Judul: Peningkatan Kualitas Ampas rumput Laut (Gracilaria sp.) Melalui Biofermentasi Menggunakan Khamir Saccharomyces cereviseae dan Schizosaccharomyces pombe
Abstrak: Ampas rumput laut memiliki kandungan mineral cukup tinggi dan berpotensi sebagai pakan karena ketersediaannya melimpah, namun terkendala bau dan aroma yang kurang baik serta kandungan protein rendah, sehingga perlu dilakukan biofermentasi. Penelitian ini untuk membandingkan dua spesies khamir (S. cereviseae dan Sch. pombe) dengan taraf berbeda (0%, 2%, 4% dan 6%) pada biofermentasi ampas rumput laut yang diharapkan akan meningkatkan kualitas. Penelitian ini menggunakan rancangan acak lengkap (RAL) pola faktorial (2x4) dengan 3 ulangan. Peubah yang diamati meliputi warna, aroma, bau, derajat keasaman (pH), aktivitas air (aw), kandungan nutrien dan energi. Tidak terdapat interaksi antara spesies dan taraf untuk nilai pH, bahan kering dan bahan organik, namun terjadi interaksi untuk parameter aw (P<0.05). Biofermentasi menyebabkan terjadinya penurunan bahan kering dan peningkatan bahan organik. Biofermentasi Sch. pombe 2% menghasilkan aroma dan bau yang harum, sedangkan S. cereviseae umumnya asam menyengat. Hasil penelitian menyimpulkan bahwa biofermentasi Sch pombe 2% mampu memperbaiki aroma dan bau ampas rumput laut.
Keyword: biofermentation, S. cereviseae, Sch. pombe, seaweed waste, Animal fedd, Factorial CRD, Color, Aroma, Odor, Nutrient content, Energy

Judul: Optimasi Rendemen dan Mutu Agar-Agar dari Rumput Laut Gracilaria verrucosa dengan Metode Respon Permukaan
Abstrak: Usually, seaweed is widely used as agar. Problems that often arise in producing mainly of gelatinous seaweed Gracilaria is the difficulty of obtaining agar gel which has good characteristics such as strength, hardness and high gel cohesiveness. One reason is that there are sulfate esters in the agar. This study aims to capitalize on Gracilaria verrucosa obtained from the cultivation of the raw material for agar by analyzing the effect of adding acetic acid (CH3COOH) with a concentration of 0.5%, 1%, 1.5%, extraction temperature 85, 90, and 95 ° C and soaking time for treatment of the addition of acetic acid (CH3COOH) such as 0.5, 1, dan1.5 hours on the yield and quality of agar produced from seaweed Gracilaria verrucosa. The design of experiments using a central composite design (CCD) with the analysis carried out by analysis yield, gel strength, moisture and ash content and optimization by the response surface method. Application response surface method in extraction of agar flour in order to demonstrate that the response of yield, gel strength, moisture content, and ash content obtained at the optimum concentration of acetic acid 0.50%, 0.64 hours of soaking time and extraction temperature 89.31 ° C with a value of desirability is 0.718 obtained yield amounts 18.28%, gel strength of 99.2 gf, 15.21% moisture content and ash content 4.58%.
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Judul: : Persamaan Tunggal sebagai Representasi Kurva Komposit
Abstrak: A mathematical method is introduced to represent a composite curve based on an extension of analytic geometry. The representation is given either with a single equation or with two equations, in the case of parametric representation. This method permits the representation of composite curves in similar manner to the conventional representation of non-composite curves. Some mathematical tools, including Heaviside unit step function and periodizer function, are used in the establishment of a single equation. In this paper, regular equations of regular and irregular polygon, as well as composite curves of two dimensions, are implemented using a computer algebraic system, Mathematica.
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