vi
ABSTRAK
PENGARUH PENAMBAHAN KITOSAN DAN PLASTICIZER SORBITOL TERHADAP SIFAT FISIKO-KIMIA BIOPLASTIK
DARI PATI BIJI DURIAN (Durio zibethinus)
Penggunaan plastik dalam jumlah besar berdampak pada pencemaran lingkungan akibat penumpukan limbah plastik yang tidak dapat diuraikan secara alami (nonbiodegradable). Penelitian bioplastik (biodegradable plastic) berbasis pati dilakukan untuk mencari alternatif pengurangan konsumsi plastik konvensional. Tujuan dari penelitian ini adalah untuk mengetahui karakteristik pati yang diisolasi dari biji durian, mengetahui pengaruh penambahan kitosan dan plasticizer sorbitol terhadap sifat fisiko-kimia bioplastik dari pati biji durian (Durio zibethinus), serta menentukan temperatur pemanasan, komposisi pati-kitosan dan sorbitol yang optimum dalam pembuatan bioplastik. Pada pati biji durian yang dihasilkan dilakukan beberapa analisis, yaitu meliputi analisis komposisi kimia, analisis FT-IR (Fourier Transform Infra – Red), SEM (Scanning Electron Microscopy) dan RVA (Rapid Visco Analyzer). Pembuatan bioplastik merujuk pada metode Weiping Band, dimana dilakukan modifikasi kimiawi pati dengan penambahan plasticizer sorbitol dan pengisi kitosan. Komposisi pati biji durian – kitosan yang digunakan adalah 7:3, 8:2 dan 9:1 (m/m), dan massa sorbitol yang digunakan adalah 2 gram, 3 gram dan 4 gram. Temperatur pemanasan larutan bioplastik divariasikan pada 70 oC, 80 oC dan 90 oC. Bioplastik yang dihasilkan dianalisis sifat fisika dan kimianya, yaitu meliputi analisis FT-IR, SEM, RVA, kekuatan tarik, perpanjangan pada saat putus, penyerapan air dan densitas. Dari hasil analisis pati diperoleh kadar pati sebesar 76,6530%, kadar air 12,73%, kadar abu 0,51%, kadar amilosa 22,34%, kadar amilopektin 54,32%, kadar protein 11,61% dan kadar lemak sebesar 0,61%. Dari analisis RVA dihasilkan temperatur gelatinisasi pati adalah 75,21oC dengan waktu gelatinisasi 188 detik, serta dapat digolongkan tipe profil gelatinisasi pati biji durian merupakan tipe A. Dari hasil analisis FT-IR pati dan bioplastik ditunjukkan adanya peningkatan gugus O-H yaitu pada bilangan gelombang 3352,28 cm-1 menjadi 3653,18 cm-1, dan dari FT-IR kitosan dan bioplastik ditunjukkan adanya peningkatan jumlah puncak serapan gugus N-H yaitu pada bilangan gelombang 1570,06 cm-1 menjadi 1550,77 cm-1 dan 1589,34 cm-1. Dari hasil SEM ditunjukkan bahwa struktur patahan bioplastik dengan pengisi kitosan dan plasticizer sorbitol lebih rapat dan kompak dibandingkan bioplastik tanpa pengisi kitosan dan plasticizer sorbitol. Dari hasil analisis bioplastik dihasilkan kondisi optimum yaitu pada perbandingan pati-kitosan 7:3 dengan massa sorbitol 2 gram dan temperatur pemanasan larutan bioplastik 70oC, dimana nilai kekuatan tarik bioplastik adalah 19,3677 MPa, nilai perpanjangan pada saat putus 2,6731%, nilai Modulus Young 724,5408 MPa, nilai penyerapan air 29,4894%, dan nilai densitas 1,63 g/cm3.
Kata kuci : pati, kitosan, sorbitol, bioplastik, biodegradable
vii
ABSTRACT
THE EFFECT OF ADDITION CHITOSAN AND PLASTICIZER SORBITOL ON PHYSICAL CHEMISTRY PROPERTIES OF
BIOPLASTIC FROM DURIAN SEED STARCH (Durio zibehinus)
The application of plastics in large amount impact on environmental pollution caused by the buildup of plastic waste that can not be decomposed naturally (nonbiodegradable). Researches on bioplastics (biodegradable plastic) were conducted to find alternative reduction of the consumption of conventional plastics. The purposes of this study were to determine the characteristics of starch isolated from durian (Durio zibethinus) seed, to determine the effect of chitosan and plasticizer sorbitol on the physico-chemical properties of bioplastics from durian seed starch, and to determine the optimum conditions includes heating temperature, composition of starch-chitosan and mass of sorbitol in the manufacture of bioplastics. At durian seed starch conducted some analysis, which includes the analysis of chemical composition, analysis of FT-IR (Fourier Transform Infra - Red), SEM (Scanning Electron Microscopy) and RVA (Rapid Visco Analyzer). The manufacture of bioplastic refers to Weiping Band’s method, which performed chemically modified starch with the addition of plasticizers sorbitol and fillers chitosan. The composition of durian seed starch-chitosan used were 7:3, 8:2 and 9:1 (w/w), and the mass of sorbitol used were 2 grams, 3 grams and 4 grams. The heating temperature of bioplastic solution were varied at 70 oC, 80 oC and 90 oC. Bioplastics were analyzed physical and chemical properties, which includes the analysis of FT-IR, SEM, tensile strength, elongation at break, water absorption and density. From the analysis of starch obtained that the starch content 76,6530%, moisture content 12,73%, ash content 0,51%, amylose content 22,34%, amylopectin content 54,32%, protein content 11,61% and the fat content 0,61%. From RVA analysis obtained that the gelatinization temperature of the starch was 75,21oC with gelatinization time was 188 seconds, and can be classified as the type of gelatinization profile of durian seed starch was type A. From the results of FT-IR analysis of starch and bioplastics indicated an increase in the O-H group from the wave number 3352,28 cm-1 to 3653,18 cm-1, and from the results of FT-IR analysis of chitosan and bioplastics indicated an increased number of absorption peaks N-H group from wave number 1570,06 cm-1 to 1550,77 cm-1 and 1589,34 cm-1. From results of SEM analysis indicated that the structure of fault bioplastic with filler chitosan and plasticizer sorbitol was denser and more compact than bioplastic without filler chitosan and plasticizer sorbitol. The analysis of bioplastics had optimum conditions at starch-chitosan ratio of 7:3 with 3 grams mass of sorbitol and heating temperature of solution bioplastic at 70°C, where the value of tensile strength bioplastic was 19,3677 MPa, elongation at break was 2,6731%, Modulus Young was 724,5408 MPa, water absorption was 29,4894%, and density was 1,63 g/cm3.
Keywords: starch, chitosan, sorbitol, bioplastic, biodegradable
