Judul: Pengaruh Gula Stevia dan Sukrosa terhadap Viabilitas Ragi Roti pada Adonan Bebas Gluten
Abstrak: Adonan gluten berbasis tepung terigu dalam pembuatan roti menggunakan sukrosa mampu mempertahankan viabilitas ragi roti, tetapi penggunaan sukrosa dan tepung terigu dalam waktu yang lama dapat menyebabkan gangguan kesehatan. Tujuan dari penelitian ini yaitu menentukan pengaruh gula stevia dan sukrosa terhadap viabilitas ragi roti pada adonan bebas gluten. Uji fermentasi ragi menggunakan metode tabung fermentasi, uji viabilitas ragi menggunakan CFU dan pengamatan mikroskopik dengan pewarnaan, sementara uji volume pengembangan menggunakan perbandingan volume roti sebelum dioven dan volume roti sesudah dioven. Hasil penelitian menunjukkan bahwa jumlah koloni tertinggi pada media pertumbuhan Saccharomyces cerevisiae adalah pada formulasi A1 yaitu sebesar 1,09 x 108 ± 2,83c dengan penambahan gula sukrosa tanpa stevia pada adonan roti yang menggunakan tepung singkong pregelatinisasi. Hal ini menunjukkan bahwa koloni ragi dapat berkembang pada adonan yang lebih banyak mengandung gula sukrosa dibandingkan dengan stevia. Berdasarkan penelitian yang telah dilakukan, terdapat pengaruh yang signifikan pada penambahan gula sukrosa dan stevia terhadap viabilitas ragi pada adonan bebas gluten., Wheat flour-based gluten dough in bread making using sucrose is able to maintain the viability of bread yeast, but the use of sucrose and wheat flour for a long time may result in health problems. The purpose of this study was to determine the effect of stevia sugar and sucrose on the viability of baker's yeast in gluten-free dough. The yeast fermentation test uses the fermentation tube method, the yeast viability test uses CFU and microscopic observation by staining, while the development volume test uses the comparison of the volume of bread before baking and the volume of bread after baking. The results showed that the number of colonies on Saccharomyces cerevisiae growth media that could live the most was in formulation A1, which was 1,09 x 108 ± 2,83c with the addition of sucrose sugar without stevia in bread dough using pregelatinized cassava flour. This shows that yeast colonies can develop in dough that contains more sucrose sugar than stevia. Based on the research that has been done, there is a significant effect on the addition of sucrose and stevia sugar on yeast viability in gluten-free dough.
Keyword: gluten, saccharomyces cerevisiae, Viabilitas, gula stevia

Judul: Effect of Less Gluten Flour
Formula and Dough Storage Time at Freezing Temperature on the Viability of
Saccharomyces cerevisiae
Abstrak: Roti umumnya terbuat dari tepung terigu yang mengandung gluten. Pemanfaatan tepung premiks dapat dijadikan alternatif untuk mengurangi konsumsi gluten. Penelitian ini bertujuan menentukan viabilitas ragi roti pada formula adonan less gluten yang disimpan pada suhu beku, serta membandingkan formula less gluten terhadap produksi CO2, volume pengembangan roti, dan kenampakan pori. Persentase tepung premiks yang digunakan adalah 25%, 50%, 75%, dan 100% dengan lama penyimpanan pada suhu beku 0, 14, dan 28 hari. Hasil penelitian menunjukkan formula adonan dengan persentase tepung premiks paling kecil tanpa penyimpanan beku memiliki nilai viabilitas yang paling tinggi, yaitu sebesar 241, Bread is generally made from wheat flour which contains gluten. The use of premixed flour can be used as an alternative to reduce gluten consumption. This research aims to determine the viability of bread yeast in a less gluten dough formula stored at freezing temperatures, and compare the less gluten formula on CO2 production, bread rising volume, and pore appearance. The percentage of premix flour used is 25%, 50%, 75%, and 100% with storage periods at freezing temperatures of 0, 14, and 28 days. The results showed that the dough formula with the smallest percentage of premix flour without frozen storage had the highest viability value, namely 241 × 106 CFU/mL, while the formula with the largest percentage of premix flour and a storage time of 28 days had the lowest viability value, namely 6.1 × 106 CFU/mL. Increasing the percentage of premix flour and the length of storage time are inversely proportional to yeast cell viability, CO2 production, and bread rising volume.
Keyword: gluten, Frozen dough, premix flour, yeast viability

Judul: Posisi Filogenetik Kura-Kura Carettochelys Insculpta  (Reptillia: Testudinata)
Abstrak: Carettochelys insculpta is an endemic freshwater turtle of southern Papua and northern Australia. Phylogenetic position of this turtle is remain unresolved until now. Most of the research conducted show close relationships of C. insculpta and members of Trionychidae family. However, some of the research show distance between C. insculpta and members of Trionychidae family. This research is conducted to analyze phylogenetic relationship between C. insculpta and other members of Testudinata using 12S rRNA, 16S rRNA, and both gene as markers. DNA samples were obtained from three different organisms of C. insculpta. Two species used as outgroups were Alligator mississippiensis and Iguana iguana. Phylogenetic analysis was carried out using Neighbor-Joining method with Felsenstein 1981 (F81) modeltest. A polytomy tree of Testudinata was produced by using 12S rRNA gene. However, analysis using 16S rRNA and both genes as markers confirmed that C. insculpta was located between the Chelonidae and the Trionychidae family.
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