DUBROW: FISH PROTEIN CONCENTRATE 



Table 1. — Effect of drying temperature and time on the salt soluble protein and emulsi- 

 fying capacity of FPC. 



Tempera- 

 ture 



Time 



Kieldahl 

 soluble nitrogen' 



Soluble protein 

 (N X 6.25) 



Emulsifying 

 capacity 



1 Mean ± standard deviation. 



The effects of drying times and temperatures 

 on the residual IPA and total volatiles are shown 

 in Table 2. The sample of FPC dried overnight, 

 under ambient conditions, had a residual IPA 

 content of 2.0%, The samples dried at 40° to 

 50°C averaged 2.76% IPA; 60° to 70°C aver- 

 aged 2.62%; 90° to 100°C averaged 2.53%; 110° 

 to 120°C averaged 2.42 %r ; and 140° to 150° av- 

 eraged 1.45%, Retention of alcohol residues of 

 about 1 to 2% has been obtained even under 

 prolonged drying for up to 4 hr at 70° to 80°C. 



Table 2. — Effect of drying temperature and time on 

 the total volatile and residual isopropyl alcohol contents 

 of FPC. 



Temperature 



Time 



Total 

 volatiles 



Residual isopropyl alcohol' 



Wet solids 

 Ambient 

 40-50 



60-70 



90-100 

 110-120 

 140-150 



2.76 



2.62 



2.53 



2.42 



1.45 



' Mean ± standard deviation and mean of the two groups combined. 



In general, the total volatile content of the 

 FPC's ranged from 5 to 10% except those dried 

 at 140° to 150°C, which contained from 2.4 to 

 3.2% volatiles. 



EXPERIMENT II: EFFECT OF 



DESOLVENTIZING ON 

 FUNCTIONAL PROPERTIES 



The results obtained from the drying tests 

 were used to set up the second phase — desolven- 

 tizing. Thus, the solids dried at ambient tem- 

 peratures, which yielded the least loss in pro- 

 tein solubility, were used to steam desolventize. 

 Also, the effect of desolventizing wet solids was 

 determined. In this phase, whole menhaden 

 (Brevoor'tia tyrannus) were used for solvent 

 extraction because previous observations had 

 shown this species to be subject to greater color 

 differences than red hake. 



MATERIALS AND METHODS 



Preparation of Samples 



Twenty pounds of whole menhaden were ex- 

 tracted with IPA by the same manner as de- 

 scribed for hake in Experiment I. After ex- 

 traction, one-half of the wet solids were dried 

 at ambient temperature and pressure overnight 



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