Lydia Ninan Lestario

Changes in polyphenolics during maturation of Java plum (Syzygium cumini Lam.)

Java plum (Syzygium cumini Lam.) is a rich source of polyphenolics with many purported health benefits, but the effect of maturation on polyphenolic content is unknown. Freeze-dried samples of Java plum from seven different maturity stages were analyzed for anthocyanin, flavonol, flavanonol and hydrolysable tannin composition by HPLC. Anthocyanins were first detected at the green-pink stage of maturity and increased throughout maturation with the largest increase occurring from the dark purple to black stages of maturation. Levels of gallotannins, ellagitannins, flavonols, gallic acid and ellagic acid were highest at early stages of maturation and decreased as the fruit ripened. For production of antioxidant-rich nutraceutical ingredients, fruit should be harvested immature to obtain extracts rich in hydrolysable tannins and flavonols. The exceptional anthocyanin content of black fruit may prove useful as a source of a natural colorant.

Pengaruh Konsentrasi Alginat dan CaCl2 terhadap Kadar Antosianin, Aktivitas Antioksidan, dan Karakteristik Sensoris Buah Duwet (Syzygium cumini Linn) Restrukturisasi

Restructuration is one of the ways for processing fresh fruit without heating, so the nutritional value of fruit can be maintained. This method has been applied to several types of tropical fruits but has never been applied to java plum fruit, while it has high antioxidant activity but has a short shelf life. The aim of this research was to produce the best formulation to make restructured java plum fruit. Fresh java plum fruit puree was mixed with several concentrations of calcium alginate (1 %, 2 %, 3 %, and 4 %) and CaCl 2 (0.75 %; 1 %). Restructured fruit products were evaluated for total anthocyanin content, antioxidant activity, texture, pH, and sensory properties. The result of this research showed that 1 % alginate and 1 % CaCl 2 gave restructured java plum fruit with the highest anthocyanin content 171.61 mg/100g (DW) and highest antioxidant activity 75.79 %. The overall organoleptic test with 20 panelists showed that restructured fruit with alginate 1 % and CaCl 2 1 % or 0.75 % resulted the highest score 3.75. ABSTRAK Restrukturisasi merupakan salah satu cara pengolahan buah segar tanpa pemanasan sehingga nilai gizi buah dapat dipertahankan. Metode ini sudah diteliti pada beberapa jenis buah tropis tetapi belum pernah dilakukan terhadap buah duwet, padahal buah duwet memiliki aktivitas antioksidan tinggi tetapi memiliki daya simpan rendah. Penelitian ini bertujuan untuk menentukan formulasi terbaik pada pembuatan restrukturisasi buah duwet. Bubur buah duwet segar dicampur dengan berbagai konsentrasi alginat (1 %, 2 %, 3 %, dan 4 %) dan CaCl 2 (0,75 %; 1 %). Produk buah hasil restrukturisasi diukur kandungan antosianin total, aktivitas antioksidan, tekstur, pH, dan sifat-sifat sensorisnya. Hasil penelitian menunjukkan bahwa alginat 1% dan CaCl 2 1% memiliki kandungan antosianin tertinggi yaitu 171,61 mg/100g (BK) dan aktivitas antioksidan tertinggi yaitu 75,79 %. Uji organoleptik dengan 20 panelis menunjukkan bahwa produk restrukturisasi buah duwet yang paling disukai panelis diperoleh dari perlakuan alginat 1 % dan CaCl 2 1 % atau 0,75 % dengan skor 3,75.