Development of gelatin/chitosan film incorporated with lemon essential oil with antioxidant properties

Abstract

This study aims to evaluate the physical, chemical, and mechanical properties of gelatin/chitosan (Ge/Ch) films enriched with different ratios of lemon essential oil (LEO; 0.25–0.50–0.75–1%) and Ge/Ch (60%/40%) based film without LEO as control. Total phenolic compound content (TPCC) of film samples enriched with LEO were found between 120.3 mg/kg and 276 mg/kg. Antioxidant activity values of LEO containing Ge/Ch films were found between 13.12% and 69.99%. As a result, it was determined that with increased LEO ratio, TPCC and antioxidant activity increased. In general, the higher LEO concentration-incorporated Ge/Ch films had better mechanical properties than the Ge/Ch film. The higher LEO concentration-incorporated Ge/Ch films were opaque and more resistant to light transmission. Considering the effect of LEO on consumers’ preference, the optimum LEO ratio has been determined as 0.75%. Fresh red apple slices were coated with Ge/Ch based film, Ge/Ch based film containing 0.75% LEO, and some samples were not coated for control purposes. All these samples were stored at + 4 °C in the refrigerator for 7 days. Total mesophilic aerobic bacteria count (TMABC) was not at detectable levels in apple slices coated with Ge/Ch films containing 0.75% LEO during storage. The Ge/Ch film incorporated with 0.75% LEO showed the best overall properties. This composite material could be a good preference for extending the shelf life of apples and decreasing food waste. Ge/Ch films incorporated with LEO have good physical, mechanical, and chemical properties therefore this natural material combination could be a green alternative to synthetic compounds for food packaging application.