麦芽中SOD活性与麦汁还原力的关系以及糖化温度对它们的影响

Relationship between Superoxide Dismutase Activity in Malts and Reducing Power of Wort,and Effects of Mashing Temperature on Them

研究了11种进口麦芽和18种国产麦芽中超氧化物歧化酶(SOD)活性的差异以及与协定麦汁还原力之间的关系。以甘啤-3号麦芽为对象,采用7种恒温糖化工艺考察了糖化温度对2者的影响。结果表明,不同品种麦芽中,SOD的差异比较明显(1205.6～2126.0U/g),而且麦芽的SOD活性与协定麦汁的还原力之间存在显著的正相关性(相关系数r=0.898,P<0.01);SOD活性随着糖化温度的升高而逐渐降低,55℃恒温糖化60min后有53.22%的酶活残存;当糖化温度升高到65℃时,SOD的活性大幅度下降,30min后仍有25.45%的酶活残存;糖化温度为70℃和80℃时SOD下降到极低的活性;麦汁的还原力随着糖化温度的升高而升高,80℃恒温糖化100min后麦汁的还原力高达3.75mmol/mL。

Differences in Superoxide dismutase （SOD） activity of eleven varieties of imported malts and eighteen kinds of domestic malts as well as the relationships among SOD activities in malts and reducing power of congress wort were studied in this paper. Ganpi-3 was used as material; seven isothermal mashing curves were employed in the investigation on effects of mashing temperature on SOD activity and wort reducing power. The results showed that evident differences of SOD activities existed in malt varieties （from 1 205.6 U/g to 2 126.0 U/g）. And remarkable relevancy between SOD activity and reducing power of congress wort were found at a positive, significant level of r=0. 898, P〈0.01. It was indicated that SOD was gradually destroyed with increasing mashing temperature and 53. 22 % of SOD activity survived after the temperature of 55 ℃ was kept 60 min. When mashing temperature reached 65 ℃, the activity of SOD sharply declined and the retention of 25.45 % was still found after 30 min. A great deal of SOD was almost deactivated when mashing temperature reached 70 ℃and 80℃ , only showing an retention of very low activity. On the other hand, as mashing temperature increased, the reducing power of wort was enhanced, which amounted to 3.75 mmol Vc/mL within 100 min at 80℃.