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Dynamic viscoelasticity of steamed rice for sake brewing
VOL. 79, 1995
Abstracts of the Articles Printed in Seibutsu-kogaku
Kaishi
Vol. 73, No. 3 (1995)
method process.
Factors Controlling the Concentration of Lysophosphatidylcholine in Saccharified Mash Prepared from Grains.+ KA~UYUKI TORII,* KENJI SATO, and MASAMI ONISHI (Research Center,
Suntory Limited, I-l-l Wakayama-dai, Shimamoto-cho, gun, Osaka 618) Seibutsu-kogaku 73: 183-189. 1995.
* Corresponding
Mishima-
of Lipids Concentration
in Saccharified
YOSHIFUMIKIYOKAWA, and TOSHIYASUYANAGIUCHI (Kizukura
Co. Ltd.,
223 Shioya-machi,
Fushimi-ku,
Kyoto
Mutant
from Sake
207-211. 1995. Temperature-sensitive autolysis mutants were isolated from a sake yeast, strain (Kyokai no. 7) of Succharomyces cerevisiae, which is thought to be diploid. Isolation was performed by positive selection using a medium on which 2-deoxy-galactose-resistant mutants were able to grow. Yeast cells (1 x 108) were spread on a 2-deoxy-galactose plate, and about 100 colonies were isolated after incubation for 5 d at 25°C. About 19; of the mutants from the isolated colonies were deficient in assimilating galactose, and these included temperaturesensitive autolysis mutants at a high frequency (about 50%). In test brewing of sake, one isolate, strain gal-3 1, had the same fermentation activity as Kyokai no. 7, and the sake produced from gal-31 had a satisfactory quality when compared with that made from Kyokai no. 7. The resultant sake cake was stored at 37°C to determine the concentrations of alkaline phosphatase and S-adenosylmethionine, which were used to indicate the extent of yeast cell autolysis. The concentrations in the sake cake from strain gal-31 increased rapidly on storage at 37”C, supposedly because autolysis in the mutant cells in the cake was progressing. These results supported the probability that storing sake cake made from temperature-sensitive autolysis mutants at a higher non-permissive temperature has a positive effect on the ripeness.
Mash
Sake 612)
* Corresponding
author.
A Study of Sake Mureka. -MonographAKIRA NISHIMURA (Hakutsuru Sake
Sumiyoshiminami-machi,
* Corresponding author. t Studies on the Suitability of Rice for Sake Brewing (I). Evaluation
Autolysis
ofBrewing Technology, Tokyo Regional Taxation Bureau, l-3-2 Ohtemachi, Chiyodaku, Tokyo 100’ and Industrial Research Institute of Chiba Prefecture, 889 Kasori-cho, Wakaba-ku, Chiba 264l) Seibutsu-kogaku 73:
Seibutsu-kogaku 73: 191-197. 1995. In the sake brewing process, it is important to comprehend the condition of the steamed rice, because this affects the process control of koji making and fermentation, and finally the quality of the sake. To measure the physical properties of steamed rice, a new system for measuring dynamic viscoelasticity was investigated. The modulus of viscoelasticity of steamed rice depended on the polishing ratio, water content of polished rice, and cooling time after steaming. The longer the soaking time required for polished rice, so the dynamic viscoelasticity of the steamed rice was gradually reduced. When the steam pressure was more than 0.08 kg/cm2 and the steaming time was more than 25 min, desirable steamed rice was obtained. When a cultivar of which the weight of 1,000 grains was heavy or which had a rich protein content was steamed, the modulus of viscoelasticity of the steamed rice was high.
Estimation of Total Evaluation from Sensory (Ginjo) Using a Neural Network.
evaluation
KUNIYASUGOTO’* and TETSUYAHOSHINO~(Ofice
Dynamic Viscoelasticity of Steamed Rice for Sake Brewing.+ YOSHINORI WAKAI,* TOMOCHIKA MIZUMA, NORIKO MIYAZAKI,
Brewing
the sensory
author.
lsotation of a Temperature-Sensitive Yeast Kyokai No. 7. -Note-
Maize contained a small quantity of lysophosphatidylcholine (LPC) and saccharified mash made from maize similarly possessed a small amount. In contrast, although malted barley contained a large quantity of LPC, saccharified mash made from malted barley possessed only a small amount. It is suggested that LPC hydrolase in the barley malt hydrolyzed the LPC and decreased its concentration in the saccharified mash. LPC acylhydrolase hydrolyzes LPC into free fatty acids and glycero phosphoryl choline, so the concentration of free fatty acids in the saccharified mash made from barley malt increased, whereas that in the filtrate decreased because the LPC concentration in the saccharified mash, which dissolves fatty acids into the filtrate, was low. * Corresponding author. 7 Studies on the Control Prepared from Barley (II).
such as a NN is effective in analyzing
of Sake
AKIHIRO KAKAMU,’ TAIZO HANAI,’ HIROYUKI HONDA,’ YOSHIO NISHIDA,~ IWAO FUKAYA,~ and TAKESHI KOBAYASHI’* (Department
of Biotechnology, Faculty of Engineering, Nagoya University, Chikusa-ku, Nagoya 464-011 and Food Research Institute, Aichi Prefectural Government, 2-I-l Shinpukuji-cho, Nishi-ku, Nagoya 45F) Seibutsu-kogaku 73: 199-205. 1995. This paper discusses modeling of the total evaluation process of sake (Ginjo) using a neural network (NN) and multiple regression analysis (MRA). In each method, the total evaluation of 61 Ginjo samples was estimated from data sets of the sensory evaluations of 7 characteristics. The values of the performance index, J, based on errors between actual and estimated values were smaller in the NN model than in MRA. In particular, the NN model with 3 input variables selected from the 7 characteristics evaluated had a simple structure and the J value was sufficiently low. Samples with a large error were found to have the characteristic of “extraordinary flavor.” Addition of “extraordinary flavor” as a new input variable in the NN decreased the error of the model. The results suggested that 4 variables (color, flavor base, aging and extraordinary flavor) are important in the total evaluation of Ginjo, and that a nonlinear modeling 623
Brewing Co. Ltd., 4-5-5 Higashinada-ku, Kobe, Hyogo 658)
Seibutsu-kogaku 73: 213-223. 1995. An unfavorable and characteristic smell is often formed in nonpasteurized sake during storage and commercial distribution at room temperature. We named this smell mureka and analyzed it by GC and GC-MS together with the use of two newly developed injector systems: a thermal desorption cold trap injector (TCT) and a purge and cold trap injector (PTI) for concentrating volatiles. Three compounds causing mureka were isolated from lower volatiles and were identified as iso-valeraldehyde (i-Val), ethyl iso-valerate (EtOVal) and 1, ldiethoxy-3-methylbutane (I, I-DEB) from their CC retention times and mass spectra. Threshold values of these three compounds and their rates of contribution to the intensity and similarity of mureka were studies using sensory evaluation methods. The shreshold values of i-Val, EtOVal and l,l-DEB in sake were determined to be 1.8, 0.5 and 1.2 ppm, respectively. i-Val alone contributed to the intensity, while EtOVal and 1, l-DEB contributed to the similarity of mureka. Changes in mureka compounds under various storage conditions were measured by the PTI system and GUMS. The results showed that the compounds were prevented from increasing by ultrafiltration or pasteurization of the sake and that they were repressed during storage at high temperatures of 40°C or 50°C. A clear relationship was observed between a decrease in the i-amylalcohol (i-AmOH) concentration and an increase in the concentration of i-Val, suggesting the existence of a particular enzymatic oxidation pathway converting i-AmOH into i-Val in non-pasteurized sake. From an experiment in which i-Val was added to sake, EtOVal and 1, l-DEB were thought to be formed from i-Val by enzymatic and chemical reactions, respectively.
Abstracts of the Articles Printed in Seibutsu-kogaku
Kaishi
Vol. 73, No. 3 (1995)
method process.
Factors Controlling the Concentration of Lysophosphatidylcholine in Saccharified Mash Prepared from Grains.+ KA~UYUKI TORII,* KENJI SATO, and MASAMI ONISHI (Research Center,
Suntory Limited, I-l-l Wakayama-dai, Shimamoto-cho, gun, Osaka 618) Seibutsu-kogaku 73: 183-189. 1995.
* Corresponding
Mishima-
of Lipids Concentration
in Saccharified
YOSHIFUMIKIYOKAWA, and TOSHIYASUYANAGIUCHI (Kizukura
Co. Ltd.,
223 Shioya-machi,
Fushimi-ku,
Kyoto
Mutant
from Sake
207-211. 1995. Temperature-sensitive autolysis mutants were isolated from a sake yeast, strain (Kyokai no. 7) of Succharomyces cerevisiae, which is thought to be diploid. Isolation was performed by positive selection using a medium on which 2-deoxy-galactose-resistant mutants were able to grow. Yeast cells (1 x 108) were spread on a 2-deoxy-galactose plate, and about 100 colonies were isolated after incubation for 5 d at 25°C. About 19; of the mutants from the isolated colonies were deficient in assimilating galactose, and these included temperaturesensitive autolysis mutants at a high frequency (about 50%). In test brewing of sake, one isolate, strain gal-3 1, had the same fermentation activity as Kyokai no. 7, and the sake produced from gal-31 had a satisfactory quality when compared with that made from Kyokai no. 7. The resultant sake cake was stored at 37°C to determine the concentrations of alkaline phosphatase and S-adenosylmethionine, which were used to indicate the extent of yeast cell autolysis. The concentrations in the sake cake from strain gal-31 increased rapidly on storage at 37”C, supposedly because autolysis in the mutant cells in the cake was progressing. These results supported the probability that storing sake cake made from temperature-sensitive autolysis mutants at a higher non-permissive temperature has a positive effect on the ripeness.
Mash
Sake 612)
* Corresponding
author.
A Study of Sake Mureka. -MonographAKIRA NISHIMURA (Hakutsuru Sake
Sumiyoshiminami-machi,
* Corresponding author. t Studies on the Suitability of Rice for Sake Brewing (I). Evaluation
Autolysis
ofBrewing Technology, Tokyo Regional Taxation Bureau, l-3-2 Ohtemachi, Chiyodaku, Tokyo 100’ and Industrial Research Institute of Chiba Prefecture, 889 Kasori-cho, Wakaba-ku, Chiba 264l) Seibutsu-kogaku 73:
Seibutsu-kogaku 73: 191-197. 1995. In the sake brewing process, it is important to comprehend the condition of the steamed rice, because this affects the process control of koji making and fermentation, and finally the quality of the sake. To measure the physical properties of steamed rice, a new system for measuring dynamic viscoelasticity was investigated. The modulus of viscoelasticity of steamed rice depended on the polishing ratio, water content of polished rice, and cooling time after steaming. The longer the soaking time required for polished rice, so the dynamic viscoelasticity of the steamed rice was gradually reduced. When the steam pressure was more than 0.08 kg/cm2 and the steaming time was more than 25 min, desirable steamed rice was obtained. When a cultivar of which the weight of 1,000 grains was heavy or which had a rich protein content was steamed, the modulus of viscoelasticity of the steamed rice was high.
Estimation of Total Evaluation from Sensory (Ginjo) Using a Neural Network.
evaluation
KUNIYASUGOTO’* and TETSUYAHOSHINO~(Ofice
Dynamic Viscoelasticity of Steamed Rice for Sake Brewing.+ YOSHINORI WAKAI,* TOMOCHIKA MIZUMA, NORIKO MIYAZAKI,
Brewing
the sensory
author.
lsotation of a Temperature-Sensitive Yeast Kyokai No. 7. -Note-
Maize contained a small quantity of lysophosphatidylcholine (LPC) and saccharified mash made from maize similarly possessed a small amount. In contrast, although malted barley contained a large quantity of LPC, saccharified mash made from malted barley possessed only a small amount. It is suggested that LPC hydrolase in the barley malt hydrolyzed the LPC and decreased its concentration in the saccharified mash. LPC acylhydrolase hydrolyzes LPC into free fatty acids and glycero phosphoryl choline, so the concentration of free fatty acids in the saccharified mash made from barley malt increased, whereas that in the filtrate decreased because the LPC concentration in the saccharified mash, which dissolves fatty acids into the filtrate, was low. * Corresponding author. 7 Studies on the Control Prepared from Barley (II).
such as a NN is effective in analyzing
of Sake
AKIHIRO KAKAMU,’ TAIZO HANAI,’ HIROYUKI HONDA,’ YOSHIO NISHIDA,~ IWAO FUKAYA,~ and TAKESHI KOBAYASHI’* (Department
of Biotechnology, Faculty of Engineering, Nagoya University, Chikusa-ku, Nagoya 464-011 and Food Research Institute, Aichi Prefectural Government, 2-I-l Shinpukuji-cho, Nishi-ku, Nagoya 45F) Seibutsu-kogaku 73: 199-205. 1995. This paper discusses modeling of the total evaluation process of sake (Ginjo) using a neural network (NN) and multiple regression analysis (MRA). In each method, the total evaluation of 61 Ginjo samples was estimated from data sets of the sensory evaluations of 7 characteristics. The values of the performance index, J, based on errors between actual and estimated values were smaller in the NN model than in MRA. In particular, the NN model with 3 input variables selected from the 7 characteristics evaluated had a simple structure and the J value was sufficiently low. Samples with a large error were found to have the characteristic of “extraordinary flavor.” Addition of “extraordinary flavor” as a new input variable in the NN decreased the error of the model. The results suggested that 4 variables (color, flavor base, aging and extraordinary flavor) are important in the total evaluation of Ginjo, and that a nonlinear modeling 623
Brewing Co. Ltd., 4-5-5 Higashinada-ku, Kobe, Hyogo 658)
Seibutsu-kogaku 73: 213-223. 1995. An unfavorable and characteristic smell is often formed in nonpasteurized sake during storage and commercial distribution at room temperature. We named this smell mureka and analyzed it by GC and GC-MS together with the use of two newly developed injector systems: a thermal desorption cold trap injector (TCT) and a purge and cold trap injector (PTI) for concentrating volatiles. Three compounds causing mureka were isolated from lower volatiles and were identified as iso-valeraldehyde (i-Val), ethyl iso-valerate (EtOVal) and 1, ldiethoxy-3-methylbutane (I, I-DEB) from their CC retention times and mass spectra. Threshold values of these three compounds and their rates of contribution to the intensity and similarity of mureka were studies using sensory evaluation methods. The shreshold values of i-Val, EtOVal and l,l-DEB in sake were determined to be 1.8, 0.5 and 1.2 ppm, respectively. i-Val alone contributed to the intensity, while EtOVal and 1, l-DEB contributed to the similarity of mureka. Changes in mureka compounds under various storage conditions were measured by the PTI system and GUMS. The results showed that the compounds were prevented from increasing by ultrafiltration or pasteurization of the sake and that they were repressed during storage at high temperatures of 40°C or 50°C. A clear relationship was observed between a decrease in the i-amylalcohol (i-AmOH) concentration and an increase in the concentration of i-Val, suggesting the existence of a particular enzymatic oxidation pathway converting i-AmOH into i-Val in non-pasteurized sake. From an experiment in which i-Val was added to sake, EtOVal and 1, l-DEB were thought to be formed from i-Val by enzymatic and chemical reactions, respectively.