CYCLIC PEPTIDES: X. Bitter Taste and Chymotryptic Hydrolysis of Cyclic Depsidipeptides Containing a Tryptophan Residue*

2009 ◽  
Vol 17 (1) ◽  
pp. 118-124 ◽  
Author(s):  
KOICHI MIYAZAKI ◽  
AKIRA YASUTAKE ◽  
NORIKAZU NISHINO ◽  
HARUHIKO AOYAGI ◽  
TETSUO KATO ◽  
...  
2001 ◽  
pp. 516-517
Author(s):  
Masao Kawai ◽  
Hatsuo Yamamura ◽  
Nobuko Izuhara ◽  
Tomotsugu Kawaguchi ◽  
Ryoji Tanaka ◽  
...  

1988 ◽  
Vol 55 (2) ◽  
pp. 239-245 ◽  
Author(s):  
Ylva Ardö ◽  
Hans-Erik Pettersson

SummarySynergic effects of proteolytic enzymes from two different microbial sources on the ripening of Swedish hard cheese were studied. When extracellular proteolytic enzymes from Bacillus subtilis (Neutrase) and/or heat treated cells of Lactobacillus helveticus (now L. delbrueckii subsp. helveticus) were added to the cheese milk, cheese ripening was accelerated; Neutrase effectively hydrolysed casein to give a softer body. Addition of heat treated lactobacilli did not accelerate hydrolysis of casein, but accelerated the breakdown of peptides which increased the amount of amino acid N in the cheese and also enhanced the intensity of cheese flavour. A bitter taste which developed in cheeses with added Neutrase could be eliminated by the simultaneous addition of heat treated lactobacilli.


2013 ◽  
Vol 652-654 ◽  
pp. 435-438 ◽  
Author(s):  
Yong Sheng Ma ◽  
Lin Tong Wang ◽  
Xian Hui Sun ◽  
Bing Chen Ma ◽  
Jian Wen Zhang ◽  
...  

Soybean protein Alcalase hydrolysate was further hydrolyzed by adopting Flavourzyme. From this further hydrolysis reaction, bitter of soybean polypeptide mixture was reduced distinctly. The optimal hydrolysis conditions of Flavourzyme was determined as that pH was 7.0 at temperature 50°C and E/S(ratio of enzyme and substrate) was 20LAPU/g. Bitter taste value was reduced to 2 after Flavourzyme hydrolysis reaction for 2 hours in optimal hydrolysis conditions. The change of molecular weight distribution range from Alcalase hydrolysate to Flavourzyme hydrolysate was not obvious. DH (Degree of hydrolysis) of soybean protein hydrolysate was increased to 24.2% which was improved 3.5% than Alcalase hydrolysate. Protein recovery proportion was increased to 73.2% which was improved 0.8% than Alcalase hydrolysate.


Author(s):  
Veriani Aprilia ◽  
Febrina Suci Hati

<p><strong>ABSTRACT</strong></p><p><em><strong>Background</strong>: Malnutrition become the problem in Indonesia. Complementary feeding has the role in solving it. Most of commercial complementary feeding are enriched by vegetable protein, whereas animal protein has more complete amino acid and better digestibility. Unfortunately, consuming animal protein</em><br /><em>often raises concern because of its allergenicity. Catfish (Clarias gariepinus) can be used as a source of high animal protein in the diet that may solve the nutritional problem after reduction of its allergen.</em></p><p><em><strong>Objectives</strong>: To develope formulate of complementary feeding porridge enriched with hydrolized protein from catfish muscle.</em></p><p><em><strong>Methods</strong>: This was experimental study. HPIL and HPIK was enzymatic hydrolized products of catfish using crude and commercial papain, respectively. Overall and partial hedonic test used 23 mothers as panelists, then selected formula were tested its acceptance by 9 babies using face scale. Nutrient content of porridge were analyzed for protein, carbohydrate, fat, protein, and water.</em></p><p><em><strong>Results</strong>: Hydrolysis of catfish using papain made the changes in color, taste, and aroma. The bitter taste limited the uses, maximum amount was 25%. Porridge with the addition of HPIK were chosen by mothers and babies panelists, whereas HPIL did not. Protein content of formulated product were lower than commercial product, but carbohydrate and fat content were higher.</em></p><p><em><strong>Conclusions</strong>: Porridge formula with addition of 25% HPIK my be developed as alternative product of complementary feeding.</em></p><p><strong>KEYWORDS</strong><em>: protein, papain, catfish, protein hydrolisate, complementary feeding</em></p><p><strong>ABSTRAK</strong></p><p><em><strong>Latar belakang</strong>: Kekurangan gizi masih menjadi masalah di Indonesia. MPASI memiliki peran penting dalam mengatasi masalah tersebut. MPASI pada umumnya diperkaya oleh protein nabati, padahal protein hewani mengandung asam amino dan daya cerna yang lebih baik. Namun demikian, protein hewani</em><br /><em>meningkatkan risiko alergi pada bayi. Lele (Clarias gariepinus) dapat dijadikan alternatif sumber protein hewani karena ketersediaan yang banyak dan harganya yang murah. Diperlukan suatu teknologi untuk mengurangi tingkat alerginya dan formulasi yang tepat dibutuhkan agar dapat diterima oleh bayi.</em></p><p><em><strong>Tujuan</strong>: Formulasi bubur bayi MPASI yang diperkaya hidrolisat protein ikan lele dumbo.</em></p><p><em><strong>Metode</strong>: Jenis penelitian ini adalah eksperimental. HPIL dan HPIK merupakan hidrolisat protein ikan lele dumbo yang masing-masing dihidrolisis secara enzimatis menggunakan enzim papain kasar dan papain komersial. Uji kesukaan keseluruhan dan parsial menggunakan 23 panelis ibu, kemudian formula terpilih</em><br /><em>diujikan daya terimanya oleh 9 bayi menggunakan skala raut muka. Uji nilai gizi bubur bayi meliputi kadar protein, karbohidrat, lemak, protein, dan air.</em></p><p><em><strong>Hasil</strong>: Proses hidrolisis kimiawi protein ikan lele dumbo menggunakan enzim papain menyebabkan perubahan warna, rasa, dan aroma produk. Adanya perubahan sifat tersebut menyebabkan penambahannya ke dalam formulasi bubur MPASI hanya sampai kadar 25%. Di atas kadar tersebut, produk berasa pahit. </em><em>Hasil uji sensoris produk formulasi HPIK dapat diterima oleh panelis ibu dan bayi, sedangkan produk HPIL tidak. Kandungan protein produk formulasi lebih rendah dibanding bubur komersial, namun kandungan karbohidrat dan lemak lebih tinggi.</em></p><p><em><strong>Kesimpulan</strong>: Formula bubur bayi dengan penambahan 25% HPIK dapat dikembangkan menjadi alternatif produk MPASI.</em></p><p><strong>KATA KUNCI</strong><em>: protein, papain, lele dumbo, hidrolisat protein, MPASI</em></p>


2009 ◽  
Vol 15 (4) ◽  
pp. 407-413 ◽  
Author(s):  
G.A. Rocha ◽  
M.A. Trindade ◽  
F.M. Netto ◽  
C.S. Favaro-Trindade

The aim of this work was to encapsulate a casein hydrolysate by spray drying using maltodextrins (DE 10 and 20) as wall materials and to evaluate the efficiency of the microencapsulation in attenuating the bitter taste of the hydrolysate using protein bars as the model system. Microcapsules were evaluated for morphology (SEM), particle size, hygroscopicity, solubility, thermal behavior (DSC), and bitter taste with a trained sensory panel by a paired comparison test (nonencapsulated samples vs. encapsulated samples). Bars were prepared with the addition of 3% casein hydrolysate at free or both encapsulated forms, and were then evaluated for their moisture, water activity (aw) and for their bitter taste by a ranking test. Microcapsules were of the matrix type, having continuous surfaces with no apparent porosity for both coatings. Both encapsulated casein hydrolysates had similar hygroscopicity, and lower values than free encapsulated hydrolysates. The degree of hydrolysis of the maltodextrin influenced only the particle size and Tg. The sensory panel considered the protein bars produced with both encapsulated materials less bitter (p < 0.05) than those produced with the free casein hydrolysates. Microencapsulation by spray drying with maltodextrin DE 10 and 20 was successful to attenuate the bitter taste and the hygroscopicity of casein hydrolysates.


1968 ◽  
Vol 23 (10) ◽  
pp. 1319-1325 ◽  
Author(s):  
F. M. Veronese ◽  
A. Fontana ◽  
E. Boccu ◽  
C. A. Benassi

The conversion of 2-thio-aryl-tryptophan and related derivatives to the corresponding 2-hydroxycompounds by acidic hydrolysis was investigated. The thioether function is introduced into the tryptophan residue by the selective reaction of sulfenyl halides with the indole nucleus. The substitution occurs under mild conditions only when the amino group of the tryptophan residue is free. The assistance of the amino group was confirmed using model compounds. Thus 2-thio-(2-nitrophenyl) -tryptamine is smoothly converted to 2-hydroxy-tryptamine whereas 2-thio- (2-nitrophenyl) -β-indolyl-propionic acid is completely stable under the same conditions. The conversion of 2-thio-aryl-tryptophan units linked in a polypeptide chain to the corresponding 2-hydroxy-tryptophan occurs only under conditions during which hydrolysis of the peptide bond occurs. It was also observed that the 2-nitro-thiophenols which are released during the hydrolysis of 2-thio- (2-nitrophenyl) -tryptophan and related compounds are converted under the conditions of the reaction to 2-aminobenzene sulfonic acids.


Tetrahedron ◽  
1998 ◽  
Vol 54 (24) ◽  
pp. 6719-6724 ◽  
Author(s):  
Hiroshi Uemoto ◽  
Yumi Yahiro ◽  
Hideyuki Shigemori ◽  
Masashi Tsuda ◽  
Toshifumi Takao ◽  
...  

ChemInform ◽  
2010 ◽  
Vol 29 (37) ◽  
pp. no-no
Author(s):  
H. UEMOTO ◽  
Y. YAHIRO ◽  
H. SHIGEMORI ◽  
M. TSUDA ◽  
T. TAKAO ◽  
...  

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