The impact of applying natural clinoptilolite (zeolite) on the chemical, sensory and microbiological changes of vacuum packed sardine fillets

Different doses (1% and 5%) of natural zeolite were applied to determine quality changes in vacuum packaged sardine fillets during 19 days at 4 +/- 1 degrees C. Zeolite had an effect to improve sensory quality of sardine especially for removing off-odour. The acceptable shelf life of vacuum packaged sardine was 8 days for control and 12 days for groups treated with 1% and 5% zeolite. The zeolite application resulted in significant reduction in total volatile basic nitrogen values, except for group treated with 5% zeolite at 15 days. Although the effect of zeolite depended on dose and specific storage days, application of zeolite had no effect on free fatty acid analysis. The use of zeolite significantly reduced ammonia and biogenic amine accumulation, especially for histamine and tyramine. The result of the study showed that the efficacy of zeolite as natural antimicrobials was high and lower dose of zeolite has to be applied to get maximum preservation effect.