The antioxidative properties of mustard leaf (Brassica juncea) kimchi extracts on refrigerated raw ground pork meat against lipid oxidation

Abstract

The efficacy of varying concentration of mustard leaf kimchi ethanolic extracts (MK) in retarding oxidative rancidity was tested with raw ground pork. Freshly ground pork meat was assigned to one of the following five treatments: control (no antioxidants); AC-0.02 (0.02% ascorbic acid); MK-0.05, 0.1, and 0.2 (0.05%, 0.1% and 0.2% MK, respectively). The pH of the samples decreased and the TBARS values and free fatty acids (%) increased considerably (P<0.05) during storage. The total bacterial count was lower in MK-0.1 and MK-0.2 than the control during storage. The internal L* value and a* value decreased (P<0.05) with the addition of MK. The internal b* value of MK treatments were higher (P<0.05) than that for the control and increased incrementally with MK concentration. The TBARS values and free fatty acids (%) of MK-0.02 was lowest among the treatments. The peroxide value of the control increased until 7 days and reached the maximum value at a certain storage time and decreased thereafter. In the other treatments it increased. All treatments had lower concentration of conjugated dienes (P<0.05) compared to the control sample, after the first day. Mustard leaf kimchi ethanolic extracts exhibited a protective effect against lipid oxidation in raw ground pork.