In studying the influence of acid and sugar on the initial coagulation temperature of egg white (different proportions of sugar and acid added to egg white, placed in test tubes for heating) it was found that sugar increased but acid lowered the initial coagulation temperature of the egg white. Adding both sugar and acid in proportions used in cakes raised the temperature at which coagulation of the egg white started. However, in spite of the lowered initial coagulation of the egg white by the addition of acid, its addition increased the tenderness of the egg white. In the test with egg white coagulated at various temperatures it was found that the lower the temperature at which coagulation occurred the more tender the egg white.

"With increases in altitude it has been shown that the amount of expansion during baking increases; the cake becomes more tender; the final cake volume changes and is related to tenderness; the amount and rate of evaporation increases; the maximum internal cake temperature decreases; the volume of the vapor escaping increases; and the color of the crust becomes lighter."

Peet and Lowe baked angel food cakes in six ranges, three electric, two gas, and one kerosene. Cakes were baked in ranges cold at the start and in preheated ovens.

The results of analysis of scores showed that the judges did not differentiate among cakes baked in the different ranges for total score, texture, and eating quality. However, for these same points the judges thought the cakes baked in the preheated ovens were superior to those baked in the same ranges from a cold start. Furthermore, these differences, as shown by analysis of variance, were highly significant.

The scores for moistness were higher for cakes baked in preheated ovens but these results were not analyzed statistically.

Tenderness was tested in two ways, one subjective and one objective test. The analysis of scores for tenderness indicated that the cakes baked in some ranges were more tender than cakes baked in other ranges. The statistical analysis showed that these results were significant. The judges, as indicated by scores, considered there were still greater differences in tenderness of cakes baked from a cold and from preheated starts, than for cakes baked in different ranges. These results were highly significant, the cakes started in preheated ovens being tenderer than those baked from a cold start. The analysis of data obtained by tensile strength measurements also indicated significant differences in tenderness of cakes baked in different ranges and highly significant differences between cakes started in cold and preheated ovens, those started in preheated ovens being more tender. The correlation coefficient between the two methods of testing tenderness was - .4014, which was significant. This indicates that in general there was agreement in the two methods of testing tenderness.

The volumes of cakes varied in the different ranges, the results being significant, i.e., cakes of larger volume were obtained in some ranges than in others. The volumes of cakes baked in preheated ovens were greatest, and the differences were significant.

Burke and Niles made angel food cake on the same day of the week throughout the year, from eggs of the same age, produced by the same flock on controlled feed for the duration of the experiment. The quality of the cakes, at first fairly good, decreased to a low in November. After a slight rise in December there was again a decline in January. A notice-able increase in quality occurred in February and March. They state that the egg-white foams during the "low" and "high" periods seemed to differ in the time required to beat to the stiff stage. During the "low" period the whites seemed much stiffer and less tender than those in the "high" when beaten for the same length of time. They state that perhaps, if the amount of beating were standardized according to some factor other than time for beating, excellent cakes could be made during the "low" months as well as the "high."

One cake each week was baked at 350°F. for 45 minutes, and three cakes at 325°F. for 1 hour. Consistently throughout the year the moisture loss was less and the volume usually noticeably larger for the cakes baked at the higher temperature. The average moisture loss for the year was 11.2 and 9.6 per cent, and the average volume 7.79 and 7.85 cm., respectively, for cakes baked at 325° and 350°F.

King, Whiteman, and Rose investigated the effect on the cake-making quality of some egg-production factors. The physical and chemical measurements of eggs, cake batter, and sponge cake were the same as those reported for King, Morris, and Whiteman, with the exception that elasticity or recovery of the cake crumb is added in the present study. They found that five different diets of the hens did not affect the properties of the eggs or the quality of the cake made from them. Most of the eggs used were obtained over a period of seven months (December-June), beginning about three months after the hens started laying, and were collected and dipped in mineral oil saturated with carbon dioxide. They found no progressive change in the properties of the eggs or the quality of the cakes over the period in the laying cycle of the hen or the seasons of the year studied. As in the earlier study they found no apparent relationship between the physical and chemical properties of the eggs studied and the quality values of the cakes.

"There was a relationship between the specific volume, elasticity, and compressibility of the sponge cakes, and between the pH and specific gravity of the batter from which the cakes were baked.

"Findings of an earlier study which indicated that there is no relationship between pH and CO2 content of egg white were confirmed."

Formulas for angel cake. Because formulas mean more to many cooks than equations, the data in Table 43 have been compiled.