Edible Coating from Green Tea Extract and Chitosan to Preserve Strawberry (Fragaria vesca L.)

¹ Chemical Engineering Department, Engineering Faculty, Diponegoro University
² Environmental Engineering Department, Engineering Faculty, Diponegoro University
³ Membrane Research Centre (Mer-C), Center of Research and Services-Diponegoro University, Jl. Prof Soedharto, Tembalang, Semarang, Indonesia 50275

^* Corresponding author: dwi.titik07@gmail.com

Abstract

Food quality is an important factor in food sector. One way to increase the quality of food is by applying edible coating to slow down the degradation of foods quality. Combination of chitosan and green tea extract is one of the types of edible coating which many function as food preservative Green tea extract is chosen because of its high antioxidant contents. The goal of this research is to make a film from the composite of chitosan and green tea extract as a food coating and to observe the effect of chitosan concentration and the addition of green tea extract to the phenolic contents and antioxidant activity of the film. Moreover, this research also aims to apply chitosan film and green tea extract to foods, especially strawberries, and observing the effect of chitosan concentration and the addition of green tea extract to the shrinking of the fruit’s weight as well as its antimicrobial activities. Strawberries were coated with five different coating formula including one set as blank (uncoated fruit). The result of this research showed that the increasing of chitosan concentration and the volume of green tea extract addition also increase the antioxidant activity on the film. The phenolic contents on the green tea extract addition will also increase its phenolic contents as well. However, the increasing number of chitosan concentration can reduce the phenolic content on the film. Meanwhile, during the application to strawberries, it is found that 3% chitosan concentration which is combined with the addition of 2.5% green tea extract will minimize the shrinking of the fruit’s weight. Also 3% chitosan concentration will give a better antimicrobial activity. In the other side the addition of green tea extract will increase antioxidant activity, the addition of green tea extract also causing a decrease in antimicrobial activity.