本研究分別利用Aspergillus oryzae BCRC 30222、Aspergillus sojae BCRC 30103、Monascus pilosus BCRC 31526為菌酛在30oC、RH 95%下進行黑豆之固態發酵10天,探討不同發酵黑豆所呈現抑制血管收縮素轉化酶(Angiotensin converting enzyme)活性及清除2,2-diphenyl-1-picrylhydrazyl (DPPH)自由基之作用。此外並檢測發酵黑豆中蛋白質之水解率與總酚、類黃酮及花青素含量。結果顯示利用麴菌發酵顯著地(P < 0.05)提升了黑豆及其水萃物抑制血管收縮素轉化酶之活性及清除DPPH自由基之能力。發酵黑豆及其水萃物所呈現對血管收縮素轉化酶活性之抑制及清除DPPH自由基之能力隨菌酛及發酵時間而不同。其中以M. pilosus BCRC 31526發酵者所呈現之活性最高,其後依序為A. sojae BCRC 30103與A. oryzae BCRC 30222發酵者。無論菌酛為何,發酵黑豆中總酚、類黃酮及花青素含量及蛋白質水解率皆顯著高於未發酵者,且隨著發酵時間之延長而增加。蛋白質水解率、總酚及類黃酮與花青素含量之提昇與發酵黑豆所呈現抑制血管收縮素轉化酶活性及清除DPPH自由基能力之提昇成正相關性。
In this study, black soybeans were fermented with Aspergillus oryzae BCRC 30222, A. sojae BCRC 30103 or Monascus pilosus BCRC 31526 at 30oC and 95% relative humidity for 6 days. The Angiotensin converting enzyme (ACE) inhibitory effect and 2,2-diphenyl -1-picrylhydrazyl (DPPH) radical-scavenging effect exerted by the various fermented black soybeans were then investigated. Besides, the degree of protein hydrolysis, total phenolics, flavonoids and anthocyanin contents of the fermented black soybeans were examined.Results revealed that fermentation, regardless of starters used, significantly enhanced (P<0.05) the ACE inhibitory activity and DPPH radical-scavenging effect of black soybeans and their water extracts. The ACE inhibitory activity and DPPH radical-scavenging effect of the fermented-black soybeans varied with starter organism and fermentation period. The M. pilosus BCRC 31526-fermented black soybeans possessed the highest ACE inhibitory activity and DPPH radical-scavenging effect followed by that fermented by A. oryzae BCRC 30222, and A. sojae BCRC 30103 in descending order. Regardless of starters used, fermentation increased the contents of total phenolics, flavonoids and anthocyanins as well as the degree of protein hydrolysis of black soybean. The enhanced ACE inhibitory activity and DPPH radical-scavenging effect of fermented black soybeans correlated positively with the increases in the degree of protein hydrolysis as well as the contents of total phenolics, flavonoids and anthocyanins.