The Effect of pH and Certain Additives on Turkey Meat Pigments in Model and Meat Systems

Authors

Douglas M. Janky, University of Nebraska-Lincoln

Document Type

Thesis

Date of this Version

8-1971

Citation

Thesis (M.S.)—University of Nebraska—Lincoln, 1971. Department of Food Science and Technology.

Comments

Copyright 1971, the author. Used by permission.

Abstract

A series of experiments were designed to show the effect of myoglobin state, pH, Neo-Cebitate and Kena on the stability of myoglobin to heat and the color of cooked meat emulsions.

The nature of the myoglobin derivative appeared to have an effect on the amount of pigment denatured by temperature in a crude myoglobin extract.This denaturation may be increased by the lowering of the pH or the addition of Neo-Cebitate.The addition of Kena to the extract tends to reduce the amount of denaturation at any given temperature studied.Mb+ appeared to be more stable to heat denaturation than either Mb or MbO₂.This may be due to the increase in polarity of Mb+ caused by the positive charge on the iron of the heme group.Mb and MbO₂ may form a green pigment, possibly cholemyoglobin, when heated to 70⁰C in the presence of Neo-Cebitate.Mb+ in the solution (normally brown in color) forms a green pigment in the presence of Neo-Cebitate + Kena at temperatures of 70⁰ to 90⁰C.This pigment was undefined.

The nature of the myoglobin derivative itself, in a meat system, seemed to have no effect on the color values of the cooked product.However, in combination with Neo-Cebitate, there was a derivative effect to increase redness.Mb+ seemed to cause the greatest increase in redness.MbO₂ was found to cause a slight greening in emulsions adjusted to pH 5.5.This may have been due to acid cleavage of the porphyrin ring.Advancing pH values tended to increase the redness values of all sausages in their adjusted state, but especially the values for sausages adjusted to Mb+.Mb+ was also shown to affect a greening reaction on the outside surface of the cooked emulsion when treated with Neo-Cebitate.This pigment had a reflectance spectrum similar to that of canned green tuna and may be cholemyoglobin.

Although further research is indicated in many areas of this research, it seems that pH and Neo-Cebitate may adversely affect the color of poultry meat products.

Advisor: Glenn W. Froning