• Applied Biological Chemistry
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• v.17 no.2
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• pp.81-92
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• 1974

In order to prepare the mashing materials for 'Takju', Korean wine, with potatoes, theywere steamed, dryed, and pulverized, and their chemical components were analyzed. As a brewing method of Takju with potatoes, general 2nd stage process with Ipkuk and Bunkuk (enzyme sources), commonly used now, was carried out and the effects of preparing conditions of Ipkuk(koji) with potato flour, mashing materials and brewing conditions on the contents of Takju mash, and of storing time on the contents of Takju, were investigated and the results obtained were summarized as follows, 1. Chemical components of steamed potatoes and potato flour were Moisture; 76.2, 10.8%, Total sugar; 16.1, 69.8%, Reducing sugar; 3.45, 13.4%, Crude protein; 2.1, 11.3%, Total acid; 0.012, 0.023% and Volatile acid; 0.0012, 0.0025% respectively. 2. The most effective preparing conditions of Ipkuk with potato flour were to incubate the potato flour added 40-50% of water for 48 hours by general preparing process of Koji, and liquefying and saccharogenic amylase activities of Ipkuk incubated at above conditions were $D40^{\circ}$ 30' 128 W.V. and 13.2 A.U.. 3. The effects of various brewing conditions on the contents of Takju mashes were as follows; 1) Optimum ratio of mashing water and materials for Takju brewing with potato flour was 140ml of water to 60g of flour in 1st stage and 260ml to 140g in 2nd stage. 2) Optimum fermentating times and temperatures for Takju brewing were at $25^{\circ}C$ for 48 hours in 1st stage and at $30^{\circ}C$ for 48 hours in 2nd stage. 3) Optimum amounts of enzyme sources for Takju brewing were 20-30% of Ipkuk and 0.5% of Bunkuk in 1st stage and 1.0% of Bunkuk in 2nd stage. 4) Methanol content of the Takju mash brewed with raw potato flour was much more than that with steamed potato flour. 5) Alcohol, fusel oil and Formol nitrogen contents of the Takju mash brewed with potato flour were less than that with wheat flour, on the contrary, methanol contents and total acidifies of them were showed conversely above. 4. The changes of chemical components and microflora in the mashes during the brewing potato flour Takju were as follows; 1) The accumulation of ethanol followed rapidly in early stage, being the highest at 72 hours (11.9%). 2) Total sugar content of the mash was decreased considerably within 48-72 hours, being 2.62% at 72 hours, and thereafter slowly. 3) Reducing sugar of the mash had a tendency of decreasing, being 0.29% at 48 hours. 4) Total acidity, volatile acidity and Formol nitrogen content of the mash were increased slowly, being 7.30, 0.20, 2.55 at 48 hours. 5) Total cells of yeast appeared the highest in 72 hours ($2.1{\times}10^8$) and thereafter decreased slowly. 6) Total cells of bacteria appeared the highest in 48 hours ($2.4{\times}10^8$) and thereafter decreased or increased slightly. 5. Takju was made from the fermented mash mixed with water to be 6% of alcohol content, and the change of alcohol content, total acidity, total cells of yeast and bacteria during the storing at $30^{\circ}C$ were as follows; 1) Alcohol content of Takju was increased slightly at 24 hours (6.2%), and thereafter decreased slowly. 2) Total acidity of Takju was increased gradually, being 6.1 at 72 hours 3) Total cells of yeast and bacteria appeared the highest at 48 hours ($2.3{\times}10^8,\;1.5{\times}10^8$), and thereafter decreased slowly. 6. Alcohol content, total acidity and Formol nitrogen content of the Takju brewed with potato flour Ipkuk or wheat flour Ipkuk and steamed potatoes(1:5) were 9.8-11.3%, 5.8-7.4, 2.5-3.3 respectively, and the color of the Takju. was similar to commercial Takju. 7. The results of sensory test for various experimental Takju, showed that the Takjues brewed with the materials combined with wheat flour and steamed potatoes(4:5 or 3.5:7.5) were not significantly different in color, taste and flavor from commercial Takju, However, those with potato flour and wheat flour (1:1 or 7:3) were significantly different from commercial Takju.

• Applied Biological Chemistry
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• v.11
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• pp.1-27
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• 1969

More than thirty kinds of sea food pickles have been eaten in Korea. Out of these salted yellow tail pickle, salted clam pickle, salted oyster pickle, and salted cuttlefish pickle were employed for the analysis of their components, identification of main fermenting microbes, and determination of enzyme characteristics concerned. Also studied was the effect of enzymic action of microbes, which are concerned with the fermenting of pickles, on the production of flavorous 5'-mononucleotides and amino acids. The results are summarized as follows: 1. Microflora observed in the pickles are: (a) Total count of viable cells after 1-2 months of pickling was found to be $10^7$ and that after 6 months decreased to $10^4$. (b) Microbial occurence in the early stage of pickling was observed to be 10-20% Micrococcus spp., 10-20% Brevibacterium spp., 0-30% Sarcina spp., 20-30% Leuconostoc spp., ca 30% Bacillus spp., 0-10% Pseudomonas spp., 0-10% Flavobacterium spp., and 0-20% yeast. (c) Following the early stage of pickling, mainly halophilic bacteria such as Bacillus subtilis, Leuconostoc mesenteroides, Pediococcus halophilus and Sarcina litoralis, were found to exhibit an effect on the fermentation of pickle and their enzyme activities were in direct concern in fermentation of pickles. (d) Among the bacteria participating in the fermentation, Sarcina litoralis 8-14 and 8-16 strains were in need of high nutritional requirement and the former was grown only in the presence of purine, pyrimidine and cystine and the latter purine, pyrimidine and glutamic acid. 2. Enzyme characteristics studied in relation to the raw materials and the concerned microbes isolated are as follows: (a) A small amount of protease was found in the raw materials and 30-60% decrease in protease activity was demonstrated at 7% salt concentration. (b) Protease activity of halophilic bacteria, Bacillus subtilis 7-6, 11-1, 3-6 and 9-4 strains, in the complete media decreased by 10-30% at the 7% salt concentration and that of Sarcina litoralis 8-14 and 8-16 strains decreased by 10-20%. (c) Proteins in the raw materials were found to be hydrolyzed to yield free amino acids by protease in the fermenting microbes. (d) No accumulation of flavorous 5'-mononucleotides was demonstrated because RNA-depolymerase in the raw materials and the pickles tended to decompose RNA into nucleoside and phosphoric acid. (e) The enzyme produced in Bacillus subtilis 3-6 strain isolated from the salted clam pickles, was ascertained to be 5'-phosphodiesterase because of its ability to decompose RNA and thus accumulating 5'-mononucleotide. (f) It was demonstrated that the activity of phosphodiesterase in Bacillus subtilis 3-6 strain was enhanced by some components in the corn steep liquor and salted clam pickle. The enzyme activity was found to decrease by 10-30% and 40-60% at the salt concentration of 10% and 20%, respectively. 3. Quantitative data for free amino acids in the pickles are as follows: (a) Amounts of acidic amino acids such as glutamic and aspartic acids in salted clam pickle, were observed to be 2-10 times other pickles and it is considered that the abundance in these amino acids may contribute significantly to the specific flavor of this food. (b) Large amounts of basic amino acids such as arginine and histidine were found to occur in salted yellow tail pickle. (c) It is much interesting that in the salted cuttlefish pickle the contents of sulfur-containing amino acids were exceedingly high compared with those of others: cystine was found to be 17-130 times and methionine, 7-19 times. (d) In the salted oyster pickle a high content of some essential amino acids such as lysine, threonine, isoleucine and leucine, was demonstrated and a specific flavor of the pickle was ascribed to the sweet amino acids. Contents of alanine and glycine in the salted oyster pickle were 4 and 3-14 times as much as those of the others respectively. 4. Analytical data for 5'-mononucleotides in the pickles are as follows: (a) 5'-Adenylic acid and 3'-adenylic acid were found in large amounts in the salted yellow tail pickle and 5'-inosinic acid in lesser amount. (b) 5'-Adenylic acid, especially 3'-adenylic acid predominated in amount in the salted oyster pickle over that in the other pickles. (c) The salted cuttlefish pickle was found to contain only 5'-adenylic acid and 3'-adenylic acid. It has become evident from the above fact that clam and the invertebrate lack of adenylic deaminase and contain high content of adenylic acid. Thus, they were demonstrated to be the AMP-type. (d) 5'-Inosinic acid was contained in the salted yellow tail pickle in a significant concentration, and it might be considered to be IMP-type. 5. Comparative data for flavor with regard to the flavorous amino acids and the contents of 5'-mononucleotides are: (a) A specific flavor of salted yellow tail pickle was ascribed to the abundance in glutamic acid and aspartic acid, and to the existence of a small amount of flavorous 5'-inosinic acid. The combined effect of these components was belived to exhibit a synergistic action in producing a specific fiavor to the pickle. (b) A specific flavor of salted clam pickle has been demonstrated to be attributable to the richness in glutamic acid and aspartic acid rather than to that of 5'-mononucleotides.