Fish gelatin monolayer and bilayer films incorporated with epigallocatechin gallate: Properties and their use as pouches for storage of chicken skin oil

The properties of monolayer and bilayer fish gelatin films and the corresponding films containing epigallocatechin gallate (EGCG) were examined. Bilayer films showed higher tensile strength, water vapor and light barrier properties but also higher opaqueness and yellowness than monolayer films. No differences in elongation at break and oxygen barrier property between monolayer and bilayer films were observed. Those films were used to produce pouches, in which chicken skin oil (CSO) was packaged. CSO packaged in the pouches prepared with the films containing EGCG showed lower peroxide value (PV), thiobarbituric acid reactive substances (TBARS) and volatile compounds after 30 days of storage in comparison with that packaged in low-density polyethylene (LDPE) pouch. Additionally, at the end of the storage, linoleic acid (C18:2 n-6) and linolenic acid (C18:3 n-9) were more retained in CSO packaged in the pouches made from the films containing EGCG. Therefore, monolayer or bilayer gelatin films incorporated with EGCG could be used as packaging for oils prone to lipid oxidation.