PENGARUH KONSENTRASI SARI KULIT BUAH NAGA MERAH (Hylocereus polyrhizus) DENGAN PENAMBAHAN SARI BUAH BELIMBING WULUH (Averrhoa bilimbi) TERHADAP KUALITAS NATA DE DRAGON DAN PEMANFAATANNYA SEBAGAI SUMBER BELAJAR BIOLOGI

Nata is a food-processed product resembling a gel formed on substrate media, that containing sugar and acid, which produced from the formation of the bacterium Acetobacter xylinum. Nata can be made from ingredients that contain many minerals, sugar, proteins with the help of Acetobacter xylinum bacteria and acidic substrate media. One of the ingredients can be used as a substrate is red dragon fruit skin and ingredients, which can acidify the media, namely star fruit. Red dragon fruit skin was found content 4.15% glucose, 3.37% maltose and 0.86% fructose. Wuluh starfruit contains citric acid about 92,6-133,8 meq acid. This study aims to determine the effect of concentrations of red dragon fruit skin extract (Hylocereus polyrhizus) by adding Wuluh starfruit juice (Averrhoa bilimbi) to Nata de Dragon's quality and its use as a source of learning biology. This research was conducted at the Production Laboratory and Nutrition Laboratory University of Muhammadiyah Malang. The type of research used true experimental research in form of factorial randomized complete design (CRD). The treatment that used consists of fours, namely 0%, 30%, 50%, 70%. The four treatments were repeated 6 times each. Data were analyzed using SPSS 22 with one way ANOVA test and continued with Duncan test. The results of the research and analysis showed that there was an effect of the concentration of red dragon fruit skin extract with the addition of Wuluh Belimbing fruit extracts to the quality of Nata de Dragon, it was seen from the thickness parameters and diagnostic tests, which included aroma, color, texture, taste). Whereas the quality of fiber content and moisture content has no effect, because the average yield obtained is almost the same height. The addition of 70% red dragon fruit skin extract concentration was the best result with the acquisition of nata thickness value with an average of 1.47 cm, water content of 98.43%, fiber content of 1.14% and organoleptic test of this treatment tended to be favored by panelists