Process to destroy biological activity in protein-containing feed

A method for destroying infectious activity of Bovine Spongiform encephalopathy (BSE) containing proteins in feed products produced from a proteinaceous mixture contained in packing house waste, poultry, poultry by-products or livestock carcasses, comprising the steps of:

• a) treating the proteinaceous mixture by adding an alkali to cause the pH of the mixture to be raised to a basic pH range where proteins in the proteinaceous mixture will be solubilized to form a gel;
• maintaining the proteinaceous mixture at a temperature above the melting point of a lipid material, in a range between about 50.degree. to 55.degree. C.;
• optionally adding sufficient lipid material, to the alkali-treated proteinaceous mixture to provide a dispersion with a ratio of lipid to proteinaceous mixture in a range from about 5 to 80, respectively;
• b) determining an optimum pH of solubilization wherein that optimum is expressed as an alkali hydrogen ion difference on a hydrogen ion difference curve,
• c) measuring rate of change of hydrogen ion difference per unit of acid equivalent,
• d) ceasing, addition of alkali when the slope of the titration curve is essentially zero,
• e) adding an acid to the lipid material/proteinaceous mixture dispersion to cause pH of the dispersion to be lowered to an acidic endpoint where the proteins in the dispersion will encapsulate the lipid material;
• the acidic endpoint being defined by
• i) determining a pH of encapsulation by titration wherein that pH of encapsulation is expressed as an acidic hydrogen ion difference on a hydrogen ion difference curve,
• ii) measuring rate of change of hydrogen ion difference per unit of acid equivalent,
• iii) ceasing addition of acid when the slope of the titration curve is essentially zero.

A method for destroying infectious activity of BSE containing proteins in feed products produced from a proteinaceous mixture comprising the steps of:

• a) treating the proteinaceous mixture by adding an alkali to cause the pH of the mixture to be raised to a basic pH range where proteins in the proteinaceous mixture will be solubilized to form a gel;
• maintaining the proteinaceous mixture at a temperature above the melting point of a lipid material, in a range between about 50.degree. to 55.degree. C.;
• optionally adding sufficient lipid material, to the alkali-treated proteinaceous mixture to provide a dispersion with a ratio of lipid to proteinaceous mixture in a range from about 5 to 80, respectively;
• b) determining an optimum pH of solubilization wherein that optimum is expressed as an alkali hydrogen ion difference on a hydrogen ion difference curve,
• c) measuring rate of change of hydrogen ion difference per unit of acid equivalent,
• d) ceasing addition of alkali when the slope of the titration curve is essentially zero,
• e) adding an acid to the lipid material/proteinaceous mixture dispersion to cause the pH of the dispersion to be lowered to an acidic endpoint where the proteins in the dispersion will encapsulate the lipid material;
• the acidic endpoint being defined by
• i) determining a pH of encapsulation by titration wherein that pH of encapsulation is expressed as an acidic hydrogen ion difference on a hydrogen ion difference curve,
• ii) measuring rate of change of hydrogen ion difference per unit of acid equivalent,
• iii) ceasing addition of acid when the slope of the titration curve is essentially zero.