Mandarin citrus (Citrus reticulata Blanco cv. Terigas) peel essential oil as a potential nanoemulsion ingredient: Formulation, physicochemical characterization, and antibacterial activity

¹ Doctoral Program of Food Science, Faculty of Agricultural Technology, Brawijaya University, Malang, 65145 Indonesia
² Food Science and Biotechnology Department, Faculty of Agricultural Technology, Brawijaya University, Malang, 65145, Indonesia
³ Research Center for Agroindustry, National Research and Innovation Agency, (BRIN), Soekarno Integrated Science Center, Bogor, 16911, Indonesia

^* Corresponding author: sdmintos@ub.ac.id

Abstract

Citrus peel essential oil can be a complementary component in food and cosmetics. Volatile molecules, such as limonin, can be useful as antibacterial agents. The hydrophobic nature of essential oils causes problems when used in commodities under normal storage conditions. Nanoemulsion technology is the most effective method to increase hydrophilicity and facilitate the application of substances to various products. This study aims to utilize Mandarin cv. Terigas citrus peel waste into essential oils using hydrodistillation with aquades solvent. The essential oil is then processed into a nanoemulsion to characterise its physicochemical and antimicrobial properties against Listeria monocytogenes bacteria. Essential oils are formulated as nanoemulsions with several concentrations (1.5%, 2%, 2.5%). The nanoemulsions obtained were then tested for their physicochemical characteristics and antimicrobial activity. The results showed that the essential oil yield was 3.661%, and 40 volatile compounds were found from GC-MS analysis. Nanoemulsion at 2% essential oil concentration has a viscosity of 2,650 mPa.S, total dissolved solids of 4,877 brix, and activity to inhibit the growth of Listeria monocytogenes of 7.6 mm. Research on the utilisation of this waste can help increase the added value of waste into products with high economic value.