## 3 Results and Discussion
### Lipid Oxidation
#### 3.2.2 Tbars  
TBARS values of all samples tested were presented on the Figure 2. Oxidative stability of the samples was significantly affected by the time and treatments (\(p<0.05\), test F). The TBARS values of the control sample stored at 4 \({}^{\circ}\)C increased significantly till the end of the period tested, whereas for the samples with the addition of spice extracts TBARS values increased up to 7 th day of storage, thereafter decreased slightly and increased again. This could result from the lipid-protein interaction during oxidation processes [40]. The initial TBARS values for the treated samples ranged from 0.47 (allspice) to 0.73 (cardamom) mg MDA/kg and were not significantly different, except cardamom sample, from the control one (0.40 mg MDA/kg) (Figure 2). Except day 0, TBARS values in the control sample were higher than in the samples containing spice extracts on all other analysis days. As shown on the Figure 2 cloves and allspice were the most potent inhibitors of TBARS formation in raw ground chicken meat throughout the storage period which was corroborated by their high ABTS* radical scavenging activities (Table 1). Black seed was also very effective antioxidant in raw chicken meat, although the extract showed low radical scavenging activity. The inhibitory effects of spice extracts on TBARS formation were as followed: Cloves \(\approx\) allspice \(\approx\) black seed \(\geq\) nutmeg \(\approx\) caraway \(\approx\) bay leaf \(>\) cardamom \(>\) control. Our findings confirmed the results of other authors who had added various plant extracts and thereby inhibited the development of lipid oxidation in chicken raw meat [9; 11; 12; 13; 29; 41].  
Although there was not any legislative limit of TBARS concentration in meat samples, TBARS value over 0.5 mg MDA/kg indicated some oxidation (rancid flavor) and above 1.0 mg MDA/kg as  
Figure 1: Effect of various spice extract treatments on conjugated dienes (CDs) in raw ground chicken legs during 12 days of storage at 4 \({}^{\circ}\)C. Means with the various superscript within the same day are significantly different (\(p\leq 0.05\), Duncan’s test). Vertical bars indicate 0.95 confidence intervals.  
possibly unacceptable level by consumers [42]. Thus, based on the results obtained in this study, clove-treated sample would be perceived as rancid after 12 days, allspice-treated sample after 7 days, and black seed-treated sample after 5 days whereas the control and other samples after 3 days of storage (Figure 2). However, apart from cardamom on 12 th day of storage, TBARS values of all treated samples remained under threshold value of 1.0 mg MDA/kg over the storage period. As reported by [9] TBARS values of the raw chicken breast containing aqueous clove extract gained the unacceptable level of 1.0 mg MDA/kg on 6 th day of storage. Thus, it could be stated that 50% aqueous ethanol extract of cloves used in this study (Figure 2) was more effective antioxidant agent in raw chicken than the aqueous extract. Moreover, in our previous study [13] almost all treated pork meat samples (except nutmeg-treated sample) were characterized by TBARS values lower than 0.5 mg MDA/kg, irrespective of storage time. This proves that lipid oxidation in chicken meat is more favorable than in pork and that meat matrix plays important role in the extent of the lipid oxidation process. The results of TBARS formation were positively correlated with the results of CD content in chicken meat with the r Pearson's coefficient of 0.46 (\(p<0.05\), Student's t test).