Effect of natural colourants and nitrites on colour attributes of frankfurters

The colour attributes in a control and six more treatments of frankfurters (18% fat) produced with natural colourants and two levels of NaNO2 (0 and 1 50 mg/kg) were studied. The following natural colourants, permitted by the EU 94/36 guideline, were used: E 100 curcumin (CU), E 120 carminic acid (CA ), E 150a caramel (CR), E 160a beta-carotene (BC), E 160g paprika-extract ( PE) and E162 betanin (B). CA, B, BC and PE significantly increased the redn ess of batter, while BC, PE and CU increased (p < 0.05) the yellowness. NaN O2 decreased (p < 0.05) the redness of batters in all treatments. Frankfurt ers with CA had the highest a* value followed by those with BC, PE and B. B C, PE and B increased the yellowness of frankfurters. NaNO2 increased (p < 0.05) the redness of frankfurters in all treatments. The storage of frankfu rters for 4 weeks had no effect on redness and yellowness of frankfurters. Exposure either for 2 h in sunlight or for 4 h in artificial light had no s ignificant effect on redness and yellowness of frankfurters from all treatm ents. Canned frankfurters (117 degrees) with B had the greatest decrease in redness while those with BC the greatest increase in yellowness. Frankfurt ers with B were the most acceptable from the consumers according to their c olour followed by these with PE. Frankfurters with B had also the highest s core for overall acceptability, followed by those with CA and nitrites. By employing discriminant analysis on the data, equations were derived for the identification of the natural colourant used in the production of frankfur ters. Results from frankfurters, produced with 0, 3.6, 14.4 and 28.8 mg of pure B kg and 100 and 150 mg/kg NaNO2, have shown that the level of NaNO2 c an be reduced from 150 to 100 mg/kg with appropriate increase in B level an d frankfurters with 14.4 mg B/kg were the most acceptable from the consumer s according to their colour. (C) 1999 Elsevier Science Ltd. All rights rese rved.