α-Amylase catalyzes hydrolysis of starch to oligosaccharides, which are further degraded to simple sugars. The enzyme has been widely used in food and textile industries and recently, in generation of renewable energy. An α-amylase from yeast Saccharomycopsis fibuligera R64 (Sfamy) is active at 50 °C and capable of degrading raw starch, making it attractive for the aforementioned applications. To improve its characteristics as well as to provide information for structural study ab initio, the enzyme was chemically modified by acid anhydrides (nonpolar groups), glyoxylic acid (GA) (polar group), dimethyl adipimidate (DMA) (cross-linking), and polyethylene glycol (PEG) (hydrophilization). Introduction of nonpolar groups increased enzyme stability up to 18 times, while modification by a cross-linking agent resulted in protection of the calcium ion, which is essential for enzyme activity and integrity. The hydrophilization with PEG resulted in protection against tryptic digestion. The chemical modification of Sfamy by various modifiers has thereby resulted in improvement of its characteristics and provided systematic information beneficial for structural study of the enzyme. An in silico structural study of the enzyme improved the interpretation of the results.

Asap tempurung kelapa merupakan salah satu metode pengawetan secara tradisional, akan tetapi masih memiliki resiko bahaya. Potensi bahaya tersebut dapat dicegah dengan mengubah asap tempurung kelapa menjadi asap cair dengan metode pirolisis. Penelitian ini bertujuan untuk menganalisis pengaruh variasi konsentrasi dan lama waktu perendaman asap cair tempurung kelapa terhadap daya tahan daging sapi. Daya tahan daging sapi dianalisis menggunakan analisis TPC. Variasi konsentrasi asap cair tempurung kelapa yang digunakan adalah 1%; 1,5%; 2%; dan 2,5% v/v, sedangkan variasi lama perendaman yang digunakan yaitu 10, 20, 30 dan 40 menit. Hasil penelitian menunjukan bahwa penentuan konsentrasi asap cair optimal dilakukan dengan merendam daging sapi dalam asap cair tempurung kelapa selama 20 menit. Analisis kadar air, kadar lemak dan kadar protein dilakukan terhadap produk hasil pengawetan dan dibandingkan dengan daging sapi yang masih segar. Konsentrasi asap cair yang optimal untuk mengawetkan daging sapi diperoleh 1,5%, dengan hasil analisis kadar air, lemak dan protein secara berturut-turut sebesar 21,79%; 7,45%; dan 28,48%. Asap cair dengan konsentrasi 1,5% dibuat variasi lama waktu perendaman selama 10, 20, 30 dan 40 menit. Analisis kadar air menunjukkan lama waktu perendaman optimal adalah 20 menit dengan kadar air sebesar 21,79%, sedangkan untuk kadar lemak dan protein sebesar 7,45% dan 28,48%. Analisis total plate count (TPC) pada daging sapi yang direndam dalam asap cair dengan konsentrasi 1,5% selama 20 menit menunjukkan bahwa daging sapi layak dikonsumsi sampai hari ketiga penyimpanan pada suhu kamar.

Edible films made of Na-alginate from brown algae have great potential to be developed as brown algae have a fairly high abundance in Indonesia but have not been widely used. Therefore, in this study conducted by making edible films made from Na-alginate modified by the addition of hydrocolloids carrageenan and glycerol plasticizier. The addition of carrageenan biopolymers is the property of the produced Edible film. The use of glycerol as a plasticizer aims to improve the properties of elasticity Edible films. This research method consists of two stages. First, the isolation and characterization of Na-alginate. Both the preparation and characterization of making edible films. Na-alginate characterization results in yield of 25.68%, 10.84% moisture content, ash content of 23.79%. The carrageenan on the formula Edible films affect the characterization of the resulting films. The value of water absorption from 333.13% to 335.45% and the elongation of 26.26% to 33.34%, and the declining value of tensile strength of 8.93 MPa to 4.17 MPa and young's modulus values of 0.34 MPa to 0.22 MPa with the addition of carrageenan on an Edible film formula.