The application of antioxidants extracted by the organic solvents have limited applications in foods due to their toxicity. Most of the antioxidants of date palm fruit (Phoenix dactylifera L.) are soluble in water. Antioxidant activity of water soluble natural antioxidants of date palm fruit using ice cream as an oxidation substrate has not been studied previously. This study has been planned with the objective to study the antioxidant characteristics and oxidative stability of ice supplemented with aqueous date palm fruit extract.
Date palm fruit extract were prepared by extracting 20 g date with 100 ml distilled water, followed by concentration and filtration. Ice cream were supplemented with date palm fruit extract at 200, 400, 600, 800 ppm and tertiary butylated hydroxy quinone 200 ppm concentrations. Ice cream were filled in plastic cups and stored at -18oC for 60 days.
Antioxidant characterization of date palm fruit extract was performed by yotal phenolic contents, DPPH free radical scavenging activity. Oxidative stability of ice cream was determined by peroxide value, anisidine value, changes in fatty acid profile sensory evaluation were performed at 0, 30 and 60 days of storage period.
Date palm fruit extract was characterized for antioxidant capacity, total phenolic contents of date palm fruit extract were 7.51% (GAE).DPPH free radical scavenging activity of date palm fruit extract was 78.8% as compared to 80.5%. Supplementation of ice cream with date palm fruit extract did not have any significant impact on fat, protein and total solids content.
Results indicated that peroxide value increased during the storage of 60 days in all the treatments and control. Rise in peroxide value was strongly correlated with the addition and dose of date palm fruit extract. Control had the highest peroxide value, followed by T1, T2, T3 and T4. Peroxide value of control and ice cream samples added with TBHQ (200 ppm) were not different
from each other (p<0.05). After 60 days of storage, anisidine value of control, T1, T2, T3, T4 and TBHQ added samples were 13.62, 10.58, 8.49, 7.36, 6.89 and 6.39, respectively.Flavor score of control, T1, T2, T3, T4 and TBHQ added ice cream were 8.2, 8.1, 8.0, 8.0, 8.1 and 8.2.
Date palm fruit extract 600 and 800 ppm can be sued for the long term stabilization of ice cream.