PENGARUH PERSENTASE PENAMBAHAN KUNING TELUR DAN STARTER TERHADAP KARAKTERISTIK FISIKOKIMIA FROZEN YOGHURT UBI JALAR UNGU (The Effect of Egg Yolk and Lactic Acid Bacterial Starter on the Physicochemical Characteristics of Purple Sweet Potato Frozen Yoghurt - Agatha Vina Melati Simanihuruk; Linda Masniary Lubis; Hotnida Sinaga (Jurnal Rekayasa Pangan dan Pertanian, 2019)
This study was conducted to find out the effect of egg yolk and lactic acid bacterial starter addition on the physicochemical characteristics of purple sweet potato frozen yoghurt. The research used a completely randomized design, which factors were the percentation egg yolk (K): (6%; 7,5%; 9%) and percentation lactic acid bacterial starter (S): (3%; 4%; 5%). The results showed that the addition of egg yolk had highly significant effect on total acid, pH value, fat content, protein content, total lactic acid, and melting point. Moreover, lactic acid bacterial starter gave a highly significant effect on total acid, pH value, fat content, protein content, anthocyanin content, total lactic acid, and melting point. Meanwhile, the interaction between the two factors had a highly significant effect on fat content, total lactic acid, and melting point. The addition of 9% egg yolk and 5% lactic acid bacterial starter produced the best physicochemical characteristics of purple sweet potato frozen yoghurt. Key words: Egg yolk, Frozen yoghurt, Purple sweet potato, Starter, Total lactid acid ABSTRAK   Penelitian ini dilakukan untuk mengetahui pengaruh penambahan kuning telur dan starter bakteri asam laktat terhadap karakteristik fisikokimia frozen yoghurt ubi jalar ungu. Penelitian ini menggunakan rancangan acak lengkap dua faktor yaitu persentase kuning telur (K) : (6%; 7,5%; 9%) dan persentase starter (S) : (3%; 4%; 5%). Hasil penelitian ini menunjukkan bahwa penambahan kuning telur memberikan pengaruh berbeda sangat nyata terhadap total asam, nilai pH, kadar lemak, kadar protein, jumlah bakteri asam laktat, dan waktu leleh. Penambahan starter memberikan pengaruh berbeda sangat nyata terhadap total asam, nilai pH, kadar lemak, kadar protein, kadar antosianin, jumlah bakteri asam laktat, dan waktu leleh. Interaksi kedua faktor memberikan pengaruh berbeda sangat nyata terhadap kadar lemak, jumlah bakteri asam laktat, dan waktu leleh. Penambahan kuning telur 9% dan starter 5% memberikan pengaruh terbaik untuk karakteristik fisikokimia frozen yoghurt ubi jalar ungu.   Kata kunci : Bakteri asam laktat, Frozen yoghurt, Kuning telur, Starter, Ubi jalar ungu