610 ANNUAL. REPORTS OF DEPARTMENT OF AGRICULTURE. 



as regards the energy expended by women in various household 

 tasks ; and to the consumption of the various classes of goods in the 

 household. One outcome of this last phase of the work is the in- 

 creasing realization of the importance of economic data in the con- 

 sideration of home-economics problems. Various features of work 

 of the office during the year were as follows : 



Results of experiments with various fruit jellies made with and 

 without pectin extracts from citrus peel or apples were used as a basis 

 for Department Circular 254, " Homemade apple and citrus pectin 

 extracts and their use in jelly making," which was published during 

 the year. Continuing this work, an effort was made to find a house- 

 hold method of extracting the citrus peel in acid solution which 

 would increase the pectin yield. Lemon juice, citric acid, and tar- 

 taric acid were compared as to suitability for this purpose. There 

 were found to be great discrepancies between apparent pectin content 

 as indicated by the amount of alcohol precipitate and jellying power. 

 In autoclave extracts the alcohol precipitate determined in the usual 

 way was from 60 to more than 100 per cent higher, whereas the 

 jellying power was from 25 to 100 per cent lower, than in com- 

 parable extracts from the same materials prepared in the open 

 kettle. The percentage of alcohol precipitate in lemon extracts is 

 considerably lower than that in orange extracts, yet the jellying 

 power of lemon extracts is about 20 per cent higher. A paper re- 

 porting this work was prepared for publication. 



Determinations of internal temperature of cooked foods were 

 continued, rates of heat penetration through different kinds of 

 animal tissue being compared. The cause of discrepancies in pub- 

 lished reports as to relative rates of penetration into the bone and 

 fatty and muscular tissues was ascertained. These facts have a 

 bearing upon time-tables for the cooking of different cuts of meat 

 of different sizes in the oven and in fireless and pressure cookers, 

 as well as upon destruction of animal parasites and toxins and 

 possibly vitamins. The internal temperatures necessary for certain 

 color changes denoted by the terms " rare," " medium," and " well 

 done," were ascertained for leg-of-lamb roasts, and for lamb, beef, 

 and veal chops, steaks, and cutlets of varying conditions and sizes 

 cooked by different methods. It was shown that the quantity of 

 heat penetrating the tissue rather than the final temperature at- 

 tained internally is often the effective factor. Determinations of 

 internal temperature are being continued with eggs cooked in 

 different ways and with various batters and doughs. 



An instrument for making numerical records of the breaking 

 strength and crushing strength of experimental pastries is being 

 designed. 



A paper on methods of determining consistency of culinary fats 

 was prepared as a result of cooperative work with the Bureau of 

 Standards. 



Studies of the best ways of improving the bread made by home 

 methods from certain types of soft winter-wheat flour are in prog- 

 ress. Five separate factors have been segregated, which are of 

 particular importance in case of these weaker flours. 



Methods of cooking vegetables continued to receive attention from 

 the standpoint of nutritive and table qualities. In cooperation with 



