PENGARUH SUHU, CAHAYA, DAN JENIS PENGEMAS SELAMA PENYIMPANAN TERHADAP WARNA, STABILITAS ANTOSIANIN, SERTA AKTIVITAS ANTIOKSIDAN MINUMAN ISOTONIK UBI JALAR UNGU (Ipomoea batatas L.)

JOSHI KURNIAWATI, Ir.Ag.Pamudji Rahardjo, MP; Dr.Andriati Ningrum, STP, M.Agr; Dr. Rini Yanti, STP, MP

2018 | Skripsi | S1 TEKNOLOGI PANGAN DAN HASIL PERTANIAN

Penambahan ekstak antosianin sebagai pewarna alami dalam minuman isotonik merupakan inovasi karena antosianin memiliki berbagai manfaat untuk kesehatan. Akan tetapi proses pengolahan akan mempengaruhi stabilitas antosianin. Kestabilan antosianin dari ubi jalar ungu dapat dipengaruhi oleh beberapa faktor antara lain suhu, dan cahaya. Ubi jalar ungu diekstrak, kemudian sebanyak 10% ekstrak antosianin dimasukkan ke dalam minuman isotonik. Setelah itu, minuman isotonik disimpan pada suhu ruang dan suhu kulkas dengan atau tanpa penutupan dengan alumunium foil. Pengamatan dilakukan setiap tiga hari sekali selama 30 hari. Notasi warna CIELAB yaitu L, a, b dan ΔE pada model minuman isotonik mengalami perubahan selama penyimpanan. Hal ini dikarenakan adanya proses degradasi antosianin menghasilkan senyawa kalkon yang tidak berwarna. Total antosianin selama proses penyimpanan juga mengalami penurunan dengan kinetika degradasi antosianin mengikuti ordo 1. Pada perlakuan jenis pengemas gelas dengan suhu dingin dan kondisi tertutup memiliki perubahan total antosianin paling rendah dan waktu paruh paling tinggi. Aktivitas antioksidan selama proses penyimpanan mengalami fluktuasi. Dengan demikian, stabilitas zat pewarna antosianin akan lebih stabil jika disimpan dalam suhu dingin dan kondisi tertutup. Kata kunci: Ubi jalar ungu, antosianin, stabilitas, aktivitas antioksidan.

The addition of anthocyanin extracts as a natural dye in isotonic drinks is an innovation because anthocyanin has many health benefits. However, the processing will affect the stability of anthocyanin. The stability of anthocyanin from purple sweet potato can be affected by several factors such as temperature, and light. The purple sweet potato is extracted, then put as much as 10% of the anthocyanin extracts into the isotonic drinks. After that, the isotonic drinks stored at room temperature (27oC) and refrigerator temperature (9oC) with or without closure with aluminum foil. Observations were done every three days for 30 days. The CIELAB color notation of L, a, b and ΔE in the isotonic beverages model undergoes changes during kept. This is because the anthocyanin degradation process produces a colorless calcon compound. Total anthocyanin during the keeping process also decreased with anthocyanin degradation kinetics following the ordo 1. In the treatment of glass packaging type with cold temperature and closed conditions had the lowest total anthocyanin change and the highest half-life. Antioxidant activity during the storage time fluctuated. Thus, the stability of the anthocyanin dye will be more stable if stored in cold (9oC) and closed conditions. Keywords: Purple sweet potato, anthocyanin, stability, antioxidant activity.

Kata Kunci : Ubi jalar ungu, antosianin, stabilitas, aktivitas antioksidan