The Effect of Pretreatment Using Citric Acid As Anti-browning Agent In Freeze Dried Malang Apple (Malus Sylvestris) and Fuji Apple (Malus Pumila)

Abstract

PT. Frootiful Natural Nusantara, located in Kemang Barat, South Jakarta, is a company engaged in the food industry. The freeze drying process is one of the dehydration methods widely used in food industries. Freeze drying is a drying process of removing water content in a product by sublimation. Apples are one of the fruits that quickly undergo a browning reaction when peeled and exposed to air due to their enzymatic browning reaction caused by polyphenol oxidase (PPO). One of the methods used to control enzymatic browning in apples is applying an anti-browning agent. Citric acid is one of the anti-browning agents commonly used to prevent browning in apples and is categorized as an acidulant, which is used to delay the browning reaction by reducing the pH of the product to minimize the activity of PPO. The enzymatic browning of apple can considerably be reduced with the use of sugar solution. In this experiment, 0.5% citric acid and 40% sugar solution were used as the anti-browning agent to prevent enzymatic browning reaction in freeze dried Malang and Fuji apples. The citric acid and sugar solution successfully inhibited the browning reaction in Malang apple. However, the addition of the anti-browning agent did not successfully inhibit the enzymatic browning reaction in Fuji apple. Furthermore, the application of citric acid and sugar solution as an anti-browning reaction did not affect sensory properties, such as texture, shape, taste, and size. For further studies, it is recommended to measure the pH of each variety of apples. Increasing the concentration of the citric acid and adding other anti-browning agents with different mechanisms can be done to increase the efficiency of the anti-browning agents in inhibiting the enzymatic browning in apples.