Study of Antioxidant and Antimicrobial Activity of Date Seed Extract and its Effects on Physicochemical, Microbial and Sensory Properties of Cupcake

Date seed as waste product can be used widely for many applications and nowadays many studies are carried out on its properties as natural preservative of food products. In this study, antioxidant and antimicrobial properties of different date seed extracts and their effects on the physicochemical, microbial and sensory properties of cupcakes were investigated. The date seed extract was obtained by using the water solvent and shaker method. The antioxidant activity of the extract was evaluated using DPPH radical scavenging method. The results showed that increasing the concentration of the extract increases the antioxidant activity. IC50 of date seed extract 1568.93 mg/L was calculated. The total phenol content of the extract was 119.53 ± 0.28 mg Gallic acid/gram extract. The antimicrobial activity of the extract against Salmonella typhimurium was evaluated by using minimum inhibitory concentration (MIC) and minimum bactericidal concentration (0.08 and 0.4 mg/ml respectively). The fraction of the extract components was evaluated using a high-performance liquid chromatography and different phenolic compounds such as Gallic acid, Catechin, Chloregenic acid, Rutin, Vanilin, p-Coumaric acid, Sinapic acid were identified. The extracts were added to the cupcake formulation at 4 levels 0, 0.05, 0.1 and 0.2%. Peroxide number, acidity, pH, proximate analysis and sensory evaluation tests were performed on cupcake samples. All cakes containing different concentrations of the extract (0, 0.05, 0.1 and 0.2µg/ml) were in the standard range for physicochemical properties. The total microbial count was performed for 28 days at 7-day intervals. The sample containing 0.2% of the date seed extract in terms of the microbial count was in the appropriate range, and in terms of sensory properties, the overall evaluation also received the highest score. Due to the presence of phenolic compounds and antioxidant and antimicrobial activity, date seed can be used as a natural inexpensive preservative in food formulations.