Effect of Ginger Extract on Lipid Oxidation and Microbial Growth During Frozen Storage of Rohu (Labeo rohita) Steaks

Abstract

Steaks of Labeo rohita (Rohu) were treated with aqueous extract of the rhizome of ginger (Zingiber officinale) before storage at -16 ± 2°C in domestic refrigerator and sensory, chemical and microbiological changes have been reported. Ginger extract (GE) was used as a source of natural antioxidants and antimicrobials for retarding lipid oxidation and microbial growth during low temperature storage. The proximate composition, phytochemicals and total phenolic content of ginger were determined. Fish steaks were treated with single and double strength GE for one/two minutes. Sampling was done at monthly intervals. Sensory study revealed that the GE-treated samples were acceptable up to 90 and 120 days respectively for treatment of one and two minutes, whereas, shelf-life in control was found to be of 60 days only. In GE-treated samples, the increase of peroxide value and thiobarbituric acid value was found significantly lower than the control. Total plate counts (log cfu g-1) decreased in all the treatments during storage. Total coliform and total psychrophilic count also decreased during storage. Rate of decrease of microbial count was enhanced in treated samples than control. The muscle stiffness as usually experienced in frozen-stored meat products was not perceived in the GE-treated samples by the sensory panel judges