Optimasi Produksi Sirup Glukosa Berbasis Pati Sagu (Metroxylon rumphii Martius) Varietas Unggul Selatpanjang Meranti Menggunakan Enzim a-Amilase dan Glukoamilase dari Mikroba Lokal

Abstract

Gula menjadi salah satu bahan baku yang selalu digunakan dalam industri pangan karena kebutuhannya sebagai sumber pemanis, meningkatkan kelembutan dan mencegah kristalisasi. Meningkatnya jumlah penduduk menekan peningkatan kebutuhan akan ketersediaan produk pangan yang mengandung gula. Sampai saat ini masih belum ditemukan solusi jangka panjang selain ketergantungan akan impor gula. Beberapa gula alternatif yang telah dikembangkan adalah sirup glukosa melalui proses hidrolisis enzimatis menggunakan sumber bahan pangan seperti sagu. Sagu “Selatpanjang Meranti” merupakan varietas unggul yang diharapkan akan menghasilkan sirup glukosa dengan rendemen yang tinggi. Permasalahan lain yang timbul dalam pengembangan sirup glukosa ini adalah ketergantungan akan enzim yang sangat besar. Sehingga solusi yang ditawarkan adalah dengan pemanfaatan mikroba lokal penghasil enzim yang lebih stabil dan tahan akan kondisi lingkungan, diantaranya Anoxybacillus flavithermus penghasil enzim a-amilase dan Aspergillus awamori KT-11 penghasil enzim glukoamilase. Berdasarkan latar belakang tersebut, tujuan dari penelitian ini adalah menghasilkan sirup glukosa berbahan dasar pati sagu varietas unggul Selatpanjang Meranti menggunakan enzim amilase dan glukoamilase dari mikroba lokal serta potensinya sebagai gula alternatif yang memenuhi syarat mutu sirup glukosa SNI 2978:2021. Desain penelitian menggunakan response surface methodology (RSM) dengan metode Combined, D-Optimal yakni campuran dari enzim a-amilase (mL/100g pati), enzim glukoamilase (mL/100g pati), serta komponen dari proses pemanasan suhu proses likuifaksi (°C) dan sakarifikasi (°C). Data kombinasi yang diperoleh akan dilakukan optimasi dengan pengaturan goals dari semua faktor dengan target yang diinginkan. Target mengacu pada syarat mutu sirup glukosa berdasarkan SNI 2978:2021, seperti kadar air (minimal), kadar abu sulfat (maksimal 1%), padatan total (minimal 70%), Rendemen sirup glukosa atau yield (maksimal), dan dextrose equivalent (minimal 20%). Berdasarkan hasil penelitian, enzim a-amilase dari isolat bakteri Anoxybacillus flavithermus dan glukoamilase dari isolat kapang Aspergillus awamori KT-11 masing-masing menghasilkan aktivitas spesifik enzim sebesar 66,432 × 103 U/mg protein dan 125,702 × 103 U/mg protein. Nilai optimal yang diberikan model Combined, D-Optimal dihasilkan dari dengan kombinasi suhu likuifaksi 95°C, suhu sakarifikasi 55,47°C, enzim a-amilase 11 mL/100 g pati, dan enzim glukoamilase 9 mL/100 g pati dengan nilai desirability 0,785. Respon dari hasil verifikasi model meliputi kadar air 18,29 ± 0,18%, kadar abu sulfat 0,89 ± 0,01%, padatan total 79,26 ± 0,34°Brix, rendemen glukosa 93,09 ± 0,2%, dextrose equivalent 96,78 ± 0,86%, kandungan timbal (Pb) 0,22 ± 0,3 mg/kg dan kadmium (Cd) 0,18 ± 0,2 mg/kg. Hasil optimasi terverifikasi memenuhi SNI 2978:2021.

Sugar is one of the raw materials that is always used in the food industry because of its need as a source of sweetener, improve softness and prevents crystallization. The growing population intensifies the demand for greater availability of food derived from sugar. Until now, there is still no long-term solution other than dependence on sugar imports. Some alternative sugars developed are glucose syrup through an enzymatic hydrolysis process using food sources such as sago. Sago "Selatpanjang Meranti" is a superior variety whose potential has not been widely explored, but it is expected to produce glucose syrup with high yields. Another problem that arises in the development of glucose syrup is the dependence on enzymes. Enzymes are highly perishable and sensitive to changes in the surrounding environment. So the solution offered is the utilization of local microbes producing enzymes that are more stable and resistant to environmental conditions, Anoxybacillus flavithermus producing the enzyme alpha-amylase, and Aspergillus awamori KT-11 producing the enzyme glucoamylase. Based on this background, the purpose of this research was to produce glucose syrup based on sago starch varieties of Selatpanjang Meranti using amylase and glucoamylase enzymes from local microbes and alternative sugar that meets the quality requirements of SNI 2978: 2021 glucose syrup. The research design used response surface methodology (RSM) with the Combined, D-Optimal method, which is a mixture of a-amylase enzyme (mL/ 100g starch), glucoamylase enzyme (mL/100g starch), and heating process of the liquefaction process temperature (°C) and saccharification (°C). The combination data obtained will be optimized by setting the goals of all factors with the desired target. The target refers to the quality requirements of glucose syrup based on SNI 2978:2021 such as moisture content (minimum), sulfate ash content (maximum 1%), total solids (minimum 70%), glucose syrup yield (maximum), and Dextrose equivalent (minimum 20%). Based on the results of the research, purified amylase from Anoxybacillus flavithermus had an activity of 13.566 U/mL, while glucoamylase from Aspergillus awamori KT-11 had 13.734 U/mL. The protein concentrations were 66.432 mg/mL for amylase and 125.702 mg/mL for glucoamylase. Optimal conditions identified through RSM were a liquefaction temperature of 95°C, saccharification temperature of 55.47°C, a-amylase concentration of 11 mL/100 g starch, and glucoamylase concentration of 9 mL/100 g starch, yielding a desirability value of 0.785. Validation tests, replicated five times, confirmed that the optimized glucose syrup met the SNI 2978:2021 criteria with moisture content of 18.29 ± 0.18%, sulfate ash content of 0.89 ± 0.01%, total solids of 79.26 ± 0.34°Brix, glucose yield of 93.09 ± 0.2%, dextrose equivalent of 96.78 ± 0.86%, and heavy metal contents of lead (Pb) at 0.22 ± 0.3 mg/kg and cadmium (Cd) at 0.18 ± 0.2 mg/kg.