Inhibitory impacts of Spirulina platensis and Chlorella vulgaris extracts on biogenic amine accumulation in sardine fillets

Inactivation of bacterial growth and their biogenic amine production in foods are essential for food safety and consequently human health. Spirulina platensis and Chlorella vulgaris are the most commonly used microalgae in the formulation of food products due to their high content of bioactive compounds with antimicrobial properties. In the present study, the influences of aqueous extracts of S. platensis and C. vulgaris (1%) on ammonia, trimethylamine and biogenic amines (BAs) were investigated in vacuum packaged sardine fillets at 4 +/- 1 degrees C for 15 days. The volatile aromatic compounds of extracts were also determined by gas chromatography-mass spectrometry (GC-MS). C. vulgaris and S. platensis extracts contained 8 and 7 components in total, of which the main components were 2-methyl-5H-dibenz[b,f]azepine (33.26%) and (3R)-3-phenyl-2,3-dihydro-1H-iso-indol-1-one (38.47%), respectively. BAs values fluctuated during storage and exhibited statistically significant differences among groups (P<0.05). Initial histamine level was 0.43 mg/100g and exceed the legal limits (10 mg/100 g) for the control on the 9th days. C. vulgaris extract was a stronger inhibitory impact on tyramine accumulation in fish meat than S. platensis extract, with 2-4 fold lower tyramine accumulation. Although the effectiveness of microalgae extracts on BAs accumulation differed, depending on amine type and storage time, C. vulgaris extracts appeared to be more effective in preventing production of ammonia and also most of toxicologically important BAs such as histamine and tyramine in fish fillets. Despite some restrictive effects of Spirulina extract, it was concluded that C. vulgaris extract could be more active and suitable preservatives on inhibiting BAs formation for food systems.