Abstract:
The present study examined the effects of Allium paradoxum (M.B.) G. Don. and Eryngium caucasicum Trauve. extracts on the lipid oxidation and quality deterioration indices, microbiological as well as sensory characteristics in silver carp (Hypophthalmichthys molitrix) fillets during storage at 4â °Câ ±â 1. Treatments applied in the study including the following: control (without plant extracts), 2% and 4% (w/v) plant extracts. The addition of plant extracts significantly delayed oxidative deterioration in silver carp fillets during refrigerated storage as shown by the PV, TBARS, Acid Value and TVBâ N data (Pâ <â 0.05). The results also showed that natural compounds from A. paradoxum and E. caucasicum extracts resulted in lower bacterial growth in fish fillets during the refrigerated storage period. Comparing to the control samples, the psychrophilic bacterial counts (PTC) and total viable count (TVC) values for the E. caucasicum (2.0%) and E. caucasicum (4.0%), A. paradoxum (2.0%), A. paradoxum (4.0%) treatments were above the acceptability limit (7 logâ â colonyâ forming unit/g) at the end of 6, 9, 12, 9 and 15th day of storage, respectively. It was observed that addition of A. paradoxum at 4% to fish fillets increased its shelfâ life while the addition of E. caucasicum at 4.0% made a positive effect on sensory quality. These results suggested that A. paradoxum and E. caucasicum extracts have the potential to be used as natural preservatives for shelfâ life extension of fish products. PRACTICAL APPLICATIONS: The exploration of naturally occurring antimicrobials in food preservation receives increasing attention because of consumer awareness of natural food products. Biopreservatives are useful in extending the foods shelfâ life, reducing or eliminating pathogenic bacteria and increasing the overall quality of food products. In this work, we evaluated the effects of two natural extracts, from Allium paradoxum and Eryngium caucasicum, on the fish product quality, such as rancidity indices, microbiological and sensory qualities during refrigerated storage. To our knowledge, the application of A. paradoxum and E. caucasicum extracts in shelfâ life extension of fish product has not been studied previously. The present study showed that both E. caucasicum, A. paradoxum extracts, regarding to their antioxidant and antibacterial properties, could efficiently retard microbial growth, delay chemical deterioration, maintain or improve sensory attributes and extend the shelfâ life of the silver carp fillets during refrigerated storage.
