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This paper offers an improved method of constructing thermal destruction curves (T.D.C). It summarizes data on the times and temperatures required to kill salmonellae in various egg products. Also, additional data are presented and T.D.C. are constructed for a wide range of conditions. Further evidence is obtained that Z for salmonellae varies in different products. Water activity influences Z. This concept provides a better method of predicting thermal process conditions. The data indicate that T.D.C. for different products intersect near a common point. A point of intersection was determined by minimizing the sum of the squares of the differences between the observed and hypothetical slopes of the T.D.C. This point for several egg products was at 29,240 minutes and 42.3°C.

Nutrient composition analyses of three commercially spray-dried whole egg, white, and yolk products were conducted. Samples were obtained from industrial sources, pooled, packaged under a nitrogen atmosphere (except white), and stored under refrigeration. Values were obtained for total nitrogen, lipid, calories, ash, amino acids, minerals, fatty acids, and vitamins. An equation, whole egg = .28 egg white + .72 egg yolk, relates the amounts of each component in the three products. Prior to this work most data on egg products were adapted from shell egg values.Calculation of percent discrepancy-WEcalc. = .28EW + .72EY. (WEC» lc --WE°bs.)/w E obs. X 100 = percent discrepancy.

The emulsifying properties of egg yolk containing 10% sodium chloride pasteurized by two methods were determined: One, a high temperature-short time method involved the use of heat treatments for five min. at 62°, 67°, 73°, and 78° C. The other, a low temperature-long time method involved holding times of 2, 4, 6 and 8 days at 52° C. Samples were evaluated immediately after pasteurization, as well as after storage for one week at 10° and -20° C. Phase inversion titrations with oil and water were used to determine emulsifying capacity. Natural egg yolk contains strongly polar phospholipids and lipoproteins, as well as weakly polar-cholesterol. The former supports o/w emulsions and the latter w/o emulsions. Neither emulsifier system appeared very sensitive to heat damage. Hence, salted egg yolk can be pasteurized at higher temperatures than previously used or investigated without damaging its emulsifying properties. Storing the product after pasteurization tended to reduce the oil needed to invert the emulsion from an o/w to w/o type, which suggests that storage may be more important than pasteurization conditions.