PENCEGAHAN PENCOKLATAN ENZIMATIK PADA PORANG KUNING (Amorphophallus oncophyllus)

Abstract

Abstract

ENZYMATIC BROWNING INHIBITION OF YELLOW PORANG (Amorphophallus oncophyllus). Glucomannan is widely used in the cosmetics, food and health industry due to its high viscosity. One sources of local glucomannan is yellow porang tuber (Amorphophallus oncophyllus). Unfortunately, the content of carotenoids, polyphenoloxidases and tannins of the tuber is high enough and causing brownish color of the flour. Sodium acid pyrophosphat (Na₂H₂P₂O₇) or SAPP is a safe whitening agent used as an food additive and categorized as generally recognized as safe (GRAS). The purpose of this work was to study the enzymatic browning inhibition of yellow porang using SAPP as well as its effect on glucomannan content. Extended maceration time up to 3 h did not increase the degree of whiteness and glucomannan levels significantly. 2% of Na₂H₂P₂O₇ increased the degrees of whiteness into 50,33. Higher degree of whiteness was obtained in maseration of the flour than that of slurry, wet chips and dried chips. In these three variables, increasing degree of whiteness was in line with the glucomannan content. SAPP provided the highest degree of whiteness (61.48), however, the highest glucomannan samples (75.08%) was obtained at maceration using NaHSO₃.

Keywords: Amorphophallus oncophyllus; degree of whiteness; glucomannan; yellow porang

Abstrak

Glukomanan banyak digunakan di industri kosmetik, makanan dan kesehatan karena viskositas yang tinggi. Salah satu sumber glukomanan lokal adalah umbi porang kuning (Amorphophallus oncophyllus). Sayangnya, kandungan karoten, polyphenoloxidases dan tannins pada umbi ini cukup tinggi menyebabkan tepung yang dihasilkan berwarna kecoklatan yang tidak diinginkan oleh pengguna. Sodium acid pyrophosphat (Na₂H₂P₂O₇) atau SAPP merupakan bahan pemutih yang aman digunakan sebagai zat additif dan dikategorikan dan termasuk ”generally recognized as safe” (GRAS). Tujuan penelitian ini yaitu mempelajari pencegahan pencoklatan pada porang kuning menggunakan SAPP serta efeknya terhadap kadar glukomanan. Peningkatan waktu maserasi hingga 3 jam tidak meningkatkan derajat putih dan kadar glukomanan secara signifikan. Konsentrasi SAPP 2% memberikan derajat putih 50,33. Maserasi tepung porang memberikan derajat putih tertinggi dibanding maserasi slurry, chips basah maupun chips kering. Pada ketiga variabel tersebut, kenaikan kadar glukomanan sejalan dengan derajat putihnya. Penggunaan SAPP pada tepung menghasilkan derajat putih tertinggi yaitu 61,48 namun kadar glukomanan tertinggi (75,08%) dicapai pada sampel yang dimaserasi menggunakan NaHSO₃.

Kata kunci: Amorphophallus oncophyllus; derajat putih; glukomanan; porang kuning