Abstract
The Sicilian sumac (Rhus coriaria L.) is considered an excellent source of natural polyphenols whose antioxidant activity is able to affect specific technological functions. The effect of the Rhus coriaria addition on the quality of beef burgers before and after cooking was evaluated, by pH, colour, protein (-SH) and lipid oxidation, total phenol content and antioxidant activity (ABTS assay). The sumac in burgers (THs) resulted in a significant increase in all dry matter components (P < 0.05), while water content and pH value decreased. Furthermore, THs, compared with control burgers (CHs), were characterised by lower L* and peroxidation values and higher a* and b* values (p < 0.05). The Rhus added in the burgers positively influenced the total phenolic content and antioxidant activity values. Cooking reduced content of phenols, -SH groups and antioxidant activity. However, in THs the reduction of -SH, phenols and antioxidant activity was more limited than in CHs (p < 0.05). Sensory analysis showed a higher appreciation for THs by consumers for all the considered attributes. The ground meat incorporated with sumac could be a valid strategy to improve its quality and sensorial evaluation.