (CT)
Source: Khiaosa-ard et al. (2009)
J. Dairy Sci. 92, 177-188
CH: grass-clover hay (control)
TF: dried sainfoin (7.9% CT)
TH: CH + A. mearnsii extract (7.9% CT)
SH: CH + Y. schidigera extract (1.1% saponins)
Department of Nutrition and Feed Technology
Influence of tannins on biohydrogenating bacteria
Inhibition of phenolics on lipase activity
Containing 6.4% tannins
from quebracho powder
Source: Vasta et al. (2010)
Appl. Environ. Microbiol. 76, 2549-2555
Department of Nutrition and Feed Technology
Source: Van Ranst et al. (2011)
Animal 5, 512-521
Department of Nutrition and Feed Technology
F. Treatment methods
Other evidences:
- Jayanegara et al. (2011), Animal Production Science 51, 1127-1136
- Jayanegara et al. (2012), Livestock Science 147, 104-112
- Palupi et al. (online first), Journal of the Science of Food and Agriculture
- Wood ash: a good source of alkali; 10% solution of oak wood ash
decreased the content of TP, CT and protein precipitation capacity by 66,
80 and 75% in oak leaves, respectively.
- Urea-ammoniation: 4% urea in fresh leaves.
- Drying: but not effective.
- Chemicals: extraction with organic solvents (30% acetone, 50%
methanol, 40% ethanol) removed ca 70% tannins from oak leaves.
- Solid-state fermentation: biodegradation of tannins using white-rot
fungi.
- Addition of tannin-binding polymers: PEG (polyethylene glycol)
incorporation, PVPP.
Department of Nutrition and Feed Technology
Department of Nutrition and Feed Technology
Department of Nutrition and Feed Technology
Department of Nutrition and Feed Technology
Thank you for your attention!
Department of Nutrition and Feed Technology
Department of Nutrition and Feed Technology