IDENTIFIKASI ASAM AMINO FRAKSI pI 7 DAN 8 PROTEIN HATI AYAM MENGGUNAKAN HIGH PERFOMANCE LIQUID CHROMATHOGRAPHY (HPLC)

NUR FITRIANI, Dr. Tri Joko Raharjo, M. Si.

2013 | Skripsi | KIMIA

Telah dilakukan fraksinasi protein dan identifikasi asam amino hati ayam dari pI 7 dan 8 menggunakan high performance liquid chromatografi (HPLC). Tujuan penelitian ini adalah menentukan kandungan nutrisi hati ayam, kandungan dan skor asam amino esensial fraksi protein hati ayam serta melakukan klarifikasi potensi fraksi protein hati sebagai sumber alternatif fortifikasi protein. Kandungan nutrisi hati ayam ditentukan dengan analisis proksimat. Kadar air ditentukan dengan analisis gravimetri, kadar lemak dengan ekstraksi Soxhlet, kadar protein dengan analisis volumetri (metode Kjeldahl), kadar abu dengan analisis gravimetri dan kadar karbohidrat ditentukan by different. Isolat protein diperoleh dengan metode pelarutan asam pada pH 2 dan pengendapan isoelektrik pada pH 7 dan 8. Identifikasi asam amino fraksi protein pI 7 dan 8 dimulai dengan hidrolisis menggunakan larutan HCl 6 M pada suhu 103 – 106 °C. Asam amino hasil hidrolisis diidentifikasi menggunakan HPLC dengan derivatisasi menggunakan o-ftalaldehida (OPA). Hati ayam mengandung 28,97% air; 11,78% lemak; 30,41% protein; 4,76% abu dan 24,08% karbohidrat. Kadar fraksi pI 7 sebesar 14,79% dari total protein hati ayam dengan kandungan asam amino esensial : 4,9% lisin; 4,85% leusin; 2,7% isoleusin; 2,67% fenilalanin; 3,15% valin; 1,82% histidin; 0,75% metionin dan 4,22% arginin. Kadar fraksi pI 8 sebesar 18,90% dari total protein dengan kandungan asam amino : 2,22% lisin; 2,37% leusin; 1,37% isoleusin; 1,35% fenilalanin; 1,6% valin; 0,52% histidin; 0,62% metionin dan 2,03% arginin. Kadar dan skor kimia asam amino esensial kedua fraksi protein tidak mencapai 30% dan tidak memenuhi standar FAO/WHO. Fraksi protein pI 7 dan 8 belum berpotensi sebagai bahan fortifikasi makanan.

Fractionation of protein from chicken‟s liver and identification of amino acid from pI 7 and 8 protein fraction had been conducted by high performance liquid chromatography (HPLC). The purposes of this research were determine the nutrition content of chicken‟s liver, the content and the level of essential amino acid of chicken‟s liver protein fraction and to clarify the potential of chicken‟s liver protein fraction as an alternative source of protein fortification. Nutrition contents in chicken‟s liver were determined by proximate analysis. Moisture content was determined by gravimetric analysis, fat content was determined by Soxhlet extraction, crude protein was determined by volumetric analysis (Kjeldahl method), ash was determined by gravimetric analysis and carbohydrate was determined by different. Protein isolate was obtained by acid solubilization at pH 2 and isoelectric precipitation at pH 7 and 8. Identification of amino acid of protein fraction was started by hydrolysis used HCl 6 M at 103 – 106 °C followed by HPLC analysis used o-phtalaldehyde (OPA) derivatization. Chicken liver has 28.97% moisture; 11.78% fat; 30.41% protein; 4.76% ash and 24.08% carbohydrate. Protein level of pI 7 fraction was 14.79% of chicken liver crude protein with essential amino acid : 4.9% lysine; 4.85% leucine; 2.7% isoleucine; 2.67% phenylalanine; 3.15% valine; 1.82% histidine; 0.75% methionine and 4.22% arginine. Protein level of pI 8 fraction was 18.90% of crude protein with essential amino acid : 2.22% lysine; 2.37% leucine; 1.37% isoleucine; 1.35% phenylalanine; 1.6% valine; 0.52% histidine; 0.62% methionine and 2.03% arginine. The level and the chemical score of essential amino acid both of fractions were less than 30% and did not meet the standard of FAO/WHO. Proteins of pI 7 and 8 fraction were not potentially as food fortification material yet.

Kata Kunci : asam amino, protein, pelarutan asam, pengendapan isoelektrik, hati ayam, fortifikasi, RP-HPLC