Potential of encapsulated rambutan peel extract (Nephelium lappaceum) as a food preservative

Abstract Rambutan peel is one of the agricultural wastes that is rarely used and contains several active compounds with antimicrobial properties. The antimicrobial properties of rambutan peel can be used as a food preservative. However, these active compounds are unstable and degraded when exposed to air, heat, light, and water. This problem can be prevented by encapsulating the extract. There are two specific objectives of this study, knowing the types of active compounds contained in rambutan peel extract and determining the best coating material for encapsulated rambutan peel extract. The encapsulation process of rambutan peel extract was done by using thin layer drying method using maltodextrin, gum arabic, and gelatin as coating material. The encapsulated extracts were stored for one month and tested weekly. Test parameters of encapsulated rambutan peel extract were moisture content and antibacterial activity. The result showed that rambutan peel extract contains flavonoids, tannins, and saponins. The use of maltodextrin and gum arabic as coating material was able to maintain bacterial inhibition against Staphylococcus aureus during storage, while the use of gelatin as coating material can only maintain up two weeks of storage. The result also showed that rambutan peel extract could not maintain bacterial inhibition against Escherichia coli during storage.