Quality enhancement of frozen Nile tilapia fillets using rosemary and thyme oil

Citation

Elhafez MA, Yehia N, Amin R, Emam W, Hamouda S & El-Magd MA (2020) Quality enhancement of frozen Nile tilapia fillets using rosemary and thyme oil [Melhoria da qualidade de filetes de tilápia do Nilo congelados com óleo de alecrim e tomilho]. Arquivo Brasileiro de Medicina Veterinária e Zootecnia, 72 (5), pp. 1821-1829. https://doi.org/10.1590/1678-4162-11855

Abstract
The food industry and the frozen fish sector in particular have benefitted greatly from advancements in food processing technologies. This study investigated the effect of adding natural antioxidants such as rosemary and thyme oil to frozen fillets of Nile tilapia (Oreochromis niloticus) in order to preserve their quality for consumers. Fillets were treated with rosemary and thyme at two concentrations (1% and 1.5%) and then were stored at 4°C. Samples were analyzed over 4 days for bacteriological (aerobic plate count, psychotropic count, and coliform count), chemical (determination of pH, thiobarbituric acid reactive substances-TBARS, and total volatile base nitrogen-TVB-N), and sensory quality examination (color, texture, and odor). Significant differences (P < 0.05) were observed among different groups in terms of aerobic plate count, psychotropic count, and coliform count during the storage. Moreover, pH, TVB-N, and TBARS mean values in the treated groups were lower than those in the untreated group. The best sensory quality was obtained at the highest concentrations (1.5%) of thyme and rosemary oil.

Keywords
nile tilapia; rosemary; thyme; shelf life; TBARS; TVB-N

Journal
Arquivo Brasileiro de Medicina Veterinária e Zootecnia: Volume 72, Issue 5

• Published version