Research On The Preparation Of Edible Film Incorporated With Natural Pigment And Its Application On Anti-photo Oxidation Of Lipid

The incorporation of red color into edible packaging material is particularly encouraged due to its ability to absorb visible light(from 400-500 nm)and protect the food from photo-oxidation.Recently,the incorporation of natural pigments into edible films has got consumers' attention due to their natural source and safety over synthetic pigments.Moreover,edible packaging materials with antioxidant properties can be prepared through incorporation of functional ingredient like anthocyanin.In the present study,composite films with antioxidant properties were fabricated by adding anthocyanin and the capability of restraining the oxidation of oil was determined.Sweet potato red was selected as optimum additive according to the stability of color and ABTS free radical scavenging tests.Hydroxypropyl methyl cellulose and methyl cellulose material HPMC and MC were compared and HPMC was selected as film matrix after evaluating the effect of natural pigment on composite film properties including optical,mechanical,water barrier,water contact angle,glass transition temperature etc.Both contact and non-contact models were tested to evaluate the efficiency of restraining oxidation and consequently an increase in anti-oxidation ability of natural color containing HPMC film was observed with the increasing content of natural pigment.The mechanism of hinder oil oxidation was different and was studied by photo-oxidation comparison test excluded oxygen permeate,oxygen barrier,WVP,and its anti-oxidation activity.There was no difference between NCF and SCF observed in photo-oxidation and WVP.Hydrogen bond was found in between HPMC matrix and polyphenol structure of anthocyanin which caused loose of network.Consequently,the better oxidation barrier of NCF compared to SCF came from the anti-oxidation function of anthocyanin which increased with the content of anthocyanin.Citric acid added to film composition to improve the stability of natural red color containing film and some properties such as color storage,mechanical strength,WVP and POV values were investigated and 10% addition of CA was found best.The plasticizing capacity was found in blended films during characterization of Tg and SEM analysis.However,improved natural color films successfully protected oil from oxidation.The mechanical properties of NCF incorporated with CA were enhanced by the addition of nano cellulose fiber.The tensile strength of 4% addition natural color film corporate with CA was improved to 48.4 Mpa,which improved 15.7% than the film without CA.