Abstract

To confirm the most correct method between different analysis methods used in the activity analysis of glucoamylase of Koji, the analysis result by several methods used commonly were compared in this study. It is showed that results were quite different between different measurement methods. Glucoamylase activity in Koji by white spirit method was 36~200 u/g; it was 144.98~318.95 u/g by the method of national standard of China (GB), it was 26.96~146.67 u/g by the DSN method, it was 392.04~419 u/g by Japanese Sake Koji analysis method. It was particularly evident in the sample amount for GB; results by enzymes extraction at 30°C were greater than that at 40°C. By different enzyme extraction methods, the result show that, the activity with the extraction method in sake was greater than that with other two extraction methods of GB and DSN. By different measurement methods, but using same extraction method, the result show measurement methods in several assays had some adaptability. In shortly, glucoamylase activity by the method used in Sake was the most stable, best embodying. Activity of glucoamylase by the extraction method (by dialysis), measuring with DNS measurement method, the results were relatively stable, closest to it.

Keywords:

Assay, extraction, GB, glucoamylase, koji, liquor koji, rice-koji,

References

1. Brewing Society of Japan, 1993. Fourth Back to Correct, Analytical Methods Set by NTS Annotation. pp: 212-228.
   
2. Cao, X., 2001. Glucoamylase activity measured in the analysis bran. Shanxi Food Ind., 2: 38-44.
   
3. GB8276, 2006. Food Additive. Glucoamylase Preparations. National Standard.
   
4. Guan H., Z.Z. Yan et al., 1993. Mutant strain of aspergillus niger purification and general nature of the amylase decomposing starch into glucose. Biochem. Biol. Phys., 25(5): 453-459.
   
5. Leng, Y., 2004. Study of Aspergillus oryzae and soy sauce rice-koji process. Ph.D. Thesis, Jiangnan University, Wuxi, China.
   
6. Shen, Y., 2014. White Spirit Production Technology Britannica. China Light Industry Press, 3(1): 618.
   
7. Wu, M. and J. Li, 1996. Impact of a-amylase on the determination of glucoamlase. Shanxi Food Ind., 2: 3-20.
   
8. Wujin, X., P. Wang et al., 2002. Research progress and trends in glucoamylase. J. Nat., 25(3): 162-163.
   
9. Xie, S. and R. Yang, 2009. Research on oryzae rice-koji conditions. Brewing Technol., 177(3): 43.
   
10. Xu, Y. and W. Xu, 1998. Chinese and Japanese sake aspergillus characteristics research. Wine, 127(4): 6.
    
11. Zhao, F. and Y. Xu, 2006. Research progress of Aspergillus oryzae. Chinese Brewing, 25(3): 8-10.
    
12. Zhou, X., 1998. Rice, wheat-koji saccharification assay with a newly developed assay. Ferment. Technol. Commun., 27(1): 42-44.
    
13. Zhu, J., Q. Wang, S. Liao et al., 2012. Purification and characterization research of a strain of acidic glucoamylase. Mod. Food Sci. Technol., 28(10): 1294.
    

Competing interests

The authors have no competing interests.

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