American Potato Journal

, Volume 56, Issue 2, pp 63–69 | Cite as

Effect of pH and temperature on the hydrolysis of disodium acid pyrophosphate (SAPP) in potato processing

  • Keng C. Ng
  • M. L. Weaver


Disodium acid pyrophosphate (SAPP) is used in the potato industry for preventing after-cooking darkening of cooked and oil-blanched French-fried potato. SAPP-treated potatoes often develop a bitter off-flavor chemical taste due to large amounts of PO4 absorbed from hydrolysis of SAPP solution. SAPP hydrolyzes directly to orthophosphate. Hydrolysis rate depends directly upon temperature and pH of the solution. The best control of after-cooking darkening is attained at pH 5 at 20–25°C. Increasing the concentration of SAPP solution has little effect on its stability at various temperatures and pH, and also made no great improvement on the color of the French-fry strips after par frying.

Key words

Disodium Acid Pyrophosphate Hydrolysis Temperature pH 


El pirofosfato disódico (SAPP) es usado en el procedimiento de la papa para prevenir el ennegrecimiento de la papa cocida y frita. Las papas tratadas con SAPP frecuentemente desarrollan un sabor amargo debido a la gran absorción de PO4 de la solución de SAPP.

SAPP se hidroliza directamente a ortofosfato. La velocidad de la hidrólisis depende directamente de la temperatura y pH de la solución. El mejor control del ennegrecimiento de la papa después de cocinada se obtiene a pH 5 á 20–25°C. El incremento de la concentración de SAPP tuvo poco efecto en su estabilidad a varias temperaturas y pH, y no provocó gran mejoramiento en el ctlor de las papas fritas después de una fritura pareja.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

Literature Cited

  1. 1.
    Bell, R.N. 1947. Hydrolysis of dehydrated sodium phosphates. Ind Eng Chem 39:136–140.CrossRefGoogle Scholar
  2. 2.
    Greig, W.S., and Ora Smith. 1955. Potato quality IX. Use of sequestering agents in preventing after-cooking darkening in pre-peeled potatoes. Am Potato J 32:1–6.Google Scholar
  3. 3.
    Hawkins, W.W., M.G. Chipman and V.G. Leonard. 1959. After-cooking darkening in oil-blanched French-fried potato, Am Potato J 36:255–261.Google Scholar
  4. 4.
    Hunsader, M., and F. Hanning. 1958. Effect of complexing and chelating agents on the after-cooking discoloration of potatoes and upon the iron and phenolic content of juice. Food Res 23:269–273.Google Scholar
  5. 5.
    Martin, J.B., and D.M. Doty. 1949. Determination of Inorganic phosphate. Anal Chem 21:965–967.CrossRefGoogle Scholar
  6. 6.
    Smith, Ora and C.O. Davis, 1960. Preventing discoloration in cooked and French-fry potatoes. Am Potato J 37:352.Google Scholar
  7. 7.
    Smith, Ora and C.O. Davis. 1962. Potato quality XIII. Preventing after-cooking discoloration in oil blanched French fries. Am Potato J 39:45–56.Google Scholar

Copyright information

© Springer 1979

Authors and Affiliations

  • Keng C. Ng
    • 1
  • M. L. Weaver
    • 1
  1. 1.Western Regional Research CenterBerkeley

Personalised recommendations