RITSKES: ARTIFICIAL RIPENING OF MAATJES-CURED HERRING 



FRACTION NUMBER 



Figure 1. — Chromatogram of the clarified brine of gutted 

 maatjes herring on Sephadex when herring were ripened 

 naturally. 



( 1959 ) . Pr 8 had a proteolytic activity of 5.3 X 

 10^ U/mg and a lipolytic activity of 0.04 Des- 

 nuelle units/mg; for TG 21/63, these values were 

 9.1 X 10-^ and 18.7, respectively. These prepa- 

 rations, like all others used in this study, were 

 supplied by N. V. Organon, Oss, the Netherlands. 

 Details concerning these preparations are sum- 

 marized in Table 2. 



The proteolytic activity of the preparations 

 was found by measuring the caseinolytic activity 

 at pH 7.5 and 35° C (Ruyssen, 1969) . The NF- 

 pancreatin reference standard was used (see 

 National Formulary XIII, 1970, p. 514). The 

 potency of the protease preparations is expressed 

 in terms of the minimum activity required by 

 NF XIII. The lipase activity was measured 

 by potentiometric titration of fatty acids hydro- 

 lyzed in an olive oil emulsion at pH 8.0 (Marchis- 

 Mouren, Sarda, and Desnuelle, 1959). The In- 

 ternational F.I. P. standard for pancreas lipase 

 was used as a standard (Ruyssen, 1969). One 



unit forms 1 /umol fatty acid per minute under 

 the conditions of the assay. 



In order to eliminate the effect of the intestinal 

 enzymes, the fish was gutted before the enzyme 

 preparations were added. 



One part of salt was added to seven parts of 

 herring (w/w). The fish was kept at 15° C 

 for 3 weeks. Analyses were taken after 1, 2, 

 and 3 weeks; organoleptic evaluation took place 

 after 2 weeks. 



Four variations were tested: (a) gutted; (b) 

 gibbed; (c) gutted and 2.0 g of Pr 8 per kg 

 herring added; (d) gutted and 1.2 g of TG 21/63 

 per kg herring added. 



^ft^<^' 



FRACTION NUMBER 



Figure 2. — Chromatogram of the clarified brine of gibbed 

 maatjes herring on Sephadex when herring were ripened 

 naturally. 



Table 2. — Enzyme preparations used in the e.xperiments. 



649 



