Improved Antioxidant Activity Of Fish Gelatin-based Films Incorporated With Guava Leaf Extract

The use of gelatin as a food packaging material has been increasing because of its excellent film formation ability,nontoxicity,and biodegradability.The religious restrictions as well as concern in safety of product derived from poultry leads fish gelatin to be bright as a better alternative.In this paper,fish gelatin-based films incorporated with 4 different plant extracts(Guava leaf,Anchan,Fruit blend,and Aloe vera)were prepared by casting method and the antioxidant activity and physicochemical properties of the film were analyzed.The main contents and results in this research are as followed:Firstly,the antioxidant activity of the 4 plant extracts was tested and all of the extracts showed high antioxidant activity,especially Guava leaf extract showed the highest activity among 4 plant extracts.Guava leaf extract efficiently scavenge DPPH radical(98.26%),ABTS radical(99.08%)and OH radical(92.92%).The fish gelatin-based films were perfectly prepared by the incorporation of plant extracts as natural antioxidant agent to prolong the shelf-life and keep the quality of food.The film forming solution of gelatin film incorporated with guava leaf extract(2%v/v)also exhibited the best antioxidant activity among 4 plant extracts by using three different assay.The DPPH,ABTS and OH radical scavenging activities were 97.55%,95.04%and 86.01%,respectively.Then,the mechanical properties of gelatin film were also determined.The results showed that the addition of extracts was beneficial to improve the mechanical properties of gelatin film.The tensile strength of gelatin film with guava leaf extract was 42.37±4.78MPa.The morphology and functional group interactions of gelatin based films were characterized by SEM,AFM and FTIR.The results showed that the surface roughness morphology of film slightly increase after the addition of extract into gelatin film and the formation of the hydrogen bonding between gelatin and plant extracts.Furthermore,film incorporated with guava leaf extract showed the highest absorption at 280 nm wavelength,which proved that guava leaf provide excellent light barrier properties against UV light and induce lipid oxidation as compare with others.At the same time,the addition of plant extracts can improve the WVP of film.Finally,in order to prepare edible packaging film with both high antioxidant and mechanical properties,the antioxidant gelatin-based films were also prepared by mixing guava leaves extract with 3 other plant extracts,respectively.The results showed that the mixture of guava leaves and anchan extract had strong antioxidant capacity,and the mechanical properties were also improved.The results indicated that the fish gelatin-based antioxidant films containing plant extracts have good potential as food packaging and extend food shelf life.