Judul: Utami, Rahayu
Abstrak: Tempe is a fermented soybean food in Indonesia. Tempe was commonly produced about 24-48 hours fermentation. Tempe is referred as over-fermented tempe after the 48 hours fermentation has been completed. The over-fermented tempe known as tempe semangit and tempe bosok. Tempe semangit is over-fermented tempe (slightly overriped) which is obtained by lengthening the fermentation 48-72 hours longer than fresh tempe fermentation, whereas tempe bosok (overripe tempe) needs more than 72 hours of over-fermentation. Therefore, over-fermented tempe has a brown color, pungent odor, and soft textures compared to the white compact cake of fresh tempe. Over-fermented tempe is popular in Javanese culture as an umami seasoning in traditional foods. Over-fermented tempe have been prepared by several different periods including : 0, 24, 48, 72 and 96 hours after the tempe production. Over-fermented tempe was extracted to obtain water soluble extracts (WSEs). The water soluble extracts (WSEs) were analyzed for crude proteins, total acids, total sugars, pH value, total amino acids, free amino acids, HPLC profile, taste activity value and umami taste dilution factors. Analysis of variance (ANOVA) was performed on crude protein, total acids, total sugars and pH value. As shown by ANOVA, crude protein and pH value were not statistically different between the fermentation periods, but were statistically different on total acids and total sugars. Free amino acids were characterized for their tasting and taste activity values. Based on the taste activity value, the taste of WSEs was umami and bitter. WSE from sample with 72 hours over-fermentation had umami taste activity value higher than bitter taste activity. The ratios of umami and sweet taste activity value to bitter taste activity were found between 1.2-1.6 in the mentioned WSE. There was a positive correlation between the taste rasio and umami taste dilution factor (r = 0.843 dan p = 0.002). The umami taste dilution factor was the result of sensory analysis of 5 times concentrated WSE. The highest ratio 1.6 belongs to WSE with 72 hours over-fermentation which had the highest dilution factor 256. Umami taste intensity WSE with 72 hours fermentation was determined with the existence of umami and bitter tasting free amino acids. In general HPLC profile indicated the composition in WSE’s fractions. Fraction 2 of each WSE of over-fermented tempe dominantly consisted of hydrophilic components, in contrast Fraction 3 of each WSE of over-fermented tempe was dominated by hydrophobic components. Fraction dominantly consisted of hydrophilic components having a higher intensity of umami taste.
Keyword: bitter taste, free amino acids, umami taste, over-fermented tempe, water soluble extract

Judul: Analisis deskripsi sensori flavor tempe
Abstrak: Tempe adalah makanan tradisional khas Indonesia yang merupakan produk fermentasi kapang Rhizopus oligosporus. Makanan ini tidak dikonsumsi mentah tetapi dikonsumsi setelah mengalami proses pengolahan seperti penggorengan dan perebusan dengan penambahan bumbu. Proses fermentasi dan proses pengolahan tersebut masing-masing menghasilkan flavor tempe yang sangat khas. Penelitian ini bertujuan untuk mengetahui deskripsi rasa dan aroma tempe mentah, tempe goreng tidak bergaram, tempe goreng bergaram, tempe rebus tidak bergaram dan tempe rebus bergaram. Analisis yang dilakukan adalah analisis deskripsi flavor secara kualitatif dan kuantitatif. Analisis kualitatif dilakukan dengan teknik In-Depth Interviews, Focus Groups dan Respondent-Plus-Client Groups. Sedangkan analisis kuantitatif dilakukan dengan metoda Quantitative Description Analysis (QDA) yang dilanjutkan dengan analisis multivariate menggunakan teknik Principal Component Analysis (PCA). Panelis yang terlibat adalah panelis terlatih dan panelis konsumen pada teknik Respondent-Plus-Client Groups. Atribut rasa dan aroma yang dideskripsikan oleh panelis pada uji kualitatif dijadikan sebagai atribut yang dinilai dalam uji deskripsi secara kuantitatif (QDA). Data yang digunakan untuk analisis PCA adalah data QDA yang telah divalidasi. Validasi data dilakukan dengan mempertimbangkan hasil GLM (General Linear Model) yang membandingkan respon panelis pada hari yang berbeda, standar deviasi respon ulangan panelis dan nilai rata-rata ulangan panelis. Hasil analisis deskripsi secara kualitatif menunjukkan bahwa semua sampel mempunyai deskripsi rasa pahit dan asam. Selain rasa pahit dan asam, tempe goreng tidak bergaram dideskripsikan mempunyai rasa gurih sedangkan rasa tempe goreng-dan-tempe-rebus yang diberi-garam-dideskripsikan-dengan-gurih-dan-asin. Deskripsi tempe rebus tidak bergaram sama dengan deskripsi rasa tempe mentah, yaitu pahit dan asam. Selain rasa dasar, beberapa aroma dan mouthfeel terdeskripsi pada tempe pada saat dikonsumsi. Hasil analisis deskripsi secara kualitatif menunjukkan bahwa atribut aroma pada tempe mentah adalah fermented soybean, raw, langu, earthy, dan soury. Analisis tersebut juga menyatakan aroma-aroma tersebut juga ada pada tempe goreng dan tempe rebus. Selain deskripsi tersebut, tempe goreng dideskripsikan dengan gurih dan berminyak/goreng-gorengan, dan tempe rebus dideskripsikan dengan kedelai rebus/rebus-rebusan. ...
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Judul: Construction of Strongly Optimal Binary Linear Code with Minimum Distance 9 and 11
Abstrak: A binary linear code of length n over q F is a subspace of n q F . A code has three parameters that attached to it, namely length, dimension, and minimum distance. A code with length n, dimension k and minimum distance d is often called [n, k, d ]-code. Usually, when two parameters are given, then we want to find a code that has the best value for the last parameter. Based on Gilbert- Varshamov bound, if a [n, k, d ]-code exists and can not be expanded, we call it a strongly optimal code. In this paper, we construct strongly optimal code with minimum distance 9 and 11. In constructing the code, we created a theorem and algorithm based on Gilbert-Varshamov bound before we implement the algorithm to MAPLE programming language. Because of computational limitations, the program can only construct up to k = 10 for d = 9 and k = 12 for d = 11.
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