Phytase Analysis, Pitfalls and Interpretation of FTU for Biological Efficacy Mike Bedford 1 & Ralf Greiner 2 1 AB Vista Feed Ingredients Ltd, Woodstock Court, Blenheim Rd. Marlborough, Wilts UK. SN8 1QJ 2 Max Rubner-Institute, Federal Research Institute of Nutrition and Food, Department of Food Technology and Bioprocess Engineering, Haid-und-Neu- Straße 9, 76131 Karlsruhe, Germany
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Phytase Analysis, Pitfalls and Interpretation of FTU for Biological Efficacy
20.10.2010 10MRI – Department of Food Technology and Bioprocess Engineering
pyridoxalphosphate
o-phospho-L-serine
14
12
o-phospho-L-serine
GTP
0
0
0
0
Interpretation of FTU for Biological EfficacypH stability and susceptibility to pepsin degradation
pH stabilityresidual activity after 24 hrs at pH 2 5 and 4°C; faba bean phytase: 22%residual activity after 24 hrs at pH 2.5 and 4 C; faba bean phytase: 22%, P. agglomerans phytase: 31%, Malaysian waste-water bacterium phytase: 95%
susceptibility to pepsin degradationin vitro at pH 2.0: Escherichia coli, Klebsiella sp., Malaysian waste-water bacterium, Yersinia rohdei phytase: more than 80% of initial activity, Aspergillus niger phytase: 26-42%, Peniophora lycii phytase: 2-20%
digesta supernatant of the stomach: Bacillus subtilis phytase: 68% Aspergillusdigesta supernatant of the stomach: Bacillus subtilis phytase: 68%, Aspergillus niger phytase: 60-70%, Peniophora lycii phytase: 59%
20.10.2010 11MRI – Department of Food Technology and Bioprocess Engineering
Interpretation of FTU for Biological Efficacyphytate degradation pathway
phytate degradation pathway / initiation site of phytate dephosphorylationanimal feeding studies do not give any clear indication that differences inanimal feeding studies do not give any clear indication that differences in bioefficacy are based on the position of initiating phytate dephosphorylation
InsP6 and InsP5 dephosphorylation capacity seems to be important for bioefficacy; 6 5 p p y p y p y;(a complete transformation of dietary phytate into myo-inositol tetra- and –trisphosphates in the stomach seems to be much more important for bioefficacy of supplementary phytase than a complete dephosphorylation of single phytate pp y p y p p p y g p ymolecules)
20.10.2010 12MRI – Department of Food Technology and Bioprocess Engineering
Thank You Very MuchThank You Very MuchyyFor Your Attention !For Your Attention !
Dr. Ralf Greiner
Department of Food Technology and Bioprocess EngineeringMax Rubner-InstituteFederal Research Institute of Nutrition and FoodFederal Research Institute of Nutrition and FoodHaid-und-Neu-Straße 9 • D-76131 KarlsruheTel.: ++49 (0)721 6625 300 • Fax: ++49 (0)721 6625 [email protected] • www.mri.bund.deg @
20.10.2010 13MRI – Department of Food Technology and Bioprocess Engineering