储藏条件对啤酒花化学组成的影响

研究了香型啤酒花扎一(SA-1)和苦型啤酒花奴革特(Nugget)、齐洛克(Ch inook)、马可波罗(M arco Polo)、青岛大花(Tsingdao flower)5个啤酒花品种在不同的储藏条件下其化学组成的变化。这些啤酒花样品分别在-10~-12℃、0~2℃和室温(20℃左右)3种条件下避光保存180 d,并定期对其主要成分α-酸、β酸、啤酒花多酚和储藏指数等指标进行分析。结果表明:样品中的各组分都发生了不同程度的质量劣变,这些变化不仅和储藏条件有关,也与品种有关。室温下储藏的啤酒花的酿造价值下降最为严重,而较低的储藏温度也只能在一定程度上减缓其氧化的速率。香型啤酒花扎一的损失率最高,在室温下储存120 d时,其α-酸的质量分数只有采收时的45.53%;合葎草酮质量分数较低的苦型啤酒花奴革特的损失率最低,在低于2℃的储存条件下,即使保存时间已达到180 d,它也还有采收时α-酸量的77.23%。

The Effects of Storage Condition on the Chemical Composition of Hops

The effects of storage condition on the chemical composition of hops of the varieties SA-1,Chinook,Nugget,Macro Polo and Tsingdao flower were studied.The hops were stored at-10～-12 ℃,0～2 ℃ and room temperature(about 20 ℃) for 180 d in the dark.The compounds of hops underwent some deterioration depending on the storage temperature and also the variety of hops.These hop varieties showed a significant changes in the content of α-acids and β-acids,tannins and hop storage index during storage at all conditions.The loss of brewing value of hop was severe at room temperature storage conditions.Cold storage did not prevent the deterioration,but reduced the rate of oxidation.The loss rate of α-acid in aromatic cultivars SA-1 was the highest(only 45.53% of the initial content remained after storage at room temperature for 120 d),while that in bitter cultivars Chinook which has a smaller content of cohumulone was much lower(77.23% initial content after storage stored at 2 ℃ for 180 d).