The objective of the research study was to determine the effect of cranberry (Oxycoccus palustris) and rose (Rosa rugosa) juices, and the mixture thereof added to pork burgers, which were thermally processed, chilled for 1 day, vacuum packed, and stored for 7 days at a temperature of 3 to 7 °C, on oxidative changes occurring in those products. To the meat mass, either a cranberry or a rose juice was added in the amount of 5 % (of the meat weight) or a mixture thereof (1:1), also in the amount of 5%. Furthermore, the effect was determined of the similar juices added to a raw beef stuffing and, then, stored at a temperature of 4 to 6 °C for 3 to 5 days under 600 lux fluorescent lighting, on the colour parameters of the stuffing. The products analyzed were made of minced meat that was previously frozen and stored for a period not exceeding 3 months, and, next, defrosted. In the burgers, there were determined, among other things: TBARS, colour parameters, and pH. It was proved that the rose juice contained more L-ascorbic acid (by 200-fold more) and more phenolics (by 13 %) than the cranberry juice. Therefore, its effect on the process of inhibiting oxidative changes in the pork burgers was stronger. A 5% addition of the rose juice caused TBARS of burgers to decrease by 9 times the value of the control sample, whereas the same amount of the cranberry juice added caused TBARS to decrease only twice or by 3 times the value of the control sample . A higher pH was also a plus point of the rose juice compared to the cranberry juice; owing to this fact, the rose juice did not significantly affect the yield of burgers after their thermal treatment (84.2 ± 1.0 % vs. 87.2 ± 1.9 % of the control sample). However, the rose juice caused the colour of the burgers to turn darker. The rose juice proved to be a weaker colour stabilizer of the raw beef stuffing than the cranberry juice. It was found that the meat colour stabilization mechanism in the case of cranberry juice was complex and covered more than only its antioxidative activity.
rose juice, cranberry juice, pork burgers, beef stuffing, colour parameters, TBARS