• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.5
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• pp.636-642
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• 1993

To improve the quality of mirin, various molds were screened for mutants with high acid carboxypeptidase (ACPase) by the method of ultraviolet radiation. Mutants, Aspergillus oryzae 9-12 and Aspergillus shiroussamii 6082-60 showed activities of ACPase about 2~6 times higher than their parent strains. Aspergillus oryzae 9-12 and Aspergillus shirosamii 6082-60 were the most suitable strains for preparing koji in mirin by the conventional or improved methods. The results showed that total sugar, reducing sugar and total nitrogen were almost the same values in mirin prepared by both methods. The yield of mirin was higher in the improved method than in the conventional method. The clouding formation of mirin appeared in the conventional method ; however, mirin prepared with the mutant koji by the improved method did not show clouding formation.

• Korean Journal of Food Science and Technology
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• v.25 no.5
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• pp.430-437
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• 1993

This study was carried out for high quality mirin Production by fusant F-50. Cellularly fused between Aspergillus oryzae 9-12 and Aspergillus shirousamii 6082-60. The conventional and the improvement methods in Mirin-making by F-50 showed high level of total sugar, reducing sugar and amino-nitrogen of 42%, 38% and 0.18%, respectively. Free amino acids in Mirin were found to 387.2 mg% glutamic acid, 283.8 mg% arginine, 244.0 mg% leucine, 218.0 mg% aspartic acid, 231.1 mg% alanine, 168.3 mg% serine and 148 mg% phenylalanine. Organic acids in Mirin were contained: oxalic acid, citric acid, malic acid, succinic acid, lactic acid, acetic acid and propionic acid. Sugars such as glucose, maltose, isomaltose, maltotriose, ribose, isomaltotriose and isomatotertraose were also found in Mirin. The clouding formation of Mirin made by F-50 showed 0.03 alcohol clouding, 0.08 water clouding and negative heat clouding.

• Korean Journal of Food Science and Technology
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• v.25 no.4
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• pp.366-372
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• 1993

This study mainly designed to high quality of mirin production by using protopast fusion. In order to enhance the acid carboxypeptidase (ACPase) activity by the method of protoplast fusion. In order to enhance the acid carboxypeptidase (ACPase) activity by the method of protopalst fusion, the mutants, Aspergillus oryzae 9-12 and Aspergillus shirosamii IFO 6082-60 were selected by mutation among various mutants. Protoplast of Aspergillus oryzae 9-12 and Aspergillus shirousamii IFO 6082-60 were formed effectively by incubation of the mixtures of chitinase (10mg/ml), cellulase (10mg/ml) and zymolase 20T (5mg/ml). For protopalst fusion, the mixture of two mutant were fused to effective under the optimum conditions by solutions containing 30% PEG 6,000, 0.01M $CaCl_2\;2H_2O$, 0.6M KCl and 0.05M glycine. Fusion frequency was 0.71% and fusant, F-50 appeared ACPase activity of 20,800 unit/g which has 1.5 times higher than that of each mutants.