PEMANFAATAN POTENSI KULIT BUAH SEMANGKA (Citrullus lanatus) DALAM PEMBUATAN SELAI DENGAN PENAMBAHAN PEWARNA ALAMI DAGING DAN KULIT BUAH NAGA MERAH (Hylocereus polyrhizus)

ABSTRACK Watermelon is a kind of fruit that become a favorite fruit by some of the people. Albedo or usually known as the peel of waternelon is a white layer of the waterwelon that still underutilized. In watermelon’s peel, there’s citrulin which has an antioxidant which is good for skin’s healthy. Citrulin can be found more in watermelon’s peel rather than in its flesh. In addition, watermelon peel also has a high pectin content. Therefore, watermelon’s peel can be used to make a jam with the addition of natural food coloring by flesh and the peel of red dragon fruit. Red dragon fruit and peel have high anthocyanin as antioxidant. This study aims to determine the interaction and influence between flesh and peel red dragon fruit with watermelon peel jam. This research applied group random design factorial consists of two factors, namely the first factor of red dragon fruit flesh consisted of three levels (10%, 15%, 20%) and the second factor was peel of red dragon fruit consited of three levels (0%, 5%, 10%). Observation analyzed were pH, dispersibility, total dissolved solids, antioxidant activity, fiber, color test (redness (a+), yellowness (b+), lightness (L), organoleptic test (taste, aroma, color) toward peel of watermelon jam. The best watermelon peel jam was obtained by D1K2 (10% of flesh red dragon fruit and 10% of peel red dragon fruit) with 32.821% of antioxidant activity, 38.866 of L score (brightness), 23.100 of a+ score (redness), 1.718% of crude fiber, 4.856 of pH, 31.667°Brix of total dissolved solids, 3.167 of taste (sweet), 3.27 of aroma (quite flavorful) and 3.380 of color (quite red)