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Phytic acid, mineral cations and phytase interactions

Phytic acid, mineral cations and phytase interactions. Roselina Angel – University of Maryland Todd Applegate – Purdue University. Phytic Acid. Fe. Zn. Protein. Ca. Starch. Protein. Cu. P C H O.

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Phytic acid, mineral cations and phytase interactions

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  1. Phytic acid, mineral cations and phytase interactions Roselina Angel – University of MarylandTodd Applegate – Purdue University

  2. Phytic Acid Fe Zn Protein Ca Starch Protein Cu P C H O

  3. Cation “Impairment” of P hydrolysisvs.Cation “release” capacity of phytase

  4. Background • Mineral inhibition of phytase • Maenz et al. (1999) • Zn2+> > Fe2+ >Mn2+ >Fe3+ >Ca2+ >Mg2+ • Soluble Ca - chelate at 1 mM Ca : 10 mM phytate • Soluble Zn - chelate at equal concentrations Zn : phytate • Mineral complex stability • Vohra et al. (1965) • Cu2+>Zn2+ >Ni2+ >Co2+ >Mn2+ >Fe3+ >Ca2+ • Maddaiah et al. (1964) • Zn2+>Cu2+ >Co2+ >Mn2+ >Ca2+ • At the same pH

  5. Cation Inhibition of Phytate Hydrolysis* Maenz et al., 1999 * mM mineral conc. for 50% inhibition

  6. Cation Inhibition of Phytate Hydrolysis* Maenz et al., 1999 * mM mineral conc. for 50% inhibition

  7. 2 mmol Phytic Acid + 30 mmol Calcium [Corn/SBM dietary phytic acid + 0.9% Calcium (2:1; H20:feed)] Angel and Applegate, 2000

  8. 2 mmol Phytic Acid + 30 mmol Calcium [Corn/SBM dietary phytic acid + 0.9% Calcium (2:1; H20:feed)] pH = 2.5 Angel and Applegate, 2000

  9. 2 mmol Phytic Acid + 30 mmol Calcium [Corn/SBM dietary phytic acid + 0.9% Calcium (2:1; H20:feed)] pH = 6.5 pH = 2.5 Angel and Applegate, 2000

  10. 2 mmol Phytic Acid + 30 mmol Calcium [Corn/SBM dietary phytic acid + 0.9% Calcium (2:1; H20:feed)] pH = 6.5 pH = 2.5 Angel and Applegate, 2000

  11. 2 mmol phytic acid+ 30 mmol Calcium [corn/SBM St diet phytic acid content+ 0.9% Ca (2:1; H20:diet)] 100 100 100 97.9 84.7 62.1 51.7 26.4 11.1 7.9 1.5 % of the phytic acid P in solution Angel, 2007

  12. 2 mmol Phytic Acid+ 30 mmol Calcium [Corn/SBM St diet phytic acid content + 0.9% Ca (2:1; H20:diet)] 100 100 100 97.9 84.7 62.1 51.7 26.4 11.1 7.9 1.5 % of the phytic acid P in solution Proventriculus/ Gizard Proximal duodenum Distal duodenum to Ileum Angel, 2007

  13. Ca & IlealPhytate-P Hydrolysis: Chick * * Applegate et al., 2003

  14. Ca & IlealPhytate-P Hydrolysis: Chick % Tamim et al 2003, 2004, unpublished Applegate et al., 2003

  15. Ca & IlealPhytate-P Hydrolysis Tamim et al., 2003, 2004, unpublished; Applegate et al., 2003

  16. Phytic Acid + 250 ppm Cu (CuSO4) pH = 6.5 pH = 2.5

  17. Copper Sulfate addition to Broiler Diets Phytase U/kg Banks & Applegate, 2003

  18. Copper Sulfate addition to Broiler Diets a a,b b c Phytase U/kg Banks & Applegate, 2003

  19. Copper Sulfate addition to Broiler Diets a -0.055 (% of diet) a,b b -0.066 (% of diet) c Phytase U/kg Banks & Applegate, 2003

  20. Pang & Applegate, 2004

  21. Cu source & Phytase activity – pH6.5 CuSO4 CuCl TBCC Cu-Lys Cu-Citrate Pang & Applegate, 2004

  22. Apparent Phosphorus Retention (% of diet) as affected by Cu source a b b b c c Lysinate Chloride Sulfate Citrate 0.20 nPP 0.40 nPP 0 0 250 250 250 250 ppm Cu Banks & Applegate, 2004 a-c: P≤ 0.05

  23. Ca & Micro-mineral source – in vivo Phytate – P hydrolysis Ca: P < 0.0001Micro mineral: P=0.39Ca*Micro: P = 0.63 ------ 0 % Calcium ------ ------ 0.5 % Calcium ------ Tamim & Angel, 2003

  24. Conclusions(& Unresolved questions…….) • Calcium has a huge impact on PP hydrolysis. This effect is heavily affected by pH --- but even at acidic pHs it can influence PP hydrolysis by phytase • In laying hens vs chicks – lower impact of phytase on PP release. Possibly because of better PP hydrolysis in the absence of phytase • Cu (up to 250 ppm) & Zn (up to 160 ppm) have inconsistent impacts on PP hydrolysis & no effect on phytase efficacy (i.e. no interaction of phytase * Cu –or- phytase * Zn)

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