Antioxidant efficacy of rice bran extract on stabilisation of ghee under accelerated oxidation condition.

The antioxidant efficacy of rice bran extract on the oxidative degradation of ghee under storage conditions of 63°C was studied by adding different concentrations of methanolic extracts to ghee. The antioxidant-treated and control samples were analysed at regular intervals to assess the extent of oxidative changes and quality markers by measuring oxidative indices (free acidity, peroxide value, p-anisidine value, TOTOX value, thiobarbituric acid and conjugated diene), fatty acid composition, FTIR spectra and sensory attributes. During storage, the oxidative indices of samples increased. The increment was faster in untreated samples as compared to the treated samples, thus confirming the slower release of oxidation products in treated samples. Ghee incorporated with bran extract displayed a stronger ability to quench DPPH radicals; this can be attributed to the antioxidant potency of bran extract. Moreover, the solvent extract showed dose-dependent efficacy and increasing the concentration of the extract led to increased effectiveness in inhibiting lipid oxidation. In FTIR, the peak intensities in the control ghee were markedly changed in comparison with the treated ghee during storage. The effects of extract addition on ghee on fatty acid composition were unremarkable during storage. The colour and flavour scores of the samples decreased up to the end of storage and the bran extract fortified ghee samples were more acceptable to the panellists than the control ghee. It can be concluded that the bran extract was found to be quite effective towards suppressing the formation of oxidation products in the tested ghee. [ABSTRACT FROM AUTHOR]