Antioxidant starch films containing sunflower hull extracts

Abstract

[EN] This study exploits sunflower hulls that are by-product from food industry for the extraction of valuable antioxidant compounds that can be used to produce antioxidant food packaging material based on starch. Fast and easy methanolic extraction of milled hulls resulted in an antioxidant extract with 137 mg GAE/100 g hulls and an antioxidant activity against DPPH* with an EC50 value of 73.5 mg raw hull material/ mg DPPH* and chlorogenic acid as main active compound. Already low amounts of extracts (1-6%) were sufficient to produce compression molded starch-glycerol films with antioxidant capacity without the loss of barrier properties. Films with the highest content of antioxidant extract showed the highest antioxidant activity and the lowest oxygen and water vapor permeability. These films were tough but less stretchable. A potential industrial use of these starch films could be in antioxidant packaging as a very thin layer in multilayer food packaging as oxygen barrier and antioxidant capacity.