DUBROW and STILLINGS : FPC PROCESSED FROM HEATED RED HAKE 



microbiologically by the method of Henderson 

 and Snell (1948). Available lysine was deter- 

 mined by the method described by Carpenter 

 (1960). 



We found only slight changes in the concen- 

 trations of amino acids in the samples (table 2). 

 The treatments that we used did not consistently 

 affect the concentrations of amino acids, except 

 for cystine and available lysine. The concen- 

 tration of cystine was reduced in the sample 

 heated at 121° C for 80 min. The concentrations 

 of available lysine were slightly lower in the 

 samples heated at 100° and 109° C for 20 min. 

 The reason for these decreases is not apparent 

 to us. 



Evans and McGinnis (1948) previously re- 

 ported that cystine was reduced when soybeans 

 were autoclaved at 130° C for 60 min. 



NUTRITIONAL QUALITY 



The nutritional quality of the samples was 

 determined in a feeding study using rats. Diets 

 were prepared that contained 10 ''r protein from 

 the heated samples, the nonheated sample, or 

 casein. The diet that contained the nonheated 

 sample served as a control, and the one that 

 contained casein served as a reference standard. 

 The composition of the basal diet was described 

 earlier by Stillings, Hammerle, and Snyder 

 (1969). 

 Male weanling rats of the Carworth Farms 



CFE strain were received when they were 22 

 days old. The rats were housed individually 

 in cages with screen bottoms and were kept in 

 an air-conditioned room maintained at about 

 23° C. During the first 2 days, the rats were 

 fed a basal diet containing 15% casein. They 

 were then allotted to groups on the basis of 

 weight, and the groups were randomly assigned 

 to different diets. Each group contained 10 

 rats, and the rats were offered feed and water 

 ad libitum for 4 weeks. 



The amount of feed consumed was recorded 

 three times each week, and the gains in weight 

 were determined once each week. At the end 

 of the experiment, the protein efficiency ratio 

 was determined by dividing the gain in weight 

 by the weight of protein consumed. 



The data were analyzed statistically. Dif- 

 ferences between means were determined by 

 Tukey's procedure as described by Steel and 

 Torrie (1960: 109). 



Table 3 shows the data on the nutritive qual- 

 ity of the FPC samples. Based on the gain in 

 weight, intakes of feed, and protein efficiency 

 ratios, the quality of the samples that were 

 heated at 100° and 109° C was not significantly 

 different from the quality of the control, which 

 was not heated. Samples that were heated at 

 121° C, however, had a lower quality than the 

 control sample. In general, the quality of the 

 samples heated at 100° and 109° C was equal 

 to that of casein or was slightly higher than 



Table 2. — Amino acid composition of FPC samples prepared from hake that were heated for varying times and 



temperatures before being extracted with solvent. 



143 



