Identification of a Umami Peptide in Tempeh (Indonesian Fermented Food) by LC-MS/MS and the Binding Mechanism to the Umami Receptor

Amin, Muhamad Nur Ghoyatul (2014) Identification of a Umami Peptide in Tempeh (Indonesian Fermented Food) by LC-MS/MS and the Binding Mechanism to the Umami Receptor. Magister thesis, Universitas Brawijaya.

Abstract

Tempe adalah produk kedelai, yang diproduksi dengan fermentasi. Diketahui pada 1700-an di Indonesia, dan pertama kali dibuat di Jawa, Indonesia. Persentase konsumsi rumah tangga tempe pada tahun 2009 adalah 69,89%, lebih dari o r produk berbasis kedelai, seperti tahu, saus, oncom, tauco dan susu kedelai. Selama fermentasi, pencernaan protein terjadi, disebabkan oleh protease yang disekresikan selama pertumbuhan Rhizopus microsporus var. oligosporus. Protein kedelai dicerna untuk membentuk asam amino bebas dan peptida. Tempe sangat populer karena rasa UMAMI, yang mungkin disebabkan oleh komposisi peptida kecil dari kisaran ukuran 1-3 KDA yang berisi beberapa sekuens GLU dan ASP. Reseptor UMAMI (T1R) memiliki dua subtipe, T1R1 dan T1R3, yang dapat berfungsi sebagai heterodimer atau homodimer. Dalam penelitian ini, tujuan kami adalah untuk mengidentifikasi peptida yang berkontribusi pada rasa UMAMI, menggunakan LC-MS / MS, evaluasi sensorik dan docking molekuler ke reseptor umami. Ekstrak larut dalam air dari tempe difraksinasi menggunakan selaput ultrafiltrasi pemotongan berat molekul 3 kDa dan profil rasa fraksi berat molekul rendah dievaluasi oleh enam panelis yang dipilih dari Departemen Ilmu dan Teknologi Biologi, Universitas Pingtung Nasional Sains dan Teknologi, Taiwan. Panelis dilatih untuk mengenali lima rasanya dasar menggunakan beberapa solusi standar untuk agen rasa termasuk manis, pahit, asam, asin dan umami diwakili oleh solusi sukrosa (1%), kafein (0,08%), asam sitrat (0,08%),, natrium klorida (0,35%), dan MSG-Garline (0,35-0,35%), masing-masing. n, panelis menguji lima rasanya dasar untuk (a) ekstrak larut dalam air dari tempe serta solusi standar. (B) Tes perbedaan untuk lima rasa dasar antara ekstrak larut dalam air dan fraksi cutoff 3 KDA. dan (c) tes perbedaan antara 3 fraksi cutoff kDa dan siny tic peptide geneeedsagiivtvk. Hasil penelitian menunjukkan bahwa umami memiliki intensitas tertinggi dibandingkan dengan selera dasar pada 3 fraksi cutoff KDA dan siny tic peptide geneeedsagiivtvk. LC-MS / MS mengidentifikasi 4 peptida dari 3 fraksi cutoff tempe pada 48 jam, termasuk geneeedsagiivtvk, yang kami sinkronisasi berukuran dan dievaluasi. Peptida ini mengintensifkan rasa umami, meskipun intensitas peptida umami tidak berbeda secara signifikan dari fraksi cutoff 3 KDA. Hasil docking molekuler menggunakan ZDock menunjukkan bahwa Peptide dapat berikatan dengan mengikat saku TIR3 dalam konformasi terbuka dan tertutup.

English Abstract

Tempeh is soybean product, which produced by fermentation. It was known in 1700s in Indonesia, and first made in Java, Indonesia. tempeh household consumption percentage in year 2009 was 69.89%, much more than o r soy based products, such as tofu, sauce, oncom, tauco and soymilk. During fermentation, protein digestion occurs, caused by proteases secreted during growth of Rhizopus microsporus var. oligosporus . soy protein is digested to form free amino acids and peptides. Tempeh is especially popular because of its umami taste, which may be caused by small peptide compositions of size range 1-3 kDa containing some Glu and Asp sequences. umami (T1R) receptor has two subtypes, T1R1 and T1R3, which can function as heterodimers or homodimers. In this study, our aims were to identify peptides that contribute to umami taste, using LC-MS/MS, sensory evaluation and molecular docking to umami receptor. water soluble extracts from tempeh were fractionated using a 3 kDa molecular weight cutoff ultrafiltration membrane and taste profile of low molecular weight fraction was evaluated by six panelists who were selected from Department of Biological Science and Technology, National Pingtung University of Science and Technology, Taiwan. panelists were trained to recognize five basic tastes using some standard solutions for taste agents including sweet, bitter, sour, salty and umami represented by solutions of sucrose (1%), caffeine (0.08%), citric acid (0.08%), sodium chloride (0.35%), and MSG–salt (0.35–0.35%), respectively. n, panelists tested five basic tastes for (a) water soluble extract from tempeh as well standard solution; (b) difference test for five basic tastes between water soluble extract and 3 kDa cutoff fraction; and (c) difference test between 3 kDa cutoff fraction and syn tic peptide GENEEEDSGAIVTVK . results showed that umami had highest intensity compared to o r basic tastes in 3 kDa cutoff fraction and syn tic peptide GENEEEDSGAIVTVK. LC-MS/MS identified 4 peptides from 3 kDa cutoff fraction of tempeh at 48 h, including GENEEEDSGAIVTVK, which we syn sized and evaluated. This peptide intensified umami taste, although umami peptide intensity is not significantly different from 3 kDa cutoff fraction. results of molecular docking using ZDOCK showed that peptide could bind to binding pocket of TIR3 in open and closed conformations.

Item Type:	Thesis (Magister)
Identification Number:	TES/641.356 55/AMI/i/041404447
Subjects:	600 Technology (Applied sciences) > 641 Food and drink > 641.3 Food
Divisions:	S2/S3 > Magister Teknologi Hasil Pertanian, Fakultas Teknologi Pertanian
Depositing User:	Endro Setyobudi
Date Deposited:	18 Aug 2014 14:28
Last Modified:	30 Mar 2022 07:58
URI:	http://repository.ub.ac.id/id/eprint/159110

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