Changes in Quality Characteristics of Meju Made with Germinated Soybean during Fermentation

싹튼 콩으로 제조한 메주의 발효기간에 따른 품질변화

  • Choi, Ung-Kyu (Department of Oriental Medicinal Food and Nutrition, Asia University) ;
  • Kim, Mi-Hyang (Department of Food Science&Nutrition, Sangju National University) ;
  • Lee, Nan-Hee (Department of Food Science and Nutrition, Catholic University of Daegu) ;
  • Jeong, Yeon-Shin (Soyventure Co. Ltd., Kyungpook National University, Division of Plant Biosciences, Kyungpook National University) ;
  • Hwang, Young-Hyun (Soyventure Co. Ltd., Kyungpook National University, Division of Plant Biosciences, Kyungpook National University)
  • 최웅규 (아시아대학교 한방식품영양학과) ;
  • 김미향 (상주대학교 식품영양학과) ;
  • 이난희 (대구가톨릭대학교 식품영양학과) ;
  • 정연신 (소이벤처(주), 경북대학교 농학과) ;
  • 황영현 (소이벤처(주), 경북대학교 농학과)
  • Published : 2007.06.30

Abstract

This research was conducted to investigate the changes in quality characteristics of meju made with 24-hour germinated soybeans according to fermentation time. The study confirmed that the amino nitrogen content immediately after soaking was 15.5 mg%, and the content rapidly increased in the beginning of the germination process and continued to increase to 312.9 mg% by 48 hours of fermentation. The number of fungi in the whole soybean meju made with 24-hour germinated soybeans was higher than the numbers of bacteria and yeast since the Aspergillus oryzae was inoculated artificially. The content of organic acids, in which the amount of citric acid was highest followed by tartaric acid and malic acid, increased with the fermentation process. The level of free amino acids in the whole soybean meju made from the 24-hour germinated soybeans increased rapidly with fermentation. The free amino acid content after 48 hours of fermentation (2,513.5 mg%) was 5.7 times higher than the content of the soaked germinated soybeans. The content of glutamic acid was highest followed by aspartic acid, lysine, leucine, and proline. The ratio of glutamic acid to the total free amino acids at 48 hours fermentation was 21.2% for the whole soybean meju. It was confirmed that the total isoflavone content, in which the content of genistein was highest followed by daidzein and glycitein, increased at the beginning of the fermentation process, but did not change thereafter.

본 연구에서는 24시간 동안 싹튼 콩을 원료로 하여 콩알 메주를 제조한 후 발효기간에 따른 각종 품질의 변화를 조사하였다. 발효 전 기간 동안 pH는 6.3-6.5로 큰 변화가 없는 것으로 조사되었다. 증자 직후의 아미노태 질소함량은 15.5 mg%였으며, 발효가 진행됨에 따라 급격히 증가하여 발효 48시간째에는 312.9 mg%를 나타내었다. 발효기간별 미생물의 변화를 확인한 결과 곰팡이의 수가 높게 나타난 반면 호기성 세균과 효모의 수는 낮게 나타났는데 이는 메주의 제조 시 Aspergillus oryzae를 접종하였기 때문인 것으로 판단된다. 발효가 진행됨에 따라 유기산 함량은 점차 높아져 발효 48시간째에는 1,067.3 mg%가 검출되었으며 함량별로는 발효 전 기간에 걸처 citric acid가 가장 많이 검출되었다. 유리아미노산 함량은 발효가 진행됨에 따라 함량이 급격히 높아져 발효 48시간째에는 2,513.5 mg%로 발효 전에 비해 5.7배 가량 많이 검출되었다. 함량별로 보면 glutamic acid가 가장 많았으며, aspartic acid, lysine, leucine 및 proline의 순으로 많이 검출되었다. glutamic acid의 총아미노산에 대한 비율은 발효가 진행됨에 따라 점차 증가하여 발효 48시간째에는 21.2%로 나타났다. 총 Isoflavone의 함량은 발효초기에 123.9 mg%로 약간 증가한 후 그 수준을 지속적으로 유지하는 것으로 나타났으며, 발효 전 기간 동안 genistein>daidzein>glycitein의 순으로 나타났다.

Keywords

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