18 NEW HAMPSHIRE EXPERi:\IENT STATION [Bull. 261 



food supplies purchased and used at the fraternity house during this 

 week. This inventorj' included any kitchen refuse and table waste. Cal- 

 culation from standard tables of food values shows that the food listed 

 in this inventory as purchased and used during the week contained ap- 

 proximatel}' 430,000 calories and 16,000 grams of protein. The edible 

 waste of the prepared food, therefore, contained about 11 per cent of 

 the energy and 10 per cent of tlie protein of the purchased food. 



The energj' per gram of air-diy matter in the various samples 

 listed in Table 1 is fairlj- uniform. A considerable amount of salt pork 

 was included in Sample 743, and the energj- content per gram of air- 

 dry matter was high, 6.5 calories. During the time that Sample 751 was 

 being dried, a large amount of fat rose to the surface and prevented 

 further evaporation. This was removed and analyzed as a separate 

 sample (751B). There were in this sample 107 grams of visible fat, 

 nearly one-eighth of the entire weight, that could be skimmed oflf and 

 analyzed separately, and the energy- value of this fat was 9.3 calories 

 per gram. When the caloric value per gram of air-dry weight is found 

 by actual combustion to be materially above 5, therefore, it is logical to 

 reason that there is an excessive amount of fat present in the edible 

 waste. The energy' values of the other samples range only from 4.0 to 

 5.8 calories per gram of air-drj^ matter. The average value, if Samples 

 743 and 751B are excepted, is 5.0 calories. If the two fat samples were 

 included, without weighting in proportion to the actual weight of the 

 air-dry matter, the average would be raised to 5.3 calories. From the 

 study at this particular fraternity house, therefore, it may be inferred 

 that the caloric value per gram of air-dry matter of the average edible 

 waste from mixed foods is 5.0 calories. 



STUDY OF EDIBLE WASTE AND OF MIXED 

 MEALS IN SORORITY HOUSE S-1 



In one of the two sorority houses where observations were made 

 and which we are calling House S-1 for purposes of reference, fourteen 

 young women and a house mother ate regularly. Meals were prepared 

 by a student instead of a professional cook, and the food was placed on 

 the table in serving dishes, each girl heli)ing herself to a variable quan- 

 tity as suited her particular preference. Unused portions were left in 

 the pantry for between-meal lunches. The edible waste at House S-1 

 was collected for a period of two weeks. The girls were asked to save 

 not only plate scrapings but also edible cooked food that remained in 

 the cooking or serving dishes and that would ordinarily bo discarded. 

 Because of the economical u.'ie of "left overs" for cooking and for lunches 

 between meals, little was included, howe\-cr, in the collection of waste 

 except plate scrapings. The results of the analyses of the various sam- 

 ples obtained during the two-week period are given in Table 2. With 

 the exception of Sample 726, which contained tough meat and some 

 pudding, the wiistc samples represented only plate scrapings. Any waste 

 not included in the samples would be the small amounts remaining on 



