본 실험에서는 Monascus sp.와 Lactobacillus sp.를 이용한 2단 발효마를 기능성식품 소재로 활용 가능성을 알아보기 위하여 2단 발효마 분말을 농도별(0, 0.1, 0.3, 0.5, 1 및 2%, w/v)로 첨가한 요구르트 제조시 pH, 적정산도, 젖산균수, 총폴리페놀 함량, DPPH radical 소거활성, 환원력(reducing power), ACE 저해활성 및 GABA 함량 등을 측정하여 생리 활성이 우수한 요구르트의 제조조건을 확립하고자 하였다. 그 결과, 2단 발효마 분말 첨가 농도별(0, 0.1, 0.3, 0.5, 1 및 2%, w/v)로 제조한 요구르트의 pH와 적정산도는 4.12-4.25, 0.94-0.97%로 조사되었고, 젖산균수는 2단 발효마 분말 0.5% 첨가시 $1.14{ imes}10^{10}$ CFU/ml의 생균수를 나타냄에 따라 관련 기준에 적합한 나타났으며, 총 폴리페놀 함량, DPPH radical 소거활성 및 환원력은 각각 161.4-329.9 mg/L, 54-94%, 1.13-1.53으로 조사되었다. 또한 ACE (angiotensin converting enzyme) 저해 활성과 GABA (${gamma}$-aminobutyric acid) 함량은 67.1-87.7%와 304.6-685.4 mg/L로 조사되었다.
This study was to examine the quality characteristics and biological activities of the yogurt containing dual fermentation MFCY (Monascus-Fermented Chinese Yam) powder. Six different contents (0, 0.1, 0.3, 0.5, 1.0, and 2.0%, w/v) of MFCY powder were added to raw milk and 5% skim milk followed by fermentation with lactic acid bacteria at $37^{circ}C$ for 12 h, and then the biological activities of the samples were investigated. Biological activities of the prepared yogurt were evaluated for acid production (pH, titratable acidity), number of viable cells, total polyphenol contents, DPPH radical scavenging activity, reducing power, angiotensin converting enzyme inhibitory effects and GABA contents. In this study, the results show that after fermentation in raw milk and 5% skim milk added with MFCY powder. The yogurt can produced pH, titratable acidity, number of viable cells, total polyphenol contents, DPPH radical scavenging activity and reducing power at 4.12-4.25 (pH), 0.94-0.97% (TA), $7.50{ imes}10^9-1.14{ imes}10^{10}$ CFU/ml, 161.4-329.9 (TP, mg/L), 54-94% (DPPH), and 1.13-1.53 (R.P), respectively. In addition, the showed ACE inhibitory activity and GABA contents was 67.1-87.7% and 304.6-685.4 (mg/L).
