This study was carried out to in investigate the use of Rhizopus oligosporus in production of Doenjang sauce. Growth characteristics and enzyme activity of R. oligosporus using different substrates were studied. The quality of Doenjang prepared using R. oligosporus and tomatoes was assessed to check if it possessed the quality characteristics of Doenjang. The study was also conducted to examine the sensory profiles of Doenjang using a standardized sensory evaluation procedure, and to identify the sensory attributes. The results are as follows:

1) The culture temperature of R. oligosporus were 30℃ and 4℃ (low temperature). There was a difference in culture time, but didn''t have a significant effect.

2) NaCl (salt) concentration affected the growth of R. oligosporus. The optimum salt concentration was appropriately 5% or less. However, R. oligosporus was able to growth at 15% NaCl concentration, but its growth was inhibited at 20% NaCl concentration.

3) The bean and mix (bean+rice) were incubated at suitable conditions for growth of R. oligosporus, but rice was found unsuitable for incubating R. oligosporus.

4) The amylase level of R. oligosporus when incubated at mix (bean+rice) was higher than the amylase level of R. oligosporus incubated at bean and rice. The amylase activity of R. oligosporus incubated with rice and mix (bean+rice) exhibited higher activity than R. oligosporus incubated with other substrates.

5) The protease level of R. oligosporus incubated with mix (bean+rice) was higher than the protease level of R. oligosporus incubated with bean and rice. R. oligosporus incubated with bean and mix (bean+rice) exhibited higher protease activity than R. oligosporus incubated with other substrates.

6) Lipase activity of R. oligosporus was found to be highest when incubated with bean and mix (bean+rice).

7) Moisture, crude protein, crude fat, crude ash, carbohydrate, total dietary fiber, soluble dietary fiber and insoluble dietary fiber of tomato were: 19.41%, 11.14%, 0.45%, 8.43%, 60.57%, 13.7%, 1.6% and 11.9% respectively.

8) The pH and titratable acidity, brix°, vitamin C contents, lycopene contents and color value of tomato were determined to be: 4.13, 0.60%, 8.99 brix°, 10.59 mg/100 g, 3.25 mg/g and L value 38.53, a value 0.18, b value 16.69, respectively.


9) Moisture, crude protein, total nitrogen, crude fat, crude ash and carbohydrate of Doenjang prepared using R. oligosporus and tomato paste, were: 60%, 24%, 3%, 2.5%, 5.3% and 15.2%, respectively.

10) The pH and titratable acidity, brix°, salinity, reducing sugar contents, volatile basic nitrogen contents, amino-nitrogen contents and color value of Doenjang prepared using R. oligosporus and tomato paste were: 5.62, 147.4 (g of 0.1 N NaOH), 7.97 brix°, 4.43%, 36 mg%, 15 mg%, 24 mg% and L value 39.13, a value 9.3, b value 17.12, respectively.

11) Peroxide value, TBA and acid value of Doenjang prepared using R. oligosporus and tomato paste were: 15.54 meq/Kg, 140 and 25.7, respectively.

12) The free sugar of Doenjang prepared using R. oligosporus and tomato paste were detected as glucose, sucrose, fructose, galactose, lactose and maltose. The organic acid of Doenjang prepared using R. oligosporus and tomato paste were detected as citric acid, malic acid, acetic acid, succinic acid, formic acid and lactic acid.

13) The α-amylase, acidic protease, neutral protease and lipase activity of Doenjang prepared using R. oligosporus and tomato paste were determined to be: 74.72, 13.28, 35.79, and 93.59 unit/mL, respectively.

14) To the descriptive analysis of Doenjang, developed and evaluated 15 descriptors by eleven descriptive analysis panelists. Significant differences among the samples for all the 15 attributes observed.


15) Three samples were produced by using a modified method from this study. For the quantitative descriptive analysis, eleven descriptive analysis panelists evaluated 8 descriptors. Significant differences among the samples for all the 8 attributes were found. The Doenjang prepared using R. oligosporus and tomato paste were rated as excellent significantly.

In this study, R. oligosporus was found as optimal strains for Doenjang preparation based on estimates of fermentation characteristics. In addition, R. oligosporus exhibited high enzyme activity and quick growth characteristics. These results proved that quick fermented Doenjang with availability can be prepared by R. oligosporus.
To make better and convenient Doenjang, multipurpose sauce was added to Doenjang prepared by R. oligosporus. Quality characteristics of 4 types Doenjang sauce, added were higher than those of commercial sauce. These results suggest that productivity and availability of fermented foods could be improved by using R. oligosporus in Doenjang preparation.