Application of microliposome of ferula leaves extract on shelf life of beef burger during refrigerated storage

Despite the development of methods to increase the shelf life and safety of food products, the economic loss caused by food spoilage is still considered one of the main challenges of  food industry. Due to the culture of the use of natural products and functional foods, the consumer's desire for natural products with extended shelf life has increased. Phenolic compounds, like many bioactive compounds, gradually become inactive and usually cause a bitter taste in food. Microliposome is one of the effective solutions to increase the stability and reduce the unpleasant taste of bioactive compounds. In this research, the Ferula leaves was extracted with ethanol and its phenolic and flavonoid properties were determined. Then, the antioxidant properties of the extract were determined by DPPH and β-carotene/linoleic acid assay at different concentration (400, 800, 1600 and 3200 PPM). Then it was added to beef burger in the form of liposomes and the oxidative, microbial and sensory characteristics and the release rate of phenolic compounds in beef burger were investigated over two weeks’ storage. The results showed that the total phenolic and flavonoid content of the Ferula leaves extract was 270.67 ± 5.8 mgGA/ g extract and 160.81±5.65 mg Quercetin/g extract, respectively. With the increase in the concentration of Ferula extract, the DPPH radical inhibition increases from 33.73 to 84.42% and β-carotene-linoleic acid from 32.56 to 74.90% at 400 to 3200 PPM. The results obtained on the shelf life of beef burger showed that the highest microbial growth and lipid oxidation were observed in the control, and the lowest one was observed in the sample containing 3200 PPM Ferula extract. Based on the oxidation test and sensory evaluation, adding microliposome of Ferula leaves extract at 1600 PPM can significantly increase the shelf life of beef burger in the refrigerator.