Ajinomoto Co., Ltd.

Hiroaki Nishiuchi

Yasushi Nishimura

Wataru Hoshino

Junko Yamazaki

Misato Morita

Reiko Sugimoto

Takayuki Ito

Yoichi Ueda

Hidehiko Wakabayashi

Masanori Kohmura

Motonaka Kuroda

Toshimi Mizukoshi

Hirokazu Kawaguchi

Minori Ishiguro, Legal Representative

Tatsuya Ishiguro, Legal Representative

Shouji Ishiguro, Legal Representative

Youhei Ishiguro, Legal Representative

Olga Aleksandrovna Sofyanovich

Mariko Suehiro

Yuki Nishimori

Dmitriy Aleksandrovich Cheshev

Koh-ichiro Sano

V Elena Matrosova

Gaku Hibino

Kazuo Yamagishi

Vsevolod Aleksandovich Serebryanyy

A yeast extract containing 0.2% or more of &#x3b3;-Glu-Abu based on dry weight of the yeast extract is produced by culturing a yeast, such asor, in a medium containing a compound selected from Abu (L-2-aminobutyric acid) and &#x3b3;-Glu-Abu (L-&#x3b3;-glutamyl-L-2-aminobutyric acid), and preparing a yeast extract from the obtained cells.

Yeast, yeast extract containing gamma-Glu-Abu, and a method for producing the same

Yeast and a yeast extract with a high content of Abu, &#x3b3;-Glu-Abu, and/or &#x3b3;-Glu-Abu-Gly are provided. By modifying yeast so that intracellular acetolactate synthase activity is reduced, yeast with a high content of Abu, &#x3b3;-Glu-Abu, and/or &#x3b3;-Glu-Abu-Gly is obtained. An yeast extract is prepared by using the yeast obtained in such a manner as a raw material.

Yeast with high content of Abu, &#x3b3;-Glu-Abu, and/or &#x3b3;-Glu-Abu-Gly

A yeast extract containing a peptide, such as &#x3b3;-Glu-X and &#x3b3;-Glu-X-Gly, wherein X can represent an amino acid or an amino acid derivative other than Cys and derivatives thereof, is prepared by culturing a yeast in a medium containing a peptide such as &#x3b3;-Glu-X, &#x3b3;-Glu-X-Gly and X-Gly, and preparing a yeast extract from the obtained cells.

Yeast extract containing &#x3b3;-Glu-X or &#x3b3;-Glu-X-Gly and a method for producing the same

A yeast which harbors a mutant glutathione synthetase having one or both of mutations selected from the group consisting of a mutation to replace a threonine residue at the position 47 with an isoleucine residue and a mutation to replace a glycine residue at the 387-position with an aspartic acid residue and produces &#x3b3;-glutamylcysteine. The yeast is cultured under suitable conditions, the resultant culture or fractionation product thereof or the resultant culture or fractionation product thereof that had been heat-treated is mixed with food or beverage materials and processed into foods or beverage to produce &#x3b3;-glutamylcysteine- or cysteine-containing foods or beverage.

&#x3b3;-glutamylcysteine producing yeast

Food containing &#x3b3;-glutamylcysteine or cysteine is produced by culturingcontaining 1% by weight or more of &#x3b3;-glutamylcysteine per dry cells in logarithmic growth phase when cultured in a minimal medium, for example,in which a gene encoding glutathione synthetase is modified so that intracellular glutathione synthetase activity is reduced, under a suitable condition and mixing the obtained culture or a fraction thereof or the culture or a fraction thereof subjected to heat treatment with a raw material of food or drink to process food or drink.

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The yeast which has &#x3b3;-glutamylcysteine-producing ability and is auxotrophic for pantothenic acid is proliferated in a medium containing a sufficient amount of pantothenic acid, and then it is cultured in a medium containing a limited amount of pantothenic acid to increase the &#x3b3;-glutamylcysteine content in its cells, whereby the yeast in which &#x3b3;-glutamylcysteine is accumulated is obtained.

Method for producing &#x3b3;-glutamylcysteine

A gene encoding glutathione synthetase fromis provided and food containing &#x3b3;-glutamylcysteine cysteine or cystenylglycine is produced by cultivatingmodified by means of a gene encoding glutathione synthetase under a suitable condition and mixing the obtained culture or a fraction thereof or the culture or a fraction thereof subjected to heat treatment with a raw material of food or drink to process food or drink.

The present invention relates to a method for the manufacture of a food material containing high quantities of cysteine. In this method, a yeast extract is prepared from yeast cells that contains &#x3b3;-glutamylcysteine and the extract is concentrated by controlling the temperature to be not greater than 60&#xb0; C. to prepare a food material in a liquid form, wherein the concentration of solids is at least 10% and the resulting food material is maintained at 70 to 130&#xb0; C.

Method for manufacture of highly cysteine-containing food material

The present invention relates to a method for producing a cysteine-rich food material by maintaining a food material containing &#x3b3;-glutamylcysteine at a ratio of at least 1 wt % to the solid content thereof at a temperature ranging from 50 to 120&#xb0; C. and at a pH ranging from 1 to 7. This process is conducted in the absence of a sugar and in the presence of water. The present invention also relates to a method for producing a cysteine-rich food material by reacting the food material with a &#x3b3;-glutamyl peptide hydrolase at a pH ranging from 3 to 9 and at a temperature ranging from 15 to 70&#xb0; C. in the present of water. Further, the present invention relates to a method for producing a flavor-enhancing material for use in food, food products obtained by these processes, and yeast cells or extracts for use in food products.

Growing community of inventors

Kawasaki, Japan

Hiroaki Nishiuchi