Isolasi dan karakterisasi protein biji nyamplung (Calophyllim inophyllum)

PUTRA, Mgs. Muhammad Prima, Dr. Ir. Chusnul Hidayat

2010 | Tesis | S2 Ilmu dan Teknologi Pangan

Nyamplung (Calophyllum inophyllum) merupakan tanaman dengan biji berkadar minyak tinggi yang potensial dimanfaatkan sebagai bahan baku biodiesel. Proses ekstraksi minyak dari biji nyamplung menghasilkan limbah berupa bungkil dengan kadar protein 11,4% yang belum dimanfaatkan. Penelitian ini bertujuan untuk mengisolasi dan mengkarakterisasi isolat protein dari bungkil biji nyamplung. Protein biji nyamplung diisolasi dari bungkil biji nyamplung rendah lemak dengan melarutkan protein pada pH 11 diikuti dengan pengendapan pada dua pH yaitu pH 3 (yang menghasilkan isolat protein IP3) dan pH 5 (yang menghasilkan isolat protein IP5). Isolat protein yang dihasilkan diuji kadar protein, sifat fungsionalnya yang meliputi daya serap air, daya serap minyak, kapasitas pembentukan buih, stabilitas buih, aktivitas emulsi, stabilitas emulsi dan kemampuan membentuk gel, komposisi asam amino, berat molekul dan warna. Pengujian kadar air dan kadar protein terhadap isolat protein yang dihasilkan memberikan hasil IP3 kadar air sebesar 21,17 ± 1,96% (db), kadar protein sebesar 91,25 ± 0,04% (db) dan IP5 kadar air sebesar 18,07 ± 1,36% (db), kadar protein sebesar 87,42 ± 1,15% (db). Hasil pengujian sifat fungsional untuk IP3 memberikan hasil daya serap air sebesar 431,03 ± 8,31 %, daya serap minyak sebesar 155,92 ± 12,44 %, kemampuan pembentukan buih sebesar 145,33 ± 1,15 %, stabilitas buih pada menit ke 60 sebesar 48,74 ± 1,1 %, kemampuan pembentukan gel metode Least Gelation Capacity (LGC) sebesar 8%, kemampuan pembentukan emulsi sebesar 59,15 ± 0,37 % dan stabilitas emulsi setelah pemanasan sebesar 55,07 ± 2,28 %. Hasil pengujian sifat fungsional untuk IP5 memberikan hasil daya serap air sebesar 252,44 ± 3,08%, daya serap minyak 171,74 ± 13,88 %, kemampuan pembentukan buih sebesar 49,83 ± 0,76 %, stabilitas buih pada menit ke 60 sebesar 11,04 ± 1,78 %, kemampuan pembentukan gel metode Least Gelation Capacity (LGC) sebesar 8%, kemampuan pembentukan emulsi sebesar 56,23 ± 0,4 % dan stabilitas emulsi setelah pemanasan sebesar 10,06 ± 0,21 %. Kedua isolat protein mengandung asam amino glisin, alanin, valin, isoleusin, leusin, prolin, fenilalanin, tirosin, serin, threonin, methionin, sistin, asam aspartat, asam glutamat, histidin, arginin dan lisin. Hasil pengujian berat molekul protein terhadap IP3 dan IP5 dengan elektroforesa menunjukkan hasil 4 pita dengan berat molekul masing-masing sebesar lebih dari 200 kDa, 32,4 kDa, 14,64 kDa dan kurang dari 6 kDa. Hasil pengujian warna memberikan hasil warna isolat protein coklat gelap dengan nilai Lab IP3 L: 33,48 ± 0,35, a: 1,56 ± 0,33, b: 15,6 ± 0,45 dan IP5 L: 33,24 ± 0,22, a: 1,08 ± 0,11, b: 15,02 ± 0,22.

Nyamplung (Calophyllum inophyllum) is an oilseeds plant, which is potential as sources of bio-oil. The extraction of bio-oil produced cake as by-product containing of11.4 % proteins those were high potential to be exploited as a source of protein isolate. Objective of the research was to isolate and characterize protein from Nyamplung. Nyamplung protein was isolated from defatted nyamplung flour at 30 °C by dissolving of proteins at pH 11, followed by precipitation at pH3 (protein isolates IP3) and pH 5 (protein isolates IP5). Protein isolates were evaluated including protein concentration, amino acid composition, molecular weight, colour, and functional properties, such as water absorption capacity, oil absorption capacity, foaming capacity, foaming stability, emulsifying activity, emulsifying stability and gelation capacity. Results showed that IP3 contained moisture of 21.17 ± 1.96 % (db) and protein of 91.25 ± 0.04 % (db); and IP5 contained moisture of 18.07 ± 1.36 % (db) and protein of 87.42 ± 1.15 % (db). Functional properties of IP3 were water absorption capacity of 431.03 ± 8.31 %, oil absorption capacity of 155.92 ± 12.44 %, foam capacity of 145.33 ± 1.15 %, foam stability at 60 minute of 48.74 ± 1.1 %, gelation using Least Gelation Capacity (LGC) of 8 %, emulsifying capacity of 59.15 ± 0.37 % and emulsifying stability of 55.07 ± 2.28 %. Functional properties of IP5 were water absorption capacity of 252.44 ± 3.08 %, oil absorption capacity of 171.74 ± 13.88 %, foam capacity of 49.83 ± 0.76 %, foam stability at 60 minute of 11.04 ± 1.78 %, gelation using Least Gelation Capacity (LGC) of 8 % and emulsifying capacity of 56.23 ± 0.4 % and emulsifying stabilityof 10.06 ± 0.21 %. Both protein isolates contained amino acid glycine, alanine, valine, isoleucine, leucine, proline, phenylalanine, tyrosine, serine, threonine, methionine, cystine, aspartic acid, glutamic acid, histidine, arginine and lysin. Molecular weight determination using electrophoresis of IP3 dan IP5 showed 4 band with molecular weight more than 200 kDa, 32.4 kDa, 14.64 kDa and less than 6 kDa. Colour determination showed dark color with Lab value IP3 L: 33.48 ± 0.35, a: 1.56 ± 0.33, b: 15.6 ± 0.45 and IP5 L: 33.24 ± 0.22, a: 1.08 ± 0.11, b: 15.02 ± 0.22.

Kata Kunci : Nyamplung (Calophyllum inophyllum),Isolat protein,Sifat fungsional,Komposisi asam amino