The antioxidative properties of Holy basil and Galangal in cooked ground pork

The ethanolic extracts from Holy basil and Galangal were examined for their extraction yield, total phenolic content, antioxidant activity against a β-carotene–linoleic acid emulsion system, DPPH scavenging activity and reducing power. Ethanolic extracts of Holy basil exhibited higher extraction yield, total phenolic content, antioxidant activity, DPPH scavenging activity and reducing power than ethanolic extracts of Galangal. Antioxidative efficiency to inhibit lipid oxidation of dried Holy basil and dried Galangal powder, ethanolic extracts of Galangal and Holy basil and commercial antioxidant mixture in cooked ground pork was investigated during refrigerated storage at 5 °C for 14 days. The quantitative measurements of thiobarbituric acid reactive substances (TBARS), conjugated diene, peroxide value (POV) and hexanal content were used as indicators of lipid oxidation. Increased levels of TBARS value, POV and hexanal content were noticed in all meat samples during storage, however most marked in cooked ground pork without antioxidants, whereas conjugated diene tended to decrease with increasing storage time. Ranking of the treatment in order of their antioxidant effectiveness showed that commercial antioxidant mixture (0.3% citric acid + 0.5% ascorbic acid + 0.02% α-tocopherol) > dried Galangal powder > dried Holy basil powder > ethanolic extracts of Galangal > ethanolic extracts of Holy basil > control. Furthermore, in cooked ground pork samples a high correlation between TBARS value and hexanal contents was obtained.