Characteristics of gelatin/sarcoplasmic protein films supplemented with red water lily petal extract

Abstract

Red water lily petal (RWLP) is a source of active compounds and its extract exhibited DPPH radical scavenging ability for 87.58 ± 0.21 %. The inhibition against E. coli was more pronounced than S. aureus, suggesting more effective to inhibit gram negative bacteria rather than gram positive bacteria. The RWLP extract (RWLPE) was then added into edible film made from a 1:1 ratio of gelatin and sarcoplasmic protein prior analyzing for their physicochemical properties, antioxidant and antimicrobial activities. RWLPE did not affect mechanical properties, water vapor permeability, and film thickness regardless of the concentration added. However, film solubility was increased upon adding RWLPE but this increasing was not depended on the concentration. The changes in color were found as increase in redness and yellowness upon adding the RWLPE. Infrared spectroscopy revealed that structural alteration of protein in edible film was pronounced by the action of RWLPE. Antioxidant activity of edible film was increased by adding RWLPE, concomitant with an increasing inhibition activity against E. coli. Based on the results, incorporating RWLPE into edible films shows promise for increasing their antioxidant and antimicrobial activity, thereby contributing to extending the shelf life of food products.