Studi Penambahan Antioksidan pada Proses Pemurnian Minyak Hasil Samping Penepungan Ikan Lele Dumbo (Clarias gariepinus)

Abstract

The objective of this research was to study the addition of antioxidant during oil refining process of catfish flouring industry by product. This study was conducted in two stages, first the separation and characterization of oil from catfish flouring industry by product, followed by characterization of the results. Second, oil refining of catfish flouring industry by product with the addition of BHT antioxidant. The refining process consist of two phases, bleaching and deodorizing. No significant effect (p>0.05) of adding BHT antioxdant was shown on the physical (melting point, viscosity, turbidity, colour, odor) and chemical characteristics (free fatty acid, acid number, palmitic acid, stearic acid, oleic acid, linolenic acid, EPA, DHA, and vitamin E), but had significant effect (p<0.05) in terms of linoleic acid content of the oil. The addition of antioxidant after bleaching could increase the damage of linoleic acid content of the oil. Catfish oil refining result with the addition of BHT antioxidant before bleaching contains 17.78% of linoleic acid, and after bleaching contains 17,21%. The microencapsulation process aims to inhibit oxidation process and facilitate aplications to various products. The process of microencapsulation in this study was based on Lin et al. (1995) with the ratio of sample : gelatin : maltodextrin : sodium caseinat : lecitin + avicel; 30:20:20:20:4+1. Water content of catfish oil encapsulates was 2.9%. The use of this method could maintain the retention of linoleic acid, therefore the linoleic acid content of catfish oil encapsulate was constantly 18.69%.

Tujuan umum dari penelitian ini adalah untuk mempelajari penambahan antioksidan pada proses pemurnian minyak hasil samping penepungan ikan lele dumbo. Tujuan khususnya adalah 1) Mempelajari proses pemurnian minyak ikan lele, 2) Mempelajari pengaruh penambahan antioksidan terhadap sifat fisik (titik cair, viskositas, kejernihan, warna, dan aroma) dan sifat kimia (persentase asam lemak bebas, bilangan asam, bilangan peroksida, bilangan TBA, asam lemak, dan vitamin E) minyak ikan lele hasil pemurnian, 3) Mengkaji daya terima minyak ikan lele hasil pemurnian, 4) Mempelajari proses mikroenkapsulasi minyak ikan lele terbaik, 5) Menganalisis retensi asam lemak esensial setelah proses mikroenkapsulasi. Tahap penelitian meliputi penelitian pendahuluan dan penelitian utama. Penelitian pendahuluan bertujuan untuk mendapatkan rendemen minyak kasar serta karakterisasinya (sifat fisik dan kimia minyak ikan lele sebelum pemurnian). Berdasarkan penelitian pendahuluan dapat diketahui bahwa minyak ikan lele sebelum pemurnian memiliki sifat fisik sebagai berikut: titik cair sebesar 30.230C, viskositas 63.5 cP, kejernihan 211 NTU, berwarna kuning, aroma sangat amis. Selain itu, sifat kimianya adalah: asam lemak bebas 0.05%, bilangan asam 0.06 mgKOH/100 gram, bilangan peroksida 0.21 mgO2/100 gram, bilangan TBA 0.68 mg/kg, asam lemak palmitat (16:0) 16.4%, asam lemak oleat (18:1) 22.65%, asam lemak linoleat (18:2) 17.79%, asam lemak linolenat (18:3) 1.21%, EPA 0.57%, DHA 3.51%, vitamin E 9.15 IU.